Comparative study of the methods used for treatment and final disposal of sewage sludge

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英语写作复习

必背摘要：Example(Non-structured):DPC4/Smad4:No Mutations, Rare Allelic Imbalances, and Retained Protein Expression in Pancreatic Endocrine Tumors(Diag Mol Pathol 2003;12:181-186)Several chromosomal loci involved in tumorigenesis of pancreatic endocrine tumors (PET) have been identified. To date, the only gene known to be frequently altered is the MEN1 gene. Recently,DPC4 mutations and homozygous deletions have been described in 5/9(55%) non-functioning PET, thus representing the most frequent genetic aberration described in PET. However, these data are in accordance with comparative genomic hybridization (CGH) results that rarely show genetic losses on chromosome 18.They have also been challenged by immunohistochemical data. We performed a detailed combined DPC4 mutation and deletion analysis in 34 benign and malignant PET. Mutations of the conserved C-terminal exons were not found in all examined PET and allelic loss (LOH) was found to be rare (‹6%) by combined microsatellite PCR and FISH analysis. In addition, DPC4 protein expression was retained in all PET that were examined by immnuohistochemistry. Therefore, DPC4 inactivation by mutation or deletion appears to be very rare in PET, which confirms the current concept of unrelated mechanisms of tumorigenesis of endocrine versus exocrine pancreatic tumors.Example(Full-structured):JAMA. 1999;281:2289-2293.Relationship of Ascorbic Acid to Blood Lead LevelsContext Some animal studies suggest that orally administered ascorbic acid may chelate lead and decrease the risk of the toxic effects of lead. However, results from several small studies in humans have yielded in conclusive evidence of a beneficial effect of ascorbic acid on lead toxicity.Objective To examine the relationship between serum ascorbic acid levels and prevalence of elevated blood lead levels.Design, Setting, and Participants Cross-sectional analysis of a probability sample of the US population enrolled in the Third National Health and Nutrition Examination Survey, 1988-1994 (4213 youths aged 6-16 years and 15,365 adults aged 17 years)without a history of lead poisoning.Main Outcome Measures Elevated and log blood lead levels by serum ascorbic acid level.Results A total of 22youths (0.5%) and 57 adults (0.4%) had elevated blood lead levels (defined as 0.72 µmol/L [15 µg/dL]) and 0.97 µmol/L [20 µg/dL], respectively). After controlling for the effects of age, race, sex, income level, and dietary energy, fat, calcium, iron, and zinc intake, youths in the highest serum ascorbic acid tertile had an 89% decreased prevalence of elevated blood lead levels compared with youths in the lowest serum ascorbic acid tertile (odds ratio, 0.11; 95% confidence interval, 0.04-0.35; P for trend=.002). Adults in the highest 2 serum ascorbic acid tertiles had a 65% to 68% decreased prevalence of elevated blood lead levels compared with adultsin the lowest serum ascorbic acid tertile (P for trend=.03). As a continuous predictor, serum ascorbic acid level was independently associated with decreased log blood lead levels among adults (P<.001), but not among youths (P=.14).Conclusions Our data suggest that high serum levels of ascorbic acid are independently associated with a decreased prevalence of elevated blood lead levels. If these associations are related causally, ascorbic acid intake may have public health implications for control of lead toxicity.Example(Semi-structured):Purine-Rich Foods, Dairy and Protein Intake, and the Risk of Gout in Men (New England Journal of Medicine V olume 350:1093-1103 V olume 350:1093-1103) ABSTRACTBackground Various purine-rich foods and high protein intake have long been thought to be risk factors for gout. Similarly, the possibility that the consumption of dairy products has a role in protecting against gout has been raised by metabolic studies. We prospectively investigated the association of these dietary factors with new cases of gout.Methods Over a 12-year period,we prospectively examined the relationship between purported dietary risk factors and new cases of gout among 47,150 men who had no history of gout at base line. We used a supplementary questionnaire to ascertain whether participants met the American College of Rheumatology survey criteria for gout. Diet was assessed every four years by means of a food-frequency questionnaire.Results During the 12 years of the study, we documented 730 confirmed new cases of gout. The multivariate relative risk of gout among men in the highest quintile五分位of meat intake, as compared with those in the lowest quintile, was 1.41 (95 percent confidence interval, 1.07 to 1.86; P for trend = 0.02), and the corresponding relative risk associated with seafood intake was 1.51 (95 percent confidence interval, 1.17 to 1.95; P for trend = 0.02). In contrast, the incidence of gout decreased with increasing intake of dairy products; the multivariate relative risk among men in the highest quintile, as compared with those in the lowest quintile, was 0.56 (95 percent confidence interval, 0.42 to 0.74; P for trend <0.001). The level of consumption of purine-rich vegetables and the total protein intake were not associated with an increased risk of gout.Conclusions Higher levels of meat and seafood consumption are associated with an increased risk of gout, whereas a higher level of consumption of dairy products is associated with a decreased risk. Moderate intake of purine-rich vegetables or protein is not associated with an increased risk of gout.Example (Semi-structured)Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study(The Lancet 2001; 358:1500-03)SummaryBackground Dietary vitamin D supplementation is associated with reduced risk oftype1 diabetes in animals. Our aim was to ascertain whether or not vitamin D supplementation or deficiency in infancy could affect development of type 1 diabetes.Methods A birth-cohort study was done, in which all pregnant women (n=12055) in Oulu and Lapland, northern Finland, who were due to give birth in 1966 were enrolled. Data was collected in the first year of life about frequency and dose of vitamin D supplementation and presence of suspected rickets. Our primary outcome measure was diagnosis of type 1 diabetes by end of December, 1997. Findings12058 0f 12231 represented live births, and 10821 (91% of those alive) children were followed-up at age 1 year. Of the 10366 children included in analyses, 81 were diagnosed with diabetes during the study. Vitamin D supplementation was associated with a decreased frequency of type 1 diabetes when adjusted for neonatal, anthropometric, and social characteristics (rate ratio [RR] for regular vs no supplementation 0.12, 95% CI 0.03-0.51, and irregular vs no supplementation 0.16, 0.04-0.74. Children who regularly took the recommended dose of vitamin D (2000 IU daily)had a RR of 0.22 (0.05-0.89) compared with those who regularly received less than the recommended amount. Children suspected of having rickets during the first year of life had a RR of 3.0(1.0-9.0) compared with those without such a suspicion.Interpretation Dietary vitamin D supplementation is associated with reduced risk of type 1 diabetes. Ensuring adequate vitamin D supplementation for infants could help to reverse the increasing trend in the incidence of type 1 diabetes.时态使用：1)present tense and/or present perfect tense used in CONTEXT/BACKGROUND一般现在时和现在完成时用于背景句。

Schools of translation theories

现代西方翻译理论与翻译学派二战后，科技、语言学和翻译事业蓬勃发展，机器翻译也悄然兴起。

人们对翻译的看法也随之而改变。

翻译不仅是一门艺术或技巧，而且是一门科学，与文艺学、社会学、心理学、数控论和信息论等多种学科相关但又自成体系的科学。

翻译理论的研究，也不再局限于哲学家、文学家和翻译家，而成为语言和翻译研究专家进行系统探讨的严肃课题。

因此，西方的翻译理论得到进一步发展。

现代西方翻译理论的发展有两大特点：（1）理论研究纳入语言学范畴，受现代语言学和信息理论的影响，因而带有明显的语言学色彩，与传统的文学翻译理论形成鲜明对照；（2）以往理论家闭门造车、不相往来的局面被打破。

理论家通过论著、杂志、论文集等方式，充分发表各自的观点。

此外，由于交通手段、出版业的进步以及国际学术组织的出现，各国翻译理论家之间的交往不断密切，学术交流日益加强。

现代西方的翻译理论主要有四大学派：布拉格派、伦敦派、美国结构派和交际理论派。

一、布拉格学派该学派的创始人为马希修斯（Vilem Mathesius）、特鲁贝斯科伊（Nikolay S. Trubetskoy）和雅可布森（Roman Jakobson）。

主要成员有雅可布森、列维、维内等重要的翻译理论家。

这一学派的主要论点为：（１）翻译必须考虑语言的各种功能，包括认识功能、表达功能和工具功能等；（２）翻译必须重视语言的比较，包括语义、语法、语音、语言风格以及文学体裁的比较。

布拉格学派最有影响的翻译理论家是罗曼·雅可布森。

他原籍俄国，后移居捷克；二战时迁至美国，加入美籍。

作为学派的创始人之一，他对翻译理论的贡献主要体现在《论翻译的语言学问题》（On Linguistic Aspects of Translation）之中。

文章从语言学的角度，对翻译的重要性、语言和翻译的关系以及存在的问题给出精辟的论述。

自１９５９年发表后，此文一直被西方理论界奉为翻译研究的经典之一。

雅可布森的论述主要有五点：（１）翻译分为三类：语内翻译（intralingual translation）、语际翻译（interlingual translation）和符际翻译（intersemiotic translation）。

托福备考托福阅读34套TPO样题+解析+译文9--2 Reflection in Teaching

托福考试复习托福阅读TPO9(试题+答案+译文)第2篇:Reflection in Teaching托福阅读原文Teachers, it is thought, benefit from thepractice of reflection, the conscious act of thinking deeply about andcarefully examining the interactions and events within their own cators T. Wildman and J. Niles (1987) describe a scheme for developingreflective practice inexperienced teachers. This was justified by the view thatreflective practice could help teachers to feel more intellectually involved intheir role and work in teaching and enable them to cope with the paucity ofscientific fact and the uncertainty of knowledge in the discipline of teaching.Wildman and Niles were particularlyinterested in investigating the conditions under which reflection mightflourish–a subject on which there is little guidance in the literature. Theydesigned an experimental strategy for a group of teachers in Virginia andworked with 40 practicing teachers over several years. They were concerned thatmany would be “drawn to these new, refreshing” conceptions of teaching only tofind that the void between the abstractions and the realities of teacherreflection is too great to bridge. Reflection on a complex task such asteaching is not easy.”The teachers were taken through a program of talkingabout teaching events, moving on to reflecting about specific issues in asupported, and later an independent, manner.Wildman and Niles observed that systematicreflection on teaching required a sound ability to understand classroom eventsin an objective manner. They describe the initial understanding in the teacherswith whom they were working as being “utilitarian … and not r ich or detailed enoughto drive systematic reflection.” Teachers rarely have the time or opportunitiesto view their own or the teaching of others in an objective manner. Furtherobservation revealed the tendency of teachers to evaluate events rather thanreview the contributory factors in a considered manner by, in effect, standingoutside the situation.Helping this group of teachers to revisetheir thinking about classroom events became central. This process took timeand patience and effective trainers. The researchers estimate that the initialtraining of the teachers to view events objectively took between 20 and 30hours, with the same number of hours again being required to practice theskills of reflection.Wildman and Niles identify three principlesthat facilitate reflective practice in a teaching situation. The first is supportfrom administrators inan education system, enabling teachers to understand therequirements of reflective practice and how it relates to teaching students.The second is the availability of sufficient time and space. The teachers inthe program described how they found it difficult to put aside the immediatedemands of others in order to give themselves the time they needed to developtheir reflective skills. The third is the development of a collaborativeenvironment with support from other teachers. Support and encouragement werealso required to help teachers in the program cope with aspects of theirprofessional life with which they were not comfortable. Wildman and Niles makea summary co mment: “Perhaps the most important thing we learned is the idea ofthe teacher-as-reflective-practitioner will not happen simply because it is agood or even compelling idea.”Thework of Wildman and Niles suggests the importance of recognizing some of thedifficulties of instituting reflective practice. Others have noted this, makinga similar point about the teaching profession’s cultural inhibitions aboutreflective practice. Zeichner and Liston (1987) point out the inconsistencybetween the role of the teacher as a (reflective)professional decision makerand the more usual role of the teacher as a technician, putting into practicethe ideas of theirs. More basic than the cultural issues is the matter ofmotivation. Becoming areflective practitioner requires extra work (Jaworski,1993) and has only vaguely defined goals with, perhaps, little initiallyperceivable reward and the threat of vulnerability. Few have directlyquestioned what might lead a teacher to want to become reflective. Apparently,the most obvious reason for teachers to work toward reflective practice is thatteacher educators think it is a good thing. There appear to be many unexploredmatters about the motivation to reflect –for example, the value of externallymotivated reflection as opposed to that of teachers who might reflect by habit.托福阅读试题1.The word “justified”in the passage(paragraph 1) is closest in meaning toA.supportedB.shapedC.stimulatedD.suggested2.According to paragraph 1, it was believedthat reflection could help teachersA.understand intellectual principles ofteachingB.strengthen their intellectual connectionto their worke scientific fact to improve disciplineand teachingD.adopt a more disciplined approach toteaching3.The word “flourish”in the passage(paragraph 2) is closest in meaning toA.continueB.occurC.succeedD.apply4.All of the following are mentioned aboutthe experimental strategy described in paragraph 2 EXCEPT:A.It was designed so that teachers wouldeventually reflect without help from others.B.It was used by a group of teachers over aperiod of years.C.It involved having teachers take part indiscussions of classroom events.D.It involved having teachers record inwriting their reflections about teaching.5.According to paragraph 2, Wildman andNiles worried that the teachers they were working with might feel thatA.the number of teachers involved in theirprogram was too largeB.the concepts of teacher reflection wereso abstract that they could not be appliedC.the ideas involved in reflection wereactually not new and refreshingD.several years would be needed to acquirethe habit of reflecting on their teaching6.The word “objective”in the passage(paragraph 3) is closest in meaning toA.unbiasedB.positiveC.systematicD.thorough7.According to paragraph3, what did theteachers working with Wildman and Niles often fail to do whenthey attempted topractice reflection?A.Correctly calculate the amount of timeneeded for reflection.B.Provide sufficiently detaileddescriptions of the methods they used tohelp them reflect.C.Examine thoughtfully the possible causesof events in their classrooms.D.Establish realistic goals for themselvesin practicing reflection.8.How is paragraph 4related to otheraspects of the discussion of reflection in the passage?A.It describes and comments on steps takento overcome problems identified earlier in the passage.B.It challenges the earlier claim thatteachers rarely have the time to think about their own or others' teaching.C.It identifies advantages gained byteachers who followed the training program described earlier in the passage.D.It explains the process used to definethe principles discussed later in the passage.9.The word “compelling”in the passage(paragraph 5) is closest inmeaning tomonly heldB.persuasiveC.originalD.practical10.According to paragraph 6, teachers maybe discouraged from reflecting becauseA.it is not generally supported by teachereducatorsB.the benefits of reflection may not beapparent immediatelyC.it is impossible to teach and reflect onone's teaching at the same timeD.they have often failed in their attemptsto become reflective practitioners11.Which of the sentences below expressesthe essential information in the highlighted sentence in the passage (paragraph3) ? Incorrect choices change the meaning in important ways or leave outessential informationA.The practice of being reflective is nolonger simply a habit among teachers but something that is externallymotivated.B.Most teachers need to explore ways toform the habit of reflection even when no external motivation exists.C.Many aspects of the motivation to reflecthave not been studied, including the comparative benefits of externallymotivated and habitual reflection among teachers.D.There has not been enough exploration ofwhy teachers practice reflection as a habit with or without externalmotivation.12. Look at the four squares [■] thatindicate where the following sentence could be added to the passage. However,changing teachers’thinking about reflection will not succeed unless there is supportfor reflection in the teaching environment.Helping this group of teachers to revisetheir thinking about classroom events became central. ■【A】This processtook time and patience and effective trainers. ■【B】Theresearchers estimate that the initial training of the teachers to view eventsobjectively took between 20 and 30hours, with the same number of hours againbeing required to practice the skills of reflection.■【C】Wildman and Niles identify three principles that facilitatereflective practice in a teaching situation. ■【D】The first issupport from administrators in an education system, enabling teachers tounderstand the requirements of reflective practice and how it relates toteaching students. The second is the availability of sufficient time and space.The teachers in the program described how they found it difficult to put asidethe immediate demands of others in order to give themselves the time theyneeded to develop their reflective skills. The third is the development of acollaborative environment with support from other teachers. Support andencouragement were also required to help teachers in the program cope withaspects of their professional life with which they were not comfortable.Wildman and Niles make a summary comment: “Perhaps the most important thing we learnedis the idea of the teacher-as-reflective-practitioner will not happen simplybecause it is a good or even compelling idea.”Where could the sentence best fit?13. Directions: An introductory sentencefor a brief summary of the passage is provided below. Complete the summary byselecting the THREE answer choices that express the most important ideas in thepassage. Some answer choices do not belong in the summary because they expressideas that are not presented in the passage or are minor ideas in the passage. Thisquestion is worth 2 points.Wildman and Niles have conducted researchon reflection in teachingA.Through their work with Virginiateachers, Wildman and Niles proved conclusively that reflection, thoughdifficult, benefits both teachers and students.B.Wildman and Niles found that considerabletraining and practice are required to understand classroom events and developthe skills involved in reflection.C.Wildman and Niles identified threeprinciples that teachers can use to help themselves cope with problems that mayarise as a result ofreflection.D.Wildman and Niles concluded that teachersneed sufficient resources as well as the cooperation and encouragement ofothers to practice reflection.E.There are numerous obstacles toimplementing reflection in schools and insufficient understanding of whyteachers might want to reflect.F.Whetherteachers can overcome the difficulties involved in reflection may depend on thenature and intensity of their motivation to reflect.托福阅读答案1.justify意思是证明……正当，支持，想到just有正义之意，所以A的support 正确。

交换生面试自我介绍,英文

竭诚为您提供优质文档/双击可除交换生面试自我介绍,英文篇一：交换生英文面试1.为何要出去交换，以及为什么选这所学校？en,firstofalltheschooliappliedforispoznaneconomicun iversity.inthisschoolmanagementisaverydominantdisci pline,itwillhelpmeimprovetheresearchabilities.andas weallknowpoznanisaveryhistoriccity,mymajoristourism management,studyinthatcityicanexpandmyknowledgeande xperience,thatwillintegratemyprofessionalknowledge, ihopethoughfurtherstudyaboard,tobeamorecompetitivet alent.2.学习的期限iwillstudyforasemesteraboutfivemonththenextyear.and itwillnotinfluencemynormaltimeofgraduation.3.你为什么想出去交换？inadditiontothereasonsforlearningicomeupbefore,ials owanttoenhancemypracticalabilityandhaveaopportunity toimprovemyenglishspeakingandindependence.multiculturalperspective,independentabilityandthepr ofessionalaccomplishmentisalliwanttogetinthisexchan geprogram.4.你父母的工作怎么样？mymotherworksingovernmentdepartmentandmyfatherworks inastate-ownedcompanyandalsodosomebusiness,imnotqui tesureabouttheirsalary,butiknowmyparentsarewillinga ndabletosupportthecostofthecourse,theythoughtitisag oodopportunity.thoughtheinteRnet,ilearnthatthecoste stimationisaboutfiftythousandyuan,ialsohaveasavingo fmyowninternshipandscholarshiptopayforthecost.5.交换期间的计划是什么样子的呢？iwillcarefullycompletethecoursecreditsinpoznan,whil econtinuingtocompletethemastersdegreethesis,asfaraspossibletounderstandandlearnthelocalscientificandcu lturalknowledge6.与其他面试者相比你有那些优势？icanbearhardshipandstandhardwork.iamoutgoing,manyto urismexperiencehelpmebecomeagoodteamplayer,andicanc ommunicatewithotherswellandiamgoodatorganizingandov ercomedifficultieswithalleffort.你毕业后的计划是什么？myresearchdirectionisthedirectionofhotelmanagement, imaycontinuemystudiesinmyresearchinhongkongiftherei ssomeopportunity.你认为这些对你毕业后是否有帮助？ivaluethisuniqueexperience。

A COMPARATIVE STUDY OF THE EFFECTS OF THE

This study is concerned with the effectiveness of computer-based multimedia for developing listening comprehension in English as a Foreign Language (EFL). The listening skill plays a significant role in communication and in language learning (Rubin, 1994; Dunkel, 1991; Rost, 1990; Anderson and Lynch, 1988) and is perhaps "the most fundamental language skill" (Oxford, 1993: p. 205). Although there is no agreed definition of the listening skill (Wolvin and Coakley, 1988) nor a complete understanding of all the processes involved in listening (Rubin, 1994; Buck, 1992), the development of the listening skill has always been of prime concern to language teachers. Listening assumes increased importance as not only is it a key language and communication skill in its own right, but it also provides a channel through which new language can be received and may become "intake". Many language learners experience and report difficulty with this skill (Underwood, 1990: p. 16). Traditionally, classroom or language laboratory-based listening work has used audio cassettes or video cassettes accompanied by varieties of tasks as 39

Comparative Studies of the Languages

Substitute vs. Repetitive（替换与重复）
Generally speaking, English doesn’t use so many repetitions as Chinese does. 英语多用替换词语；汉语多用重复形式。 You should help her since you have promised to do so. Men and nations working apart created these problems; men and nations working together must solve them.
During the wartime, years like these would have meant certain death for many people. Many would have become beggars and others would have been compelled to sell their children. 战争期间碰到这样的年景，很多人肯定会死去，很多人会逃荒要饭，很多人会被迫卖儿卖女。 Thus encouraged , they made a small bolder plan for the next year. 由于受到这样的鼓励，他们为第二年制定了一个更大胆的计划。
Synthetic vs. Analytic (综合性与分析性)
English is a Synthetic language marked with inflexnguage without any inflexion, which is usually implied in the context or explicitly shown in such words as “ 着 ” “了”“过”etc. 英语属综合性语言，其标志为词的曲折变化形式；汉语为分析性语言，靠 “着”， “了”“过”之类的助动词表达不同的时间关系。

A_comparative_study_of_survivial_models_for_breast

A comparative study of survival models for breast cancer prognostication based on microarray data: a single gene beat them all?
B. Haibe-Kains, C. Desmedt, C. Sotiriou and G. Bontempi
Introduction to microarray
• /courses/geno mics/chip/chip.html • 清華大學郝旭昶
Introduction - Motivation
• Survival prediction of breast cancer (BC) patients, independently of treatment, also known as prognostication, is a complex task.
Introduction - Results
• Complex prediction methods are highly exposed to performance degradation despite the use of cross-validation techniques for the following reasons:
Introduction - Difficulties
• Censored information cannot be exploited by traditional supervised classification the regression methods, but demands the adoption of specific survival analysis techniques, like the semi-parametric Cox’s proportional hazards model. • When the number of explanatory variables exceeds by far the number of petients in the sample cohort, overfitting of naively applied data mining methods and overoptimistic performance assessment lie in wait. At the same time, it is very difficult to select the most relevant variables for prediction, because of their interdependency.

烯丙基半胱氨酸综述

大蒜蒜氨酸：S-烯丙基-L-半胱氨酸亚砜alliinSACS蒜氨酸酶：蒜苷酶alliinase大蒜素：蒜素allicin二烯丙基硫醚：daillylsulfide，DAS二烯丙基二硫醚：diallyldisulfide，DADS二烯丙基三硫醚：diallyltrisulfide，DATS阿霍烯：ajoeneS-烯丙基-L-半胱氨酸：脱氧蒜氨酸、S-烯丙基半胱氨酸、S-烯丙基别半胱氨酸、L-脱氧蒜氨酸、烯丙基-L-半胱氨酸；S-allylcysteine，SAC，S-烯丙基硫基半胱氨酸：S-allylmercaptocysteine，SMACγ-谷酰胺半胱氨酸化合物：γ-glutamy-l-S-allylcystein)一、《大蒜中含硫氨基酸研究进展》药理活性1、清除自由基与抗氧化活性：SAC保护肺动脉内皮细胞由H2O2引起的细胞损伤，抑制内皮细胞释放乳酸脱氢酶(LDH)，抑制脂质过氧化物的产生（Kourounakis，1991）。

在1，1-二苯基-2-二苦基偕腙肼(DPPH)检测中，SAC显示出对自由基的消除作用。

（InaiJ，1994）。

2、抗肿瘤活性：SAC除能保护肝细胞外，对DMH诱发的结肠癌有预防作用，对人体成神经细胞瘤有抗增生的作用（NagaeS，1994）。

每周灌胃3次，连续两周，SAC可有效地抑制大鼠乳房组织中7，12-二甲基苯并蒽诱导的DNA加合物的形成，提示有抗乳腺癌发生作用（SongK，1999）。

3、保肝活性：Hikino等用原代培养的大鼠肝细胞进行试验，证明大蒜挥发油和SAMC对CCl4所致肝细胞毒有拮抗作用，主要有效成分也包括SACS及微量的SAC 和SMC。

4、神经营养活性：Moriguchi报道从大蒜中提取的几个有机硫化物能促进小鼠海马神经元功能，SAC能提升有学习效应的轴索分支神经的功能，该研究结果也证明了S-烯丙基基团对产生神经营养作用是必须的。

二、《大蒜提取单体化合物生物学功能的研究进展》施枝军，唐圣松，20081、大蒜所含的主要单体化合物γ-谷酰胺半胱氨酸化合物(γ-glutamy-l-S-allylcystein)是天然生大蒜中存在的最主要含硫物质，除此之外，其他绝大多数含硫化合物都并非天然存在于大蒜的球茎内，而是以γ-谷酰胺半胱氨酸化合物为前体转化而来。

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ReviewComparative study of the methods used for treatment and ﬁnal disposal of sewage sludge in European countriesAlexandros Kelessidis a ,Athanasios S.Stasinakis a ,b ,⇑a School of Science and Technology,Greek Open University,Patra,GreecebWater and Air Quality Laboratory,Department of Environment,University of the Aegean,University Hill,81100Mytilene,Greecea r t i c l e i n f o Article history:Received 7October 2011Accepted 15January 2012Available online 14February 2012Keywords:Sewage sludge Management European Union Treatment Disposal ReuseLegislationa b s t r a c tMunicipal wastewater treatment results to the production of large quantities of sewage sludge,which requires proper and environmentally accepted management before ﬁnal disposal.In European Union,sludge management remains an open and challenging issue for the Member States as the relative Euro-pean legislation is fragmentary and quite old,while the published data concerning sludge treatment and disposal in different European countries are often incomplete and inhomogeneous.The main objective of the current study was to outline the current situation and discuss future perspectives for sludge treat-ment and disposal in EU countries.According to the results,speciﬁc sludge production is differentiated signiﬁcantly between European countries,ranging from 0.1kg per population equivalent (p.e.)and year (Malta)to 30.8kg per p.e.and year (Austria).More stringent legislations comparing to European Directive 86/278/EC have been adopted for sludge disposal in soil by several European countries,setting lower limit values for heavy metals as well as limit values for pathogens and organic micropollutants.A great variety of sludge treatment technologies are used in EU countries,while differences are observed between Member States.Anaerobic and aerobic digestion seems to be the most popular stabil-ization methods,applying in 24and 20countries,respectively.Mechanical sludge dewatering is pre-ferred comparing to the use of drying beds,while thermal drying is mainly applied in EU-15countries (old Member States)and especially in Germany,Italy,France and UK.Regarding sludge ﬁnal disposal,sludge reuse (including direct agricultural application and composting)seems to be the predominant choice for sludge management in EU-15(53%of produced sludge),follow-ing by incineration (21%of produced sludge).On the other hand,the most common disposal method in EU-12countries (new Member States that joined EU after 2004)is still landﬁlling.Due to the obligations set by Directive 91/271/EC,a temporary increase of sludge amounts that are disposed in landﬁlls is expected during the following years in EU-12countries.Beside the above,sludge reuse in land and sludge incineration seem to be the main practices further adopted in EU-27(all Member States)up to 2020.The reinforcement of these disposal practices will probably result to adoption of advanced sludge treatment technologies in order to achieve higher pathogens removal,odors control and removal of toxic com-pounds and ensure human health and environmental protection.Ó2012Elsevier Ltd.All rights reserved.1.IntroductionDuring the last 20years,the implementation of Urban Waste Water Treatment (UWWT)Directive 91/271/EC (CEC,1991)forced EU-15countries (old Member States)to improve their wastewater collecting and treatment systems.As a result,an almost 50%in-crease of annual sewage sludge production in EU-15was noticed,from 6.5million tons dry solids (DS)in 1992to 9.8million tons DS in 2005(Hall,1995;EC,1999,2004,2006;EEA,2002;BIOPROS,2006;http://epp.eurostat.ec.europa.eu ).On the other hand,the annual sewage sludge production in EU-12(new Member States)was estimated to be 1.1million tons DS in 2005(http://epp.eurostat.ec.europa.eu ),resulting to a total amount of 10.9million tons DS for EU-27(all Member States)in 2005.It is obvious that the implementation of UWWT Directive (CEC,1991)by EU-12countries is going to cause a signiﬁcant increase of annual sewage sludge production in EU during the following years,exceeding 13million tons DS up to 2020(Milieu Ltd.,WRc and RPA,2010;Leonard,2011).0956-053X/$-see front matter Ó2012Elsevier Ltd.All rights reserved.doi:10.1016/j.wasman.2012.01.012⇑Corresponding author at:Water and Air Quality Laboratory,Department of Environment,University of the Aegean,University Hill,81100Mytilene,Greece.Tel.:+302251036257;fax:+302251036246.E-mail addresses:alex.keles@ (A.Kelessidis),astas@env.aegean.gr (A.S.Stasinakis).So far,there is not a clear view concerning sewage sludge han-dling(treatment and disposal practises)as well as relative legisla-tion in EU area.Some relevant reports have been published by Eurostat,European Commission(EC)and European Environmental Agency(EEA);however,most of them refer mainly to agricultural utilization of sludge;whereas they are usually incomplete,inhomo-geneous and contain sometimes contradictory data(Jacobsen et al., 1997;EC,1999,2004,2006,2009;EEA,2002;EL and IEEP,2009).The lack of continuity among these reports and the relevant lack of data for new Member States complicate further the study of this topic.On the other hand,limited scientiﬁc papers have been published, comparing sewage sludge management and legislation in different European countries.Most of them are quite old(Hall,1995;Davis and Hall,1997;Leschber et al.,2002)or report data for speciﬁc EU countries(Przewrocki et al.,2004;Jensen and Jepsen,2005). Contrary to sludge management,several papers are available in literature comparing other wastewater management options in EU countries;such as wastewater treatment and reuse(Angelakis et al.,1999;Angelakis and Bontoux,2001;Bixio et al.,2006).The main objective of the current study was to review pub-lished reports on sludge management in EU countries and to unify existed data in order to outline the current situation and discuss future perspectives for sludge treatment and disposal in EU parison of sludge management issues between old and new EU Member States was performed and the speciﬁc conditions for each country were discussed based on most recent available data.For this purpose,EC’s reports concerning the implementation of UWWT Directive(CEC,1991)and Sewage Sludge Directive86/ 278/EC(CEC,1986)for the period1992–2006,data originated from Eurostat,EEA and other organizations as well as references from individual countries were used.2.Sewage sludge production in EU-27Sewage sludge production seems to be differentiated signiﬁ-cantly between different countries in European area(Table1).Be-tween EU-15countries,the highest sludge production was observed in Germany,UK,Spain,France and Italy(Table1).These countries contribute to almost73%of total sludge produced in EU-15.Regarding EU-12countries,Poland was the greatest sludge producer,producing almost42%of total sludge amounts,while Malta was the smaller(Table1).It should be mentioned that Po-land,Hungary and Czech Republic contribute to more than70% of produced sludge in this group of countries.Comparison of speciﬁc sludge production(expressed as kg per p.e.and year)shows that the highest speciﬁc sludge production for all EU-27countries is observed in Austria,followed by UK, Finland and Luxembourg(Table1).Signiﬁcant differences are observed between different countries as well as between old and new Member States,resulting to mean speciﬁc sewage sludge production equal to21.9and11.5kg per p.e.and year for EU-15 and EU-12,respectively.These differences are due to variations in percentages of population that are served by centralized wastewa-ter treatment systems(WWTSs)as well as to variations in waste-water treatment applied in each country and contribution of the industrial sector.According to Wieland(2003),more than90%of population in Germany,Netherlands and UK is connected to urban wastewater treatment,whereas lower percentages are observed in Mediterranean and Eastern Europe countries.Regarding the type of treatment applied,some countries such as Finland,Germany,Den-mark,Sweden and Netherlands apply tertiary treatment in munici-pal wastewater at percentages higher than80%,while secondary treatment is predominant in Southern and EU-12countries(Wie-land,2003).Moreover,it is known that the use of extended biolog-ical processes(e.g.extended aeration systems,constructed wetlands)produce smaller amounts of sludge comparing to WWTSs that apply conventional activated sludge process or use physico-chemical methods for phosphorus removal(Tchobanog-lous et al.,2002).Calculation of speciﬁc sewage sludge production per population equivalent served by WWTS(p.e.s.)show that the highest speciﬁc sludge production for EU-27countries is observed in Cyprus,followed by Finland,Hungary,and Austria(Table1).In this case,mean speciﬁc sewage sludge production is equal to25.4 and21.1kg per p.e.s.and year for EU-15and EU-12,respectively.3.Sewage sludge legislation in EU-27According to UWWT Directive(CEC,1991),the collection and treatment of municipal wastewater is compulsory for agglomera-tions with p.e.of more than2.000.The sludge reuse is encouraged andﬁnal disposal to surface waters has been forbidden since31/ 12/1998.The implementation deadline for UWWT Directive was 2005for the older EU-15Member States and2015or2018for the countries that joined EU after2004(EC,2009).On the other hand,Decision2001/118/EC(CEC,2001)enlist sludge in non hazardous wastes(Chapters19and20),whereas according to European policy the following waste hierarchy shall apply as a priority order in waste management:(a)Prevention, (b)Preparing for re-use,(c)Recycling,(d)Other recovery,e.g.en-ergy recovery,(e)Disposal.Based on these principles,the Landﬁll Directive99/31/EC(CEU,1999)prohibited landﬁlling of both liquid and untreated wastes and set restrictions as well as quantitative targets for bio-degradable municipal solid wastes(such as sewage sludge)that are disposed in landﬁlls.According to these,a reduc-tion of50%and65%of produced solid waste by years2013and 2020should be achieved,respectively.Apart from the above,na-tional legislations of some Member States have set very strict lim-its for the organic matter or total organic carbon(TOC)contained in sludge(e.g.Germany,Austria,Netherlands),practically prohibit-ing sludge landﬁlling(Table2).Additional to the above,the main legislative text that refers to sludge management is Sewage Sludge Directive86/278/EEC(CEC, 1986)which describes beneﬁcial sludge(biosolids)use on soils.This Directive seeks to encourage safe use of sewage sludge in agriculture and to regulate its use in such a way as to prevent harmful effects on soil,vegetation,animals and humans.Among others,it speciﬁes rules for the sampling and analysis of sludge and soils,sets out record keeping requirements and limit values for concentrations of heavy metals in sewage sludge and soil.The Member States are able to ap-ply stricter restrictions than those determined in Directive86/278/ EEC and this is observed in several cases(Table2).Speciﬁcally,16 out of27EU countries(63%)have set more stringent national requirements for heavy metals concentrations in sludge comparing to EU Directive provisions,whereas10out of27countries(37%)have set stricter limit values for the concentrations of heavy metals in soil. There is a wide variation in national limit values for heavy metals, even between similar geographical areas,such as the Nordic or Baltic countries.In most cases,Nordic countries(Finland,Sweden,Den-mark and Netherlands)have set the lowest limit values.On the other hand,except of France,Malta and Slovenia,Mediterranean countries have adopted the limit values that are proposed by EU Directive (Table2).Apart from heavy metals included in EU Directive86/278, several countries have set limit values for chromium as well as for other categories of pollutants commonly detected in sludge such as pathogens and organic micropollutants.Limit values for total chromium in sludge have been set by19out of27countries (70%),while different legislation on this matter is observed in dif-ferent Belgium areas(Table2).The limit values of total Cr range from40mg kgÀ1DS(Slovenia)to1750mg kgÀ1DS(Luxembourg).A.Kelessidis,A.S.Stasinakis/Waste Management32(2012)1186–11951187So far,except of Hungary that has set a limit value of1mg kgÀ1DS for Cr(VI),no limit values have been set for this chromium species by other European countries,despite the fact that it is considered much more toxic than total chromium(Stasinakis and Thomaidis, 2010).Similarly to EPA regulations(U.S.EPA,1992),11out of27 countries(41%)have set limit values for pathogens(Table2).In most cases,these limit values refer to the existence of salmonella, enterovirus and helminths eggs.Regarding organic micropollu-tants,9out of27countries(33%)have set limit values for several synthetic organic compounds.Among them,7belong to old EU countries and only2(Czech Republic and Slovenia)in new EU countries(Table2).The proposed chemical compounds and the maximum acceptable values differentiate between countries.In general,halogenated organic compounds,linear alkyl benzene sul-phonates(LAS),phthalates,nonylphenols,polycyclic aromatic hydrocarbons,polychlorinated biphenyls(PCBs)and polychlori-nated dibenzodioxins/dibenzofuranes have been included in these national legislations and their limit values range between 0.2mg kgÀ1DS(PCBs)to1300mg kgÀ1DS(LAS).Most EU countries have prohibited the disposal of untreated sludge in soil(Table2).In some cases,speciﬁc obligations for treat-ment have been set such as biological or chemical stabilization be-fore reuse,while there are few countries that allow the use of untreated sludge under certain authorized conditions(e.g.France, Sweden and Estonia).Finally,the use of sludge in forests,silvicul-ture,mines and green areas has been prohibited in several coun-tries(Table2).4.Sewage sludge treatment methods in EU-27A great variety of sludge treatment technologies is used in EU-27,which are related with theﬁnal disposal practices and the size of WWTS.According to Table3,signiﬁcant differences can be ob-served between EU Member States as well between different re-gions of the same country(e.g.Belgium).Regarding sludge stabilization,anaerobic and aerobic digestion seem to be the most common used methods in EU-27,applying in 24out of27countries(89%)and20out of27countries(74%), respectively.Anaerobic digestion is most commonly used in Spain, UK,Italy,Finland and Slovakia,whereas aerobic digestion is the prevailing technology in Czech Republic and Poland(Table3).Hav-ing in mind that aerobic digestion is usually applied in cases of small WWTSs,even in the aforementioned countries the greatest part of produced sludge is treated anaerobically.For instance,in Czech Republic anaerobic stabilization is applied to approximately 97%of sludge(EC,2006).The p.e.criterion for using anaerobic digestion instead of aerobic varies between different countries ranging between5000p.e.in Czech Republic and50,000p.e.in cases of Italy and Austria.Chemical stabilization,conditioning with lime or other chemicals are generally of minor importance, although they are used mainly in some EU-15countries(Table3). On the other hand,composting is used in25out of27countries (93%).However,in most Member State’s reports,it is reported as sludge disposal method,causing confusion on extrapolation of the results.In fact,most composting applications constitute ad-vanced stabilization treatment in order to achieve sludge hygieni-zation for land use.It should be mentioned that some countries such as Germany apply combinations of technologies,e.g.anaerobic stabilization fol-lowed by lime treatment.An innovative stabilization technique that is also applied in more than20German WWTSs since1990 is a combination of mesophilic and thermophilic anaerobic diges-tion in different stages with multiple reactors,called Tempera-ture-Phased Anaerobic Digestion(TPAD).Table1Amounts of sewage sludge and speciﬁc sewage sludge production for total population and population served by WWTS in EU-27 countries.The year that data is available for sewage sludge production is reported in brackets(http://epp.eurostat.ec.europa.eu).Country Sewage sludge production(103ton DS/year)Speciﬁc sewage sludgeproduction(kg/p.e./year)Speciﬁc sewage sludgeproduction(kg/p.e.s.a/year)Germany(2005)217026.327.7United Kingdom(2005)177129.532.0Spain(2005)112126.028.6France(2004)105917.021.3Italy(2005)105318.119.2Netherlands(2005)34822.022.2Austria(2006)25430.833.5Sweden(2005)21023.327.1Portugal(2007)18918.026.1Finland(2005)14828.234.8Denmark(2007)14026.029.2Greece(2005)11510.512.4Belgium(2004)10310.820.4Ireland(2005)6014.617.3Luxemburg(2003)1427.829.2EU-15980621.925.4Poland(2005)48612.721.2Hungary(2004)18418.233.7Czech Republic(2005)17216.823.0Romania(2005)68 3.111.6Lithuania(2005)6619.127.8Slovakia(2005)5610.519.1Bulgaria(2005)42 5.413.1Estonia(2005)2922.129.9Latvia(2005)2712.520.0Slovenia(2005)14 6.818.4Cyprus(2005)711.136.8Malta(2005)0.10.10.2EU-12115111.521.1EU-2710,95717.724.3a p.e.s.:population equivalent served by WWTS.1188 A.Kelessidis,A.S.Stasinakis/Waste Management32(2012)1186–1195As far as concerning the new EU countries,Czech Republic is the region’s leader in sludge management innovation (Le Blanc et al.,2008).This can be illustrated by the full-scale use of mechanical sludge disintegration and the use of sludge lysate being produced during the disintegration or by rich experience on thermophilic anaerobic digestion (Zabranska et al.,2009).Such innovative tech-niques of disintegration by mechanical (ultrasound,mills,homog-enizers),thermal,chemical (acids,lyes)and biological (enzymes)means have also been studied and applied mainly in Germany and less in Sweden and Italy with encouraging results (WPCF,1989;Kunz et al.,1996;Lee and Welander,1996;Sakai et al.,1997;Krogmann et al.,1997;Muller,2000;Le Blanc et al.,2008).On the other hand,sludge dewatering seems to be an important step in sludge management of most EU-27countries.According to Table 3,the majority of European WWTSs use mechanical dewatering instead of drying beds that are preferred mainly in small WWTSs and are reported in 6out of 27European countries.From ﬁnancial point of view,the prevailing sludge dewatering technologies in descending order are centrifuges (41%),belt ﬁlter presses (28%)and ﬁlter presses (23%)( ).Regarding other sludge treatment methods applied in European countries,thermal drying has prevailing position in sludge man-agement of EU-15(Table 3).It should be mentioned that 110ther-mal drying plants were operated in EU in 1995(Hall,1995),the drying lines were increased to about 370in 1999(EC,1999),while today they exceed 450.Most of these plants constitute the ﬁrst stage of incineration units.Fig.1represents distribution of sludge drying plants in European countries.Except of Luxembourg and Finland,all EU-15countries apply this technology (Drace medio-ambiente,2010;Milieu Ltd.,WRc and RPA,2010).As Fig.1reveals,the big majority of thermal drying plants (almost half of them)are operated in Germany,following by Italy,UK and France.Rotary Drum Dryers (RDD)is the most commonly used system,following by other types as Fluidized Bed Dryers (FBD)or Belt Dryers (BD)(/library/print.asp?id=3539;Arlabos-se et al.,2012).An innovative method called Direct Microwave Drying has also been used in Ireland (Turovskiy and Mathai,2006).On the other hand,excepting Slovenia,there are no thermal drying units in the new EU-12countries (Fig.1).Long term storage is also applied in several old or new Member States (9out of 27)as it is an easy and cheap method for sludgemanagement but it requires proper climates and great areas.Other methods such as cold fermentation,solar drying or pasteurization are scarcely referred in a limited number of countries (Table 3).5.Sewage sludge disposal in EU-27The change of sewage sludge disposal methods in EU-15after implementation of 91/271Directive (CEC,1991)can be seen in Fig.2.It should be mentioned that the most recent available data for all European countries are these of 2005.According to the re-sults,landﬁlling presents a signiﬁcant and continuing decrease be-tween 1992and 2005,from 33%to 15%.On the other hand,sludge incineration has been almost doubled (from 11%to 21%),following the estimate-target (EC,1999).Biosolids reuse,which mainly in-cludes agricultural utilization and composting,has been slightly increased,while an important part of total sludge production (9%in 2005)has been managed using several practices.This part of sludge is reported in several reports as ‘‘others’’and include meth-ods such as pyrolysis,temporary storage (e.g.Greece,Italy),long storage (e.g.Poland,Estonia,Lithuania),reuse in green areas and forestry (e.g.Ireland,Latvia,Slovakia),landﬁll cover (e.g.Sweden,Flanders),exportation of sludge amounts to other countries (e.g.granulated sludge from Netherlands to Germany for incineration,sludge for composting or incineration from Luxembourg to Ger-many)as well as possible differences between total sludge produc-tion and disposal amounts.Besides the banning of sludge dumping to the sea after 1998,it is possible that high values of ‘‘others’’ob-served in 2000could also be due to the continued apply of this practice in some European countries (EC,2004).Sludge disposal methods for year 2005in EU-15and EU-12are presented in Fig.3a and b,respectively.As it can be seen,the phi-losophy of sludge management is quite different between old and new Member States.The prevailing technology in EU-15is recy-cling in agriculture (44%).In contrary,the status in new countries is quite unclear,as for 35%of sludge no speciﬁc disposal manner is declared.This uncertainty mainly originates from Poland which,as it was mentioned in Section 2,is the greatest sludge producer in EU-12countries.Almost half of produced sludge in Poland (48%)has no speciﬁc outlet,while according to data reported in BIOPROS project (2006),it seems that this percentage include stockpiling and lagooning.Taking into account this notice,landﬁlling(28%)654266149Landfill Surface waters OthersA.Kelessidis,A.S.Stasinakis /Waste Management 32(2012)1186–11951191is considered the most common ﬁnal disposal method of sludge in EU-12countries (Fig.3b),having twofold penetration compared to EU-15(Fig.3a).On the other hand,the second most preferable disposal practice in old Member States is incineration (21%),while this technology is scarcely applied in EU-12(Fig.3b).Regarding composting,this method is applied more often in EU-12,comparing to EU-15coun-tries (Fig.3a and b).At the moment,the distribution of applied sludge disposal methods in whole European Union (EU-27)is very close to that of EU-15(Fig.3a and c),as the old Member States pro-duce almost 90%of the total amount of sludge (Table 1).Based on the most recent data available from Eurostat (http://epp.eurostat.ec.europa.eu )for sludge disposal methods in different European countries,a descending sorting of EU-27Member States in ‘‘green’’line can be created,having in mind that total sludge re-use is the ﬁrst choice in hierarchy of European Environmental Policy,while incineration is the second (Decision 2001/118/EC,Directive 2008/98/EC).It should be mentioned that in many cases,there is unevenness among countries’data concerning the use of terms.For instance,composting is often included in agriculturalutilization and vice versa.According to Fig.4,the ‘‘greener’’Mem-ber State is Finland with nearly 100%biosolids reuse,almost exclu-sively after composting (97%).Luxembourg,Cyprus and Portugal follow,reusing more than 87%of produced sludge either directly in agriculture or after composting.The last positions concerning environmentally accepted sludge management practices are occu-pied by Malta (100%landﬁll),Greece (46%‘exported’incineration and 39%landﬁll)and Slovenia (63%‘exported’incineration and 18%landﬁll).More than 50%of EU-27countries apply direct sludge agricul-tural use to a percentage higher than 50%,while older EU countries seem to be ‘‘greener’’than new ones (Fig.4).Speciﬁcally,agricul-tural reuse has been adopted by 21Member States,while 7of them (only Hungary from EU-12)apply this practice at percentages higher than 50%.Eighteen countries apply composting before land use,but only 3of them have percentages higher than 50%(Finland,97%;Estonia,78%and Slovakia,67%).On the other hand,incinera-tion is applied in 17countries including Greece and Slovenia that export sludge for herlands presents the greater preference in all types of incineration (68%),followed by Belgium (53%)and Germany (51%).Sludge management practices vary sig-niﬁcantly among regions of the same country.Typical examples are Belgium and UK.In Flemish region of Belgium,incineration is ap-plied in 88%of produced sludge,while in Brussels region 42%of sludge is landﬁlled and in Wallonia 35%of sludge is used in agricul-ture.Similarly in UK,Scotland and Northern Ireland prefer inciner-ation (65%and 36%,respectively),while England and Wales traditionally prefer recycling to agricultural land.Wide variations on the type of incineration applied are noticed among different Member States (EC,2004).Germany,UK and Den-mark have been at the forefront of mono-incineration,having 23,11and 5dedicated sludge incinerators,respectively,while Nether-lands,France,Belgium,and Czech Republic seem to chose co-incineration.Innovative technologies such as pyrolysis,gasiﬁcation and wet oxidation are under research in some cases,but still beyond a wide commercial apply in European area.The most important wet oxidation facility is the deep shaft technology in Netherlands.A similar method has also been used since 2008in the new Northern WWTSs (Brussels region,Belgium).6.Current trends and future perspectivesAn estimation of current trends in sludge disposal practices applied in EU-27is shown in Table 4.For this reason,recent data (up to 2009)originated from Eurostat (http://epp.euro-stat.ec.europa.eu )for European countries have been compared with data of year 2000(BIOPROS,2006;EC,2006).It should be mentioned that some of these data,especially those of EU-12,have low reliability.Furthermore,in some countries the amounts of sludge that are reported as ‘‘others’’are signiﬁcant (e.g.Lithuania),affecting the calculation of sludge percentages that are disposed otherwise.According to the results presented in Table 4,a signiﬁcant aban-donment of sludge landﬁlling is noticed in most European coun-tries,whereas only three countries report a slight increase of landﬁll use (Italy,Denmark,Estonia).Incineration is enforced in most EU-15countries.Greece and Slovenia present the greatest increasing trends (Table 4),however as mentioned in Section 5these countries export sludge for incineration.Between other EU-15countries,Germany (28%)and Netherlands (16%)appear the greatest development of this technology,while Denmark (À22%)and Belgium (À12%)present a decreasing trend.From new Mem-ber States,only Cyprus seems to invest in incineration facilities.Regarding agricultural reuse,an increasing trend is observed in 7out of 15old countries and 6out of 12new countries.The most44%21%15%10%9%Landfill Compost Others35%28%21%16%1%Others Landfill Compost 41%19%17%12%12%Landfill Others Compost1192 A.Kelessidis,A.S.Stasinakis /Waste Management 32(2012)1186–1195signiﬁcant increase is observed in Portugal,Cyprus and Bulgaria (Table4).On the other hand,a signiﬁcant decreasing trend in agricultural reuse is observed in countries such as Slovakia and Czech Republic.In these cases,composting seems to replace direct agricultural reuse(Table4).It should be mentioned that the observed trends depend on local political,social and legal condi-tions.Relevant examples can be observed in Germany,Sweden, Czech Republic and Flanders.For instance,the adaptation of strict legal restrictions on Probable Toxic Elements detected in sludge by Flanders in1998,resulted to a signiﬁcant decrease of agricultural reuse from22%(1998)to2%(2002).According to the latest relative EU projects(EL and IEEP,2009; Milieu Ltd.,WRc and RPA,2010),all Member States of EU-27will probably have completed their obligations regarding Directive91/ 271by2020.Based on this scenario,sewage sludge production will be increased by20%in EU-15and by100%in EU-12.Having in mind the urgent situation that new countries will face out,a temporary in-crease of sludge amounts that will be landﬁlled could be expected in EU-12during the following years.However,a predominance of agri-cultural reuse could be expected up to2020due to the agricultural lands found in these countries,the globalﬁnancial recession and the low cost of this technology.Regarding EU-15countries,agricultural recycling(direct or after composting)and incineration seem to be the two main practices that will be further adopted.Incineration procedures have been undergone signiﬁcant improvements during the last years concerning technology level, cost reduction and environmental protection.However several topics such as the cost of treatment ofﬂue gases and ashes,the emissions of dioxins and furans,the release of heavy metals and the handling of solid residues are still of signiﬁcant important for thermal processes(Fytili and Zabaniotou,2008).Old Member States will continue to lead on these technologies and probably by2020thermal treatment with energy recovery could have a share of37%,over-doubled compared to EU-12.It is possible that co-incineration in coal-ﬁres,use of cement kilns plants or Munici-pal Solid Waste(MSW)incinerators are going to be preferred,ex-cept from cases that phosphorus recovery is pursued.Several technologies for phosphorus recovery from sewage sludge have been performed in large-scale projects worldwide(Dichtl et al., 2007).However the aforementioned technology as well as other innovative technologies such as pyrolysis seem to continue being of minor importance for the following years for most European countries.The further adoption of incinerations technologies will also result to adoption of drying technologies as this is necessary for transfer cost reduction and increase of sludge heating value. Solar drying could be an economic alternative to conventional drying systems,especially in areas with proper climatic conditions (Dichtl et al.,2007).))))))Compost OthersTable4Trends on sludge disposal methods applied in EU-27countries between2000and2009(BIOPROS,2006;EC,2006;http://epp.eurostat.ec.europa.eu).Country Agricultural use(%)Compost(%)Incineration(%)Landﬁll(%)EU-15Austria4À5À12À5Belgium30À1À19DenmarkÀ10À224FinlandÀ9170À6FranceÀ3202À16GermanyÀ4À828À6GreeceÀ2À146À56Ireland2800À44ItalyÀ4À10À212LuxembourgÀ152211À18Netherlands0216À14Portugal7100À77Spain110À4À2Sweden820À12UK1310À3EU-12Bulgaria3600À72Cyprus503813À100Czech RepublicÀ28311À9EstoniaÀ107414Hungary31À201À16Latvia1340À38Lithuania2390À78Malta0000Poland8À30À28Romania0200À27SlovakiaÀ63670À1SloveniaÀ3À1163À67A.Kelessidis,A.S.Stasinakis/Waste Management32(2012)1186–11951193。