Effects of low temperature on sludge settleability and nutrients removal performance treating d
厌氧折流板反应器_ABR_的启动及酸化的恢复
厌氧折流板反应器 (ABR - Anaerobic Baffled Reactor) 是一种新型高效厌氧反应器 ,从结构看相当于几个升流式 污泥床反应器 (USB - Upflow Sludge Bed)的串联 ,实现了 产酸菌群和产甲烷菌群在不同隔室生长的条件 ,在高浓度 有机废水的处理中有特殊的优势 。本文介绍了厌氧折流 板反应器的原理及其相关研究的进展情况 。 1 厌氧折流板反应器的原理 111 良好的水力特征 ABR反应器内设置若干竖向导流 板 ,将反应器分隔成串联的几个反应室 ,每个反应室都可 以看作一个相对独立的升流式污泥床系统 ( upflow sludge bed,简称 USB ) ,废水进入反应器后沿导流板上下折流前 进 ,依次通过每个反应室的污泥床 ,废水中的有机基质通 过各反应室并与其中的微生物充分接触而得到去除 。借 助于水流的上升和沼气搅动的作用 , 反应室中的污泥上 下运动 ,水流在不同隔室中流态呈现完全混合态 。但是由 于导流板的阻挡和污泥自身的沉降性能 ,污泥在水平方向 的流速极其缓慢 ,从而大量的厌氧污泥被截留在反应室 中 ,反应器在整个流程方向则表现为推流式流态 [1, 2 ] 。 112 阶段化多相厌氧反应器 在展望先进的厌氧处理技 术时 , Lettinga[3 ] 提出了阶段化多相厌氧 ( staged M ulti一 Phase Anaerobic reactor system ,简称 SMPA )反应器 ,它不仅 能在更高的负荷率下提供更好的处理效率 ,而且适应于极 端的环境条件和抑制性化合物 。
tech1 1997, 69 ( 2) : 276 - 284
(责编 :张杨林 )
(上接 66 页 ) PolII p romoter sequences, B ioinformatics, 1999, 15:
生物炭对苗期花生镉含量影响的文献综述
文献综述题目：生物炭在农业生产上的研究进展生物炭在农业生产上的研究进展摘要：作为重要的土壤改良剂、污染物质吸附剂的生物炭在农业和环境中具有巨大的应用价值和现实意义，因而受到国内外学者们的普遍关注。
生物炭具有多孔性和巨大的表面积，它能够增加土壤的持水量、增加对营养元素的吸附以减少其流失并改善土壤的结构，此外生物炭本身含有丰富的营养元素并能够缓慢释放以供作物吸收，因此生物炭能改善土壤肥力并增加农作物产量。
同时，生物炭巨大的吸附功能可以降低重金属和有机污染物在土壤及污水中的活性，起到降低污染物浓度的作用。
因此生物炭在农业增产和减少污染方面有巨大的潜力。
本文基于生物炭在农业增产和重金属污染治理方面的国内外研究文献，综述了生物炭的基本理化特性及对土壤重金属污染的改良作用，分析了生物炭对土壤肥力及作物增加产量提高品质的影响，阐述了生物炭对土壤重金属污染修复机理,及该领域未来的发展动向，为生物炭的全面研究和应用提供参考。
关键词：生物炭；农业增产；土壤改良；重金属污染治理1 引言生物炭是一种细粒度和多孔的物质，外观类似木炭，是由生物质在缺氧条件下高温热解或燃烧生成。
而在国际生物炭组织(IBI)对生物炭的定义中，进一步强调了其被目的性地施用到农业土壤及其环境效益的需求。
生物炭的生产工艺相对简单, 原材料来源广泛且价格低廉, 使得炭在农业生产上应用成为了可能。
生物炭施入土壤以后, 可以增加土壤的碳汇, 缓解气候危机; 还可以提升土壤肥力, 增加作物产量。
在中国，重金属污染和农业面源污染已经成为国家和科学家们重点关注的环境问题，并且我国的重金属治理形势极其严峻。
同时由于70年代以来，农民过量使用化肥和杀虫剂等造成了Ｎ、Ｐ等营养元素以及有机污染物通过土壤进入水体造成了严重的有机污染以及水体富营养化，鉴于生物炭的多孔性以及较大的表面积，为改善中国的面源污染提供了可靠的途径。
2 生物炭在农业生产上的研究进展2.1 生物炭的概念及其理化性质目前为止，生物炭还没有十分确切的定义。
低温、紫外胁迫对植物的影响的英语
低温、紫外胁迫对植物的影响的英语1. The effects of low temperature and UV stress on plants have been extensively studied.2. Researchers have investigated the impact of low temperature and UV stress on different plant species.3. This study aims to analyze the responses of plants to low temperature and UV stress.4. The effects of low temperature and UV stress can be detrimental to plant growth and development.5. Understanding the mechanisms underlying the response of plants to low temperature and UV stress is important for crop breeding.6. Low temperature and UV stress can induce significant changes in physiological and biochemical processes in plants.7. Recent studies have shown that low temperature and UV stress can alter the expression of genes involved in plant defense mechanisms.8. The effects of low temperature and UV stress on plants are mediated by various signaling pathways.9. Plant tolerance to low temperature and UV stress can be enhanced through genetic modification.10. The effects of low temperature and UV stress on plants can vary depending on the duration and intensity of exposure.11. Low temperature and UV stress can lead to the accumulation of reactive oxygen species in plants.12. The production of antioxidants is increased in response to low temperature and UV stress in plants.13. Certain plant species have developed specific mechanisms to cope with low temperature and UV stress.14. The effects of low temperature and UV stress on photosynthesis in plants have been extensively studied.15. Plant growth and development can be hindered by low temperature and UV stress.16. The effects of low temperature and UV stress on plant metabolism have been well-documented.17. Low temperature and UV stress can affect the nutritional composition of plants.18. Plants exposed to low temperature and UV stress may exhibit changes in leaf morphology.19. The effects of low temperature and UV stress on plant reproductive processes have been investigated.20. Stress-responsive genes are upregulated in plants subjected to low temperature and UV stress.21. Low temperature and UV stress can lead to alterations in plant hormone signaling pathways.22. Plant defense mechanisms are activated in response to low temperature and UV stress.23. The effects of low temperature and UV stress on plant water relations have been studied.24. Low temperature and UV stress can induce cell membrane damage in plants.25. The impact of low temperature and UV stress on plant yield and quality has been evaluated.26. Strategies for mitigating the effects of low temperature and UV stress on plants are being explored.。
外文翻译--- 利用厌氧消化从微波加热的污泥中获取沼气
附录一Biogas recovery from microwave heated sludge byanaerobic digestionBiogas generated from sewage sludge, livestock waste, and food waste by anaerobic digestion is a valuable renewable energyresource. However, conventional anaerobic digestion is not an efficient process. A long hydraulic retention time and low biogasrecovery rate hinder the applications of those resources. An effective pretreatment method to destroy sludge microbial cellshas been one of the major concerns regarding improvement of the biogas production. This article focuses on the effects of microwave heating on sludge anaerobic digestion. Volatile suspended solid (VSS) and chemical organic demand solubilization of heated sludge were investigated. Microwave heating was found to be a rapid and efficient process for releasing organic substrates from sludge. The increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave heating. The effect of the VSS solubilization was primarily dependent on heating temperature. The highest value of VSS dissolving ratio, 36.4%, was obtained at 170°C for 30 min. The COD dissolving ratio was about 25% at 170°C. Total organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min, respectively. A biochemical methane potential (BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas production. The total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of digestion. Biogas production was 11.1% to 25.9% higher for excess sludge than for untreated sludge. The VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher, respectively, compared to the untreated sludge.biogas recovery, microwave heating, sludge, anaerobic digestion 1 IntroductionWastewater treatment plants produce large amounts of primary and excess sludge that contains organic bacterial microbes and inorganic mineral components. State EPA reports have indicated that there are approximately 11 million tons of dewatered sludge cakes (about 80% moisture content) generated annually in China. In recent years, treatment and disposal of sludge have become a serious problem in many cities.Anaerobic digestion is a common process for sludge treatment. Compared with other processes, its advantages are lower energy requirement, better stabilized product, and generation of usable gas. However, the biological gel structure properties of sludge result in difficulties in anaerobic digestion. Pavlostathisetal.andVavilin et al.found that the bacterial cell wall restrained the biodegradability of sludge. An effective pretreatment method to destroy microbial cells has therefore been one of the major concerns in the sludge pretreatment process. Wang et al. Baier et al. Lin et al.and Tanaka et al.separately carried out sludge pretreatment research to improve biogasproduction and included ultrasonic, mechanical,alkaline, and thermal-chemical treatments for degradation of microbes. Heat treatment was a harsh process that disrupted bacterial cell wall, and released and hydrolyzed high molecular weight materials. Brook found that the hydrolysis of organics was a dominant characteristic that distinguished heat treatment from other methods. Industrial application has proven the effectiveness of heat treatment; for example, Kepp et al. stated that when sludge was heated with a Cambi process at 170°C, the volatile solids (VS) removal ratio of the treated sludge increasedfrom about 40% to approximately 60%. Using the advantages of the improved settling performance of heated sludge,Wang et bined heat treatment with an anaerobic sequenced batch reactor to increase the VS removal ratio to 60% with a lower hydraulic retention time (10 days).However, conventional heat treatment is time-consuming .For the purpose of heating sludge, microwave irradiation might serve as an alternative and much more rapid method .In recent years, the use of microwave as a novel technique to treat sludge has attracted much interest.A uniform microwave field generates energy through the realignment of dipoles with oscillating electric fields to generate heat both internally and at the surface of the treated material. Sludge is a multiphase medium containing water,mineral and organic substances, proteins, and cells of microorganisms.Due to its high water content, sewage sludge can absorb significant amounts of microwave energy.Zlotorzynski analyzed the application of microwave irradiation to analytical and environmental chemistry.Eskicioglu et ed sludge heated by microwave to 96°C in a batch anaerobic digestion test and found a 17% biogas increase over untreated sludge. Compared to conventional heat treatment, microwave treatment resulted in more soluble proteins and volatile fatty acids but a lower sugar content of the sludge. Park etal.reported that microwave treated sludge could produce 79% higher methane production than untreated sludge. Wojciechowska used microwave to condition sludge and found that after 180 s of microwave heating, the specific resistance to filtration (SRF) of mixed sludge (primary and secondary sludge)and anaerobic digested sludge decreased by 73% and 84%,respectively. Liao et al.reported that organic hydrolysis,induced by combing microwave with hydrogen peroxide and acid, could be used to recover sludge nutrients.It is evident that the effectiveness of microwave treatment has been recognized by many researchers. However,the exact nature of the sterilization effect, as well as whether this is due solely to thermal effects or to non- thermal effects, has continued to be a matter of controversy. In most conventional heat treatments, sludge is heated at a mild temperature using an open vessel. The higher temperature and pressure that are generated by microwave treatment of sludge in terms of overall biodegradability were investigated in the present paper.2 Materials and methods2.1 Sludge samplingSludge was sampled from three local municipal wastewater treatment plants (the Gaobeidian, Qinghe, and Beixiaohe wastewater treatment plants) in Beijing. These three wastewater works primarily treat municipal sewage. Table 1 presents the characteristics of the sludge. The mixturesludge (MS) was mixed by combining primary and excess sludge sampled from the gravity thickening tank in the Gaobeidian and Beixiaohe plants. Excess sludge (ES) collected from Qinghe plant was thickened in laboratory to a suspended solid (SS) content of 2.8%. After sampling, sludge wasscreened through a 3.2 mm×3.2 mm mesh sieve to remove large particles. The screened sludge was then stored in a refrigerator at 4°C until further testing.MS from Gaobeidian plant was used for the investigation of organics solubilization of sludge with microwave heating.Microwave treated MS from Beixiaohe plant and ES from Qinghe plant was used for evaluation of biodegradation by abiochemical methane potential (BMP) test. Table 1 shows the SS, VS, total COD, and pH.2.2 Microwave heating procedureA commercial domestic microwave oven (2450 MHz, 1000W, MSD6, Shanghai Sineo Co., Ltd) and PTFE vessels were used for microwave irradiation. This frequency of microwave energy has been widely used in scientific research.Sludge microwave heating was performed as batch tests using 30 mL of sludge in a 70 mL PTFE vessel. All test samples were subject to microwave heating at temperatures of 80, 120, 150 and 170°C. The microwave heating holding times were 1, 5, 10, 20 and 30 min. Sludge temperature and pressure were measured and controlled by the microwave oven.2.3 Biochemical methane potential (BMP) testA biochemical methane potential test was used to evaluate biogas recovery from sludge after microwave pretreatment.A 60 mL sample of microwave-heated sludge, seeded with 150 mL of anaerobic digestion sludge, was fed into a 250mL serum bottle. The seed sludge was collected from an anaerobic digestion tank at the Gaobeidian plant. In this plant, gravity thickened sludge was digested at 35°C with 30 days of HRT. A separate 60 mL sample of untreated sludge was used as a control sample. Each test was performed with parallel samples. The BMP tests were performed in a water bath at 35°C. The cumulative gas production was measured using a water displacement method. The serum bottles were shaken every 12 h to allow for sufficient blending. The methane content in the biogas was measured by a gas chromatograph equipped with a thermal conductivity detector.2.4 Analysis methodsThe total COD (TCOD) was determined by the potassium dichromate/ferrous ammoniumsulfate method. Sludge particles were kept uniformly suspended by a magnetic stirrerwhile sampling. The supernatants were separated from sludge by centrifuging (LG10-2.4A) at 2775 g for 10 min and were used for soluble COD (SCOD) determination. The total solid (TS) and SS were measured by drying sludge slurry at 105°C for 24 h; VS and VSS were tested by burning the dried sludge at 600°C for 2 h. For SS and subsequent VSS analysis, sludge was centrifuged prior to heating,to remove soluble solids as described in SCOD determination.TOC of sludge liquid was measured by Shimadzu’s TOC-5000.3 Results and discussion3.1 Temperature increases by microwave heatingCompared with conventional sludge heating, microwave heating is much more rapid. When materials are heated by high frequency electromagnetic waves, the heating effect arises from the interaction of the electric field component of the wave with charged particles in the material. Power absorbed by materials becomes higher as the penetration depth decreases. As a result of the complicated composition of sludge, the absorption of microwave energy will be influenced by organics (such as proteins, lipids, and carbohydrates)and solid concentration, as well as by the heatingLoad. Hong et al.reported that water absorbed microwave energy was in an exponential relationship with the heating load, and that the absorption efficiency could reach 80%.Figure 1 presents the heating and cooling curves in sludge microwave treatment at 120, 150 and 170°C for 5 min. Under microwave irradiation, sludge temperature increased rapidly, and the heating ratios were similar for the different temperatures. The microwave irradiation times to 120, 150 and 170°C were 4, 7 and 7.5 min, respectively. When the sludge was heated to pre-set temperature, sludge was kept at a stable temperature for 5 min. This time was called heating time. When the heating finished, the reactor filled with sludge was transferred from microwave oven into a cool water bath. The decline parts of the curves in Figure 1 representthe cooling of sludge.3.2 Organic sludge dissolving trendsThe conventional heat treatment performed by Wang et al. demonstrated that inorganic components dissolved at a lower dissolution ratio, and that the main part of the solid dissolution was due to VSS hydrolysis. Brooks presented a summary of the solid matter in the sludge and followed their pathways of dissolution and hydrolysis. First of all, the floc of microorganism was found to disperse anddisintegrate. The intracellular material was released, dissolved,and hydrolyzed as follows: lipids were hydrolyzed to palmitic acid, stearic acid, and oleic acid; proteins were degraded to a series of saturated and unsaturated acids,ammonia, and some carbon dioxide, while carbohydrates were broken down to polysaccharides of smaller molecular weight and, possibly, even to simple sugars. Therefore,volatile suspended solid (VSS) were generally taken as a principal parameter of organic hydrolysis.VSS dissolution depicted the tendency of sludge to become an inorganic product. Figure 2 presents changes in sludge VSS dissolution under different conditions. Holding times from 1 to 30 min were used at the temperatures of 80,120, 150 and 170°C. The VSS dissolution ratios substantially increased with rising temperature and prolonged holding time. However, the increases in dissolution were not obvious when the holding time was beyond 5 min. The effect onthe VSS dissolution was mainly dependent on the temperature. The highest value of VSS dissolution ratio,36.4%, was obtained for a treatment at 170°C for 30 min.The COD dissolution was the portion of TCOD in the sludge solid that was hydrolyzed into the liquor during the microwave irradiation. COD dissolution showed organicmatter dissolution. Microwave irradiation caused significant increases in COD concentrations. This corresponded to cell damage as a mechanism of microwave thermal treatment.The highest COD dissolution was 25.8% at 170°C for 10min (seen in Figure 3).The tendency toward COD dissolution, as affected by microwave heating temperature and time, was consistent with the VSS dissolution. Accordingly, SCOD concentration of treated sludge also showed a similar trend with temperature and holding time. As shown in Figure 4, at 170°C,the SCOD of sludge was about 10 g/L. As also shown in Figure 5, the mean value of TOC concentration increased with the microwave irradiation temperature and time, and reached the highest value, 3.4 g/L, with a treatment of 170°C for 30 min. The microwave thermal pretreatment caused a substantial dissolution and hydrolysis of organics.This suggests that microwave irradiation is capable of additionally decomposing complex chemical compounds and hydrolyzing them into simple compounds that can then be easily decomposed by bioprocesses. This effect can be used to enhance the sludge digestion process, as shown in the present results.3.3 Biogas recovery from microwave treated sludgePino-Jelcic et al. compared microwave treatment with conventional heat treatment at 60–65°C,and found that the sludge VS removal ratio of microwave-treated sludge by anaerobic digestion was 53.9%, while the ratio was 51.3%for conventional thermal treated sludge with anaerobic digestion.Microwave treatment was helpful in disrupting the cell membranes of sludge bacteria, destroying more E. Coli and releasing more intracellular materials. Heo et al. used a BMP test to evaluate the anaerobic digestibility of alkaline-treated sludge. A hydrolysis test showed that the VSS dissolution did not increase significantly with the prolongation of holding time beyond 5 min and that VSS dissolution was low at 80°C.In the present study, microwave heated sludge used for the BMP test was heated to temperatures of 120, 150 and 170°C for 5 and 10 min. Compared to ES, primary sludge and amixture of primary and ES could be readily digested.In order to analyze the microwave effect on different types of sludge, both MS from Beixiaohe and ES from Qinghe were tested. Cumulative biogas production of MS is shown in Figure 6. After microwave treatment, total biogas production increased by 12.9% to 20.2% over the control after 30 days of digestion. Figure 7 presents the cumulative total biogas production of ES. This production was 11.1% to 25.9% higher than untreated sludge. The highest biogas production was obtained from the sludge treated by microwave at 170°C for 10 min. Microwave heating as a pretreatment method for MS and ES therefore appeared to be effective in obtaining higher biogas production.Both batches used for BMP gas production showed a fast rate for the first 10 days, then the gas production ratio decreased and stabilized. As seen in Figures 6 and 7, the amount of biogas generated for MS from Beixiaohe plant was higher than that from ES. This was most likely due to differences in organic load, as MS contains more organic content than ES. However, microwave pretreatment improved the sludge anaerobic digestibility for both MS and ES. The microwave treatment temperature was more sensitive for MS than for ES.VS removal ratio in anaerobic digestion was another parameter that affected sludge biodegradability. Figures 8 and 9 present the VS removal ratios of the microwave treated MS from Beixiaohe plant and ES from Qinghe plant, respectively.The VS removal ratio of MS microwave treated at 170°C for 5 min was 12% higher than that for the untreated sludge. For ES, the VS removal ratio increased by 11%compared to untreated sludge.4 ConclusionsMicrowave heating using a domestic microwave oven with a frequency of 2450 MHz wasable to accomplish a rapid temperature increase in sludge. Therefore, as an alternative method, microwave treatment should also prove effective on an industrial scale. VSS dissolution approached values comparable to those by conventional heat treatment. The COD dissolution and the changes of TOC also indicated the same degree of organic component hydrolysis. At 170°C,the VSS dissolution ratio of treated sludge reached 36.4% and COD dissolution ratio was about 25%. Under this typical hydrolysis parameter, microwave irradiation could shorten holding time to 5 min, compared to conventional processes that require more than 30 min. This provided the possibility of shortening system sludge retention time,therefore saving energy and construction costs for industrial applications.Compared with microwave conditioning, higher temperature with a pressure vessel could also bring notable effects with relatively mild temperatures. Microwave irradiation was shown to be effective at improving sludge biodegradability for both MS and ES, allowing a greater recovery of biogas. The BMP test showed a significant improvement in biogas production and in the VS removal ratio. The results of this study indicate that higher biogas production is possible at temperatures no higher than 170°C.利用厌氧消化从微波加热的污泥中获取沼气通过厌氧消化的污水污泥，禽畜废物，食品废物产生沼气是一种宝贵的可再生能源资源。
The Effect of Temperature on Protein Conformation
The Effect of Temperature on ProteinConformationProteins are essential components of living organisms and are responsible for carrying out various cellular functions. They are composed of long chains of amino acids that are folded into intricate 3-dimensional structures. The specific shape of a protein, or its conformation, plays a critical role in its function. Temperature is one of the key factors that can influence protein conformation. In this article, we will explore the effect of temperature on protein conformation and how it impacts their function.Temperature-induced protein denaturationProtein denaturation is a process in which the protein loses its native conformation and unfolds into a linear or random coil structure. This process can be triggered by several factors, including pH, salts, mechanical stress, and temperature. Among these, temperature is the most commonly studied factor that can induce protein denaturation.When proteins are exposed to high temperatures, the thermal energy causes the bonds that hold the protein structure together to break. Hydrogen bonds, which are weaker than covalent bonds, are the first to be broken. As the temperature continues to rise, the more significant covalent bonds that hold the protein together begin to break, further destabilizing the structure. Ultimately, the protein loses its native conformation, and its function is impaired.The effect of temperature on protein stabilityThe stability of a protein refers to its ability to maintain its native conformation in the face of various environmental conditions, including temperature. The stability of a protein is influenced by several factors, including the amino acid sequence, solvent conditions, and the presence of ligands or cofactors. Temperature can disrupt the stability of a protein by altering its structure and causing it to denature.Proteins have a range of thermal stability that depends on their amino acid sequence and their specific structure. Generally, proteins that are stable at higher temperatures have a higher content of hydrophobic amino acids, which can help to stabilize the structure through hydrophobic interactions. In contrast, proteins that are stable at lower temperatures tend to have more polar amino acids and a lower content of hydrophobic amino acids.The temperature at which a protein denatures is known as its melting temperature or Tm. The Tm of a protein is influenced by its intrinsic stability as well as the specific conditions under which it is studied. For example, the pH, salt concentration, and presence of other molecules can all affect the Tm of a protein.The effect of temperature on protein functionThe specific conformation of a protein plays a critical role in its function. Therefore, changes in protein conformation due to temperature can have a significant impact on their function. The effect of temperature on protein function can vary depending on the specific protein and the conditions under which it is studied.Some proteins are more sensitive to changes in temperature than others. For example, enzymes, which catalyze chemical reactions in the cell, have a specific optimal temperature range at which they function best. Outside of this range, the reaction rate can slow down or even stop altogether due to changes in protein conformation.Other proteins, such as transporters and receptors, are also sensitive to changes in temperature. Changes in protein conformation due to temperature can affect the ability of these proteins to bind to their ligands and carry out their function.ConclusionIn conclusion, temperature has a significant impact on protein conformation. High temperatures can cause proteins to denature, while changes in temperature can alter their stability and affect their function. Understanding the effect of temperature on protein conformation and function is essential for designing experiments and developing new drugs and therapies that target specific proteins.。
UASB反应器降解偶氮和蒽醌染料废水的特性
UASB反应器降解偶氮和蒽醌染料废水的特性吕仪婧，邓志毅*，肖利平（湘潭大学环境科学与工程系，湖南湘潭411105）摘要：采用UASB反应器，在中温（35±1℃）条件下，分别处理了偶氮类（活性艳红X-3B和KD-8B）和蒽醌类（活性艳蓝K-GR）模拟染料废水，对比研究了反应器运行条件，探讨了回流比、水力停留时间和染料种类等因素对染料脱色率的影响。
结果表明：采用维持水力停留时间（hydrodynamic retention time, HRT）为24 h，逐步提高进水染料浓度的方式，在约25d内成功启动反应器。
当偶氮类（活性艳红X-3B）和蒽醌类（活性艳兰KG-R）染料的进水浓度为100 mg/L，回流比为2~2.5倍时，系统的COD 去除率和脱色率均可达到90%以上；过高的回流比不利于染料的脱色；染料种类的变化对其脱色影响不大，但HRT的缩短对染料脱色有较大的影响。
紫外-可见光谱分析显示，偶氮染料脱色是通过偶氮键的断裂，而蒽醌染料脱色则是通过蒽醌共轭结构的破坏来实现的。
关键词：UASB；厌氧；染料废水；偶氮染料；蒽醌染料Degradation Performance of Azo and Anthraquinone Dye1Wastewater Treated by UASB ReactorsLV Yijing，DENG Zhiyi*，XIAO Liping(Department of Environmental Science and Engineering，Xiangtan University，Xiangtan 411105，Hu’nan，China)Abstract: The dyeing wastewaters, which is composed of azo dye – X-3B(C.I.Reactive Red2，referred to as X-3B or RR2), KD-8B(C.I.Reactive Red20，referred to as KD-8B or RR20) and anthraquinone – KG-R （C.I.Reactive Blue19，referred to as K-GR or RB19）respectively, were treated by two same size Upflow Anaerobic Sludge Bed (UASB) reactors under mesophilic condition (35±1℃). During this experiment, the effect of effluent recycle rate, hydraulic retention time (HRT) and the type of dyes were all investigated. The results indicated that two reactors were all successfully started up in about 25 d through the operation fashion of improving the influent dye concentration step by step and maintaining HRT of 24h. The COD removal and decoloration rate could obtain above 90% in two reactors with the influent X-3B and K-GR concentration of 100 mg/L and recycle rate of 2~2.5 times. High recycle rate is not benefit for improving decoloration rate. The change of dye types had little effects on its decoloration rate, but the decrease of HRT had large effects on the decoloration rate. Based on the results of UV-Vis spectra analysis, the decoloration of azo and anthraquinone dye was achieved by the breakage of azo and anthraquinone bond respectively.基金项目：国家重大专项东江项目子课题四（2009ZX07211-005-04）,湘潭大学博士启动基金(08QDZ31)。
温度对半导体影响的书
温度对半导体影响的书英文回答：The effect of temperature on semiconductors is acrucial aspect to consider in the field of electronics. As temperature changes, it can have both positive and negative impacts on the performance and reliability of semiconductor devices.One of the main effects of temperature on semiconductors is the change in electrical conductivity. Generally, as temperature increases, the conductivity of a semiconductor also increases. This is due to the increased thermal energy, which allows more charge carriers to move freely within the material. As a result, the resistance of the semiconductor decreases, and it becomes more conductive.However, this positive effect of temperature on conductivity can also have negative consequences. For instance, if the temperature rises too high, it can lead tothermal runaway, where the increased conductivity causes excessive heating and further increases the temperature. This can ultimately result in the device failing or even burning out.Another important effect of temperature on semiconductors is the impact on bandgap energy. The bandgap energy is the energy difference between the valence band and the conduction band in a semiconductor. At higher temperatures, the bandgap energy decreases, which meansthat the semiconductor becomes more conductive and allows more charge carriers to move across the bandgap. This can affect the performance of devices such as diodes and transistors, as it can lead to increased leakage currents and reduced efficiency.Furthermore, temperature can also affect the mobility of charge carriers in semiconductors. Mobility refers to the ease with which charge carriers can move through the material. At higher temperatures, the mobility of both electrons and holes in a semiconductor generally increases. This can lead to improved device performance, as the chargecarriers can move more freely and quickly. However, at extremely high temperatures, the mobility can besignificantly reduced due to scattering effects, which can negatively impact device performance.In addition to these electrical effects, temperaturecan also affect the mechanical properties of semiconductors. For example, as the temperature changes, the coefficient of thermal expansion of the semiconductor material can cause stress and strain in the device. This can lead to mechanical failure or even cracking of the semiconductor.中文回答：温度对半导体的影响是电子领域中需要考虑的一个关键因素。
2024年高一英语气候科学研究进展练习题40题
2024年高一英语气候科学研究进展练习题40题1.Climate change is mainly caused by the increase in _____.A.greenhouse gasesB.pollutionC.wasteD.noise答案：A。
“greenhouse gases”是温室气体，气候变化主要是由温室气体增加引起的。
“pollution”污染，范围太广，不一定直接导致气候变化。
“waste”废物，和气候变化关系不大。
“noise”噪音，与气候变化毫无关系。
2.Scientists are studying ways to reduce _____.A.climate changeB.global warmingC.pollution levelsD.carbon emissions答案：D。
“carbon emissions”是碳排放，科学家正在研究减少碳排放的方法。
“climate change”气候变化是结果不是要减少的对象。
“global warming”全球变暖也是结果。
“pollution levels”污染水平，比较宽泛，不如减少碳排放具体针对气候变化。
3.The melting of glaciers is a result of _____.A.rising temperaturesB.polluted airC.waste disposalD.noise pollution答案：A。
冰川融化是温度上升的结果。
“polluted air”污染的空气，不是冰川融化的直接原因。
“waste disposal”废物处理，与冰川融化无关。
“noise pollution”噪音污染，和冰川融化毫无关系。
4.One way to combat climate change is to increase the use of _____.A.fossil fuelsB.renewable energyC.nuclear powerD.coal答案：B。