环境化学英文课件18
CHEMISTRY of the ENVIRONMENT(环境化学课件1)共29页
2. Branch of Environmental Chemistry
Chemistry of the Environment
Analytical chemistry of the environment
Organic analytical chemistry of the environment
2. Haiou Wang, Guihua Wang, Yanjun Zheng, Jiemin Liu, Aijun Gong, Chemistry of the Environment Solutions Manual, University of Science and Technology Beijing Press, 2nd edition, 2019
6. Liu Zhaorong, atal. Introduction to chemistry of the environment, Chemical intrustry press, 2019
7. Wang Xiaorong, Chemistry of the Environment, Nanjing University Press,1993
8. Deng Nansheng, Wu Feng, Introduction of Chemistry of the Environment, Wuhan University Press, 2000
9. Eldon D. Enger, Bradley F. Smith, Environmental Science – A Study of Interrelationships (Seventh Edition), Mc Graw-Hill，Qinghua university press,2000
环境化学课件
当今人类面临的环境问题
9 土壤、固体废物污染
当今人类面临的环境问题
10 人口激增
当今人类面临的环境问题
11 全球变暖
• • • 北极海冰区域大约每10年收缩9%； 海平面上世纪平均上升了10到20厘米； 20世纪90年代是自19世纪中期开始温度记录工作以来最温暖的 十年，在记录上最热的几年依次是：1998年，2002年，2003年， 2001年和1997年。
What does an environmental chemist do?
Environmental Chemist
Environmental Measurement & Monitoring
Environmental Research
Environmental Regulation
一、环境化学的形成
伦敦烟雾事件
时间地点: • 1952年 英国伦敦； • 中毒情况：胸闷、咳嗽、喉痛和呕吐 ， 5天内4000人死亡，共发生12起，死 亡近万人； • 原因：粉尘中Fe2O3使 SO2转变成硫 酸，附着在烟尘，吸入肺部。
世界著名环境问题
水俣病事件
时间地点: • 1953年 日本九州水俣； • 中毒情况：口齿不清、面部痴呆、全身麻木，最后精神失常致死亡，患 者180人死亡50人； • 原因：食用含有甲基汞的鱼。我国是世界第三大产汞国，中国80％汞由 贵州提供，贵州汞污染危害已经显现，为世界所关注。
Lecture notes and handouts
Lecture slides (except videos) will be put in the desktop of the computer after each lecture ； Handouts （if there some）will be distributed in class.
环境化学课件AboutHaze
Haze is air pollution in which is mixed up with dust, smoke and other dry particles ,and it obscure the clarity of the sky and interacts with the natural environment.This kind of air pollutant come from a variety of natural and manmade sources. Natural sources can include windblown dust, and soot from wildfires. Manmade sources can include motor vehicles, and industrial fuel burning, and manufacturing operations. The one of the main cause that touches off haze is manufacturing operations. Many factories were over measure produced the smog that had over the standard and the smog seriously influence the air become air pollution.Since the development of the technology, the society gets modernized, people make use of the high technology to pursue more profit. Though the government has noticed the problem that people do to the environment, they still can’t prevent negative result that the polluted environment brings.Many years ago, the most prominent problem of the polluted environment is that the river and the water were changed their color, some fish even died for the polluted river. Now the situation becomes ever worse, lately, in the big city, like Beijing and Shanghai, people are annoyed by the bad weather. It is not the rainy day, but the haze around the sky, there is no way for people to run away for it. The haze contains toxic elements, people breathe it and hurt their bodies.The haze problem is the result of people’s pursuit for t he profit, what people did to the environment now has been paid back by the environment. Now people have realized the revenge from the nature is so huge, protecting the environment is the main task. No matter how bad the environment is, people still need to do something to fix their mistake.Haze will bring many hazards. The health impact of haze is dependent on one's health status (e.g. whether one has pre-existing chronic heart or lung disease), the PSI (Pollutant Standards Index) level, and the duration and intensity of outdoor activity. Reducing outdoor activities and physical exertion can help limit the ill effects from haze exposure. Persons who are not feeling well, especially the elderly and children, and those with chronic heart or lung conditions, should seek medical attention.As large areas of northern China experienced strong haze in recent days and Beijing issued its first ever red alert for air pollution, it is clear what needs to be done."I think it means that China is in the process of industrialization and urbanization, and we should transform our development patterns and adjust the economic, industrial and energy structures accordingly. There is a synergistic effect between solving the problems of haze and addressing the climate change," Xie Zhenhua said.Xie, who has been China's lead negotiator at the annual UN Climate Conference since 2009, stated that China will address the pollution issue on its own terms as part of the fight to combat climate change. "Therefore, Chinese President Xi Jinping pointed out that coping with the climate change and solving the environmental problems in China is not something that is imposed from outside, it is something that we need to do ourselves. By doing so, we will resolve our own problems and make a contribution to the world in terms of coping with global climate change as well," said Xie.To settle this problem, a series of measures should be taken as follows.First ,government should strengthen air monitor to lower the levels of small particulate pollutants and make some chemistry changes during the manufacturing process to reduce harmful emissions.Second, government should enact more strict laws and regulations and keep perfecting our current law on environmental protection to regulate people 's daily action and the industrial production and punish those factories that ignore the protection and keep emitting dangerous material that cause haze.Third, government should develop green and energy-saving energy to lower the emission of haze and improve air quality. As far as i am concerned ,if we work together to be able to do such measures ,our environment will getting better and better and haze weather will vanish completely.While thinking when is the haze going to leave us alone, let's pay attention to how to prevent it from affecting our health!In the first place, Drink more water and increase the intake of fresh fruits and vegetables. They help the body to flush out toxins absorbed through the skin and lungs, and improve the immune system. Taking moreanti-inflammatory fruits and vegetables also help to reduce inflammation that may be triggered by harmful fine particles in the air.Furthermore, Avoid outdoor activities, especially outdoor sports. Children, pregnant women, the elderly, and those suffering from chronic illnesses, especially heart and respiratory disease, should remain indoors when haze hits unhealthy levels. Healthy adults should avoid unnecessary outdoor activities. If you must exercise outdoor, avoid exercising in highly congested areas near busy roads and freeways, particularly during rush hours.Last but not least, Limit or avoid smoking indoor and the use of gas stove, wood fireplace, candles, incense and anything that burns and emits smoke. In an enclosed area, smoke, gases and pollutants emitted from burning sources are trapped indoor and can build up to hazardous level if they continue to burn for an extended period of time.。
环境化学PPT
报告目录 Contents
PART 1
Pollutants
PART 2
Sources And Sinks
PART 3
Chemical Behaviors
PART 4
Control
ChemilO+O2 ·ClO+O→O2+·Cl O+O3 →2O2
Chemical Behaviors
ClO+ClO+M→(ClO)2+M (ClO)2+hv→Cl+ClO2 ClO2+M→O2+Cl+M 2(Cl+O3) →2(ClO+O2) 2O3+hv→3O2
报告目录 Contents
PART 1
Pollutants
PART 2
Sources And Sinks
PART 3
Chemical Behaviors
用作聚氨醋泡沫塑料的发泡剂， 广泛用于冰箱、冷库、空调及热
泵中
是一种很好的溶剂,用做清洗剂。
Sources Of CFCs
液相法 不同的氯代烃原料在卤化锑催化剂、反应温度 (一般为45～200℃)和压力(最高可达3.5MP） 下可以制得不同的氟化合物
气相法 使用装有氟化铝、氟化铬和氟氧化铬催化剂的 固定床反应器或流化床反应器， 以甲烷、氯气 和氟化氢为原料，在催化剂存在下，一步合成 氟氯甲烷
PART 4
Control
开发代用品
代用品的开发应考虑： 1）具有优异的物化 性能； 2）价格适宜，能被市 场接受； 3）对臭氧破坏潜能低；
减少使用
逐渐减少和终止臭氧耗 竭物质的排放和使用
Control
化学专业英语-EnvironmentalChemistry
5 Alkalinity
The capacity of water to accept protons is called alkalinity. Generally, the basic species responsible for alkalinity in water are bicarbonate ion, carbonate ion, and hydroxide ion:
Concepts and terms
4.
Temperature, transparency and turbulence
Temperature, transparency, and turbulence are the three main physical properties affecting aquatic life.
(pH=8.3), or total alkalinity, corresponding to titration with acid to the methyl orange endpoint (pH=4.3), where both bicarbonate and carbonate species have been converted to CO2 .
e-
as pE.
8 Humic substances as complexing agents
The most important class of complexing agents that occur naturally are humic substances. There are degradationresistant materials formed during the decomposition of vegetation. They are best classified on the basis of solubility. If a material containing humic substances is extracted with strong base, and the resulting solution is acidified , the products are (a) a nonextractable plants residue called humin; (b) a material that precipitates from the acidified extract, called humic acid; and (c) an organic material that remains in the acidified solution, called fulvic acid.
《环境化学》全套教学课件pptx
水体中污染物迁移转化规律
1 2
污染物的迁移方式 包括对流、扩散、吸附、沉淀等。
污染物的转化过程 包括光化学转化、生物转化、化学转化等。
3
影响污染物迁移转化的因素 如水温、水流速度、水体pH值、微生物活动等。
04
土壤环境化学
土壤组成与性质
矿物质
有机质
土壤矿物质是岩石经过风化作用形成的不同 大小的矿物颗粒。包括砂粒、粉粒、黏粒等。
07
当代环境问题与可持 续发展战略思考
当代环境问题概述
空气污染
工业废气、汽车尾 气、室内空气污染 等。
生物多样性丧失
物种灭绝、生态系 统破坏、基因资源 流失等。
全球气候变化
温室效应、极端天 气件频发、海平 面上升等。
水资源危机
水资源短缺、水污 染严重、水生态破 坏等。
土壤污染与退化
化肥农药过量使用、 重金属污染、土壤 侵蚀等。
影响生物体免疫系统
污染物质可能影响生物体的免疫系统， 降低生物体的免疫力，使其更容易受 到病原体的侵袭。
06
环境质量评价方法及 标准
环境质量评价概述
环境质量评价的定义和意义
环境质量评价是对环境的优劣进行定量或定性的描述和评估，为 环境管理、规划和决策提供科学依据。
环境质量评价的内容和范围
包括大气、水、土壤、生物等环境要素的质量评价，以及环境噪声、 放射性、电磁辐射等污染因素的评价。
土壤中污染物迁移转化规律
物理迁移
污染物在土壤中的物理 迁移主要包括扩散、对 流和机械搬运等作用。
化学迁移
污染物在土壤中的化学 迁移涉及溶解、沉淀、 氧化、还原等化学反应
过程。
生物迁移
土壤中的生物活动如植 物吸收、微生物降解等 作用可以影响污染物的
《环境化学》双语课件19
Example
Suppose an insecticide is applied to a crop to eradicate fruit flies. Assume that one out one million fruit flies possesses an enzyme that breaks down the insecticide into nontoxic metabolic products. Assume further that the normal fruit flies die off quickly, the population of the resistant flies increases geometrically (that is, 1,2,4,8,…). If a new generation occurs every 23.5 days, in how many days will the fruit fly population be restored?
Each application is effective for a long time
DDT binds to the nerve cells of insects hold open the molecule channels for sodium ions uncontrolled firing of the nerves kill the insects.
Pesticides
Pests and pesticides
• Pest: ANY UNWANTED organism that directly or indirectly interfere human activity is called a pest. • Pesticides, or biocides, are substances that can kill organisms that we consider to be undesirable. • The most widely used types of pesticides:
环境化学全英ppt第1章 绪论 chapter 1 introduction
Pollutant
• If the concentration of a substance already present in nature or a new substance increases to undesirable proportion by human action so that it spoils the environment and lowers the quality of life or effects health • CO, SO2, NO2, Dust, Pollen etc. • Compounds of metals like Zn, Hg, Cd, As etc.
Global, regional & local, pollutants
• A global pollutant refers to a pollutant whose damage is determined by its concentration in the upper atmosphere • CO2 is often cited as a contributor to the greenhouse effect • Chloroflourocarbon emissions are linked to ozone depletion
Lithosphere
• Outer mantle of solid earth • Mineral occurring in earth crust & soil • Soil -most important component
Biosphere
The biosphere is made up of the parts of Earth where life exists—all ecosystems. • Realm of living organism & their interaction with environment • Biological world intimately linked with energy flow in environment
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Acute (急性) and chronic (慢性) toxicity
• Acute toxicity refers to a rapid and serious response to a high but short-lived dose.
– Acute poisons interfere with essential physiological processes, leading to a variety symptoms of distress, even death.
Dioxin toxicity varies among the congeners
International Toxicity Equivalency Factors (TEF) for PCDDs and PCDFs
Congener
2378
PCDD series PCDF series
1 (defined) 0.1
Index of acute toxicity:LD50
LD50 is the lethal dose for 50% of a population.
Dose is expressed as the weight of a chemical consumed by an experimental animal per kg of body weight of the animal.
The TEFs allow the conversion of various congener concentrations into a single toxicity equivalent quantity (TEQ)
Dioxin toxicity: general rules
• TCDD is the most toxic of the dioxins • Toxicity decreases when Cl atoms are removed from 2,3,7,8 positions or added to the remaining positions on the rings. • There are similar toxicity pattern for PCDD and PCDF series.
Food Ocean fish Meat TCDD (pg/g) 500 35
Cheese
Sour cream Cream Ice cream Cottage cheese Milk Coffee
16
10 7.2 5.5 2.1 1.8 0.1
Orange juice
0.2
Formation of dioxins
Atrazine
Malathion Aspirin
1,870
1,200 1,000
Nicotine
Dioxin (TCDD) Botulin toxin
1
0.001 0.00001
Almost every chemical is toxic at some level, and the difference between toxic and nontoxic chemicals is a matter of degree.
• Combustion
– In any situation where Cl, C, H, and O come into contact with heat, PCDD/Fs could be formed as trace by-products. – Dioxin emission correlates with the Cl content of the combustion feed.
Multiple exposure pathways
Biochemistry of dioxin toxicity
• PCDD/Fs are planar aromatic molecules. • The planar structure allows them to bind to Ah (Aryl hydrocarbon) receptor protein that is present in all animal species. • The Ah receptor interacts with the cell’s DNA. • Dioxin toxicity is roughly proportional to the strength of binding to the Ah receptor. • This explains that 2378-TCDD is the most toxic one.
• Manufacture of certain chlorophenol chemicals
– Dioxin was produced as a contaminant of the herbicide 2,4,5-T, a component of Agent Orange
Formation of dioxins in combustion processes
How much dioxin do we congest?
Country
Estimated Dietary Intakes of PCDD/Fs per day
Dietary Intake (pg I-TEQ/day)
Canada
Germany Italy Japan Netherlands Norway Russia
9 8 1 9 2 8 1 2
O
7 6
O
4
3
7 6
O
4
3
Dibenzodioxin PCDD
Dibenzofuran PCDF
Cl
O
Cl
Cl
Cl
Cl
O
2378-TCDD
Cl
Cl
O
2378-TCDF
Cl
Toxicity of Dioxins
• Extraordinary toxic to lab animals (LD50 in male guinea pigs is only 0.6 mg/kg)
• Chronic toxicity refers to a time-lagged response to a relatively low but prolonged exposure.
– Effects are more subtle. – Set in motion a chain of biochemical events that lead to disease states, including cancer.
• Risk to humans is less clear
Human risk of dioxin exposure
• USEPA concludes that dioxins likely increase cancer incidence. • WHO classifies 2378-TCDD as a probable human carcinogen. • At high levels, PCDDs cause chloracne (氯痤倉), a painful skin inflammation. • Risk from breathing dioxin-laden air is minimal. • The main exposure route for human is dietary (meat, dairy products, and fish). (Due to bioaccumulation of dioxins) • Absorption of dioxins by infant through mothers’ milk is efficient.
LD50 of selected chemicals for rats or mice
Chemical Sugar ethanol Vinegar Table salt LD50 (mg/kg) Chemical 29,700 14,000 3,310 3,000 Caffeine DDT Arsenic Parathion LD50 (mg/kg) 130 100 48 3.6
Dioxins
(二噁英):
General structures
• The term dioxins denotes a family of chemical compounds, known as polycholorinated dibenzopara-dioxins (PCDDs) and polycholrinated dibenzofurans (P-480 63 70 51-85 139
UK
US Hong Kong
70
18-192 105
Source: An Assessment of Dioxin Emissions in Hong Kong, HKEPD, 2000.
Average content of 2378-TCDD in various foodstuff (U.S)
• Incomplete combustion of organic wastes in the combustion chamber leads to the formation of organic fragments which serve as organic precursors to the PCDD/F molecule. • The waste provides a source of chlorine, and of metals. The latter are incorporated into fly ash, which carries over to the cooler (250-400oC) post-combustion zone of the incineration system. • The organic precursors adsorb onto the surface of the fly ash in the post-combustion zone, and following a complex sequence of reactions which are catalyzed by metals (primarily copper) in the fly ash, lead to the formation of PCDD/Fs along with other chlorinated trace organics.