Chen guo hua

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Chen guo hua

  1. 1. Heavy metal pollution of soil 土壤的重金属污染
  2. 2. 什么是土壤的重金属污染 土壤重金属污染现状 土壤重金属污染的特点 土壤重金属污染的来源 土壤重金属污染的危害 治理方法及特点 农业生态修复
  3. 3. 前言 土壤是一个国家最重要的自然资源,它是农业发展的物质基础,没有土壤就没有农业,也就没有人们赖以生存的衣食等基本原料,土壤一旦遭受污染,特别是重金属的污染,很难修复。 重金属污染是当今面积最广,危害最大的环境问题之一,土壤中重金属污染不仅降低土壤肥力和作物的产量与品质,而且恶化环境,并通过食物链危及人类的生命和健康。
  4. 4. Preface Soil is a country's most important natural resources.It is the material basis of agricultural development, if there is no soil ,there would be no agriculture, no survival of the people’s food and clothing and other basic raw materials. Once the soil suffer from pollution, especially heavy metal pollution, it is difficult to repair Heavy metal pollution is one of the most damaging environmental problems and the most widely in area tody. It is not only reduces the soil fertility and crop yields and quality, and the deterioration of the environment, and through the food chain to threaten human life and health
  5. 5. 一 . 什么是土壤的重金属污染 1. 什么是重金属?  重金属指比重大于 4 或 5 的金属,约有 45 种,如铜、铅、锌、铁、钴、镍、钒、铌、钽、钛、锰、镉、汞、钨、钼、金、银等。 , 而我们常说的重金属污染指的就是因人类活动导致环境中的重金属含量增加,超出正常范围,并导致环境质量恶化。
  6. 6. What is heavy metal pollution of soil 1.What is heavy metal ? Heavy metal refers to the proportion of heavy metal more than 4 or 5,about 45 species,such as copper,lead,zinc,iron,cobalt,nickel,vanadium, niobium,tantalum,titanium,manganese,cadmium, mercury,tungsten,molybdenum,gold,silver and so on. What we often say that heavy metal pollution is the increase of heavy metals in the environment, which outside the normal range, and leading to the deterioration of environmental quality caused by human activities.
  7. 7. 2. 土壤重金属污染 土壤重金属污染是由于废弃物中重金属在土壤中过量沉积而引起的土壤污染。污染土壤的重金属主要包括汞、镉、铅、铬和类金属砷等生物毒性显著的元素,以及有一定毒性的锌、铜、镍等元素。主要来自农药、废水、污泥和大气沉降等,如汞主要来自含汞废水,镉、铅污染主要来自冶炼排放和汽车废气沉降,砷则被大量用作杀虫剂、杀菌剂、杀鼠剂和除草剂。过量重金属可引起植物生理功能紊乱、营养失调,镉、汞等元素在作物籽实中富集系数较高,即使超过食品卫生标准,也不影响作物生长、发育和产量,此外汞、砷能减弱和抑制土壤中硝化、氨化细菌活动,影响氮素供应。重金属污染物在土壤中移动性很小,不易随水淋滤,不为微生物降解,通过食物链进入人体后,潜在危害极大,应特别注意防止重金属对土壤污染。
  8. 8. Heavy metal pollution of soil Heavy metal pollution due to waste excessive deposition of heavy metals in the soil caused by soil pollution. Heavy metal polluted soils include mercury, cadmium, lead, chromium and arsenic and other metalloid elements of significant toxicity, as well as certain toxicity of zinc, copper, nickel and other elements. They mainly from agricultural chemicals, waste water, sludge and atmospheric deposition, such as mercury mainly from the mercury-containing waste ,and cadmium, lead pollution from car exhaust emissions and smelting settlement, and a large number of arsenic were used as insecticides, fungicides, rodenticides and herbicides. Excessive heavy metals can cause plant physiological disorders and nutritional disorders. Cadmium, mercury and other elements in the crop seed in the high enrichment factor, even over food hygiene standards,it does not affect crop growth, development and production, In addition to mercury, arsenic can be reduced and inhibited soil nitrification, ammonification bacteria activities, and impact of nitrogen supply.Mobility of heavy metal pollutants in the soil is very small and difficult to filter with water washout, and not for microbial degradation.There is potentially lethal to human body through the food chain, so particular attention shoud be made to prevent heavy metals on soil pollution.
  9. 9. 二 . 土壤重金属污染现状 土壤是人类赖以生存的主要自然资源之一,也是人类生态环境的重要组成部分。随着工业、城市污染的加剧和农用化学物质种类、数量的增加,土壤重金属污染日益严重,目前,全世界平均每年排放 Hg 约 1.5 万吨, Cu340 万吨, Pb500 万吨, Mn1500 万吨, Ni100 万吨。据我国农业部进行的全国污灌区调查,在约 140 万公顷的污水灌区中,遭受重金属污染的土地面积占污水灌区面积的 64.8% ,其中轻度污染的占 46.7% ,中度污染的占 9.7% ,严重污染的占 8.4% 。
  10. 10. Soil Heavy Metal Pollution Soil is one of the major natural resources of human life, and an important part of the human environment.With the increased species of industrial, urban pollution and agricultural chemicals , the increasing number of heavy metal pollution is worsening, the current world average of about 1.5 thousand tons per year emissions of Hg, Cu 3.4 million tons, Pb 5 million tons, Mn15 million tons, Ni 1 million tons.According to the Ministry of Agriculture of the National Sewage Irrigation survey, about 1.4 million hectares of waste water irrigation in heavy metal pollution of the land area being accounted for 64.8% of the sewage irrigation area, which accounted for 46.7% of light pollution, accounting for 9.7 % of moderate pollution, and8.4% serious pollution.
  11. 11. 三 . 土壤重金属污染的特点 重金属污染的主要特点:污染范围广、持续时间长、污染隐蔽性、无法被生物降解,并可能通过食物链不断地在生物体内富集,甚至可转化为毒害性更大的甲基化合物,对食物链中某些生物产生毒害,或最终在人体内蓄积而危害健康。
  12. 12. Characteristics of Heavy Metal Pollution The main features of heavy metal pollution: pollution of a wide range of long duration, pollution hidden and can not be biodegradable, and may continue through the food chain accumulation in vivo, and even more can be transformed into toxic methyl compounds in the food chain toxicity of certain organisms, or eventually accumulate in the body which is hazardous to health
  13. 13. 四 . 土壤重金属污染的来源 随着大气沉降进入土壤的重金属 随着污水进入土壤的重金属 随着固体废弃物进入土壤的重金属 随着农用物资进入土壤的重金属
  14. 14. Sources of heavy metal pollution With the atmospheric deposition into the soil With the sewage into the soil With the solid waste into the soil With the agricultural materials into the soil
  15. 15. 五 . 土壤重金属污染的危害 1. 土壤污染使本来就紧张的耕地资源更加短缺 2. 土壤污染给人民的身体健康带来极大的威胁 3. 土壤污染给农业发展带来很大的不利影响 4. 土壤污染也是造成其他环境污染的重要原因 5. 土壤污染中的污染物还具有迁移性和滞留性,有可能继续造成新的土地污染 6. 土壤污染严重危及后代子孙的利益,不利于农村经济的可持续发展
  16. 16. The hazards of heavy metal pollution Soil pollution makes more intense of the already intense shortage of land resources Soil pollution brings great threat to the health of the people Soil pollution has brought great negative impact to the agricultural development Soil pollution is also the important reasons of causing other environmental pollution Pollutants in soil pollution also has the mobility and retention,which is possible to create new land contamination Soil pollution seriously endangers the interests of future generations and goes against to the sustainable development of rural economy
  17. 17. 六 . 治理方法及特点 治理方法及特点:包括工程治理、生物治理、化学治理及农业治理方法。工程治理效果彻底、稳定,但实施复杂、治理费用高、易引起土壤肥力下降;生物治理实施简便、投资少,对环境破坏小,但是治理效果不理想;化学方法治理效果和费用都适中,但容易再度活化;农业治理方法易操作、费用低,但是周期长、效果不显著。
  18. 18. Control method and characteristics Control method and characteristics: including project management, biological control, chemical management and agricultural management methods. Engineering control effect completely, stable, but the implementation of complex, high cost of treatment, can lead to declining soil fertility; biological control implementation simple, low investment and little damage to the environment, but management is not satisfied; chemical treatment effects and costs are moderate, but easy re-activation; agricultural management methods and easy to operate, low cost, but the cycle is long, the effect is not significant
  19. 19. 七 . 农业生态修复 农业生态修复主要包括两个方面:一是农艺修复措施。包括改变耕作制度,调整作物品种,种植不进入食物链的植物,选择能降低土壤重金属污染的化肥,或增施弄够固定重金属的有机肥等措施,来降低土壤重金属污染。二是生态修复。通过调节诸如土壤水分、土壤养分、土壤 ph 值和土壤氧化还原状况及气温、湿度等生态因子,实现对污染物所处环境介质的调控。我国在这一方面研究较多,并取得了一定的成效。但利用该技术修复污染土壤周期长,效果不显著。
  20. 20. Agro-ecological restoration Agro-ecological restoration includes two aspects : The first is agricultural rehabilitation measures.Including changes in farming systems, adjustment of crop varieties, planting the plants do not enter the food chain, choose to reduce heavy metal pollution of soil fertilizer, or increase the facilities enough to get a fixed metal organic fertilizer and other measures to reduce heavy metal pollution.The second is ecological restoration.By adjusting such as soil moisture, soil nutrients, soil ph values and soil redox conditions and temperature, humidity and other ecological factors, to achieve the environmental media in which the regulation of pollutants.In our country many studies do in this area , and have achieved some results. However, remediation of contaminated soil using the technology cycle is long, and the effect is not significant.
  21. 21. 结束语 地球是我们人类赖以生存的家园,土地是我们生活的自然资源,我们只有保护好我们的家园,我们人类才能生活下去,才能得到发展。
  22. 22. Conclusion Earth is that home to human life,and the land is the natural resources of our life. Only we protect our homeland, can we humans life be developed
  23. 23. That ' s all Thanks

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