土壤污染及防治(英语).ppt

Environmental pollution and prevention,Crew：滕达、朱梦浩、沙科成、路飞,Environmental pollution and prevention,First,the concept of the characteristics of the soil pollution,What is soil pollution？Soil pollution harmful toxic substances into the soil beyond the self-purification capacity of the soil,resulting in soil physical,chemical and biological properties change,reducing crop yields and quality,the phenomenon of harm to human health.From the perspective of environmental science to define soil pollution is the waste and toxic and hazardous substances into the soil over the soil self-purification capacity,destruction of the state of the natural balance of the soil system completely soil quality deterioration or recession phenomenon.,2 major pollutants,1.Inorganic contaminants(such as heavy metals,acids,salts,etc.)2.Organic pesticides(such as fertilizers,pesticides,herbicides,etc.)3.Organic waste(such as biodegradable or degradable organic waste,etc.)4.Sludge,slag and fly ash,radioactive substances,parasites,pathogens,1 soil pollution has hidden and lag2 Accumulation of soil pollution3 soil pollution irreversible4 soil pollution refractory rational,3.Characteristics of land contamination,Second.Soil pollution reasons,1 sewage for irrigation2 air pollution3 excessive application of fertilizers4 heavy use of pesticides5 solid waste6 of heavy metals7 radioactive material contamination of soil,1 sewage for irrigation,Sewage and industrial waste water,containing nitrogen,phosphorus,potassium and many plants need nutrients,so reasonable use of Sewage Irrigation,general stimulation effect.Sewage containing heavy metals,phenols,cyanide and other toxic and hazardous substances directly used for farmland irrigation,will pollute the soil.,2 air pollution,Atmospheric pollution can be divided into two categories:gas pollution,such as sulfur dioxide,fluoride,ozone,nitrogen oxides,hydrocarbons,etc.;aerosol pollution,such as dust,soot and other solid particles and liquid smoke,fog and other particles,they are by sedimentationor precipitation into the soil and cause pollution.,3.Excessive application of fertilizers.,Long-term large-scale use of chemical fertilizers such as nitrogen,phosphorus,will destroy the soil structure,resulting in soil compaction,degradation of arable soil tilth shallow plowing deteriorated security fertilizer capacity decline and deterioration of the biological properties,and increase the cost of agricultural production,the impactthe crop yield and quality,4 heavy use of pesticides,Crops from the soil to absorb pesticides accumulated in plant roots,stems,leaves,fruits and seeds,and endanger human and livestock health through food,feed,5 solid waste,Industrial waste and municipal waste soil solid contaminants.For example,a wide range of all kinds of trash generated management,recycling poor,the large amount of waste was left on the land caused by land pollution.,6 Heavy metal elements,Heavy metal pollutants into the soil to the presence of soluble and insoluble particles,such as fluorine,mercury,cadmium,Zn,Pb,Ni such as arsenic,chromium in the soil that can be absorbed by plants and enriched.,7 Radioactive substances contaminated soil,Soil radiation contamination source of uranium and thorium mining,uranium enrichment,nuclear waste disposal,nuclear weapons explosions,nuclear experiments,coal-fired power plants,phosphate ore mining processing.Easily adsorbed by the soil,the residence time is longer.,Third.Hazards and the status quo of the land,Hazard:1.Soil pollution worsens already strained more shortage of arable land resources2.Soil pollution tremendous threat to peoples health3.Soil pollution to adverse impact on agricultural development has brought great4.Soil pollution is also an important reason to cause environmental pollution5.Pollutants in soil pollution migration and retention,and may continue to cause land contamination6.Soil pollution seriously jeopardize the interests of future generations,is not conducive to the sustainable development of the rural economy,Currently,the uproar cancer villages.China cancer village space distribution is very uneven,in addition to the four provinces of Tibet,Qinghai,Gansu,Ningxia has not been found outside the village of cancer,are distributed in 27 provinces across the country,the number of significant differences between these provinces cancer village.Number of cancer Village in Henan Province,more than 39 is the greatest.Causes,removal of part of the formation of the unexplained cancer villages,the formation of the cancer villages remaining 90%are associated with modern industrial pollution.Such factories and mines mainly include chemical plants,printing and dyeing,paper mills,pharmaceutical plants,tanneries,alcohol plants,power plants,lime kilns,where the chemical plant caused environmental pollution lead to the the cancer villages phenomenon most common.,Status:,At present,the overall situation of soil pollution in China is grim,serious soil pollution in some areas,the soil heavily polluted area in heavy polluting enterprises or industry-intensive areas,the mining mining areas and the surrounding region,urban and peri-urban areas and high-risk areas.Various types of soil pollution,showing the coexistence of old and new pollutants,inorganic-organic composite pollution situation.Soil pollution pathway,the reasons are complicated,difficult to control.Soil environmental supervision and management system is not perfect,inadequate investment in soil pollution prevention,social prevention awareness.Agricultural products quality and safety problems caused by soil pollution and mass incidents are increasing year by year,become important factors that affect the public health and social stability.,Land pollution status of general characteristics:,1.Increased pollution levels According to incomplete survey,the national contaminated farmland and about 1.5 million mu,3250 mu of arable land irrigated with sewage pollution,solid waste dumps covers an area of 200 mu and Hui Tian,together account for about one-tenth of the total area of cultivated landabove,most of which is concentrated in the more economically developed regions.,2.Huge pollution hazard.,It is estimated that the country each year due to heavy metal contamination of food amounted to 12 million tons,resulting in direct economic losses of over 20 billion yuan.Soil pollution caused by harmful substances accumulated in the crop enters the body through the food chain and cause various diseases,ultimately endanger human health.Soil pollution directly affects the structure and function of the soil ecosystem,will eventually become a threat to ecological security.,3.Pollution prevention foundation is weak,Currently,the area of the national soil pollution,distribution and extent is unclear,the lack of prevention measures targeted.Prevention of soil pollution laws or blank,nor the formation of soil environmental standard system.Limited capital investment,soil science research is difficult to carry out in-depth.A considerable part of the masses and the enterprises are lack of awareness of the seriousness and danger of soil pollution。,Fourth,the prevention of soil pollution,1.Soil pollution prevention and control,including two aspects:First,the anti,is to take measures to prevent soil pollution;The second is the rule is already contaminated soil improved governance.,2.Soil pollution prevention measures,1 scientific use of Sewage Irrigation2 Rational use of pesticides,and actively3 develop high-efficiency low-residue pesticides3 Actively promote biological pest4 to raise public awareness of soil conservation,3.Soil pollution control measures,1 Bioremediation of contaminated soil2 contaminated soil chemical methods of governance3 increase organic fertilizer4 regulation of soil redox conditions5 to change the rotation system6 Changing soil and tilling the soil7 implementation of targeted measures,In short,according to the environmental policy of prevention first,the primary task of preventing soil pollution control and eliminate soil pollution,prevent soil pollution;contaminated soil,it is necessary to take all effective measures to remove the contaminants in the soil,improve the soil,preventing the migration and transformation of pollutants in the soil.,thank you,