土壤污染及防治(英语).ppt

Environmental pollution and preventionSoil pollution hazards and the status quo3The concept of characteristics of the soil pollution1Soil pollution reasons24Of soil pollution prevention and control measuresFirst,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 pollutants1.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,pathogens1 soil pollution has hidden and lag2 Accumulation of soil pollution3 soil pollution irreversible4 soil pollution refractory rational 3.Characteristics of land 3.Characteristics of land contaminationcontaminationSecond.Soil pollution reasons1 sewage for irrigation2 air pollution3 excessive application of fertilizers4 heavy use of pesticides5 solid waste6 of heavy metals7 radioactive material contamination of soil1 sewage for irrigation1 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 pollution2 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.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 quality4 heavy use of pesticides4 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,feed5 solid waste5 solid wastenIndustrial 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 elementsnHeavy 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 soilnSoil 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 landHazard:Hazard:1.Soil pollution worsens already strained more shortage of 1.Soil pollution worsens already strained more shortage of arable land resourcesarable land resources2.Soil pollution tremendous threat to peoples health2.Soil pollution tremendous threat to peoples health3.Soil pollution to adverse impact on agricultural 3.Soil pollution to adverse impact on agricultural development has brought greatdevelopment has brought great4.Soil pollution is also an important reason to cause 4.Soil pollution is also an important reason to cause environmental pollutionenvironmental pollution5.Pollutants in soil pollution migration and retention,and 5.Pollutants in soil pollution migration and retention,and may continue to cause land contaminationmay continue to cause land contamination6.Soil pollution seriously jeopardize the interests of 6.Soil pollution seriously jeopardize the interests of future generations,is not conducive to the sustainable future generations,is not conducive to the sustainable development of the rural economydevelopment 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