Response Of Soil,Crop And Microbials To Sludge Application And It's Effect To Pb,Cd Pollution

Pot culture experiment was conducted to study the effect of applying sewage sludge amended with Pb Cd on heavy metal contents in soils and plants, soils enzyme activities, microbial specials and population and results show that:1 There are heavy metals especially high concentration of Cu Zn in industry sludge and sewage sludge, but the concentration of heavy metals are low than the limited standards of heavy metals in sludges which can be disposaled in farms land. Heavy metals in both sludges are live in unchangable fractions or unbioavailable fractions.2 Both sludges can be disposaled in farms land and sewage sludge can improve the growth of plant. Applying of both sludges cann't increase heavy metals concentration in plants, and applying of sewage sludge can decrease the concentration of heavy metals in plant; but both of sludges's applying can increase the accumulation of heavy metals in plants. The heavy metals in soils lived in unchangeable and un-carbon-combind styles. Fraction of Pb Zn Cd in soils are more activity than C Cr Ni Pb Cd concentration in soils increase with the applying of sludges.3 Beer plant sludge has high content of organic matters and can improve the growth of cotton. Applying of beer plant sludge also cann't effect the concentration of heavy metals in soils and plants.4 Applying of organic-manure orsewage sludge, the concentration of heavy metals in rape plant and rapeseed has no changes but the accumulations of heavy metals in rape plant and rapeseeds were increased obviously.The applying of organic-manure can increase the activities of neutral phosphatase and urease as weapplying sewage sludge, but the neutral phosphatase activities was decreased with applying of more sewage sludge, the biomass C and biomass P has positive relationship with the exchangable heavy metals concentration in soils.5 Applying of sewage sludge has no obviously effect on Pb Cd concentration in soils, but Pb Cd concentration in soils has obviously positive relationship with the concentration of Pb Cd in soils.6 Yield of Chinese cabbage and soy bean were increased with the applying of sewage sludge, and Pb or Cd pollution in soils can decrease the yield of Chinese cabbage and soy beans. The Cd polluted soils can decrease the biomass yield and increase the yield ofsoybeans, but Pb polluted soils has no effect on soybean yields.7 Applying of sewage sludge increase Pb Cd concentration in cabbage and soybean. Applying of sewage sludge amended with Pb Cd can obviously increase the Cd concentration in cabbage and soybean plants and Pb concentration in soybeans. Cd concentration in cabbage and soybeans has obviously positive relationship with Cd concentration in soils, Pb concentration in cabbage has no relationship with Pb concentration in soils. Pb polluted in soils can improve cabbage and soybeans to absorb more Cd and Pb can depress the soybeans to absorb the Pb.8 Appliying of sewage sludge increase the urease, polyphenol oxidase and neutral phosphatase activities. Pb polluted soils can depress the polyphenol oxidase neutral phosphatase and urease activities, but the enzyme activities has different changes with concentration of Pb in soils. Lower concentration of Cd can improve the polyphenol oxidase, neutral phosphatase and urease activities and these enzyme activities were decressed with the increase of Cd concentration in soils.9 Appliying of sewage sludge improve the populations of bacterials and actinomycetes in soils, especially improve the actinomycetes obviously. And increase the populations of microorganism in soils. The applying of sewage sludge also can improve the number of bacterial in soil with second times of plants (soybeans), but decreases the antinomycetes and fungus in soybeans soils.Pb Cd polluted soils increase populations of bacterial and antinomycetes in cabbage soils, popolation of bacterial increase with increase of Pb concentration. Population of bacterial decrease with increase of Cd concentration in soils, and there are no relati...