城市污泥复合肥的肥效及其对小麦重金属吸收的影响

The Effects of Compound Fertilizer Made From Municipal Sewage Sludge Compost on N P K and Heavy Metals Uptake of Wheat

通过盆栽和大田试验 ,初步探讨了污泥复合肥种植小麦的肥效及其对小麦重金属吸收的影响。试验结果表明 ,污泥复合肥对小麦的增产效果和土壤的培肥效果明显优于化肥 ,等同于市售复合肥。它能促进植株生长发育 ,提高小麦产量 ,对土壤速效养分的积累有明显的促进作用 ;污泥复合肥处理的小麦籽粒中重金属 Cu、Zn、Pb、Cd的含量均在国家食品卫生标准范围内。

The amount of sewage sludge production is increasing with the raising of wastewater treatment in China,how to dispose it has been an urgent problem for government and wastewater treatment plants.Sewage sludge contains various kinds of pathogenic bacterium and heavy metals which may cause serious environmental pollution if without correctly disposed.However,sludge also contains various kinds of nutrients and organic matter,which are necessary for plant growth,and would be a resource if it were utilized for plant growth properly.After harmlessly and steadily treated,the sewage sludge compost can be used as soil ameliorant or fertilizer for agricultural lands.There are lots of researches focused on the sewage sludge compost using for vegetable and crop.But it has derived of different viewpoints for sewage sludge compost application in agricultural land,since many pollutants are persistent and agricultural soils are irreplaceable.In this study,the sewage sludge compost was combined with the chemical fertilizers and made into compound fertilizer,in which the heavy metal contents should be lower and nutrient contents should be higher than sewage sludge compost.We studied the wheat growth,N P K and heavy metals uptake of wheat.The experiments including pot and field experiments for wheat growth were carried out in 1998 and 1999.The sewage sludge collected from Fangzhuang wastewater treatment plant was composted and made into compound fertilizer in Institution of Geographical Sciences and Natural Resources Research.The pot experiment was conducted in green house with temperature of 15～25℃ and 10 hours of light per day.The relative humidity of the green house was kept between 50～60 percent.The field experiments were carried out in Beijing and Shijiazhuang province respectively.Four treatments were composed of the check(pot and plot experiment only),the sewage sludge compost(equal nutrient contents to chemical fertilizer,1.13t/hm 2)and the marketable compound fertilizer(equal N content to the chemical fertilizer and sewage sludge compound fertilizer,higher P and K content than the two fertilizers,1.13t/hm 2),the chemical fertilizer(Co(NH-2)-2,(NH-4)-2HPO-4 and KCl),each one was replicated four times.The results showed that the treatment of sewage sludge compound fertilizer did good effect on soil fertility and yield far higher wheat production than the chemical fertilizer,and equal to marketable compound fertilizer.In field experiments,the sewage sludge compound fertilizer improved the wheat yield by 10.7%～17.0%,statistically greater(α=0.05)than chemical fertilizer.Wheat N uptake of all experiments was much higher in sewage sludge compound fertilizer treatments than which in chemical fertilizer and marketable compound fertilizer treatments.Compared with the other two fertilizer treatments,the nutrients utilization ratio of sewage sludge compound fertilizer treatment were enhanced 15.9% and 9.94% of N and 1.66% and 4.48% of P respectively.The soil nutrient contents were also improved after one year of sewage sludge compound fertilizer application.Increasing of heavy metal concentrations(Cu,Zn,Pb,Cd)in wheat seeds were observed with sewage sludge compound fertilizer application,but none exceeded the National Hygienic Standard for Foods.