【摘要】 为提升堆肥品质及安全性,采用不同添加剂以促进氮素固持及重金属钝化效果。选择以鸡粪为主原料,采用发酵桶好氧堆肥的形式,探究4种添加剂[生物炭(BC)、聚天冬氨酸(PA)、土壤改良液(TG)、水果垃圾发酵液(FW)]对堆肥过程中氮素、重金属含量和形态变化的影响。结果表明,好氧堆肥方式不同程度促进了堆体氮素和Cu、Zn、Cr的"浓缩效应",但对不同重金属的钝化效果存在差异性。好氧堆肥方式显著促使Cu的其他形态向可还原态转化11.42%(P<0.05)的同时,促使Zn由残渣态、可氧化态向可还原态转化10.21%(P<0.05),Cd由残渣态向酸可溶态转化2.52%(P<0.05);添加剂的使用则有效促进了好氧堆肥过程中氮素固持和重金属钝化效果,其中PA处理通过官能团螯合作用和促腐功能,促使腐熟堆体中全氮含量增幅为CK处理的3.91倍(P<0.05),BC和TG处理亦具有一定氮素固持效果,但与CK处理间的差异并未达到显著水平(P>0.05),FW处理氮素固持效果弱于其他添加剂处理组,可能源自其添加量不足,未能实现堆体pH的有效控制所致;PA、BC处理对重金属钝化过程的促进作用优于其他处理,且PA处理可显著促进Cu、Cd分别向残渣态转化0.98%、4.87%(P<0.05);此外,堆肥前后重金属的形态变化分析结果表明,4种添加剂对堆体重金属的钝化效果可能均与促腐作用相关。PA处理对堆肥过程氮素固持和重金属钝化的综合作用效果最佳,且其可完全分解,是一种绿色安全的堆肥添加剂。更多还原

【Abstract】 In order to improve the quality and safety of compost, different additives are used to promote nitrogen fixation and heavy metal passivation.The aerobic compost was conducted with chicken manure as the main raw material in barrel, the effects of biochar(BC), polyaspatric acid(PA), mineral solution(TG), and fermentation broth of fruit waste(FW) on the contents and forms of nitrogen and heavy metals were investigated.The results show that the “concentration effect” of nitrogen and Cu, Zn and Cr in raw material of compost has been promoted with varying degrees by aerobic compost, but there are differences in the passivation effect of different heavy metals.The transformation of Cu is promoted from other fraction to reducible fraction by 11.42% significantly(P<0.05), while the chemical form of Zn changes from residual fraction and oxidizable fraction to reducible fraction by 10.21% totally(P<0.05) and the reducible fraction of Cd converts to acid soluble fraction by 2.52%(P<0.05).The effect of nitrogen retention and heavy metal passivation are promoted by different additives during aerobic compost.The increment of total nitrogen content in PA treatment is 3.91 times higher than the CK treatment by the chelating function of group and the promotion of humification of PA(P<0.05), and the BC, TG and FW treatment also show an positive effect on the retention of nitrogen(P>0.05).The insufficiency of FW amount during aerobic compost could be the reason of its inconspicuous effect in nitrogen retention.Comparing with other treatment, the PA and BC treatments show much better effect on the heavy metals passivation, furthermore, the residual fraction proportion of Cu and Cd in compost could be increased by 0.98%, 4.87% separately by the addition of PA(P<0.05).In addition, the passivation effect of four additives on heavy metals probably have relation with the promotion of humification.Not only does the PA perform better on the nitrogen retention and heavy metals passivation, but also it can be degraded completely.In conclusion, PA is a green and safe compost additive.更多还原