Sánchez-Monedero M A, Mondini C, de Nobili M, Leita L, Roig A
Department of Soil and Water Conservation and Organic Waste Management, Centro de Edafología y Biología Aplicada del Segura, CSIC, PO Box 4195, 30080 Murcia, Spain.
Waste Manag. 2004;24(4):325-32. doi: 10.1016/j.wasman.2003.08.006.
The effect of land application of biosolids on an agricultural soil was studied in a 2-month incubation experiment. The soil microbial biomass and the availability of heavy metals in the soil was monitored after the application of four different composting mixtures of sewage sludge and cotton waste, at different stages of composting. Land application caused an increase of both size and activity of soil microbial biomass that was related to the stabilization degree of the composting mixture. Sewage sludge stabilization through composting reduced the perturbance of the soil microbial biomass. At the end of the experiment, the size and the activity of the soil microbial biomass following the addition of untreated sewage sludge were twice those developed with mature compost. For the mature compost, the soil microbial biomass recovered its original equilibrium status (defined as the specific respiration activity, qCO2) after 18 days of incubation, whereas the soil amended with less stabilized materials did not recover equilibrium even after the two-month incubation period. The stabilization degree of the added materials did not affect the availability of Zn, Ni, Pb, Cu, Cr and Cd in the soil in the low heavy metal content of the sewage sludge studied. Stabilization of organic wastes before soil application is advisable for the lower perturbation of soil equilibria status and the more efficient C mineralization.
在一项为期2个月的培养实验中，研究了在农业土壤上施用生物固体的效果。在施用四种不同的污水污泥和棉花废料堆肥混合物后，在堆肥的不同阶段监测了土壤微生物生物量和土壤中重金属的有效性。土地施用导致土壤微生物生物量的大小和活性增加，这与堆肥混合物的稳定程度有关。通过堆肥实现的污水污泥稳定化降低了对土壤微生物生物量的扰动。在实验结束时，添加未处理污水污泥后土壤微生物生物量的大小和活性是成熟堆肥处理后的两倍。对于成熟堆肥，培养18天后土壤微生物生物量恢复到其原始平衡状态（定义为比呼吸活性，qCO2），而用稳定性较差的材料改良的土壤即使在两个月的培养期后也没有恢复平衡。在所研究的污水污泥重金属含量较低的情况下，添加材料的稳定程度不影响土壤中锌、镍、铅、铜、铬和镉的有效性。为了减少对土壤平衡状态的扰动和更有效地进行碳矿化，建议在土壤施用前对有机废物进行稳定化处理。
