Reduction of bioavailability and leachability of heavy metals during agitated pile composting of Salvinia natans weed of Loktak lake
Reduction of bioavailability and leachability of heavy metals during agitated pile composting of Salvinia natans weed of Loktak lake
复制标题
DOI：
10.1007/s40093-015-0094-2
复制
发表时间：
2015-04
影响因子：
1.5
通讯作者：
W. Singh;Shashi Kumar Pankaj;Ajay S. Kalamdhad
中科院分区：
文献类型：
--
作者：
W. Singh;Shashi Kumar Pankaj;Ajay S. Kalamdhad
目的对印度曼尼普尔洛克塔克湖的淡水丹参进行堆肥，以保护珍贵的湖泊免受杂草的滋生，但在将最终堆肥用作土壤改良剂之前，需要评估最终堆肥的重金属和矿物的总量和生物有效形态。方法研究了搅拌堆肥过程中土壤理化参数的变化以及重金属和矿物的总量、生物有效性和可浸出形态。在五种不同的组合中添加稻壳和牛粪的纳坦[试验1(5S.纳坦：4个牛粪：1个稻壳)，试验2(6S.纳坦：3个牛粪：1个稻壳)，试验3(7秒。纳坦：2个牛粪：1个稻壳)，试验4(8秒。纳坦：1牛粪：1稻壳)和试验5(10秒。纳坦：0牛粪：0稻壳)。结果在试验2中监测到的最高温度为52.2℃，试验2过程中牛粪含量为30%。试验2中水分含量和挥发性固体的最大降幅证实了温度分布。土壤重金属总量(锌、铜、锰、铁、镍、铅、镉、铬)、养分总量(钠、钾、钙、镁)和水溶态养分含量显著增加。水溶态、植物有效态和可淋溶态金属的降幅较大，降幅最大的是试验2。研究还表明，最终堆肥中锌(211-254 mg/kg)、镍(310-345 mg/kg)和铅(805-891 mg/kg)的总浓度高于铬(140-207 mg/kg)，但水溶态锌(占总锌的3.6-4.7%)，堆肥中的镍(NIL)和铅(占总铅的0.7-1.0%)低于铬(占总铬的13.3-19.3%)，表明堆肥中的铬具有较高的毒性潜力。可浸出重金属均在规定的农业应用阈值范围内。结论堆肥OFS适当比例的牛粪可降低生物质中重金属的生物有效性和可淋溶形态。
PurposeComposting of harvestedSalvinia natansweed of Loktak lake of Manipur, India can protect the precious lake from the unwanted growth of the weeds but there is a need to assess the total amount and bioavailable forms of heavy metals and minerals of the final compost before application as a soil conditioner.MethodsStudies were conducted on the transformations of the physico-chemical parameters and the total amount, bioavailable and leachable forms of heavy metals and minerals during agitated pile composting ofS. natanswith rice husk and cattle manure in five different combinations [trial 1 (5S. natans: 4 cattle manure: 1 rice husk), trial 2 (6S. natans: 3 cattle manure: 1 rice husk), trial 3 (7S. natans: 2 cattle manure: 1 rice husk), trial 4 (8S. natans: 1 cattle manure: 1 rice husk) and trial 5 (10S. natans: 0 cattle manure: 0 rice husk)].ResultsThe highest temperature (52.2 °C) was monitored in trial 2 having 30 % cattle manure during the process. Highest reduction of moisture content and volatile solid in trial 2 corroborated the temperature profile. Total concentrations of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd and Cr), total concentration of nutrients (Na, K, Ca, and Mg) and the water-soluble forms of the nutrients were enhanced significantly. The water-soluble, plant-available and leachable metals decreased favorably with maximum reduction observed mostly in trial 2. The study also revealed that the total concentrations of Zn (211–254 mg/kg), Ni (310–345 mg/kg) and Pb (805–891 mg/kg) of the final composts were higher than that of Cr (140–207 mg/kg) but the water-soluble forms of Zn (3.6–4.7 % of total Zn), Ni (NIL) and Pb (0.7–1.0 % of total Pb) were lower than that of Cr (13.3–19.3 % of total Cr) indicating that Cr in the composts had higher toxicity potential. The leachable heavy metals were within the threshold limits prescribed for agricultural application.ConclusionsComposting ofS. natansbiomass with appropriate proportion of cattle manure reduced the bioavailable and leachable forms of the heavy metals in the biomass.