高温堆肥对畜禽粪中抗生素降解和重金属钝化的作用

Degradation of Antibiotics and Passivation of Heavy Metals During Thermophilic Composting Process

【目的】规模化养殖畜禽粪中含有多种抗生素药残和重金属元素,其对畜禽粪在农业中利用的影响已引起广泛的重视。通过试验研究探索对畜禽粪中抗生素降解和重金属钝化的技术途径。【方法】利用高温堆肥方法,比较不同堆肥处理对畜禽粪中四环素类抗生素TTC(四环素)、OTC(土霉素)和CTC(金霉素)的降解特点以及对重金属Cu、Zn、Cr、As元素水溶态的影响。【结果】不同堆肥处理的TTC、OTC、CTC均以P+S处理、C+S处理去除效果最好;添加专门选择的BM菌剂可以促进四环素类抗生素的降解,添加BM菌剂处理对TTC、OTC、CTC的降解去除效果好于P+S+TCs处理和C+S+TCs处理。所有处理对OTC降解去除效果较差,C+S+OTC处理去除率最低为40.23%。所有堆肥处理降解去除率由大到小的顺序均为:TTC>CTC>OTC。添加风化煤堆肥处理对水溶态Cu、Zn、Cr、As的钝化效果显著地好于P+S和C+S处理。猪粪堆肥添加风化煤钝化剂处理的Cu、Zn、Cr、As元素水溶态含量,堆肥后比堆肥前分别减少了6.17%、6.40%、4.17%和1.83%。鸡粪堆肥添加风化煤钝化剂的处理,堆肥后比堆肥前分别减少了7.07%、5.69%、5.50%和2.07%。【结论】在不同堆制条件下,高温堆肥对四环素类抗生素具有不同程度的降解效果,外源添加有益降解菌剂有助于抗生素药物残留的去除;高温堆肥也可以降低重金属生物有效性,风化煤对畜禽粪堆肥中的水溶态重金属元素具有钝化作用。

[Objective] The problem that there are various antibiotic medicines and heavy metal elements in excrements of livestock and poultry have been concerned on the farm utilization extensively. The techniques for the antibiotics degradation and heavy metals passivation were studied in the experiments. [Method] As composting is a new alternative bioremediation technology for treatment of brganic pollutants and heavy metals, two experiments were conducted to evaluate the effect of using thermophilic composting to break down the content of tetracyclines（Trc, OTC, CTC） and H2O extractible of heavy metals（Cu, Zn, Cr, As）. [Results] The result of TCs degradation test indicated that the degradation of TFC, OTC and CTC using P＋S and C＋S in all treatments was effective, but in comparision, the addition of BM bacterium for TCs degradation in treatment was more effective, and its biodegradation rate was higher than that of P＋S＋TCs and C＋S＋TCs treatment. The biodegradation rate of OTC was the lowest in all treatments, and the rate of C＋S＋OTC treatment was 40.23%. The order of the three TCs biodegradation rate was TFC〉 CTC〉 OTC. The air-slaked coal has a passivation effect on the heavy metal elements in excrements of livestock and poultry. The result of heavy metal passivation test showed that the effect of addition of air-slaked coal to H2Oextractible content of heavy metals, such as Cu, Zn, Cr and As, were obvious, the passivation effect of aft-slaked coal treatment was better than that of control. The H20 extractible content of heavy metals of Cu, Zn, Cr and As, after composting of pig manure, reduced by 6.17%, 6.40%, 4.17% and 1.83%, respectively, meanwhile, the H2O extractible contents after composting of chicken manure reduced by 7.07%,5.69%, 5.50% and 2.07%, respectively. [Conclusion] With the different thermophilic composting conditions, tetracyclines antibioticses can be degraded, and the addition of foreign beneficial bacterium can reduce residues in antibiotic medicine. Thermophilic composting also can lower the effects of heavy metals on plants. Air-slaked coal has passivation function on extractible heavy metals.