通过批实验,考察了树皮作为固体碳源和反应介质去除地下水中高氯酸盐(ClO4-)的可行性,研究了树皮用量、温度、ClO4-污染负荷等因素对高氯酸盐去除效果的影响. 结果表明,相比玉米芯、红薯及马铃薯,树皮可与PRMs结合高效去除地下水中的ClO4-,可被微生物利用的DOC是影响ClO4-去除效果的制约因素. 以树皮为固体碳源,降解10 mg ClO4-需要耗用35~40 mg DOC; 当树皮用量增至3:500时,高氯酸盐的去除速率约比1:500时提高3倍; 若将树皮用量提高至大于5:500,不能明显提高ClO4-的去除速率. 当温度为(38±1)℃ 时,ClO4-的表观速率常数最大[1.365 mg·(L·d)-1],表观活化能Ea为31.08 kJ·mol-1. 树皮支持的厌氧生物法对水质具有良好的抗冲击性,ClO4-的污染负荷较高时,未造成底物抑制作用.
Batch experiments were conducted to check the feasibility of perchlorate removal from underground water with bark as a carbon source and reaction media, the effect of bark dosage, temperature and initial perchlorate concentrations on perchlorate reduction were also investigated. The results indicated that compared to corn cob, sweet potato and potato, bark in combination with perchlorate reducing microorganisms (PRMs) can efficiently achieve perchlorate removal from underground water, the concentrations of dissolved organic carbon (DOC) which was available to PRMs was the limiting factor that affected the perchlorate removal efficiency. Degradation of 10 mg perchlorate needed to consume 35-40 mg DOC when using bark as the solid carbon source. The removal rate of perchlorate was increased by about 3 fold when the bark dosage was increased from 1:500 to 3:500; however, further increase of solid-liquid ratio (over 5:500) provided no further benefit to the perchlorate reduction rate. The rate constant reached 1.365 mg·(L·d)-1 at (38±1)℃ which was the highest in the batch experiments. The activation energy was 31.08 kJ·mol-1. Anaerobic biological reduction supported by bark had a good impact on the water quality; the high perchlorate concentration did not cause substrate inhibition.