不同固定化微生物颗粒降解养殖尾水中污染物的性能评价

选取3种载体（凹凸棒土、卡拉胶以及硅藻土）进行固定化微生物颗粒制备，并对不同颗粒性能、污染物去除性能及主要影响因素进行了研究。颗粒性能研究表明：凹凸棒土与硅藻土固定化微生物颗粒具有较好的机械强度，卡拉胶机械强度低；在有营养补充的前提下，凹凸棒土和卡拉胶可以稳定释放1.50×106 CFU/mL和2.60×105 CFU/mL的微生物，硅藻土固定化微生物颗粒缓释性能较差；利用Monod方程拟合可得，对于CODMn，硅藻土固定化微生物颗粒具有最大的比降解速率（μmax），卡拉胶与之相当，凹凸棒土最低，同时硅藻土固定化微生物颗粒的Ks值显著低于其他两种颗粒；同时，氨氮降解动力学也呈现了相似的规律。环境条件对固定化微生物颗粒降解污染物的影响分析表明：中性（pH=7）条件下，凹凸棒土、卡拉胶、硅藻土固定化颗粒降解CODMn的一级速率常数最高；凹凸棒土与硅藻土固定化微生物颗粒在中性和碱性条件下的降解氨氮速率更高，卡拉胶在中性条件下降解氨氮速率最高。固定化微生物颗粒降解CODMn、氨氮的一级反应速率常数随温度的升高而增大，其中凹凸棒土固定化微生物颗粒对温度的变化更为敏感。除了硅藻土固定化微生物 颗粒以外，随着污染物初始浓度的增加，其余两种降解CODMn的一级反应速率常数k1值显著上升（P＜0.05）。不同曝气强度下3种固定化微生物颗粒降解CODMn一级反应速率无显著性差异（P＞0.05），更高的曝气强度对氨氮降解有利。

Selection of immobilized carrier and evaluation of microbe performance of degradation in aquaculture wastewater treatment

Three carriers (including Bumpy clay, Carrageenan and Diatomaceous earth) were selected for the preparation of immobilized microbial particles, and the different particle properties, pollutant removal performance and influencing factors were investigated in the present paper. The particle performance studies showed that the mechanical strength of the immobilized particles was high for Bumpy clay and Diatomaceous earth and low for Carrageenan; with nutrient supplementation, Bumpy clay and Carrageenan could stably release 1.50×106 CFU/mL and 2.60×105 CFU/mL of microorganisms, while the release of Diatomaceous earth was poor. According to fitting results of the Monod equation, it can be obtained that the Diatomaceous earth immobilized microbial particles have the largest specific degradation rate (μmax) for CODMn. Carrageenan was comparable to it, and the lowest μmax was observed for Bumpy clay. While the Ks of Diatomaceous earth particles was significantly lower than the other two particles. Also, the kinetics of ammonia degradation showed a similar pattern to that of CODMn. The effect of environmental conditions on the degradation performance of the immobilized microbial particles showed that the highest first-order rate constants (k1) for CODMn were found under neutral (pH=7) condition for the three materials. The k1 for ammonia degradation were higher for Bumpy clay and US diatomaceous earth under neutral and alkaline conditions, however the highest rate of ammonia degradation was found for Carrageenan under neutral conditions. The k1 of CODMn and ammonia by immobilized microbial particles increased with the increase of temperature, among which the Bumpy clay was more sensitive to the change of temperature. Except for the Diatomaceous earth particles, the k1 for CODMn degradation by the other two immobilized microorganisms increased significantly (P < 0.05) with the increase of the initial concentration of the pollutant. There was no significant difference in the k1 of CODMn at different aeration intensities (P > 0.05), and higher aeration intensity was beneficial to the degradation of ammonia.