利用微生物电解池法增强冷水鱼循环水养殖系统水质处理能力

Enhancing water quality treatment capacity of cold-water fish circulating aquaculture system by microbial electrolysis pool method

为了解决传统曝气生物滤池对养殖废污水中氨氮和硝酸盐去除效率较低的问题,本文利用微生物电解池(MEC)法研究低温条件下不同碳源种类、电压强度对MEC系统化学需氧量(COD)、氨氮(NH_(3)-N)、硝氮(NO_(3)^(-)-N)、总氮(TN)和总磷(TP)的脱除效率,了解最优碳源和电压强度条件下微生物电解池强化淡水冷水鱼养殖系统的水处理能力并探讨其去除机理。结果表明:乙酸钠为碳源时,COD、NH_(3)-N、NO_(3)^(-)-N和TP去除率分别达到82.10%、87.56%、98.64%和73.64%;电压强度为0.30 V时,COD、NH_(3)-N、NO_(3)^(-)-N和TP去除率分别达到81.01%、73.15%、76.74%和83.97%。宏基因测序结果显示,在最佳碳源和电压强度条件下,属水平下的链霉菌属、假单胞菌属和伯克霍尔德菌属为微生物群落中主要的优势菌属;氮代谢通路涉及到的关键功能基因amoCAB、nxrAB、nirBD、nrfA和nifDHK等表明,MEC系统主要通过同步硝化反硝化路径进行氮去除代谢。

In order to solve the problem of low removal efficiency of ammonia nitrogen and nitrate in the treatment of aquaculture waste water by traditional aeration biological filters,the effects of diffe-rent carbon sources and voltage intensities on the removal efficiency of chemical oxygen demand(COD),ammonia nitrogen(NH_(3)-N),nitrate nitrogen(NO_(3)^(-)-N),total nitrogen(TN)and total phosphorus(TP)in microbial electrolysis cell(MEC)system are investigated by using MEC me thod at low temperatures.The aim is to explore how MEC enhance water treatment capacity of freshwater cold-water fish culture system under the conditions of optimal carbon source and voltage intensity,and to explore its removal mechanism.The results show that when sodium acetate is carbon source,the removal rates of COD,NH_(3)-N,NO_(3)^(-)-N and TP reach 82.10%,87.56%,98.64%and 73.64%respectively.When the voltage intensity is 0.30 V,the removal rates of COD,NH_(3)-N,NO_(3)^(-)-N and TP are 81.01%,73.15%,76.74%and 83.97%respectively.Marco gene sequencing results show that under the optimal carbon source and voltage intensity,Streptomyces,Pseudomonas and Burkholderia are the dominant genera in the microbial community at genus level.The key functional genes amoCAB,nxrAB,nirBD,nrfA and nifDHK involved in the nitrogen metabolism pathway show that MEC system mainly undergoes nitrogen removal metabolism through the pathway of simultaneous nitrification and denitrification.