基于耗氧速率的毒性预警装置影响因素分析

Influence Factors and Parameters Optimization for Toxicity Warning Device Based on OUR

基于活性污泥耗氧速率(OUR)的生物毒性预警装置,是利用污水处理厂自身的污泥活性判断进水水质变化的预警方法,能够直观地反馈废水毒性对活性污泥的影响。该文以Ni2+、苯酚为例,研究了影响预警反应器的影响因素并对运行参数进行了优化。随着MLSS由5 000 mg/L降低至1 000 mg/L时,对Ni2+和苯酚的抑制率分别从20.19%、33.45%逐步提高至60.62%、75.52%,说明高污泥浓度对毒性物质的冲击有一定的缓冲能力。随着微生物与毒性物质接触时间(HRT)的延长,抑制率逐步提高,但时间-抑制率曲线呈非线性关系。通过正交试验筛选出最优的预警反应器运行参数:MLSS=500 mg/L,HRT=10 min,其中首要影响因素为污泥浓度。

The early warning by activated sludge inhibitory rate has been used to direct feedback wastewater toxicity. The influence factors and parameters for the early warning device were studied base on oxygen uptake rate index. Taking Ni2＋ and phenol for exam- ple, when MLSS of reactor reduced from 5 000 mg/L to 1 000 rag/L, the OUR inhibitory rate increased from 20.19 %, 33.45 % to 60.62 %, 75.52 %, respectively. It indicates that high sludge concentration has a buffer capacity towards toxic compounds. As the re- tention time between microbial and toxic compound increases, the inhibition rate becomes greater slowly. But the relationship of the time-inhibition rate curve is a non-linear one. The operation parameters for early warning reactor were optimized by single factor and orthogonal test, which results indicate that the best parameters were： MLSS=500 mg/L, HRT=10min.