焦化废水驯化的EGSB反应器内颗粒污泥产甲烷活性

为了确定处理焦化废水的EGSB反应器快速启动和高效稳定运行的可行性,在22～27℃的环境温度下,稳定进水COD为2 200 mg/L左右,通过逐渐提高焦化废水的添加比例来驯化EGSB反应器内的颗粒污泥,待进水完全为焦化废水后开始微氧曝气,对驯化过程中以及微量曝气后污泥产甲烷活性的变化进行了研究。结果表明:焦化废水会对EGSB反应器内颗粒污泥产生毒性抑制作用,使其产甲烷活性明显降低,与未添加焦化废水时相比,添加比例为100%时产甲烷活性降幅达75.8%。但颗粒污泥真正的产甲烷活性却几乎没有被抑制,当以乙酸钙为基质时产甲烷活性的降幅仅为6.23%。焦化废水对污泥产甲烷活性的抑制是可逆的,随着微生物菌群逐渐适应焦化废水的水质,颗粒污泥的活性又开始恢复。微氧曝气能够明显提高颗粒污泥的产甲烷活性。微氧时污泥的产甲烷活性比厌氧时提高了32.2%,对COD的去除率也由58%提高到了87.4%。

Changes in Methanogenic Activity of Granular Sludge Acclimated by Coking Wastewater in EGSB Reactor

At ambient temperature ( 22 to 27℃) , and with the influent COD concentration of a-bout 2 200 mg/L, the granular sludge in the expanded granular sludge bed (EGSB) reactor was acclimated through gradually increasing coking wastewater supplement ratios to determine the feasibility of rapid start-up, efficient and stable operation of the EGSB reactor in the treatment of actual coking wastewater. When the influent is totally coking wastewater, the micro-aerobic treatment began. The methanogenic activity of granular sludge at the acclimation stage and micro-aerobic stage was studied. The results indicate that the coking wastewater can distinctly restrain the granular sludge and reduce its methanogenic activity. But the methanogenic activity of the granular sludge is not really restrained. When using 100% coking wastewater instead of 0% coking wastewater, the decrease of methanogenic activity is 75. 8% when using coking wastewater as substrate, but only 6.23% when using calcium acetate as substrate. Moreover, the inhibition effect of coking wastewater on the methanogenesis is reversible, and the methanogenic activity of the granular sludge begins to recover as different microbial communities gradually adapt to the coking wastewater. The methanogenic activity of the granular sludge under the micro-aerobic condition is 32. 2% higher than that under the anaerobic condition. Also, the COD removal efficiency is increased from 58% to 87.4%.