微氧EGSB反应器处理焦化废水的启动研究

Start-up of EGSB Reactor Treating Coking Wastewater under Microaerobic Condition

进行了微氧EGSB反应器处理焦化废水的启动试验。结果表明:在进水COD为630～2 300 mg/L、进水流量为1.0 L/h左右的条件下,逐渐提高回流柱的曝气量(反应器DO维持在0.5～1.0 mg/L),EGSB反应器经过174 d(近6个月)启动成功,此时反应器出水COD平均值仅为90 mg/L(最低达到76 mg/L),对COD的去除率达到89%。反应器启动阶段要保证有足够的碳酸氢盐碱度来中和水解和发酵阶段产生的有机酸,缓解有机酸对产甲烷菌的抑制;微量氧的加入使部分颗粒污泥破碎解体,导致粒径减小,但颗粒污泥中的微生物菌种丰富,其活性并没有降低。

Start-up of EGSB reactor treating coking wastewater was researched under microaerobic condition. The results showed that at the influent flow rate of 1.0 L/h and COD of 630 to 2 300 mg/L, it took 174 d （about 6 months） to successfully start up the EGSB reactor by gradually increasing the aeration rate （ DO was 0.5 - 1.0 mg/L） in the reflux column. The average effluent COD was only 90 mg/L （ minimum of 76 mg/L） with a removal rate of 89%. In addition, organic acids coming from the hydrolysis and fermentation period could restrain methanogenic activity, so the system should have sufficient bicarbonate alkalinity to neutralize them during the start-up stage. Supplement of limited oxygen broken up granular sludge so that the particle size was decreased. However, there were still rich bacteria in the granular sludge and the activity of bacteria was not reduced.