生物洗涤塔降解氯苯废气性能研究

Using Suspended-Growth Reactors to Treat Chlorobenzene-Gas

以活性污泥为介质 ,探讨洗涤塔中氯苯废气的生物降解性能。实验表明 ,洗涤塔对氯苯废气有较强的降解能力。当负荷F小于 1mg/ (g·h)时 ,比降解速率 -γ随F的增加而增加 ,在F =1.0— 2 .0mg/ (g·h)时 ,-γ达到最大值 0 .8mg/ (g·h) ,当F低于 0 .8mg/ (g·h)时 ,氯苯降解效率 η维持在 90 %。装置中污泥混合液挥发性悬浮固体与混合液悬浮固体质量浓度之比 (MLVSS/MLSS)由驯化初期的 0 .5增至 0 .7,逐步趋于稳定 ;氯苯的生物降解为一级反应 ,降解速率常数k =0 .6 31h-1。降解过程中产酸 ,较低的 pH值抑制了微生物的活性 ,使氯苯的生物降解减弱 ,为此在洗涤塔运行过程中 ,必须投加pH缓冲药剂 ,维持污泥正常 pH范围。试验获得的操作曲线 。

An aerobic suspended-growth reactor (SGR) removes volatile organic compounds (VOCs) by biologically treating contaminated air bubbled through an aqueous suspension of active microorganisms. This research focused on the performance of SGR for the removal of chlorobenzene-gas. SGR was proved to be highly efficient in biodegradation of chlorobenzene-gas in the test conditions. When inlet load F was lower than 1mg/(g·h), removal rate-γ increased with F and reached maximum, which was 0.8 mg/(g·h) corresponding to F=1.0-2.0 mg/(g·h). When F was lower than 0.8 mg/(g·h), the removal rate η was always higher than 90%. With the running of the system, the ratio of MLVSS to MLSS changed from 0.5 at the initial stage of accumulation to 0.7 . In the process of biodegradation, the reaction submitted to the first series reaction and the rate constant was 0.631 h~ -1 , the production of acidic compounds resulted in decline of pH, furthermore restrained the activity of microorganisms and weakened the biodegradation of chlorobenzene, so, it was necessary to add buffer solution to maintain a proper range of pH. According to the operating curve achieved in the study, SGR to treat chlorobenzene-gas could be designed accurately.