SMSBR去除焦化废水中有机物及氮的特性

选用一体化膜—序批式生物反应器 (SubmergedMembraneSequencingBatchReac tor ,简称SMSBR)处理焦化废水 ,考察了能否通过膜分离的强化作用提高生物处理系统对焦化废水的处理效果 ,使出水COD达到新的排放标准 ( <10 0mg/L) ,并提高脱氮效率。研究结果表明 :在HRT为 32 .7h ,平均COD容积负荷为 0 .4 5kg/ (m3·d)的条件下 ,出水COD可以稳定在 10 0mg/L以下 (平均为 86.4mg/L) ;要使COD达到新的排放标准 ,进水COD容积负荷应低于 0 .67kg/ (m3·d) (该负荷下出水COD在 10 0mg/L上下波动 ,平均为 10 6.3mg/L) ;好氧段存在明显的反硝化现象 ,使COD的去除得到强化 ;在保证系统温度、碱度、溶解氧和不受进水COD负荷冲击的情况下 ,出水NH3-N可低于 1mg/L ,但泥龄太长所产生的微生物代谢产物抑制了硝化反应过程中的硝酸盐细菌 ,使好氧段出水NO2 -N/NOx-N平均为 91.1% ,因此系统获得极其稳定高效的短程硝化作用 ,有利于进一步脱氮 ;按“缺氧 1—好氧—缺氧 2”方式运行时 ,若“缺氧 2”的HRT>8.4 4h ,可实现 81.34 %的反硝化率 (外加碳源 :COD/N为 2 .1g/g) ,平均TN去除率为 87.2 % ,最高达 90 .2 %。

Characteristics of Submerged SMSBR in Removal of Organic Matters and Nitrogen from Coke Plant Wastewater

A SMSBR was used for treating coke plant wastewater and enhanced effects of membrane separation on the treatment efficiencies were investigated. The purpose of the study was to make effluent COD meet the new discharge standard( ＜ 100 mg/L), and increase the removal efficiency of nitrogen. The result shows that effluent COD is steadily below 100 mg/L (86.4 mg/L on the average)at the HRT of 32.7 h and the COD volume loading rate of 0.45 kg/(m3 · d). To reach the new effluent discharge standard, COD volume loading rate should be lower than 0.67 kg/(m3·d). In this condition effluent COD fluctuates around 100 mg/L (106.3 mg/L on the average). The COD removal is enhanced by denitrification appearing in the aerobic stage. The effluent NH3 - N is lower than 1 mg/L when temperature, alkalinity, and dissolved oxygen in the system are under control and there is no COD shock－load. NO2－NJNO3－N in the effluent from the aerobic stage is 91.1% on the average because nitrifers in nitrification process are inhibited by the metabolic products of microorganisms due to long sludge age. This shows that short－cut nitrification/denitrification is obtained with high efficiency and stability in the system, and is benefit for further removal of nitrogen. SMSBR system operates in anoxic－aerobic－anoxic mode, HRT of the second anoxic stage is longer than 8.44 h and carbon source is added ( COD/N = 2.1), the average removal efficiency of total nitrogen can reach 87.2 %(90.2 % as the maximum) and efficiency of denitrification can reach 81.34 % 。