OHO-MBR组合工艺处理实际焦化废水的可行性

焦化废水因其生物毒性强、高腐蚀性及高COD/TN比的特点，对传统生物处理工艺提出了更高的挑战，故新型生物工艺的探索对于特殊水质达标可行性及工艺经济性具有重要意义。为此，构建了新型好氧-水解-好氧(OHO)-膜生物反应器(MBR)组合工艺用于焦化废水处理，利用实际焦化废水开展了现场小试研究，考察了焦化废水中典型污染物的去除效果，结合工艺运行参数和水质指标测定结果，解析了典型污染物在OHO-MBR工艺中的转化规律。在稳定运行情况下，焦化废水经OHO-MBR工艺处理的实际运行结果表明：当总停留时间设定为56 h时，进水COD、TN、${{rm{NH}}_4^ +} $-N、SCN−-N的平均值分别为3 063、146、27.3、85.1 mg·L−1的条件下，组合工艺即使在环境温度偏低(10~20 ℃)的情况下仍能实现对COD、TN、${{rm{NH}}_4^ +} $-N、SCN−-N平均85.9%、65.4%、95.1%、98.6%的去除；在膜通量为20 L·(m2·h)−1的条件下，工艺运行90 d，跨膜压差维持在10 kPa以内，表明组合工艺处理实际焦化废水的初步可行性；在OHO的O2反应器中添加膜组件可去除焦化废水中的悬浮物及胶体组分，有效截留和富集常规工艺中不易增殖的特种功能微生物，提高反应器处理负荷与抗冲击能力。以上结果表明，在无需对基建设施进行大规模改造的前提下，OHO-MBR可以作为现有工艺提升出水水质的改进技术选择。

Feasibility test of OHO-MBR combined process for actual coking wastewater treatment

Coking wastewater poses a higher challenge to traditional biological treatment processes due to its strong biological toxicity, high corrosiveness, and high COD/TN ratio. The exploration of new biological processes is of great significance to the feasibility of meeting special water quality standards and the economy of the process. Based on these considerations, this study constructed a new type of Aerobic-Hydrolysis-Aerobic (OHO)-Membrane Bioreactor (MBR) combined process for coking wastewater treatment. The actual coking wastewater was used to carry out an on-site small test study and investigate the treatment effect of typical pollutants in the coking wastewater. Combining the measurement results of process operating parameters and water quality indicators, the conversion characteristics of typical pollutants in the OHO-MBR process were analyzed. Under stable operation conditions, the actual operation results of coking wastewater treated by OHO-MBR process showed that, under the conditions of HRT = 56 h and the average influent COD, TN, ${rm{NH}}_4^ + $-N and SCN−-N of 3 063, 146, 27.3 and 85.1 mg·L−1, respectively, the average removal rates of COD, TN, ${rm{NH}}_4^ + $-N and SCN−-N achieved by the combined process were 85.9%, 65.4%, 95.1% and 98.6% even at low ambient temperatures(10~20 ℃), respectively. After 3 months running of the process with the membrane flux of 20 L·(m2·h)−1 for the membrane module, the transmembrane pressure maintained below 10 kPa, which showed the preliminary feasibility of the combined process to treat actual coking wastewater. The potential direction of the process to further improve the effect of pollutant treatment was clarified. The existence of the membrane module in the O2 reactor of OHO could remove the suspended solids and colloidal components in the coking wastewater, effectively intercepted and enriched the special functional microorganisms that were not easy to proliferate in the conventional process. The loading rate and shock resistance capability increased for the process without the need for large-scale transformation of infrastructure facilities, and it can be used as an improvement technology option for the existing process to improve the quality of the effluent.