Start-up Operation Of EGSB Reactor Treating Coking Wastewater

Coking wastewater is a typical industrial wastewater which contains a number of toxic and refractory organic compounds. It brought severe harm to our environment and. The wastewater flow is a lager number and hard to meet the requirements of discharge standard. Start-up operation of the lab-scale EGSB reactor treating coking wastewater was studied in this paper, and the removal efficiency and characteristic of sludge acclimation were analyzed, in order to quest a simple and economic start-up scheme, which was a great preparation for later work.Digestion sludge was cultivated and acclimated as seed sludge to have adaptability for poisonous and hardly-degradable coking wastewater. Experiment results showed that : after seven-month-startup, the removal efficiency of COD was 55% at 18～35 ambient temperature, while the COD and ammonia-nitrogen concentration were 1500～2500 mg/L and 50～210 mg/L in coking wastewater, PH was 6.5～8.5 and color was 150～500; Granular properties and microbial activity in rector was good and the system maintained stable state, the startup working ended.Digestion sludge was cultivated with brewery wastewater that the COD concentration was 200～2000 mg/L, system started cultivation phase, improving proportion of coking wastewater in culture solution gradually , to make microbe adapt the quality of titer and recalcitrant-rich coking wastewater. Along with the removal rate of COD stable, The sludge developed from floc to granule, that have regular surface,favorable sedimentation rate and microbial performance. At the end of startup, the maximal diameter of granular sludge achieved 2.5 mm and the methanogenic activities of the granules was well tensity. Observed under the scanning electronic microscopy,the granules have an enrichment microcommunity, bacillus and was predominance.At the process of experiment, the sludge was restrained by toxicant of coking wastewater ,the removal rate of system falled in short period ,but the rector got right quickly by improving liquid velocity from 1.02m/h to 3.13 m/h and extending hydraulic retention time (HRT) from 3.6h to 18h. Along with the proportion of coking wastewater increasing, the removal rate of system was fluctuating, the minimum rate was 31% and it kept 55% at the end period; the experiment proved that: Start-up operation of EGSB reactor treating coking wastewater is responsible, it is a kind of simple and efficient technology, that laid a solid foundation for the next operation.