Efficiency of submerged ceramic flat membrane bioreactor in the treatment of coal chemical wastewater

Coal chemical wastewater inhibits the development of the modern coal chemical industry. This study used a submerged ceramic flat membrane bioreactor to treat coal chemical wastewater. By combining the character-istics of high flux and high strength of ceramic flat membrane with the characteristics of high sludge concen-tration of Membrane Bio-Reactor (MBR). The treatment effect of ceramic flat membrane bioreactor on coal chemical wastewater and related influencing factors were studied. The Chemical Oxygen Demand (COD) con-centration, ammonia nitrogen concentration, total phenol concentration, and turbidity of coal chemical waste-water could be reduced to below 31.4 mg/L, 3.03 mg/L, 3.76 mg/L, and 0.4 NTU. The ceramic flat membrane bioreactor achieved the optimal removal effect on pollutants when Hydraulic Retention Time (HRT) was 21 h, Dissolved Oxygen (DO) concentration was 3.2-4.0 mg/L and pH was 7.1-7.5. Among them, the total phenol removal ratio reached the maximum value of 95.31 %, and the COD removal ratio remained at 93 % -94 %, ammonia nitrogen removal ratio was stable at 95 % -97 %. The microorganisms in the mixture and membrane mainly were aerobic bacteria, and the content of organic-degrading bacteria, nitrifying and denitrifying bacteria was high. The addition of a membrane module not only prevented the loss of activated sludge in the reactor but also kept a high sludge concentration. Meanwhile, the addition of a membrane module also improves the biodiversity and stability of sludge treatment system.

Automated summary

This study used a submerged ceramic flat membrane bioreactor to treat coal chemical wastewater and studied its treatment effect and influencing factors on the wastewater. The ceramic flat membrane bioreactor achieved significant removal of pollutants, with COD concentration, ammonia nitrogen concentration, total phenol concentration, and turbidity reduced to low levels. The optimal removal effect was achieved with specific conditions such as Hydraulic Retention Time (HRT), Dissolved Oxygen (DO) concentration, and pH.