Oscillating Membrane Photoreactor Combined With Salt-tolerated Chlorella Pyrenoidosa For Landfill Leachates Treatment

Landfill leachates?LFL?has the characteristics of high NH₃-N,high salinity,various heavy metal ions and toxic substances.It is considered to be a biological refractory wastewater,which would have a negative impact on our water environment and land resources.The current physicochemical methods used in landfill leachate treatment are complex and costly,and microbial growth is not stable in biological treatment methods such as activated sludge and anaerobic biological methods.Therefore,to explore environmentally-friendly and effective technology for LFL treatment is necessary.Chlorella pyrenoidosa have high salt tolerance,low environmental requirements,which supposed to be a wide application.Thus,integrating Chlorella cultivation with LFL treatment can not only realized the treatment of LFL,but also achieve the purpose of wastewater recycling.In addition,the easy sedimentation,smaller biomass,and difficulty in harvesting restricts the widespread application of Chlorella in wastewater treatment.In this paper,according to crank rocker mechanism,the oscillating membrane photobioreactor?OM-MPBR?,oscillating/aerobic membrane photobioreactor?OM-MPBR?and comparative aeration membrane photobioreactor?CMPBR?were used to treat LFL and cultivate of Chlorella.The treatment effectiveness and performance of three types of MPBR were measured by analyzing microalgae biomass,COD and NH₃-N removal,membrane fouling control and energy consumption.Furthermore,in order to further reduce operating cost,the influence of light modes on Chlorella growth and LFL treatment were explored.The results showed that the highest Chlorella biomass concentration of OM-MPBR and OM/aerobic-MPBR was 0.63 g/L and 0.53 g/L respectively,and the NH₃-N of effluent was 3 mg/L and 11 mg/L respectively,and the maximum membrane flux was 99.6 L/m²h bar and 91.7 L/m²h bar respectively,which is significantly better than CMPBR.This demonstrated that the when dynamic membrane module base on the crank-rocker mechanism swings back and forth in the liquid,a strong shear force and impact on interface of liquid-membrane,which increase the Chlorella biomass concentration and reduce the membrane fouling.Comparing different light patterns,the comprehensive performance of OM-MPBR in12 h light/dark?Mode-2?was the best in terms of Chlorella biomass,wastewater treatment effect,membrane flux and energy consumption.