Enhancement Of Activated Carbon Addition On Anaerobic Dynamic Membrane Bioreactor:Performance And Mechanism

The dynamic membrane bioreactor(DMBR),combined with dynamic membrane and membrane bioreactor technology,has the notable advantages of low capital cost and less energy demand.Anaerobic dynamic membrane bioreactor(AnDMBR)has many advantages in the application of dynamic membrane technology to anaerobic wastewater treatment.Nevertheless,due to the adsorption/deposition of anaerobic activated sludge particles on the membrane module,the membrane pollution caused by the increase of anaerobic dynamic membrane thickness,the decrease of pore size,the increase of filtration resistance and the blockage of membrane pore is still exist At the same time,the stability of process operation needs to be improved urgently.A new and effective way is to add carriers into the reactor to enhance the operational performance of the reactor by improving the sludge properties in the reactor.Powered activated carbon(PAC),which have developed pore structure and large specific surface area,can reduce membrane pollution and improve the treatment and filtration performance of the reactor.Because of the significant impact of PAC on improving the performance of MBR and DMBR,this article studies the performance of AnDMBR enhanced by adding PAC.By comparing and analyzing the performance of three reactors(C-AnDMBR(0 g/L PAC),PAC-AnDMBR1(1 g/L PAC),PAC-AnDMBR2(3 g/L PAC))to low-strength synthetic wastewaters,we have explored the physicochemical properties,microbial characteristics and the macroscopic performance of AnDMBR.Eventually,the underlying mechanisms based on which the PAC addition enhanced reactor performance were revealed.The main conclusions were summarized as follows(1)PAC addition enhanced the processing performance of AnDMBR.The average COD concentration of PAC-AnDMBR1 and PAC-AnDMBR2 was 50.16 mg/L and 40.21 mg/L respectively,which was 22.5%and 37.9%lower than that of C-AnDMBR.The average removal efficiency of COD increased to 82.72%,86.18%respectively.In addition,the average VFA concentration of PAC-AnDMBR1 and PAC-AnDMBR2 decreased to 7.7 mg/L and 7.0 mg/L(2)PAC addition enhanced the filtration performance of AnDMBR.The effluent flux of PAC-AnDMBR2 was 20 L/m2·h and 10 L/m2·h higher than that of PAC-AnDMBR1 and C-AnDMBR,respectively.Furthermore,the addition of PAC also reduces the filtration resistance of the reactor,which maintains low effluent turbidity,and achieves a good retention effect(3)PAC addition changed the physicochemical properties of anaerobic dynamic membrane.Compared with that in C-AnDMBR,the dynamic membrane structure in PAC-AnDMBR1 and PAC-AnDMBR2 has a loose structure,low EPS content,and improved reactor filtration capacity.As the depth of dynamic membrane increased,the average particle size of sludge increased and the EPS content decreased.Moreover,with the increase of PAC dosage,the hydrophobicity of dynamic membrane sludge decreased,the Zeta potential was improved,and the specific surface area and pore volume were improved(4)PAC addition optimized the community structure of bacterial in AnDM Compared with Dynamic Membrane in C-AnDMBR,Microbial diversity and abundance of Dynamic Membranes in the PAC-AnDMBR1 and PAC-AnDMBR2 increased,and the abundance of Proteobacteria and Bacteroidetes related to anaerobic hydrolysis acidification increased by 6.9%and 13.3%respectively(5)PAC can optimize the community structure of Archaea in AnDMBR,which is beneficial to the expression of methanogenic archaea.Compared with that in C-AnDMBR,the relative abundance of Methanosaeta in PAC-AnDMBR1 and PAC-AnDMBR2 increased 8.4%and 13.0%respectively,indicating that PAC addition further enhanced the dominance of Methanosaeta.