Study And Application Of Nitrogen And Phosphorus Removal Using Novel MABR Technology

The membrane-aerated biofilm reactor （MABR） is a promising technology forwastewater treatment using gas permeable membrane as a carrier of biofilm and asupplier of oxygen to achieve the removal of chemical oxygen demand （COD）, totalnitrogen （TN） and other contaminants. The three characteristics of MABR system is:no bubble aeration, oxygen-vary heterogeneous mass transfer, microbial hierarchicalstructure, which is also advantages of MABR. It is apparent that the MABR hasseveral advantages over conventional biofilm technology.The FT-MABR was designed to overcome feed flow short circuiting and achievefacilitated mass transfer. In the FT-MABR, the flow velocity was uniform and theflow direction was almost perpendicular with the hollow fiber membranes. The effectsof feed flow velocity, loading rate and COD/TN ratio on TN and COD removal wereinvestigated through a long-term study, a loading rate study and several batch studies.Nitrogen removal mechanism was mainly discussed. With the increase of flowvelocity, resistance impact load capability and oxygen utilization efficiency of theFT-MABR were enhanced. Meanwhile, ammonium was removed preferentiallycompared with COD. Batch studies indicated that, the increase of feed flow velocitysignificantly strengthened the accumulation of nitrite and TN removal in theFT-MABR. at the feed flow velocity of0.05m/s, when COD/N ratios were3,5and7,the TN removal efficiency reached to50.7%,72.8%and83.5%, respectively. TheFT-MABR is a feasible technology for the treatment of wastewater with low COD/TNratio.In this paper, a novel enhanced nitrogen and phosphorus removal technology-SMABR was developed with the combining the MABR technology with intermittentaeration operation and artificial enhanced biofilm shedding. The effects of nitrogenand phosphorus removal on operating parameters were studied and explored. SMABRis able to create aerobic nitrification, anaerobic denitrification/release of phosphorusand aerobic absorption of phosphorus in the same reactor. The removal efficiency ofCOD, TN and phosphorus in SMABR could reach to90%,95%and65%. Thisexperiment realized the removal of nitrogen and phosphorus in single MABRimplementation for the first time. A pilot-scale integrated membrane-aerated biofilm reactor （MABR） system,consisted of hydrolysis/acidification pretreatment, MABR process and activatedcarbon adsorption post-processing, was designed to treat the high-loading mixedpharmaceutical wastewater. A study of MABR process was conducted to investigatethe effect of aeration condition, circulation flow rate and water quality onperformance over260days. The performances of these processes were evaluated bythe removal efficiency of COD, BOD5, turbidity, NH₄⁺-N and TN. MABR processcould effectively remove above90%of COD and98%of ammonia. The capacitiesper unit volume of MABR reached to1348gCOD/m³d,48.2gNH₄⁺-N/m³d, andoxygen utilization rate was up to43.74%. After post-processing, the effluent ofintegrated treatment MABR system kept stable with COD below200mg/L andNH4+-N below3mg/L. The effluent quality of integrated MABR system could meetthe wastewater discharge standard. The results of LC/ESI/MS indicated that theintegrated MABR system could effectively remove the complex and persistentorganic compounds.