Toxic organic micro-pollutants removal mechanisms in long-term operated membrane bioreactor treating municipal solid waste leachate

Effect of membrane fouling on the removal of micro-pollutants from municipal solid waste landfill leachate, i.e. 4-methyl-2,6-di-tert-butylphenol (BHT), bisphenol A (BPA), and bis(2-ethylhexyl)phthalate (DEHP), in membrane bioreactor (MBR) was investigated. Modifications of membrane surface properties were analyzed to determine their relationship with their removals. Membrane fouling was simulated with foulants of different particle sizes on cellulose acetate (CA) microfiltration membrane to investigate the effect of foulant characteristics on BHT, BPA, and DEHP retention in the filtration experiment. The rejection efficiencies of the organic micro-pollutants in the MBR were 82–97% by fouled membrane, and 70–90% by cleaned membrane. The fouled membrane provided higher rejection of micro-pollutants from about 5% for BPA and BHT to 19% for DEHP. These improvements were due to the modification of membrane surface characteristics in terms of surface morphology, and contact angle after membrane fouling. The degree of rejection was found to be dependent upon the characteristics of foulant deposited on CA membrane surface. Increasing foulant particle size and its density shifted the mechanism of micro-pollutant rejection from membrane pore narrowing to pore blocking and cake formation while increasing pollutant adsorption capacity onto the foulant layer.

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The materials flow and membrane filtration performance in treating the organic fraction of municipal solid waste leachate by a high solid type of submerged anaerobic membrane bioreactor

Bioresource Technology ◽

10.1016/j.biortech.2021.124927 ◽

2021 ◽

Vol 329 ◽

pp. 124927

Author(s):

Zhiyue Wu ◽

Yuan Liu ◽

Junqiang Yao ◽

Xiaoyu Zheng ◽

Simon Mdondo Wandera ◽

...

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Membrane Filtration ◽

Membrane Bioreactor ◽

Organic Fraction ◽

High Solid ◽

Anaerobic Membrane Bioreactor ◽

Filtration Performance ◽

Waste Leachate ◽

Solid Type

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Effect of Aeration on Fresh and Aged Municipal Solid Waste in a Simulated Landfill Bioreactor

Water Quality Research Journal ◽

10.2166/wqrj.2004.031 ◽

2004 ◽

Vol 39 (3) ◽

pp. 223-229 ◽

Cited By ~ 2

Author(s):

Mostafa A. Warith ◽

Graham J. Takata

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Ammonia Concentration ◽

Air Injection ◽

Bioreactor Landfills ◽

Time To Stabilization ◽

High Ammonia ◽

Simulated Landfill ◽

Term Monitoring

Abstract Municipal solid waste (MSW) is slow to stabilize under conventional anaerobic landfill conditions, demanding long-term monitoring and pollution control. Provision of aerobic conditions offers several advantages including accelerated leachate stabilization, increased landfill airspace recovery and a reduction in greenhouse gas emissions. Air injection was applied over 130 days to bench-scale bioreactors containing fresh and aged MSW representative of newly constructed and pre-existing landfill conditions. In the fresh MSW simulation bioreactors, aeration reduced the average time to stabilization of leachate pH by 46 days, TSS by 42 days, TDS by 84 days, BOD5 by 46 days and COD by 32 days. In addition, final leachate concentrations were consistently lower in aerated test cells. There was no indication of a gradual decrease in the concentration of ammonia, and it is likely this high ammonia concentration would continue to be problematic in bioreactor landfill applications. This study focussed only on biodegradability of organics in the solid waste. The concentrations of the nonreactive or conservative substances such as chloride and/or heavy metals remain in the bioreactor landfills due to the continuous recirculation of leachate. The results of this study demonstrate the potential for air injection to accelerate stabilization of municipal solid waste, with greatest influence on fresh waste with a high biodegradable organic fraction.

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