Biological nutrient removal from on-site wastewater treatment systems using a membrane aerated bioreactor

摘要

This study aimed to develop a low cost bioreactor process to efficiently removeorganic compounds and nutrients from on-site wastewater treatment systems. Alaboratory-scale anaerobic membrane-aerated biofilm bioreactor (ANMABR) using agas-permeable silicone tubing covered with non-woven fabrics was constructed toevaluate the efficiency of chemical oxygen demand (COD) and nitrogen removal inthe system.After 250 days of continuous reactor operation, the experiment results showedconsistent COD and NH4-N removal efficiencies at 89±6 and 82±5%, respectively.The total nitrogen (TN) removal efficiency was 64±8% with an effluent average totalnitrogen concentration of 11 mg/L. From day 89 to day 120 the biofilm reactorexperienced a shock load running with C/N ratio of 2:1 with influent NH4-N increasedto 150 mg/L. The COD removal efficiency was not affected after the shock load, butNH4-N and TN removal efficiencies were decreased down to 44 and 22%,respectively.This study demonstrated that gas-permeable tubing/membrane could beused to treat wastewater containing low organic and nitrogen loadings from on-sitewastewater treatment systems. Improvement is still needed under the shock loadingconditions for on-site wastewater treatment systems.