Wastewater treatment efficiency of a multi-media biological aerated filter (MBAF) containing clinoptilolite and bioceramsite in a brick-wall embedded design

Enhanced long-term ammonium removal and its ranked contribution of microbial genes associated with nitrogen cycling in a lab-scale multimedia biofilter

“…), respectively. These COD removal efficiencies are higher than those of filter systems with high air-based aeration costs, which are commonly constructed to treat drinking water (COD = 6-107 mg/L) with typical removal efficiencies ranging from 42% to 94% (Hasan et al, 2014;Ji et al, 2011Ji et al, , 2013Van den Akker et al, 2008). Influent and effluent DO content during the start-up phase was 8.98 ± 0.15 mg/L and 10.31 ± 0.20 mg/L, respectively.…”

“…Due to the different responses of microorganisms associated with nitrogen cycling to such inconsistent loading, NH 4 + -N removal in biofilters fluctuates substantially, and the results of treatment are often unsatisfactory. Previous studies have showed that COD and NH 4 + -N loading significantly influence nitrogen transformation and removal processes in biofilters (Ji et al, 2011;Ling and Chen, 2005;Tan and Ji, 2010). Nitrogen removal in biofilters is often inhibited by increased organic carbon concentrations due to competition between autotrophic and heterotrophic nitrifying bacteria (Guerdat et al, 2011;Michaud et al, 2006).…”

“…Several studies have reported the impacts of COD loading on nitrification processes and NH 4 + -N removal. Ji et al (2011) investigated the impacts of COD loading on NH 4 + -N removal in the different portion of a biofilter (from top to bottom). NH 4 + -N removal slightly decreased following an increase in COD loading.…”

Quantifying nitrogen transformation process rates using nitrogen functional genesin a multimedia biofilter under hydraulic loading rate constraints

“…Anammox and archaeal are two functional genes involved in ammonium oxidation processes (Leininger et al, 2006;Rothrock et al, 2011). Published studies have demonstrated that nitrogen removal in biofilters is often restricted by increased HLR (Ji et al, 2011;Tan and Ji, 2010). A study by Li et al (2011) on the effects of HLR on pollutants removal showed that both the effluent concentration of NH 4 + -N and COD increased with increasing HLR.…”

“…Specifically, microbial ammonia oxidation, which is the first and rate-limiting step for subsequent nitrogen transformation and removal, is impaired by a higher HLR. This phenomenon arises because higher HLR causes organic loading (Ji et al, 2011;Tan and Ji, 2010). Van den Akker et al (2011) studied the structure of nitrifying biofilms in a biofilter designed for potable water pre-treatment.…”