Removal of Pharmaceuticals and Personal Care Products during Water Recycling: Microbial Community Structure and Effects of Substrate Concentration

Abstract

Many pharmaceuticals and personal care products (PPCPs) have been shown to be biotransformed in water treatment systems. However, little research exists on the effect of initial PPCP concentration on PPCP biotransformation or on the microbial communities treating impacted water. In this study, biological PPCP removal at various concentrations was assessed using laboratory columns inoculated with wastewater treatment plant effluent. Pyrosequencing was used to examine microbial communities in the columns and in soil from a soil aquifer treatment (SAT; a method of water treatment prior to reuse) site. Laboratory columns were supplied with different concentrations (0.25, 10, 100, or 1,000 g liter ؊1 ) of each of 15 PPCPs. Five PPCPs (4-isopropyl-3-methylphenol [biosol], p-chloro-m-xylenol, gemfibrozil, ketoprofen, and phenytoin) were not removed at any tested concentrations. Two PPCPs (naproxen and triclosan) exhibited removals independent of PPCP concentration. PPCP removal efficiencies were dependent on initial concentrations for biphenylol, p-chloro-m-cresol, chlorophene, diclofenac, 5-fluorouracil, ibuprofen, and valproic acid, showing that PPCP concentration can affect biotransformation. Biofilms from sand samples collected from the 0.25-and 10-g liter ؊1 PPCP columns were pyrosequenced along with SAT soil samples collected on three consecutive days of a wetting and drying cycle to enable comparison of these two communities exposed to PPCPs. SAT communities were similar to column communities in taxonomy and phylotype composition, and both were found to contain close relatives of known PPCP degraders. The efficiency of biological removal of PPCPs was found to be dependent on the concentration at which the contamination occurs for some, but not all, PPCPs.

Removal of micropollutants through a biological wastewater treatment plant in a subtropical climate, Queensland-Australia

“…Some compounds are biodegraded by bacteria and in these cases the removal rates can depend on their initial concentration as the removal depends partially on enzyme kinetics [42]. These effects are, however, unlikely to explain sufficiently the extremely high removal rate of ACE found in this study.…”

Microbial community changes induced by Managed Aquifer Recharge activities: linking hydrogeological and biological processes

“…The aquifer thickness in the vicinity is 10-15 m, with alternating sands and gravels. Non-continuous fine-grained sediments are widely present (Pedretti et al, 2012). The distance from the bottom of the pond to the water table oscillated from 9 m (July 2014) to 7 m (March 2015) in the period under study.…”

COMBI, continuous ozonation merged with biofiltration to study oxidative and microbial transformation of trace organic contaminants

“…34 Therefore, the combined effect of ozonation and subsequent biofiltration leads to significant reduction of the ecotoxicity of the treated water. [35][36][37][38][39][40] The degradation of TrOCs during biofiltration depends on several factors, such as contaminant concentration, 41 retention time, 42,43 age, diversity and adaptation of the microbial community, 44,45 substrate availability and composition for microbial metabolic processes, 46,47 redox conditions, 48,49 and temperature. 50 Similar relationships during biofiltration can be expected for the removal of transformation products.…”