Biodegradation of Emerging Pharmaceuticals from Domestic Wastewater by Membrane Bioreactor: The Effect of Solid Retention Time.

Raghad Asad Kadhim ALOBAIDI,Rasha Khalid Sabri MHEMID,Ozer CINAR,Kubra ULUCAN-ALTUNTAS,Neslihan MANAV-DEMIR

doi:10.3390/ijerph18073395

Abstract

Although conventional biological treatment plants can remove basic pollutants, they are ineffective at removing recalcitrant pollutants. Membrane bioreactors contain promising technology and have the advantages of better effluent quality and lower sludge production compared to those of conventional biological treatment processes. In this study, the removal of pharmaceutical compounds by membrane bioreactors under different solid retention times (SRTs) was investigated. To study the effect of SRT on the removal of emerging pharmaceuticals, the levels of pharmaceuticals were measured over 96 days for the following retention times: 20, 30, and 40-day SRT. It was found that the 40-day SRT had the optimum performance in terms of the pharmaceuticals’ elimination. The removal efficiencies of the chemical oxygen demand (COD) for each selected SRT were higher than 96% at steady-state conditions. The highest degradation efficiency was observed for paracetamol. Paracetamol was the most removed compound followed by ranitidine, atenolol, bezafibrate, diclofenac, and carbamazepine. The microbial community at the phylum level was also analyzed to understand the biodegradability of pharmaceuticals. It was noticed that the Proteobacteria phylum increased from 46.8% to 60.0% after 96 days with the pharmaceuticals. The Actinobacteria class, which can metabolize paracetamol, carbamazepine, and atenolol, was also increased from 9.1% to 17.9% after adding pharmaceuticals. The by-products of diclofenac, bezafibrate, and carbamazepine were observed in the effluent samples.

Highlights

Introduction published maps and institutional affilThe increase in the use of micropollutants, including pharmaceuticals, has become a major environmental problem in recent years
Toanalyze analyzethe theselected selected compound compound by were rerequired to be concentrated by the solid-phase extraction method: different solvents quired to be concentrated by the solid-phase extraction method: different solventsand and cartridges their recoveries
The biodegradation of six pharmaceuticals was investigated in a membrane bioreactor

Summary

Introduction

The increase in the use of micropollutants, including pharmaceuticals, has become a major environmental problem in recent years. While the presence of pharmaceutical compounds is limited in the environment, knowledge of the long-term threats to aquatic species and human health even with low levels of drugs remains lacking. The concentration and effects of micropollutants on the environment and, perhaps, human beings have increased over the past few decades. Only partially removed during treatment, and when disposed of in the environment over a long period, cause substantial pollution. The European directive, Water Framework Directive 2000/60/EC, is a global framework that underlines the importance of micropollutants in superficial water (rivers and lakes), transitional water (estuaries), coastal waters, and groundwater. Traditional water and wastewater treatment plants are successful in controlling pollutants such as organic substances and nutrients, they cannot remove the iations

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