Spoilt for choice: A critical review on the chemical and biological assessment of current wastewater treatment technologies

Abstract

The knowledge we have gained in recent years on the presence and effects of compounds discharged by wastewater treatment plants (WWTPs) brings us to a point where we must question the appropriateness of current water quality evaluation methodologies. An increasing number of anthropogenic chemicals is detected in treated wastewater and there is increasing evidence of adverse environmental effects related to WWTP discharges. It has thus become clear that new strategies are needed to assess overall quality of conventional and advanced treated wastewaters. There is an urgent need for multidisciplinary approaches combining expertise from engineering, analytical and environmental chemistry, (eco)toxicology, and microbiology. This review summarizes the current approaches used to assess treated wastewater quality from the chemical and ecotoxicological perspective. Discussed chemical approaches include target, non-target and suspect analysis, sum parameters, identification and monitoring of transformation products, computational modeling as well as effect directed analysis and toxicity identification evaluation. The discussed ecotoxicological methodologies encompass in vitro testing (cytotoxicity, genotoxicity, mutagenicity, endocrine disruption, adaptive stress response activation, toxicogenomics) and in vivo tests (single and multi species, biomonitoring). We critically discuss the benefits and limitations of the different methodologies reviewed. Additionally, we provide an overview of the current state of research regarding the chemical and ecotoxicological evaluation of conventional as well as the most widely used advanced wastewater treatment technologies, i.e., ozonation, advanced oxidation processes, chlorination, activated carbon, and membrane filtration. In particular, possible directions for future research activities in this area are provided.

Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

“…Traditionally, both chemical and biological treatments or a combination of them have been employed [3]. However, biological treatments have many advantages because they are cheaper, more reliable, can be done on site and their efficiency can be improved by the choice of a variety of microorganisms [4]. Bioremediation processes explore the use of biological mechanisms to destroy, transform or immobilize environmental contaminants…”

Biosensor-based comparison of the ecotoxicological contamination of the wastewaters of Southern Russia and Southern Germany

“…One of the results of their response is a change in light emission intensity depending on sample toxicity degree. Results from luminescent bacteria acute toxicity test proved to be a valuable tool for efficient wastewaters pollution control (Rodrigues and Umbuzeiro 2011;Kokkali and Delft 2014;Prasse et al 2015).…”

“…Genotoxicity assessment is of great importance for public and environmental health; therefore, genotoxicity testing is among the most widely used bioassays in ecotoxicology (Prasse et al 2015).…”

The chlorination behaviour and environmental fate of the antiretroviral drug nevirapine in South African surface water

“…Inroads into understanding the transformation of antibiotics are being made by various researchers and it has been found that while most antibiotics lose their activity during water disinfection, a few do form biologically active transformation products (Dodd et al, 2009;Escher and Fenner, 2011;Mestankova et al, 2012;Keen and Linden, 2013). In addition to understanding the chemistry behind their transformation, various technologies are in development to effectively remove pharmaceuticals and their disinfection transformation products from wastewater (Prasse et al, 2015). These technologies are however in their infancy and have yet to be adopted widely in -first world countries‖, let alone in developing countries such as South Africa.…”