Effectiveness of wastewater treatment systems in removing microbial agents: a systematic review

Abstract

Background: Due to unrestricted entry of wastewater into the environment and the transportation of microbial contaminants to humans and organisms, environmental protection requires the use of appropriate purification systems with high removal efficiency for microbial agents are needed. The purpose of this study was to determine the efficacy of current wastewater treatment systems in removing microbes and their contaminants. Methods: A systematic review was conducted for all articles published in 5 Iranian environmental health journals in 11 years. The data were collected according to the inclusion and exclusion criteria and by searching the relevant keywords in the articles published during the years (2008-2018), with emphasis on the efficacy of wastewater treatment systems in removing microbial agents. Qualitative data were collected using a preferred reporting items for systematic reviews and meta-analyzes (PRISMA) standard checklist. After confirming the quality of the articles, information such as the name of the first author and the year of publication of the research, the type of study, the number of samples, the type of purification, the type of microbial agents and the rate of removal of microbial agents were entered into the checklist. Also the removal rates of the microbial agents mentioned in the studies were compared with united states environmental protection agency (US-EPA) standards. Results: In this study, 1468 articles retrieved from 118 issues of 5 environmental health journals were reviewed. After reviewing the quality of the articles in accordance with the research objectives, 14 articles were included in the study that were published between 2010 and 2018. In most studies, two main indicators Total coliforms and Fecal coliforms in wastewater were investigated. Removing fungi and viral contamination from wastewater was not found in any of the 14 studies. Different systems (activated sludge, stabilization ponds, wetlands, and low and medium pressure UV disinfection systems were used to remove microbial agents in these studies. Most articles used active sludge systems to remove Total coliforms and Fecal coliforms, which in some cases were not within the US-EPA standard. The removal of Cysts and Parasitic eggs was only reporte from stabilization pond systems (SPS) where removal efficiency was found in accordance with US-EPA standards.

Efficient removal of water bacteria and viruses using electrospun nanofibers

“…The World Health Organization has stated that safe drinking water accessibility is the concern of about 785 million people and 2 million people use a contaminated water source for drinking ( WHO, 2020 ). Aiming to obtain purified water, the unsought biological contaminants including bacteria or viruses and chemical pollutants such as toxic heavy metal ions have to be eliminated ( Bridge et al, 2010 ; Aghalari et al, 2020 ).…”

A glance at one decade of water pollution research in Iranian environmental health journals

“…1). Table 1 Specifications of Iranian environmental health specialist journals (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017) http://jreh.mums.ac.ir/journal/about?lang= en Data collection was done by a researcher-made checklist about which there was previous experiences (Tirgar et al, 2019;Aghalari et al, 2020). To select the most important and common variables, recommendations for articles in the formulation of articles by the International Committee of Medical Journal Editors (ICMJE 2019) and the World Association of Medical Editors (World Association of Medical Editors (WAME) and Editorial Policy and Publication Ethics Committees, 2019) were the criteria of choice.…”

Donnan Membrane Process for the Selective Recovery and Removal of Target Metal Ions—A Mini Review

“…Metals, specifically heavy metals in effluent and sludge discharges from anthropogenic sources such as households, agriculture, manufacturing and process industries, are of major concern to environmental regulators [ 1 , 2 , 3 ]. Notable amongst the metals and those that are classified as the most hazardous metal species are As, Cr, Ni, Cd, Pb, Co, Zn and Cu.…”