In most studies, two main indicators Total coliforms and Fecal coliforms in wastewater were investigated.

After reviewing the quality of the articles in accordance with the research objectives, 14 articles were included in the study that were published between 20. In this study, 1468 articles retrieved from 118 issues of 5 environmental health journals were reviewed. Also the removal rates of the microbial agents mentioned in the studies were compared with united states environmental protection agency (US-EPA) standards. 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. Qualitative data were collected using a preferred reporting items for systematic reviews and meta-analyzes (PRISMA) standard checklist. 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. MethodsĪ systematic review was conducted for all articles published in 5 Iranian environmental health journals in 11 years. The purpose of this study was to determine the efficacy of current wastewater treatment systems in removing microbes and their contaminants. 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.

Sludge in wastewater treatment