Diversity of antibiotics in hospital and municipal wastewaters and receiving water bodies and removal efficiency by treatment processes: a systematic review protocol

Background: Antibiotics are extensively discharged into the environment through sewages. These emergent contaminants cause health and environmental risks by toxicity, allergic impacts, non-biodegradability and more importantly advancing antibiotic resistance. Antibiotics are hardly removed by conventional treatment processes and frequently are being reported in aquatic environments. The systematic review outlined in this protocol will compile and synthesize literature on the variety and concentrations of antibiotics in wastewaters and receiving water resources. Also, the review will address the efficiency of treatment processes in elimination of antibiotics from aqueous solutions. Outcomes of the study could help wastewater treatment plant engineers with providing reliable design data and outline a road map for future researches. Methods: The review will be performed according to the Collaboration for Environmental Evidence (CEE) guidelines for systematic review and evidence synthesis in environmental management, and will be reported according to ROSES reporting standards for systematic evidence syntheses. The published articles will be screened by considering the defined inclusion and exclusion criteria at the title, abstract and full-text levels. Included studies will be exposed to a critical appraisal for validity and quality assessment. The articles will be assessed on the susceptibility to bias and the studies with high bias will be excluded from the data synthesis. The data from included studies will be combined into a narrative synthesis. Random effect Meta-analysis will be conducted due to the likely range of underlying effects. If the heterogeneity exists, the source of heterogeneity will be sought by met-regression and subgroup analyses.