Evaluation of Fecal Coliform Prevalence and Physicochemical Indicators in the Effluent from a Wastewater Treatment Plant in the North-West Province, South Africa.

Stenly Makuwa,Elvis Fosso-Kankeu,Ezekiel Green,Matsobane Tlou

doi:10.3390/ijerph17176381

Abstract

Compliance of the effluents from wastewater treatment plants (WWTPs) to the regulatory standards, which mostly entail the removal/reduction of organic waste and deactivation of the potential microbial pathogens is of great importance. The detection of indicator parameters can be used to determine the effectiveness of a WWTP and the level of compliance with the South African regulatory standards. The performance of the WWTP was assessed by biological, physical and chemical measures in wastewater final effluent. The Escherichia coli ranged from 0 and 2420 count/100 mL in the final effluent. The recorded values for the physicochemical parameters were within the following ranges: pH (7.03–8.49), electrical conductivity (81.63–126.5 mS/m), suspended solids (0.40–20.4 mg/L), ammonia (0–22.15 mg/L), Chemical Oxygen Demand (COD) (1–73 mg/L), nitrate (0–16.1 mg/L), ortho-phosphate (0–8.58 mg/L) and free chlorine (0–3.21 mg/L). Furthermore, the concentration of toxic heavy metals was recorded to be between 1–10 ug/L for arsenic, cadmium, lead and mercury. In conclusion, all the parameters that were evaluated in this study indicate that the studied WWTP is performing in accordance with the prescribed general limits.

Highlights

Wastewater is derived from raw sewage from anthropogenic activities [1,2], while sewage effluent refers to treated or untreated wastewater generated from a treatment plant [3]
The organism was detected in 96.43% of the 336 final effluent samples studied, with 98.81% of the samples below the permissible general limit of 1000 counts/100 mL as recommended by the
The study results were evaluated against the special limit and the outcomes indicated a lower compliance of 3.57% out of the 336 samples studied

Summary

Introduction

Wastewater is derived from raw sewage from anthropogenic activities [1,2], while sewage effluent refers to treated or untreated wastewater generated from a treatment plant [3]. Insufficient management of municipal wastewater in many urban areas is a major challenge that leads to poor quality effluents entering public surface waters and posing high risk to downstream users and aquatic life [2,4,5]. In South Africa (SA), 19% of the rural population lacks access to potable water [6] and continues to use untreated surface water which is often contaminated by polluted wastewater effluents [7,8]. The quality of effluents for most WWTPs has been adequate to meet discharge regulations and standards in the past, the drastic increase in population for a developing country like SA, often means high volumes of wastewater discharged into the environment and environmental pollutants that are a threat to public health [9,10]. Public Health 2020, 17, 6381; doi:10.3390/ijerph17176381 www.mdpi.com/journal/ijerph

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