Using Constructed Wetlands to Remove Pathogenic Parasites and Fecal Coliforms from Wastewater in Dar es Salaam and Iringa, Tanzania

  • Abdallah Zacharia Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
  • Wajihu Ahmada Department of Chemical and Mining Engineering, University of Dar es Salaam, Tanzania
  • Anne H. Outwater Department of Community Health Nursing, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
  • Billy Ngasala Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
  • Rob Van Deun Life Sciences and Chemistry Unit, Thomas More University of Applied Sciences, Belgium
Keywords: helminth, protozoa, fecal coliform, wastewater treatment, constructed wetland

Abstract

Wastewater treatment is a widely used health protection measure that can be applied to control the transmission of wastewater-related infectious diseases to communities exposed to wastewater. This study determined the efficiency of three full-scale constructed wetlands (CWs) in removing pathogenic parasites and fecal coliform (FC) bacteria from wastewater. Wastewater samples were collected from three CW systems located in the Dar es Salaam and Iringa regions of Tanzania. The modified Bailenger and modified Ziehl-Neelsen stain techniques were used to detect and quantify parasites. The membrane filtration method was used to detect and quantify FC bacteria. Data were analysed using IBM SPSS version 20. Helminth (Ascaris lumbricoides, hookworm, and Taenia spp.) eggs were completely removed by two CW systems. In all the systems, the removal of protozoa ranged from 99.8% to 100%. The mean concentrations of FCs in effluents ranged from 5 to 6 log units/100 mL. Effluents of all CW systems met the recommended parasitological quality requirements of the World Health Organization for the safe reuse of wastewater. FC effluents concentrations did not meet the local discharge standards of the Tanzania Bureau of Standards. Therefore, improvement to the CWs’ design, operation, and maintenance are required for the efficient removal of bacteria.

Keywords: helminth, protozoa, fecal coliform, wastewater treatment, constructed wetland

Published
2022-03-31
Section
Articles

Journal Identifiers


eISSN: 2507-7961
print ISSN: 0856-1761