Using Constructed Wetlands to Remove Pathogenic Parasites and Fecal Coliforms from Wastewater in Tanzania
DOI:
https://doi.org/10.4314/tjs.v48i1.17Keywords:
helminth, protozoa, fecal coliform, wastewater treatment, constructed wetlandAbstract
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 coliforms (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 quantity parasites. The membrane filtration method was used to detect and quantify FC. 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 systems, the removal of protozoa ranged from 99.8% to 100%. The mean concentration of FC in effluents ranged from 5 to 6 log units/100mL. Effluents of all CW systems met the recommended parasitological quality requirements of the World Health Organisation (2006) 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.
