Comparative study on removal of enteric pathogens from domestic wastewater using Typha latifolia and Cyperus rotundus along with different substrates

A comparative study was carried out to evaluate the efficiency of different substrate materials along with macrophytes Typha latifolia and Cyperus rotundus in treating domestic wastewater intended for reuse in agriculture. The study was conducted over a period of 6 months with different retention times, and observations were taken twice per month. One-way analysis of variance and Tukey's Honest Significant Difference (HSD) tests were used to determine statistical significant differences between experimental columns. Treatment with T. latifolia planted in sand and mix substrate with 4-day retention time remarkably reduced the concentration of all bacterial pathogens. Log reductions observed were approximately 5.01 and 4.82 for total coliform (TC), 4.46 and 3.93 for Escherichia coli, and 5.52 and 5.48 for Shigella, respectively. Moreover, these treatments were also efficient in completely removing fecal coliform (FC) and Salmonella. Maximum parasites were removed by the treatment having sand alone as a substrate containing C. rotundus, but the difference was not significant from those planted with T. latifolia in the same substrate. The results suggest that T. latifolia aids in bacterial pathogens removal, while C. rotundus aids in parasites removal. Thus, wastewater treatment through constructed wetland having mix plantation of these species along with sand can eliminate some of the major enteric pathogens.