The Comparative Evaluation of the Performance of Two Phytoremediation Systems for Domestic Wastewater Treatment

Abstract

The constructed wetlands as well engineered techniques have been used effectively for phytoremediation of wastewater and pollution control during the last decades. In these technologies, the naturally occurring processes of plants alongside micro-organisms present in the biofilm attached to the roots, soil substrate and water column degrade the organic pollutants. The study seeks to compare the potential use of Phragmites sp. reed bed and floating macrophyte water hyacinth (Eichhornia crassipes) system for domestic wastewater treatment. The sewage treatment performance is evaluated as 80 % & 76 % chemical oxygen demand (COD), 90 % & 87 % biological oxygen demand (BOD5 ), 24 % & 18 % total dissolved solids (TDS), 69 % & 67 % total suspended solids (TSS), 12 % & 5 % Chlorides, 73 % & 69 % ammonia nitrogen (NH3 -N), 42 % & 3 1 % phosphate (Po4 _P), 93 % & 91 % most probable number (MPN) and 95 % & 92 % total viable count (TVC) reduction at optimum hydraulic retention time (HRT) of 24 & 43 h in Phragmites sp. and water hyacinth systems, respectively. Likewise, the floating macrophyte pond contrary to reed bed process shows insignificant pollutant diminution at 24 h HRT. This paper also highlights the microbial population present through the wetland systems by estimation of total viable count (TVC). The botanical aspect with reference to the plant growth is shown a significant increase in vegetation yield. The overall studies indicate the better treatment efficiency by preferred Phragmites sp. root zone system at low footprint area for domestic wastewater.