PERFORMANCE EVALUATION OF CONSTRUCTED WETLAND AND REMOVAL OF HELMINTHES PARASITES

Abstract

Pakistan has moved from water surplus country to water scarce country. Increase in climate and environmental issues have worsened water crisis. There is a need for an effective water management and effective water technology. Constructed wetland is an engineered biological system, highly cost effective, sustainable and ecofriendly. The present study was conducted at constructed wetland located at NUST H-12 campus, Islamabad. The main aim of the study was to analyze performance efficiency of constructed wetland and helminth parasites removal along with removal of trace metals from construct wetland. In this study, continuous monitoring of different physicochemical and biological parameters was conducted from January to May 2018 and it was further statistically analyzed in relation to air temperature, global horizontal irradiance and relative humidity. Significant correlation was found between dissolved oxygen, pH, electric conductivity, turbidity, chemical oxygen demand and biological oxygen demand with air temperature, global horizontal irradiance and relative humidity (%). Removal efficiency of constructed wetland was 80 for total Suspended solids, 89 for Total coliforms, 70 for chemical oxygen demand, 61.2 for biological oxygen demand, and 75% for turbidity. High concentration of helminth parasite eggs was found in wastewater. Most predominant helminths species found were Ascaris lumbricoides, Hook worms, Trichuris trichuria, Hymenolepis nana and Enterobius vermicularis. Up to 100% removal of helminths eggs was observed in the wetland, which shows removal efficiency of wetland. A strong relationship was observed between selective meteorological and water quality parameters (Global horizontal irradiance, relative humidity, total coliforms, ambient temperature, turbidity, and total suspended solids) and helminths eggs concentration. Removal efficiency of Constructed wetland was 53, 80, 70 and 71% for Zinc, Lead, Manganese, and Iron. Highest uptake of trace metals was observed in Typha latifolia due to its high biomass and efficient root system. Highest concentration of iron uptake from all wetland plants was observed during July. Highest concentration of metals was observed in roots than leaves and shoots. Results shows that performance efficiency of constructed wetland is highly influenced by seasonal variation. It also depicts that constructed wetland is capable for improving water quality. Key words: Constructed wetland, Physico-chemical parameters, Biological parameters, Meteorological parameters, Biological treatment system