RELATIVE DISTRIBUTION OF POLLUTANTS FROM URBAN CANAL AND AQUACULTURE FARM ONTO NATURAL WETLAND OF PHNOM PENH, CAMBODIA

Abstract

Under the rapid development of Phnom Penh, the pollutants control from different sources intothe main natural wetland, Tamouk lake is consequentially required for its ecosystem as well as thesustainable development. Therefore, this work aims to investigate the distribution of thepollutants from the urban canal and aquaculture farm to Tamouk lake through the analysis ofwater quality in both dry and rainy seasons. Twelve sampling sites, i.e., two from urban canals, onefrom aquaculture farm, and nine from the investigated lake, were selected for their water qualityassessment. As the results from both seasonal analyses, the maximum concentrations of totalsuspended solids (TSS), chemical oxygen demand (COD), and ammonia (NH3+) of the effluentfrom aquaculture farm and urban canal to the lake range of 107-134 mg l-1, 76-184 mg l-1, and 8.5-14.9mg l-1 in the dry season and 105-263mg l-1, 75-140 mg l-1, and 7.5-9.2 mg L-1in the rainy season,respectively. In addition, TSS and COD in the lake were only 72-93 mg l-1and 46-77mg l-1 of bothseasons, respectively, whereas NH3+ was estimated to be 7-14 times lower than that in urban canaland aquaculture farms. According to the result analysis, the lake’s water pollution was mainlycontributed by the discharge from the urban canal and aquaculture farm in both seasons. Higherrelease of pollutants from many sources during the rainy season could compensate for rainwater’sdilution effect, resulting in the high remaining of organic and nitrogen in lake water. Hence, toreduce the risk of the lake water to humans and ecosystems, the effluent from aquaculture farmsand urban water is highly suggested to have a proper treatment before discharging to the lake.