Evaluation of the Efficiency of Wetlands to Treat water Pollution in the Litani River "studying the Biochemical Oxygen Demand"

Abstract

Evaluation of the Efficiency of Wetlands to Treat water Pollution in the Litani River (Studying the Biochemical Oxygen Demand)

Pollution is one of the major challenges that countries are facing which threatens the continuity of life. Water pollution is one of the most challenging obstacles humanity faces, and for that many methods and procedures were taken in an attempt to treat water pollution starting from water treatment plants reaching natural and artificial wetlands.

Hence, the research background which discusses the technique of natural wetlands arises. This technique is a factual solution capable of treating water pollution or at least reducing its rates at the lowest cost possible. This research considered the wetlands in Joub Jannine, West Beqaa of Lebanon as a chosen site of study and evaluation of the effectiveness and capability of these lands in treating water pollution resulting from domestic wastewater discharges. In order to get the best results and to check out their validity, the researcher tested 96 samples halved into 48 before the wetland construction (Litani River) and 48 after it. The researcher goal was to study the effect of the hydraulic retention time and the flow rate in treating water pollution, that's why he tested the samples stucked in for 3 and 6 days with flow rate equal to 30, 60, 90 L/s, and to verify the accuracy and credibility of the results, the test was repeated 2 times per day.

The results showed that the average removal rate of the Biochemical Oxygen Demand before and after the wetland was 61.07%. This percentage differs as the HRT and flow rate differs. It was found that HRT of 6 days with pumping at rate of 30 L/s was the best during months of drought, where it reaches 87.16%.

Within the limits of this study, we conclude that wetlands are able to reduce the Biochemical Oxygen Demand, where we found that the value of the indicator after the constructed wetland is less than the threshold regression model. Based on what mentioned, this method is useful and beneficial concerning its efficiency in treating water pollution mainly caused by domestic wastewater discharges, in addition to its economic benefits where its low-cost compared to conventional treatment systems.