Assessment of Wastewater Quality of Selected Sewers Connected to the Buriganga River Submitted

Abstract

Sewage systems are essential for modern society, and the main pollutant in the Buriganga River is wastewater from Dhaka City. Unchecked and untreated discharge of waste is having a negative effect on the river's water quality. The main source of pollution is the Hazaribagh tannery, which has been in operation for a while without a treatment facility. Sewage lines are the entire system of pumps, pipelines, and mains used to collect wastewater and each community has its own sewage system. Urban infrastructure must include sewerage systems to safeguard against flooding and the spread of waterborne diseases. It is important to make existing infrastructure more capable and to ensure proper care, as they react to the chemical composition of wastewater, changing it. Here we have studied various parameters of wastewater including pH, temperature, turbidity, TDS, DO, BOD, and COD so on. These parameters are analyzed through some significant analysis and seasonal differences are highlighted. We obtained a maximum p-value of 1 from a one-way ANOVA analysis, which is the p-value for cadmium. And for temperature, copper, and nickel, the lowest p-value was 0, which was also the case. The pH value, on the other hand, was discovered to be 0.009. Using Cohen's d, we were able to determine the specifics of the effect size. It appears that temperature has the biggest effect size (Cohen's d), with a value of 4.156; turbidity, DO, and TDS have medium effect sizes, ranging from 0.727 to 0.913; and Cd and Ni have no effect sizes, with values of 0.From WWQI, EC has a maximum value of 118400 and Cd has the minimum value of 0.0152. Ni, Pb, Cu have excellent water quality. pH, turbidity, temperature, BOD, COD EC, TDS are very polluted. DO is in poor condition. Other parameters are excellent. pH was higher in autumn than in summer, and turbidity was also similar to pH, but turbidity increased abnormally in Dhaka Uddan during the autumn season. Electrical conductivity was higher in autumn than in summer.DO was higher in autumn but was found to be unusually low at one point compared to summer. Also, TDS in the summer season is less than in the autumn season. As seen in BOD and COD, BOD is always lower than COD. Again, at the Kamrangirchar Beribadh, there is some discrepancy in both cases that is slightly higher in summer than in autumn. Copper is less available in autumn than in summer. Most of the increase in chromium was observed in the summer season but in some cases, it was the same in both seasons. Nickel is high in summer and low in autumn. Reducing the toxicity of waste involves source control, advanced treatment methods, improving sewage treatment processes, promoting public awareness, regular monitoring, separation of hazardous waste, and collaboration between governments, industries, and communities. These steps can help to minimize the toxicity of sewage waste, leading to a cleaner and healthier environment.