APPLICATION OF POLLUTION FLOW ANALYSIS IN WATER QUALITY MANAGEMENT AT SAEN SAEP CANAL, BANGKOK

Abstract

Min Buri District in Bangkok is rapidly expanding economically. The number of people who have moved in to reside and work in the district is increasing, hence the higher water consumption. As a result, more wastewater is directly discharged from residences and business establishments into canals in the area, causing the degradation of the water quality. This research analyzed the water quality in the Saen Saep Canal and its branch canals, using Material Flow Analysis (MFA) to specify sources, types, and directions of pollution in the Saen Saep Canal. The results showed that when the season changed from winter to summer, the water quality parameters of the four branch canals that tended to rise were pH and DO, while BOD, COD, TKN, and T-P slightly increased or decreased. The result found that pH and DO of  Pharajchadamri 1 canal  Sam-Wa canal and Bang-Chan canal were within the normal range of  the surface water source standard. While, the Chek canal was not in the standard and the BOD result of all 4 branches canal was over the standard. Regarding the Saen Saep Canal, it had a pH of 7.32, which was normal for surface water standards, a DO of 4.87 mg/L, a BOD of 6.45 mg/L, and was categorized as the Type 5 surface water source. The results from MFA also showed that the amounts of DO remaining in the Saen Saep Canal during winter and summer were 0.14 and 1.79 tons per day, respectively. Meanwhile, the amounts of BOD, COD, TKN, and T-P were not found remaining in the canal as they were released along with the flow. The factors contributing to the pollution index in the system included the discharge of streams and activities in the area. According to the pollution flow analysis, Ratchadamri 1 was the branch canal that discharged the most pollutants into the Saen Saep Canal since it flows through the dense community area with schools, housing developments, markets, and transportation.