Performance Evaluation of Oxidation Ditch at Guhyeshwori (Kathmandu)

Inhaltsangabe oder Einleitung

The objective of the study is to evaluate the Performance of oxidation Ditch at Guhyeshwori (Kathmandu). Physicochemical and biological parameters were measured and analyzed. Study covered the performance of Grit Chamber and biological treatment process (oxidation ditch and secondary clarifier).

The major problems of Bagmati River are pollution because of unlimited domestic, hospital, and industrial wastes as well as construction waste dumping into river course. GWWTP has recently completed the treatment facilities, which covers the part of the major drainage of river Bagmati.

This carrousel type of oxidation ditch is the first and only one in Kathmandu. One of the guiding factors for future recommendation in wastewater treatment could be the performance of this plant. Therefore the performance evaluation of the oxidation ditch in this environment has thought to be performed as a study.

Bagmati Area Sewerage Construction/Rehabilitation Project has constructed an Oxidation Ditch at the right bank of Bagmati River near Guhyeshwori Temple and it is in operation for more than a year. Since it is the first of its kind, performance study and evaluation will help to establish other treatment units in the future.

From the very beginning, the performance of the treatment plant was monitored. The study was included in the analysis of the physicochemical and biological parameters. BOD5, COD, MLSS, MLVSS, TKN, Ortho Phosphate, DO, TSS, and SS were analyzed and these parameters were used for the evaluation of the performance of the grit chamber and biological units. During the eleven months, five cycles of two to four hours of composite samples were analyzed.