Management Efforts of Domestic Wastewater in Urban Based on Socio-Economic Variables

Abstract

This paper presents the analysis of data related to domestic wastewater characteristics from area situated in Yogyakarta city of Sewon Wastewater Treatment Plant (WWTP). BOD load, which has not been used, is 416 kg/day (8.16%) in the ability of WWTP operational with the average rate of degradation  for 1.85 day ^-1 and the retention time for 4.27 day and also the ability to degrade average organic materials for 86,54%. Simple regression models are presented for the prediction of basic wastewater characteristics, such as water consumption (l/person day), wastewater production (m³/day), Biochemical Oxygen Demand (BOD) load (l/person/day) and BOD concentration (mg/l). The models are based on simple socio- economic variables, with special attention to easily obtainable variable of total family income (number of minimum salaries earned per month). Most of the models are able to give an excellent prediction of the desired wastewater variables. Additionally, behavior of the main wastewater characteristics according to the day is analyzed used to variation data period 1.5 years. Based on the results obtained, it is suggested that the classical figures of BOD concentration of 413.69 mg/l and per capita BOD load 96.69 l/person/day do apply to typical population predominant in Yogyakarta city. The actual BOD data concentration are frequently lower than 300 mg/l, while the BOD load is frequently lower than 96 l/person/day. Sewon IPAL is eficient enough in dealing with the process of wastewater treatment. The result obtained can be used for design purposes in the area studied, and possibly in areas of similar characteristics.