THE FLUCTUATION OF DOMESTIC WASTEWATER DISCHARGED FROM OFFICE BUILDING

Abstract

The domestic wastewater from office building has been recognized to be different from other sources of wastewater discharge. The objectives of this research were to know the fluctuation of quantity, fluctuation of quality, and a peaking factor of wastewater discharge. The samples were taken from hourly sampling and daily sampling from 7 am to 5 pm and from Monday to Friday during the working time. The results showed that wastewater discharge varied over time and the quantity of Blackwater, greywater and mixed wastewater were ranging from 20.4 to 22.6, 18.7 to 23.3 and 39.61 to 49.93 liter/person/day, respectively. The quality of mixed wastewater varied over time such as for COD, TN, and TP was 252.45±88.96, 85.42±24.08 and 3.01±1.92 mg/L (mean± standard deviation), respectively. The low concentrations were in the morning and peak concentrations were in the afternoon after lunch time. The peaking factor of Blackwater, greywater and mixed wastewater discharge were 1.67, 1.6 and 1.83 at the beginning of working time and the praying time of Muslim Indonesian culture, respectively. It is proposed that domestic wastewater from office building has specific characteristics and the findings of this research can be served as useful information for designing of domestic wastewater treatment system for office buildings.