RETROFIT PROPOSAL FOR IMPROVING pH PERFORMANCE IN WASTEWATER TREATMENT PROCESS (CASE STUDY: WASTEWATER TREATMENT PLANT 2, PT. JABABEKA INFRASTRUKTUR)

Abstract

PT. Jababeka Infrastruktur is a subsidiary company of PT. Jababeka Tbk., which have a role as estate manager. One of PT. Jababeka Infrastruktur duty is to manage Wastewater Treatment Plant 2 (WWTP2). The incoming wastewater pH in WWTP2 PT. Jababeka Infrastruktur tend to be low and fluctuating, it is because the most incoming wastewater quantity came from food industries, where it has a potential to degrade into fatty acid. pH is one of the important parameters in treating wastewater, especially in biological wastewater treatment system as applied in WWTP2. pH value can affect the microorganism performance in decompose the pollutant compound in wastewater. pH control action is needed to make the treatment run more effective. The purpose of this research was to know the primary settling tank (PST) with ̴ 3 hours detention time performance in equalizing wastewater pH. The research also aims to analyse whether existing PST detention time met the preferred value, and to find out whether utilizing existing PST as equalization tank than building new equalization tank based on hydraulic system and financial aspect. The method used in this research was statistical analysis of secondary data by comparing standard deviation value of wastewater before and after accommodated in PST also paired sample t-Test to see the performance of PST in equalizing of pH. Besides that, inlet wastewater pH was taken and measured every one hour with and without adding to the previous wastewater inlet sample to determine the preferred wastewater detention time in terms of pH. The research result showed that PST was significant unit process that can equalize the pH value. The observation of pH characteristic pattern by time showed that the preferred equalization time was 1-2 hours which less than the existing PST detention time. The financial analysis showed that, developing new equalization tank is a better alternative rather for full (24 hours) operation. However, if the pH of inlet wastewater can be controlled so that the pH value is less than 6.5 as much as 17%, utilizing the existing PST as an emergency unit is a better alternative.