Performance evaluation and upgrade options for existing sequence batch reactor for nutrient removal

• Main Authors: Abenoja, Jeremy Ynnos L., Lantin, Jahziel P., Ly, Jason H.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Sewage > Purification; Effluent quality > Testing; Sewage disposal plants > Upgrading; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/8801
• Institution: De La Salle University

DAO 35 is the existing effluent standard before it was updated into DAO 2016-08. The change of regulations require compliance to all parameters and thus, improvement of existing wastewater treatment plants (WWTPs) is necessary. This study aims to evaluate the performance of WWTPs and their potential upgrade on DAO 2016-08. The objectives of this study are the following: (1) to monitor compliance of sewage treatment plants (STPs) with the standards stated in DAO 2016-08 including chemical oxygen demand (COD), total suspended solids (TSS), nitrates, phosphates and ammonia, (2) to evaluate the recyclability of the STP effluent for toilet flushing and landscape irrigation based on international standard and (3) to conduct simple multi criteria analysis of several options for upgrading the existing STPs based on the results of the parameters monitored. Four different WWTPs were monitored for 12 weeks with respect to the parameters stated. The biological oxygen demand (BOD) was also monitored but was limited to a single WWTP for 4 weeks. The data gathered in terms of samples which complied to the standards are the following: 5 of 55 samples (9.09%) for ammonia, 1of 4 (25%) for BOD, 24 of 60 (40%) for COD, 19 of 60 (31.67%) for nitrates, 33 of 60 (55%) for pH, 2 of 60 (3.33%) for phosphates and 59 of 60 (98.33%) for TSS. Meanwhile, for the recycling standards: none of the four samples complied for BOD while 33 of the 60 samples (55%) complied for pH. Analytical hierarchy process (AHP) for multi-criteria analysis was used to choose the best option to improve the effluent quality of WWTPs. The options for improvement were as follows: (1) addition of an SBR tank (2) diversion of wastewater to a different treatment facility and (3) converting the SBR into membrane bioreactor (MBR). Considering the criterion technical aspect, environmental aspect, cost and ease to upgrade, option 2 was the most preferred decision followed by option 1 and option 3.