Propane Dehydrogenation Wastewater Treatment using Sequencing Batch Reactors

• Main Author: Akosua Abongile Kade Danso, Akosua Abongile
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi Petronas 2010
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://utpedia.utp.edu.my/id/eprint/1012/1/0001.pdf; http://utpedia.utp.edu.my/id/eprint/1012/

The purpose of this study was to determine the effectiveness of using a Sequencing Batch Reactor (SBR) in treating PDH wastewater, to determine the effect of various organic loading rates on SBR performance and lastly, to determine the optimum operating conditions for the SBR. Industrial wastewaters commonly contain high organic loads as well as toxic and inhibitory substance such as sulphide. Therefore, the conventional activated sludge process is inefficient in treating wastewater of this nature. The wastewater sample was collected from a Propane Dehydrogenation (PDH) plant in Kuantan, Pahang. The initial wastewater characteristics of the sample before treatment were determined. Biomass obtained from the Sewage Treatment Plant (STP) at Universiti Teknologi Petronas (UTP), which was cultured for three months in a reactor in the Environmental laboratory, was used to inoculate the wastewater in the SBR. The performance of the SBR in treating the PDH wastewater was investigated with a suspended biomass configuration and operating under the following sequence: fill, react, settle and decant. The effects of four different organic loading rates were investigated. Two sequencing batch reactors were operated simultaneously, each initially having a total cycle period of 24 hours and respective organic loading rates of 0.7 kgCOD/m3/day and 1.5 kg COD/m3/day, which were respectively reduced to 0.35 kgCOD/m3/day and 0.183 kgCOD/m3/day after 30 days of operation. The performance of the SBR was assessed by measuring the COD, BOD and sulphide concentrations after each cycle, among other parameters. It was determined that the optimum operating conditions for the SBR were a 0.35 kgCOD/m3/day organic loading rate with a subsequent HRT of 20 days and a 24 hour cycle period, where the COD, BOD and sulphide removal efficiencies of up to 96%, 98% and 97% respectively were achieved. Results showed that a high organic loading rate inhibited the SBR performance. The sulphide concentration was sufficiently reduced to meet the Environmental Quality (sewage & industrial effluent) Regulations, 1979 under the 3`d schedule Environmental Quality Act, 1974, where the sulphide limit is 0.5 mg/L for both standard A and B.