Anaerobic Fluidized Membrane Bioreactor for Steel-Making Cold-Rolling Wastewater Treatment

Abstract

With the increasing concern of water protection wastewater treatment of industrial or domestic is more and more important Nowadays the treatment technology is efficient enough Additionally due to more attention on energy restricted and global warming treatment process which saves more energy or even creates energy is proposed to replace the traditional process In wastewater treatment aspect anaerobic fluidized membrane bioreactor (AFMBR) has been proposed to treat domestic wastewater However AFMBR utilized in industrial wastewater has not been understood completely In this study an AFMBR pilot treating steeling making cold-rolling wastewater was investigated Also several batch tests and molecular biotechnology were seen as comparison of the pilot There were three periods for AFMBR operation The first period is from day 0 to day 155 before second time inoculation The second period is from day 155 to 218 with MLSS control The last period is steady operation after 218 day The adsorption effect of granular activated carbon (GAC) on cold-rolling wastewater indicated that 6 7 mg-TOC could be adsorbed by 1 g of GAC and the GAC in pilot would be saturated in 16 days The bio-methane potential (BMP) batch test and result of gas production for AFMBR pilot both showed that methane wasn’t produced before second time inoculation but detectable methane appeared after second time inoculation Besides the batch results also showed that the performance of GAC in producing methane and COD removal is better than the performance of sludge However decrease of COD concentration in the beginning is caused by GAC adsorption rather than microorganism degradation The COD and TOC removal efficiency of AFMBR pilot are 90% and 91% when HRT of pilot is 2 3 days OLR of pilot is 0 38 kg COD/m3/d Methane yield of AFMBR pilot is 0 064 L CH4/g CODremoved with 16 8% methane recovery efficiency Average 10 L of methane and 4 L of CO2 can be produced from AFMBR pilot per day The MLSS and MLVSS concentration in AFMBR pilot might affect transmembrane pressure (TMP) Thus MLSS concentration should be lower than 1500 mg/L in order to maintain TMP The t-RFLP results of GAC and sludge are different For GAC methanosaeta is majority no matter before or after second time inoculation Besides other methanogens appeared after second time inoculation such as methanosarcina and methanomethylovorans For sludge after second time inoculation ratio of methanomethylovorans and methanosarcina decreased with increase ratio of methanosaeta However ratio of methanosaeta started to decrease with ratio of other methanogens and unknown increase

Date of Award	2016 Aug 18
Original language	English
Supervisor	Liang-Ming Whang (Supervisor)