PMID: 19927825Nov 26, 2009Paper

Characteristic of sludge thermal hydrolysis using microwave heating with alkali addition

Huan jing ke xue= Huanjing kexue
Wei QiaoZhongzhi Zhang

Abstract

NaOH was added into sludge to improve thermal hydrolysis when heated with microwave irradiation. Volatile suspended solid (VSS) rapidly dissolved into aqueous phase when adding 0.1 g NaOH per gram into suspended solid (SS) of sludge. More than 60% of VSS solubilized at 170 degrees C, and VSS to SS ratio of treated sludge reduced to 25%. For 5 min treatment, soluble COD (SCOD) in treated sludge liquid phase was 9.8, 12.8, 15.1, and 14.5 g/L respectively at 80, 120, 150 and 170 degrees C. Accordingly, the SCOD to TCOD (total COD) ratio was 24.0%, 31.3%, 36.9% and 35.6%. The pH of the microwave heated sludge decreased with higher temperature and longer hydrolysis time, while the finale pH of different testes were still higher than 10.5. Alkali dose effect on organic matters dissolving was analyzed at the range of 0-0.2 g NaOH into per gram SS. Results showed that when alkali dose was above 0.05 g, the rapid dissolving trend became level for VSS and SS. BMP (biochemical methane potential) test was used to investigate treated sludge digestibility at NaOH dose of 0.05 g with 5 min microwave heating at set temperature and 0.1 g with 1 min heating. Results showed that adding 0.05 g NaOH improved sludge anaerobic digestion, the biogas p...Continue Reading

Related Concepts

Related Feeds

Biofuels (ASM)

Biofuels are produced through contemporary processes from biomass rather than geological processes involved in fossil fuel formation. Examples include biodiesel, green diesel, biogas, etc. Discover the latest research on biofuels in this feed.

Bioremediation (ASM)

Bioremediation is the treatment and removal of harmful pollutants or contaminants through the use of microorganisms. Discover the latest research here.