Granulation and Biodegradation by Microbial Species in Granular Sequencing Batch Reactor for Soy Sauce Wastewater Treatment

Abstract

At least 80,000 tonnes of the condiments were produced in Malaysia and estimated to increase in volume by 5% by the following year. In addition, one tonne of soy sauce generates about 7–9 tonnes of high strength wastewater. Aerobic granules are known to be regular, smooth, and nearly round in shape with excellent settling ability. They also have dense and strong microbial structure and high biomass retention with the ability to withstand high organic loading. These advantages encouraged recent development of aerobic granulation technology to treat high strength wastewaters such as soy sauce wastewater. Therefore, an efficient Granular Sequencing Batch Reactor (GSBR) treatment system ought to be in place to treat the high strength wastewater. The metagenome sequencing analysis revealed an abundance of microbial diversity accommodating in aerobic granular sludge cultivated with soy sauce wastewater. Existence of 77.52% exopolysaccharides substances (EPS)-producing bacteria such as Pseudomonas and Bacteroides which had the capability in biodegraded waste in wastewater biological treatment were found in aerobic granular sludge. Thus, the performances of aerobic granular sludge in biodegraded organic and nutrient from soy sauce wastewater were in consequence to the bacterial community that occupied in aerobic granules.