The Effect of Glycerol on Microbial Community in Industrial Wastewater Treatment Plant

Abstract

In this paper, we developed and analyzed lab-scale reactors that model the industrial saline wastewater treatment plant (SWWTP) used in North Water SWWTP in Delfzijl, the Netherlands. This industrial wastewater treatment plant is different from a typical municipal wastewater treatment plant, where the wastewater has some recalcitrant chemicals that are hard to degrade and contains a high COD-to-nitrogen ratio and a high concentration of NaCl. The process also differs from other standard industrial wastewater plants, where the anaerobic process precedes the aerobic process. The proposed lab-scale reactors are shown to be stable and able to represent the studied industrial SWWTP where glycerol is present in abundance, and there is no similar lab-scale model that has investigated the effect of glycerol on the process. The removal of COD (glycerol) and nitrogen in the system and the changes in the microbial community in both reactors were followed over time. Based on the data, we were able to study the growth of the microbial population that is present in the sludge. The result of the experiment showed that glycerol and ammonia were completely removed, and some nitrate was left in the effluent. At the end of the experiment, we determined that the order Actinomycetales dominated the anaerobic reactor since it is known as the organisms that use glycerol as the carbon source and is quite tolerant with a high salt concentration in the influent. On the other hand, the order Flavobacteriales dominated the aerobic reactor as it is correlated with the ammonia concentration.