Low Temperature Start-up of Coating Wastewater Treatment Works

Abstract

The purpose of this paper was to realize rapid start-up of coating wastewater treatment works under low temperature. Thermal insulation treatment was carried out to the pool wall and pool top of the reactor, heating equipment was arranged to ensure that the reactor can provide appropriate temperature conditions for the inoculated sludge, the amount of influent water was reasonably controlled to ensure that microorganisms have appropriate proportion of nutrient elements, and the effluent water of the reactor was continuously detected and the biophase of the sludge was continuously observed. The practice results showed that the reactor ran stably, and the effluent water met the requirements on quality of washing water and boiler make-up water in Urban Wastewater Reclamation and Reuse Industrial Water Quality (GB/T 19923-2005). The coating wastewater has a complex composition, a high COD content and poor biodegradability (Sun et al., 2009; Zhang and Li, 2009; Dong et al., 2013) as it contains a large amount of residual acrylic resin, amino resin, nitrocellulose film-forming agent, water-soluble dye colorants, brighteners, surfactants and other additives. The present works processed the coating wastewater by adopting a process of coagulation-hydrolytic acidification-contact oxidation-sand filtration-activated carbon adsorption. When the project started, the local maximum temperature was about 0 ˚C and the average temperature was -5 ˚C, which was not suitable for the growth of microorganisms. The present works adopted rock wool covered insulation, electric heating system configuration and other measures to ensure successful start-up of the hydrolytic acidification pond and contact oxidation pond.