Circular water economy: cellulose recovery industry of multilayer packaging

Abstract

Herein it is reported the implementation and start up of a Wastewater Treatment Plant (WWTP) installed in a cellulose recovery company from multilayer packings. Initially, it was verified the treatability of the water sample by an aerobic-anaerobic biological procedure. Based on the obtained results of the initial stage, it was proposed the design, construction, start up and evaluation of the WWTP. It was achieved the total recovery of the treated water (zero discharge) and an economic benefit for the company since the available amount of water was almost enough for the requirements of the company and only a small fraction was purchased to external contractors. These principles fit well with the concept of circular economy and sustainability. The proposed WWTP configuration included the following components: sieving, activated sludges, a secondary sedimentation and a third treatment with sand filters, activated carbon and disinfection of the water. It was attained the following results: 82% of removal of oils and fats, 85% of removal of settleable solids, 70% of removal of suspended solids and 75% of removal of DBO5. Nevertheless, it was necessary the monthly utilization of an inoculum in the biological reactor to avoid the presence of pathogens in the recovered cellulose. The correct operation of the tertiary process is necessary to avoid the presence of pathogens in the recovered cellulose, likewise, zero discharge is obtained by reusing the total treated water, saving approximately 90% of the cost of water per month.