Wastewater from the plant is the main source of effluents from USI. According to KSEPB’s effluent runoff discharge permit, effluents that cannot be re-used after treatment and comply with the environmental protection laws and regulations can be discharged to the surface water body—Houjing River. The 2020 water discharge reduced by 14.511Ml over 2019 to 284.858Ml.
Wastewater discharge from the plant includes process wastewater and domestic wastewater from employees. Wastewater is transported to the water treatment plant for treatment via wastewater pipelines. The wastewater treatment system includes the pre-treatment and primary (physical) treatment. Through trash screening, oil removal, sedimentation, and chemical treatment, and the sludge treatment unit for wastewater solid-liquid separation, effluents meet the drainage quality before discharge. In addition, to reduce the environmental impacts of effluents and implement water recycling, apart from following the environmental protection laws and regulations, we purchased the dissolved air flotation system and fiber filtration system in 2018 to enhance wastewater treatment capacity, improve effluent water quality, reduce wastewater discharge, and increase water recycling volume.