A Study on the Treatment of Construction Wastewater Using Multi-Stage Settlement

Wastewater generated from tunnel excavation and construction site is constantly generating complaints and disputes due to environmental pollution problem caused by turbid water in a river near a construction site. Therefore, there is a lot of research on the processing method. In this study, a continuous multistage (3-stage) flocculation and precipitation reactor was developed to treat the construction wastewater with high concentration of suspended solids and strong alkalinity. This R & D technology can carry out mixing, coagulation, sedimentation and concentration in one reaction tank. And has a high response to the deterioration of the wastewater which is continuously changing. This technology is an economical and efficient technology for treating construction wastewater without the need for a separate sewer facility. In order to verify the performance of the equipment, we collected and analyzed the actual construction waste water. As a result, SS 88.31%, Turbidity 81.14% and CODcr 54.17% were removed. Therefore, it is expected that the use of this technology will reduce water treatment costs and increase treatment efficiency. This technology can reduce the facility cost and the required site area compared to the existing coagulation sedimentation technology. It is also possible to remove suspended matters with high efficiency without using coagulant and coagulant.