Purification of River Water Quality Using Precast Porous Concrete Products

Abstract

The effects of porous concrete on water quality improvement in artificial sewage water were examined in the laboratory test. In-situ test using water channel confirmed the purifying function of precast porous concrete products on water quality. Purification practice to improve water quality of an urban river was conducted by placing precast porous concrete products in the river. For the porous concrete used in the tests, two different sizes of coarse aggregate of 5~10, 10~15 mm were used. Three void contents of 20, 25 and 30 percent were designed for the porous concrete. Variation of water quality was observed by the indexes of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total phosphorus (T-P) and total nitrogen (T-N) in the laboratory test and in-situ test. It was found that during the period of 70~170 days since the experiment started, void content of porous concrete did not influence the purifying ratio of TOC in sewage, while the purifying ratio of TOC in laboratory by porous concrete changed to around 60 to 80 percent. The purifying ratio of T-P in laboratory was about 20~40 percent, whereas river water purification test showed a higher purifying ratio of T-P. It was found that BOD, COD of the river water decreased about 30 to 60 percent by placing porous concrete products in the river.