A field test of car washing using harvested rainwater in the parking lot
ZHANG Yan-Juan1, XU Xiang-Zhou1, SHU Li-Ming2, LIU Lu1
1. School of Hydraulic Engineering, Dalian University of Technology,116024, Dalian, Liaoning, China;
2. Faculty of Chemical Environmental and Biological Science and Technology, Dalian University of Technology, 116024, Dalian, Liaoning, China
Abstract Application of rainwater harvesting technology in parking lot can increase the comprehensive benefits of rainwater and promote the harmonious development of human, car, and environment. We design a car washing system with a rainwater collecting device according to the rainfall characteristics in urban China, and then carry out a field test in the study area. The results are as follows. 1) The device is convenient and observable, and can dispose rainwater into high quality water. Water supply from the device is also continuous, for tap-water can be auto-added if stored rainwater is insufficient. The amount of collected and consumed water can be quantitatively observed. People can spray rainwater to the car with airbrush, and wash towels with hands in tap-water. Hence they should not directly touch the collected rainwater. 2) It was observed in this experiment that the volume of water needed for washing a car was 58 L while sewage was not reused. However, generally 55 L of water per car would be enough in the commercial business. 3) The filters significantly affect the turbidity and concentration of the suspended substance in the rainwater, but hardly have any effects on COD, TP, TN, etc. Moreover, the bag-styled filter is more effective than the U-shaped filter. 4) Nevertheless, the amount of collected rainfall is only 15.1% of the total collectible runoff in the study area. More rainfall could be utilized if the device were improved. As a result, the device is easy to use and can efficiently improve the quality of collected rainwater. Thus, it can be widely applied in the future.
ZHANG Yan-Juan,XU Xiang-Zhou,SHU Li-Ming, et al. A field test of car washing using harvested rainwater in the parking lot[J]. SSWCC, 2014, 12(1): 109-113.
