Decentralized Methods of Water Treatment for Reuse of Residential Gray Water

Abstract

Water shortages continue to cause negative economic, environmental, and social effects. This could be partially solved by reducing residential water consumption. This could be achieved by recycling graywater through an on-site graywater recycling system. Such a system would need to treat graywater to meet local water quality standards, be able to treat the graywater load from a typical home, be compact enough to fit in or near a home, and be relatively affordable. Three systems intended to treat residential graywater were examined: a drawer compacted sand filter, a semi-batch vertical flow wetland, and a moving bed biofilm membrane bioreactor. After an analysis of the three solutions, the semi-batch vertical flow wetland was recognized as the best graywater recycling system to use in residential buildings. This system produced treated graywater with the highest water quality and that contained no detectable escherichia coli. This system also was compact, and could process the highest amount of graywater. If successful, this system could help residential graywater recycling become more common and therefore reduce residential water consumption. This could help reduce the severity of water shortages and the negative effects associated with them.