气候变化领域集成服务门户

The search for sustainable and effective water reclamation technologies has been stimulated by increasingly urgent water scarcity. Graywater (GW) is an excellent potential resource for relieving the water scarcity problem because it has a relatively low pollution level and because it is abundant and accessible. GW makes up approximately 70% of domestic wastewater. A new technology, shredded tire biofilter (STB), combined with a membrane bioreactor (MBR), was demonstrated to be an efficient method for treating GW to a level that satisfies the USEPA's water reuse guidelines. In the proposed technology, the MBR ensured adequate effluent water quality, and the STB pretreated the GW. The technology may significantly reduce the energy required to treat GW by MBRs alone. It was further observed that increasing hydraulic retention time and decreasing shredded tire particle size enhanced the removal of BOD5 in the STBs. Analysis of biofilms on shredded tire chips showed that microorganisms could attach and grow on tire shreds. Moreover, this combination would be economically feasible and environmentally sustainable for an average household (i.e.,three to four people), making it a potentially promising technology for decentralized wastewater treatment.