An evaluation of the re-circulated vertical flow bioreactor to recycle rural greywater for irrigation under arid Mediterranean bioclimate

Increasing demand for conservation of water resources has stimulated greywater (GW) recycling. In rural areas of Jordan, low water consumption, GW quality, and user acceptance are the major obstacles. Low cost and easy to operate modified re-circulated vertical flow bioreactor was evaluated in the Jordan Valley under arid conditions. The treatment system efficiently removed BOD5, COD, PO4, and TSS by up to 97%, 94%, 100%, 90%, respectively. DO was significantly increased by up to 98%. Removal efficiency of NO3, Cl, and SO4 was satisfactory ranging from 19% to 66%, up to 45%, and 55%, respectively. EC and TDS fluctuated considerably with time and quality of untreated GW. TCC and Escherichia coli were considerably reduced by up to 2.5 and 2.3 log, respectively. According to WHO guidelines, treated GW is suitable for irrigation of ornamentals, fruit trees and fodder crops. Removal efficiencies of the treatment system were higher than those of other systems operated in Jordan. The reduction in indicator organisms, however, was not adequate to allow unrestricted reuse of treated GW. Practical disinfection technique can be incorporated into the treatment system. Current treatment system demonstrates great potential for treating low quality GW in rural areas achieving socio-economic and ecological benefits.