Quantitative and qualitative characteristics of grey water for reuse requirements and treatment alternatives: the case of Jordan

The objective of this work is to assess the potentials and requirements for grey water reuse in Jordan. The results revealed that urban, rural and dormitory grey water production rate and concentration of TS, BOD₅, COD and pathogens varied between 18–66 L cap⁻¹d⁻¹, 848–1,919, 200–1,056, and 560–2,568 mg L⁻¹ and 6.9E2–2.7E5 CFU mL⁻¹, respectively. The grey water compromises 64 to 85% of the total water flow in the rural and urban areas. Storing grey water is inevitable to meet reuse requirements in terms of volume and timing. All the studied grey waters need treatment, in terms of solids, BOD₅, COD and pathogens, before storage and reuse. Storage and physical treatment, as a pretreatment step should be avoided, since it produces unstable effluents and non-stabilized sludge. However, extensive biological treatment can combine storage and physical treatments. Furthermore, a batch-fed biological treatment system combining anaerobic and aerobic processes copes with the fluctuations in the hydrographs and pollutographs as well as the present nutrients. The inorganic content of grey water in Jordan is about drinking water quality and does not need treatment. Moreover, the grey water SAR values were 3–7, revealing that the concentrations of monovalent and divalent cations comply with agricultural demand in Jordan. The observed patterns in the hydrographs and pollutographs showed that the hydraulic load could be used for the design of both physical and biological treatment units for dormitories and hotels. For family houses the hydraulic load was identified as the key design parameter for physical treatment units and the organic load is the key design parameter for biological treatment units.