Characterization and treatment of grey water : option for (re)use

Addressing the issues of water shortage and appropriate sanitation in Jordan, domestic grey water treatment receives growing interest. Grey water comprises the domestic wastewater flows excluding waters associated with the toilet. The topics of concern for grey water are its characteristics, treatment and potentials for use after treatment. The target of this thesis is to develop a concept for treating grey water on-site for agricultural usage, thus sustaining a recycling process of grey water in Jordan. A review was made regarding the currently available grey water treatment technologies. In addition, grey water was quantitatively and qualitatively characterized, and then grey water reuse requirements including treatment, were analyzed. Biodegradability and biodegradation rates of the grey water were investigated for selecting appropriate design and operation criteria of the treatment technology to be developed. A low-tech semi-technical scale treatment system was tested to treat grey water discharges from a dormitory at the Jordan University campus. The treatment system was evaluated on obtained removal efficiencies and conformity of the effluent to the guidelines for the use of reclaimed water for irrigation in Jordan. Finally, the objectives, approaches and the results of each chapter are summarized, and then both the results and the potential of applying decentralised sanitation and reuse (DeSaR) concepts in Jordan are discussed. Results show that storage and treatment are prerequisites for any type of grey water use. Grey water is aerobically and anaerobically biodegradable but the conversion rates are low. The core of the treatment concept consists of an integrated storage and anaerobic treatment unit, fed with a natural influent flow pattern, in a down-flow mode, up to a one day operational cycle, i.e. a variable HRT ≤ 24 hours. The second step consists of an aerobic post-treatment, mechanically aerated in a down-flow mode and a one day operational cycle, i.e. 24 hours HRT. Both units need insulation in the winter period. The final effluent, stable in winter and summer, meets the Jordanian standard, except for the pathogens, for usage in restricted irrigation. The achievable treatment efficiency for the CODtot is 44% in the anaerobic unit and 70% in the combined anaerobic-aerobic, unlike the high anaerobic and aerobic biodegradability in batch experiments, viz. 70 and 86%, respectively. The highest removal efficiency achieved was for the CODss fraction, viz. 71% in the anaerobic and 85% in the combined system. Therefore, it is expected that the CODtot removal efficiency of the system can be improved, by enhancing the CODcol and CODdis, removal, i.e. applying filtration and/or adding chemicals such as adsorbents, coagulants and/or flocculants to the treatment units. <br/

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(-1) d(-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

Grey water treatment systems: A review

This review aims to discern a treatment for grey water by examining grey water characteristics, reuse standards, technology performance and costs. The review reveals that the systems for treating grey water, whatever its quality, should consist of processes that are able to trap pollutants with a small particle size and convert organic matter to mineralized compounds. For efficient, simple and affordable treatment of grey water with safe effluent reuse, a combined anaerobic-aerobic process is recommended, with disinfection being an optional step. The removal and subsequent conversion of suspended and colloidal particles in the anaerobic process need further improvement. Furthermore, the reuse standards should be revised and classified considering the reuse options and requirements

Grey water treatment systems: A review

This review aims to discern a treatment for grey water by examining grey water characteristics, reuse standards, technology performance and costs. The review reveals that the systems for treating grey water, whatever its quality, should consist of processes that are able to trap pollutants with a small particle size and convert organic matter to mineralized compounds. For efficient, simple and affordable treatment of grey water with safe effluent reuse, a combined anaerobic-aerobic process is recommended, with disinfection being an optional step. The removal and subsequent conversion of suspended and colloidal particles in the anaerobic process need further improvement. Furthermore, the reuse standards should be revised and classified considering the reuse options and requirements

Grey water treatment in a series anaerobic – Aerobic system for irrigation

This study aims at treatment of grey water for irrigation, focusing on a treatment technology that is robust, simple to operate and with minimum energy consumption. The result is an optimized system consisting of an anaerobic unit operated in upflow mode, with a 1 day operational cycle, a constant effluent flow rate and varying liquid volume. Subsequent aerobic step is equipped with mechanical aeration and the system is insulated for sustaining winter conditions. The COD removal achieved by the anaerobic and aerobic units in summer and winter are 45%, 39% and 53%, 64%, respectively. Sludge in the anaerobic and aerobic reactor has a concentration of 168 and 8 mg VS L-1, respectively. Stability of sludge in the anaerobic and aerobic reactors is 80% and 93%, respectively, based on COD. Aerobic effluent quality, except for pathogens, agrees with the proposed irrigation water quality guidelines for reclaimed water in Jordan

Grey water treatment in a series anaerobic – Aerobic system for irrigation

This study aims at treatment of grey water for irrigation, focusing on a treatment technology that is robust, simple to operate and with minimum energy consumption. The result is an optimized system consisting of an anaerobic unit operated in upflow mode, with a 1 day operational cycle, a constant effluent flow rate and varying liquid volume. Subsequent aerobic step is equipped with mechanical aeration and the system is insulated for sustaining winter conditions. The COD removal achieved by the anaerobic and aerobic units in summer and winter are 45%, 39% and 53%, 64%, respectively. Sludge in the anaerobic and aerobic reactor has a concentration of 168 and 8 mg VS L-1, respectively. Stability of sludge in the anaerobic and aerobic reactors is 80% and 93%, respectively, based on COD. Aerobic effluent quality, except for pathogens, agrees with the proposed irrigation water quality guidelines for reclaimed water in Jordan

Anaerobic treatment as a core technology for energy, nutrients and water from source-separated domestic waste(water)

Based on results of pilot scale research with source-separated black water (BW) and grey water (GW), a new sanitation concept is proposed. BW and GW are both treated in a UASB (-septic tank) for recovery of CH4 gas. Kitchen waste is added to the anaerobic BW treatment for doubling the biogas production. Post-treatment of the effluent is providing recovery of phosphorus and removal of remaining COD and nitrogen. The total energy saving of the new sanitation concept amounts to 200 MJ/year in comparison with conventional sanitation, moreover 0.14 kg P/p/year and 90 litres of potential reusable water are produce

Anaerobic treatment as a core technology for energy, nutrients and water from source-separated domestic waste(water)

Based on results of pilot scale research with source-separated black water (BW) and grey water (GW), a new sanitation concept is proposed. BW and GW are both treated in a UASB (-septic tank) for recovery of CH4 gas. Kitchen waste is added to the anaerobic BW treatment for doubling the biogas production. Post-treatment of the effluent is providing recovery of phosphorus and removal of remaining COD and nitrogen. The total energy saving of the new sanitation concept amounts to 200 MJ/year in comparison with conventional sanitation, moreover 0.14 kg P/p/year and 90 litres of potential reusable water are produce