Emir. J. Food Agric ● Vol 34 ● Issue 9 ● 2022 731 Moving Bed Bioflm Reactor (MBBR) for decentralized grey water treatment: Technical, ecological and cost effciency comparison for domestic applications Naeema Al Hosani 1 , Eihab Fathelrahman 2 *, Hamza Ahmed 3 , Elfatih Rikabi 4 1 Department of Geography and Urban Sustainability, College of Humanities and Social Sciences, United Arab Emirates University, Al Ain, UAE P.O. Box 15551, 2 Department of Integrative Agriculture, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain, UAE, POBOX 15551, 3 Department of Systems Engineering, Colorado State University, Engineering Building 202, 6029 Campus Delivery, Fort Collins, Colorado, U.S. 80523-6029, 4 Landmark Landscaping, Dubai, United Arab Emirates, P.O. Box 25030 *Corresponding author: Eihab Fathelrahman Department of Integrative Agriculture, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain, UAE, POBOX 15551. E-mail: eihab.fathelrahman@uaeu.ac.ae Received: 02 November 2021; Accepted: 22 March 2022 BACKGROUND The United Nations Educational, Scientifc, and Cultural Organization (UNESCO) declared that the earth’s freshwater resources could meet the water needs of the world’s expanding population if managed effectively and sustainably. However, water scarcity and water quality degradation are considerable challenges. Water quality degradation is the greatest threat to the health of ecosystems and people all over the planet which requires prompting immediate action to maintain the health of our ecosystems (Connor, 2015). The defnition of various qualities of water levels or water footprints is classifed into green water, blue water, greywater, and blackwater. Green water is the water from precipitation stored in the soil root zone that has evaporated, transpired, or been incorporated by plants. It is particularly relevant for horticultural, agricultural, and forestry products. Bluewater is water sourced from surface or groundwater resources and is either evaporated, incorporated into a product, taken from one water body, returned to another water body, or returned at a different time. Bluewater is relevant for domestic, industry, and irrigated agriculture purposes (Fig. 1). Greywater is wastewater generated in households or offce buildings and commercial sites from streams without fecal contamination. Greywater is generally wastewater from showers, baths, basins, and washing machines and shows promising results for water reuse and recycling. In the sanitation context, blackwater is the wastewater from toilets, which likely contains pathogens. Blackwater can contain feces, The reuse of greywater has several advantages, including reduced freshwater extraction from rivers, aquifers, and groundwater; reduced need for desalination; less environmental impact from septic tanks and water treatment plants; decreased energy consumption; and reduced chemical pollution. The main objectives of this review study are to assess the technical attributes, ecological impacts, and cost-effciency of Moving Bed Bioflm Reactor (MBBR) water treatment technology compared to similar available technology for small to medium-sized, decentralized applications in residential and commercial settings such as home gardening, sanitation, and landflls. Previous studies indicate that hybrid technologies such as MBBR are the most promising methods for the total removal of contaminants in wastewater in a decentralized setting. However, the initial capital cost of this technology for small and medium-scale domestic applications worldwide is high and so is a limiting factor in the expansion of its utilization. Expansion of domestic use of such Decentralized Wastewater Treatment Systems (DWTS) could increase the economies of scale and therefore reduce the initial capital costs for this useful water treatment. For the MBBR system, Chemical Oxygen Demand (COD) removal effciency was found to be 70%, Total Suspended Solids (TSS) removal was found to be 97%, and turbidity removal was 98%. Keywords: Water Treatment; Moving Bed Bioflm Reactor (MBBR); Decentralized, Technical; Ecological; Effciency; Cost; Gardening, Domestic Reuse; Membrane Bioreactor (MBR) Emirates Journal of Food and Agriculture. 2022. 34(9): 731-742 doi: 10.9755/ejfa.2022.v34.i9.2848 http://www.ejfa.me/ ABSTRACT RESEARCH ARTICLE