Sustainable Water Management with Design and Economic Evaluation of Recycling Greywater at Abu Dhabi University—A Case Study on Decentralization

Abstract

Wastewater can be segregated as greywater and blackwater separately. The greywater generated in malls, restaurants, and university buildings is generally dilute, while it will later become concentrated when it is merged into the main sewage collection line. It would be more economical and environmentally friendly if the greywater is treated locally using a modular wastewater treatment facility that produces treated water amenable for other uses such as irrigation or horticulture. The objective of this article is to study the economic feasibility and design a decentralized plant that produces fresh water from greywater generated at the Abu Dhabi university campus located in the United Arab Emirates. The proposed unit will consist of a compact design of filtration, chemical treatment and disinfection processes that would generate treated wastewater that can be used for horticulture in and around the local campus or can be stored and supplied for irrigation purposes. Several parameters such as total suspended solids, biological oxygen demand, and chemical oxygen demand are measured and monitored throughout the entire process and are regulated by appropriate operations performed for each unit. This study shows that decentralization of greywater treatment is not only economical but also essential for the management of fresh water, which in turn assures environmental sustainability. By using coagulation, flocculation and chlorination with a 30 mg/L alum dosage, 0.6 mg/L of polyacrylamide and 0.12 mg/L of sodium hypochlorite, respectively, greywater is treated to meet the water specification for reusing it for horticulture. Further, a modular plant with an investment of USD 8 M is proved to process 90,000 tons of greywater with a 34% discounted rate of return.

Corporate Social Responsibility (CSR) and Sustainability in Water Supply: A Systematic Review

“…Part of the water stewardship mission is to use water in ways that make it socially equitable. Living in areas that experience severe water scarcity is usually associated with social problems such as poverty [72,83,102]. Building reservoirs enhances equitable water distribution by enabling low-income populations to access safe drinking water for domestic purposes.…”

“…Building reservoirs enhances equitable water distribution by enabling low-income populations to access safe drinking water for domestic purposes. The reservoirs may also help local communities to minimize various health challenges associated with water scarcity [90,98,99,102]. CSR initiatives have also been significant tools for educating local communities about water conservation and waste reduction.…”

“…Nearly 40% of the current water scarcity problems can be attributed to climate change effects, including prolonged droughts, flooding, and poor rainfall patterns. The Peruvian "Water Security and Climate Change Adaptation Project" is addressing the challenge by converting the glacier-fed river basins into sustainable water sources [2,98,102]. This project has won the support of local communities that are assisting government agencies and corporations to identify glaciers that have been swept down to the river basins and convert them into dams [2,98,103].…”

“…For sustainable water supply, companies need to begin with reducing their water consumption and enhancing efficiency in their operations. Companies that need huge volumes of water in their operations have to create alternative sources to minimize pressure on the nearby rivers and lakes [83,102]. Reducing water consumption should be part of an organization's short-term objectives to become leaner and less susceptible to environmental challenges [102].…”

“…Companies that need huge volumes of water in their operations have to create alternative sources to minimize pressure on the nearby rivers and lakes [83,102]. Reducing water consumption should be part of an organization's short-term objectives to become leaner and less susceptible to environmental challenges [102]. Responsible supply chains also encourage other organizations to improve their business practices and minimize pollution [11,29,93].…”