Design Aspects, Energy Consumption Evaluation, and Offset for Drinking Water Treatment Operation

Conceptual Design of a Compact Water Purification Unit Using Reed Bed Filtration

One of the most widespread global challenges is the insufficient provision of potable water, which affects individuals across diverse geographical regions. It is anticipated that issues related to water scarcity and quality will escalate in tandem with the expanding human population and the rapid pace of global development. Water sources are massively polluted hence, not safe for drinking nor irrigation. As a consequence, it is very important to have a water purification treatment plant to provide good water quality. Given the pressing need to ensure universal access to safe and clean drinking water, this investigation aims to engineer a compact and space-efficient apparatus that can expeditiously produce purified water. The proposed system seeks to optimize water purification performance while minimizing spatial requirements and operational duration. Its size is minimized by combining the three processes: coagulation, flocculation, and clarification together in one tank. Following to the aforementioned reservoir, an integrated natural system is employed to reduce the usage of chemicals and establish an ecologically sustainable platform. A hydraulic study is conducted to obtain the dimensioning of the several units which can be later scaled according to the flowrate. The latter was assumed in this study to be 2 L/s, then the compact unit can serve up to 800 persons by scaling the model and adjusting it.

Water–Energy–Carbon Nexus Analysis for Water Supply Systems with Brackish Groundwater Sources in Arid Regions

Limited knowledge on the water–energy–carbon nexus of water supply systems (WSSs) with brackish groundwater sources in arid regions exists to date. In addition, the large amount of fossil-fuel energy utilized by treatment processes generating a significant amount of carbon emissions remains a challenge for the municipalities in Saudi Arabia to meet long-term sustainability goals. To achieve Saudi Arabia Vision 2030’s target of sustainable cities with reduced CO2 emissions, the present study aimed to analyse the water–energy–carbon nexus for WSSs and propose mitigation measures for reducing energy and carbon footprints from both the water management and treatment technologies perspectives. The detailed energy consumption data for three main components (source extraction, water treatment, and conveyance and distribution) of the main WSS, serving the 600,000 population of Buraydah City (Qassim, Saudi Arabia), was obtained from the concerned municipality. The city water treatment plant removes naturally occurring iron, TDS, and radionuclides in the source water with the help of ion detention, oxidation, sand filtration, ultrafiltration, reverse osmosis, chlorination, and backwash water management. The study found that the treatment facility consumes around half of the total system’s energy (131,122 kWh/day); while, with deep confined aquifer (>600 m) and an average water loss of 8%, conveyance and distribution (34%) and source extraction (18%) are consistent with the reported literature. With oil-driven energy, carbon emissions were found to be 10.26, 27.18, and 19.72 million tons CO2 eq/year for source extraction, water treatment, and conveyance and distribution, respectively. The reverse osmosis process, with higher energy consumption—1.1 kWh/m3 of treated water—than the global average, consumes most (88%) of the treatment plant’s energy and thus needs effective energy management practices. Moving to renewable (solar and wind-driven) sources, subject to a detailed life cycle analysis, can achieve significant energy and associated carbon emission reductions. To sustainably meet the water demand of the growing population in arid regions, the study also suggests raising the awareness of the public about how water conservation can control CO2 emissions, proactive maintenance of aging infrastructure, and increasing rainwater and treated wastewater reuse, to enhance the operational life of existing treatment facilities.