Algal pathway towards meeting United Nation’s sustainable development goal 6
H.M.K. Delanka-Pedige, S.P. Munasinghe-Arachchige, I.S.A. Abeysiriwardana-Arachchige, Yanyan Zhang, Nagamany Nirmalakhandan
Abstract
Recent reports have pointed out that, at the current rate of development, the world will fail to meet Goal 6 of the United Nation’s 17 Sustainable Development Goals (SDGs) to ensure the availability of sanitation and water for all. Over half the world’s population in the middle- and low-income countries will not have sanitation and water with sufficient quality and quantity due to limited financial and freshwater resources. An algal-based wastewater treatment (A-WWT) system is proposed here as an appropriate and affordable pathway to support SDG 6 as well as 11 other related SDGs. Our previous reports on this A-WWT system have documented its ability to produce discharge-ready water, comparable in quality to that of the conventional activated sludge-based (CAS) system, but at lower initial cost and lower energy needs. In the current study, we demonstrate that activated carbon adsorption and ozonation are potential follow-up processes to reclaim high-quality water for beneficial reuse. The quality of water reclaimed by the A-WWT system is shown to be superior to what is currently possible with the CAS system. Microbial assessments and Microtox toxicity assays confirm that the reclaimed water from the A-WWT system is safe for agricultural reuse. The A-WWT system holds promise as a greener alternative to meet the four targets under SDG 6: improving water quality, wastewater treatment, and safe reuse; increasing water-use efficiency and ensuring freshwater supplies; implementing water reuse management; and protecting and restoring water-related ecosystems.