Department of Environmental Science, School of Engineering and Sciences, SRM University-AP, Andhra Pradesh, India.
Department of Mechanical Engineering, Center for Nanofibers and Nanotechnology, National University of Singapore, Singapore, 119260, Singapore.
Chemosphere. 2022 Mar;291(Pt 1):132753. doi: 10.1016/j.chemosphere.2021.132753. Epub 2021 Nov 12.
Wastewater (WW) contains nitrogen (N) and phosphorus (P), where N oxidizes to nitrate followed by denitrification to release N and P is accumulated in sludge. Higher concentrations of N and P leads to eutrophication and algal blooming, thereby threatening the aquatic life systems. Such nutrients could be potentially recovered avoiding the fertilizer requirements. Distinct nutrient recovery systems have been demonstrated including chemical precipitation, ion-exchange, adsorption, bio-electrochemical systems, and biological assimilation at various scales of volumes. This study focusses on the nutrient recovery possibility from wastewater in India. The resource estimation analysis indicates that at 80% recovery, 1 million liters per day (MLD) of sewage can generate 17.3-kg of struvite using chemical precipitation. When compared with traditional fertilizers, nutrient recovery from sewage has the potential to avoid 0.38-Mt/a in imports. Replacing conventional fertilizer with struvite recovered from WW avoids 663.2 kg CO/ha in emissions (53%). Prevailing WW treatment looks at maintaining the discharging standards while recovering nutrients is an advanced option for a self-reliant and sustainable circular economy. However, more detailed assessments are necessary from techno-economic and environmental perspective in realizing these technologies at an industrial scale.
污水（WW）中含有氮（N）和磷（P），其中 N 氧化为硝酸盐，随后反硝化释放 N，而 P 则积累在污泥中。较高浓度的 N 和 P 会导致富营养化和藻类大量繁殖，从而威胁到水生生态系统。这些营养物质可以通过回收利用来避免对化肥的需求。已经证明了多种不同的营养物质回收系统，包括化学沉淀、离子交换、吸附、生物电化学系统和生物同化，这些系统适用于不同规模的体积。本研究重点关注印度从废水中回收营养物质的可能性。资源评估分析表明，在 80%的回收率下，每天处理 100 万升污水可以使用化学沉淀法生成 17.3 公斤鸟粪石。与传统肥料相比，从污水中回收营养物质有潜力避免每年进口 0.38 百万吨。用从 WW 中回收的鸟粪石代替传统肥料，可避免每公顷 663.2 公斤 CO 的排放（53%）。目前的 WW 处理方法着眼于维持排放标准，而回收营养物质是实现自给自足和可持续循环经济的一种高级选择。然而，为了在工业规模上实现这些技术，从技术经济和环境角度进行更详细的评估是必要的。
