Department of Civil Engineering, Jamia Millia Islamia (A Central University), New Delhi, 110025, India.
Department of Life Science, Institute of Information Management and Technology, Aligarh, India.
Chemosphere. 2021 Aug;277:130328. doi: 10.1016/j.chemosphere.2021.130328. Epub 2021 Mar 18.
Water scarcity and its pollution has become a concern in recent times. The disposal of nutrient-rich (nitrogen and phosphorous) wastewater is also one of the main cause of water pollution through eutrophication, reduced dissolved oxygen that poses threat to aquatic ecosystems. As a result, nutrient removal has become a mandate apart from the removal of organics. However, the removal of nutrients from sewage is a challenging task. Conversely, conventional biological treatment processes provide little relief in nutrient removal. The treated effluents from conventional biological processes do not achieve the stringent nutrient removal disposal standard limits and become primary cause of pollution in the receiving water bodies. This has stressed upon the need for eco-friendly, low-energy and cost-efficient nutrient removal treatment technologies. Various biological treatment combinations or variants are in use for the efficient removal of nutrients. The biological processes in itself or in combination with chemical processes are preferred over technologies based solely on physico-chemical processes for its treatment performance at lower cost. This review summarizes the existing treatment processes and their possible up-gradation with the aim to accomplish the marked effluent standards for the nutrients. The concept of conventional systems and advanced systems for nutrients (nitrogen and phosphorous) removal which are already developed or under development are deeply discussed. Further, the challenges of each treatment systems are abridged. Finally, the possible suggestions for the modification/retrofitting of existing treatment systems for achieving stringent disposal standards are pointed out.
水资源短缺及其污染问题近来备受关注。富营养化（氮和磷）废水的处理也是水污染的主要原因之一，它会降低水中的溶解氧，从而对水生态系统造成威胁。因此，除了去除有机物外，去除营养物质也成为了一项强制性要求。然而，从污水中去除营养物质是一项具有挑战性的任务。相反，传统的生物处理工艺在去除营养物质方面收效甚微。传统生物处理工艺产生的处理后的废水无法达到严格的营养物质去除排放标准，反而成为受纳水体污染的主要原因。这就强调了需要开发环保、低能耗和具有成本效益的营养物质去除处理技术。为了高效去除营养物质，各种生物处理组合或变体正在被应用。生物处理工艺本身或与化学处理工艺相结合，优于仅基于物理化学处理工艺的技术，因为前者在较低成本下具有更好的处理性能。本综述总结了现有的处理工艺及其可能的升级，旨在达到标记的营养物质排放标准。深入讨论了已经开发或正在开发的常规系统和先进系统（氮和磷）去除营养物质的概念。此外，还概述了每个处理系统的挑战。最后，针对达到严格处理标准，提出了对现有处理系统进行修改/改造的可能建议。
