Vol.:(0123456789) 1 3 Environmental Sustainability https://doi.org/10.1007/s42398-020-00124-y REVIEW Removal of nutrients from domestic wastewater using constructed wetlands: assessment of suitable environmental and operational conditions Saroj Kumar 1  · Bhanu Pratap 1  · Divya Dubey 1  · Venkatesh Dutta 1 Received: 9 December 2019 / Revised: 21 August 2020 / Accepted: 3 September 2020 © Society for Environmental Sustainability 2020 Abstract Constructed wetlands (CWs) ofer an eco-friendly wastewater treatment technology primarily for decentralized locations. They support a dense growth of macrophytes which help in the reduction of water velocity, development of conducive micro- environments and provide adherence sites for microorganisms to develop bioflms. Several environmental and operational parameters are crucial for the efcient working of CWs wherein, suitable pH, temperature and dissolved oxygen (DO) are more signifcant. The performance of CWs has been enhanced signifcantly through efuent recirculation and artifcial aera- tion. Removal of phosphorus proceeds via adsorption within media material, sedimentation, cation exchange, precipitation and uptake by macrophytes and the removal of nitrogen occurs mainly by microbial communities and macrophytic uptake. In colder climates, the bioaugmentation of microbial communities is required to increase the treatment efciency. Various previous research fndings showed several aspects of CWs that could potentially afect removal efciency of the nutrients from the wastewater. However, maintaining suitable environmental and operational conditions for the efective operation of CWs remains a challenge. Therefore, the objectives of this review-based study are to provide the most favorable environmental conditions for the efective operation of CWs. Recent developments in operational and working parameters of CWs focusing on the selection of macrophytes and substrate material, carbon source, feeding mode, hydraulic loading rates and retention times are discussed. The study also provides efect of efuent recirculation, bioaugmentation of microbes, suitable C/N ratio and artifcial aeration for the domestic wastewater treatment. Keywords Constructed wetlands · Domestic wastewater · Macrophytes · Sustainability · Treatment efciency Introduction Due to the lack of proper management and efcient treat- ment technology particularly in decentralized and remote locations, the majority of untreated wastewater is discharged directly into nearby water bodies (Kumar and Dutta 2019a,b). These practices cause severe contamination of both surface as well as groundwater. The situation becomes worse with rapid urbanization (Abou-Elela et al. 2017). Var- ious conventional technologies such as membrane bioreac- tors, activated sludge process and membrane separation are applied successfully for the management of domestic waste- water in metropolitan cities. Due to high cost involvement, the use of these technologies is not practical on commercial scale especially in decentralized systems (Zhang et al. 2020). Constructed wetlands (CWs) are man-made ecosystems uti- lized for treatment of several types of wastewater (Kumar and Dutta 2019a; Kumar et al. 2020). These systems are environment friendly, cost-efective, easily operated and maintained and very efective in the removal of wastewater contaminants. Currently, the application of CWs have been stretched globally due to the enhancement in their confgura- tions and operational features and they ofer a more aesthetic * Saroj Kumar sarojbhargava73@gmail.com Bhanu Pratap bhanu791bbau@gmail.com Divya Dubey divyadubey.sai21@gmail.com Venkatesh Dutta dvenks@gmail.com 1 Department of Environmental Science, Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow, India