Constructed wetlands as a sustainable technology for wastewater treatment with emphasis on chromium-rich tannery wastewater

• Published in: Journal of hazardous materials 2022-01, Vol.422, p.126926-126926, Article 126926
• Main Authors: Younas, Fazila, Niazi, Nabeel Khan, Bibi, Irshad, Afzal, Muhammad, Hussain, Khalid, Shahid, Muhammad, Aslam, Zubair, Bashir, Safdar, Hussain, Muhammad Mahroz, Bundschuh, Jochen
• Format: Article
• Language: English
• Subjects: Adsorption; Chromium - analysis; Contamination; Ecosystem; Humans; Phytoaccumulation; Technology; Toxicity; UN-Sustainable Development Goals; Waste Disposal, Fluid; Waste Water - analysis; Water; Water Pollutants, Chemical - analysis; Water Purification; Wetlands
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.126926

Water scarcity is a major threat to agriculture and humans due to over abstraction of groundwater, rapid urbanization and improper use in industrial processes. Industrial consumption of water is lower than the abstraction rate, which ultimately produces large amounts of wastewater such as from tannery industry containing high concentration of chromium (Cr). Chromium-contaminated tannery industry wastewater is used for irrigation of food crops, resulting in food safety and public health issues globally. In contrast to conventional treatment technologies, constructed wetlands (CWs) are considered as an eco-friendly technique to treat various types of wastewaters, although their application and potential have not been discussed and elaborated for Cr treatment of tannery wastewater. This review briefly describes Cr occurrence, distribution and speciation in aquatic ecosystems. The significance of wetland plant species, microorganisms, various bedding media and adsorbents have been discussed with a particular emphasis on the removal and detoxification of Cr in CWs. Also, the efficiency of various types of CWs is elaborated for advancing our understanding on Cr removal efficiency and Cr partitioning in various compartments of the CWs. The review covers important aspects to use CWs for treatment of Cr-rich tannery wastewater that are key to meet UN’s Sustainable Development Goals. [Display omitted] •This review elaborates on constructed wetlands (CWs) for Cr-rich wastewater treatment.•Various types of CWs and their performance efficiency are delineated for wastewater treatment.•Key role of wetland plants, microorganisms, bedding media, and adsorbents is elucidated.•Cr partitioning in various compartments of the CWs system is also presented.•Performance of CWs for Cr removal is presented with outlooks to meet UN’s SDGs.