Fidelis Odedishemi Ajibade1, Hong-Cheng Wang2, Awoke Guadie3, Temitope Fausat Ajibade4, Ying-Ke Fang5, Hafiz Muhammad Adeel Sharif6, Wen-Zong Liu2, Ai-Jie Wang7. 1. Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Department of Civil and Environmental Engineering, Federal University of Technology Akure, PMB 704, Nigeria. 2. School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China. 3. Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; Department of Biology, College of Natural Sciences, Arba Minch University, Arba Minch 21, Ethiopia. 4. University of Chinese Academy of Sciences, Beijing 100049, PR China; Department of Civil and Environmental Engineering, Federal University of Technology Akure, PMB 704, Nigeria; Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China. 5. Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. 6. Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. 7. Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, PR China. Electronic address: ajwang@rcees.ac.cn.
Abstract
Biochar was utilized to intensify constructed wetland (CW) for further organic and nitrogen removal from secondary wastewater. Four sets of non-aerated biochar amended vertical flow CW (VFCW) were developed to investigate the synergistic effects of biochar and microbes on pollutant removal. Results showed that the average COD and nitrogen removal efficiencies of VFCW1 (with 1% w/w biochar with microbe and plants) achieved 89.1 ± 5.6% and 90.2 ± 3.1% respectively, and their corresponding removal rates of 10.2 ± 0.8 mg-COD/(m3.d) and 3.57 ± 0.3 mg-TN/(m3.d) which were 35 and 52.3% higher than control. The biochar's dissolved organic carbon release in VFCWs indicated that water and acidic media portray the optimum conditions for nitrogen removal. The 16S RNA gene sequencing analysis indicated that in the biochar-amended VFCWs, bacterial phylum Proteobacteria (24.13-51.95%) followed by Chloroflexi (5.64-25.01%), Planctomycetes (8.48-14.43%), Acidobacteria (2.29-11.65%) were abundantly enhanced. Conclusively, incorporating biochar in non-aerated VFCWs is an efficient technique for enhancing nitrogen removal from secondary effluent.
Biochar was utilized to intensify constructed wetland (CW) for further organic and nitrogen removal from secondary wasten class="Chemical">water. Four sets of non-aerated biochar amended vertical flow CW (VFCW) were developed to investigate the synergistic effects of biochar and microbes on pollutant removal. Results showed that the average COD and nitrogen removal efficiencies of VFCW1 (with 1% w/w biochar with microbe and plants) achieved 89.1 ± 5.6% and 90.2 ± 3.1% respectively, and their corresponding removal rates of 10.2 ± 0.8 mg-COD/(m3.d) and 3.57 ± 0.3 mg-TN/(m3.d) which were 35 and 52.3% higher than control. The biochar's dissolved organic carbon release in VFCWs indicated that water and acidic media portray the optimum conditions for nitrogen removal. The 16S RNA gene sequencing analysis indicated that in the biochar-amended VFCWs, bacterial phylum Proteobacteria (24.13-51.95%) followed by Chloroflexi (5.64-25.01%), Planctomycetes (8.48-14.43%), Acidobacteria (2.29-11.65%) were abundantly enhanced. Conclusively, incorporating biochar in non-aerated VFCWs is an efficient technique for enhancing nitrogen removal from secondary effluent.