Corncob biocarriers with available carbon release for Chlamydopodium sp. microalgae towards enhanced nitrogen removal from low C/N rare earth element tailings (REEs) wastewater. (November 2022)

• Record Type: Journal Article
• Authors: Xiong, Zhensheng; Lai, Ling; Ding, Yanyan; Yang, Liming; Geng, Yanni; Pavlostathis, Spyros G.; Shao, Penghui; Zhang, Yakun; Luo, Xubiao
• Is Part Of: Chemosphere. Volume 307:Part 1(2022)
• Publication Date: 2022-11
• Subjects: Biocarrier -- Microalgae -- Immobilization -- Ammonia nitrogen -- Mining wastewater; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135673
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Low nitrogen (N) removal efficiency limits the potential of microalgae technology for the treatment of high nitrogen and low carbon rare earth tailings (REEs) wastewater. In this study, waste corncob was utilized as a biocarrier immobilizing Chlamydopodium sp. microalgae to realize high-efficient treatment of the REEs wastewater. In only 2.5 d, corncob-immobilized microalgae allowed the residual concentrations of N lower than the emission standards, and ammonia nitrogen (NH4 + -N) removal rate is 83.3 mg L −1 ·d −1, total inorganic nitrogen (TIN) removal rate is 86.7 mg L −1 ·d −1, which was 18.5 times that of the previously-reported microalgae (4.68 mg L −1 ·d −1 ). Compared with other microalgae immobilization carriers, corncob possesses the ability to release available carbon sources for microalgae. Composition analysis and sugar verification experiments showed that the main content of TOC released by corncob was monosaccharide, and in a certain range, the removal rate of N was positively correlated with the TOC concentration. The utilization of biomass wastes with dual functions as biological carriers has great potential to improve the performance of microalgae, and is conducive to the development of engineering applications. Graphical abstract: Image 1 Highlights: Rapid removal of NH4 + -N and TIN by microalgae was achieved in REEs wastewater. The removal efficiency of TIN can reach 100%, and rate can reach 86.7 mg L −1 ·d −1 . The removal rate of N by corncob-immobilized microalgae reached the highest. Corncob possess dual functions of biocarrier and available carbon source.