School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China.
School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China.
Environ Pollut. 2021 Dec 15;291:118269. doi: 10.1016/j.envpol.2021.118269. Epub 2021 Sep 30.
Arsenic contamination of ground water is a worldwide issue, causing a number of ailments in humans. As an engineered and integrated solution, a hybrid vertical subsurface flow constructed wetland (VSSF-CW) amended with BCXZM composite (Bacillus XZM immobilized on rice husk biochar), was found effective for the bioremediation of arsenic contaminated water. Biological filter was prepared by amending top 3 cm of VSSF-CW bed with BCXZM. This filter scavenged ∼64% of total arsenic and removal efficiency of ∼95% was achieved by amended and planted (As + P + B) VSSF-CW, while non-amended (As + P) VSSF-CW showed a removal efficiency of ∼55%. The unplanted and amended (As + B) VSSF-CW showed a removal efficiency of ∼70%. The symbiotic association of Bacillus XZM, confirmed by SEM micrographs, significantly (p ≤ 0.05) reduced reactive oxygen species (ROS) and malondialdehyde (MDA) accumulation in Typha latifolia, hence, increasing the plant growth (2 folds). An increase in the indole acetic acid (IAA) and arsenic accumulation in plant was also observed in As + P + B system. The removal efficiency of the system was compromised after 4th consecutive cycle and 48 h was observed as optimum retention time. The FTIR-spectra showed the involvement of -N-H bond, carboxylic acids, -CH stretching of -CH and -CH carbonyl groups, -C-H, C-O-P and C-O-C, sulphur/thiol and phosphate functional groups in the bio-sorption of arsenic by BCXZM filter. Our study is a first reported on the simultaneous phytoextraction and biosorption of arsenic in a hybrid VSSF-CW. It is proposed that BCXZM can be applied effectively in CWs for the bioremediation of arsenic contaminated water on large scale.
地下水砷污染是一个全球性问题，会导致人类出现多种疾病。作为一种经过工程设计和集成的解决方案，一种混合垂直潜流人工湿地（VSSF-CW），并用 BCXZM 复合材料（固定在稻壳生物炭上的 XZM 芽孢杆菌）进行改良，被发现对受砷污染的水的生物修复非常有效。通过在 VSSF-CW 床的顶层 3 厘米处添加 BCXZM 来制备生物过滤器。这种过滤器去除了约 64%的总砷，而经过改良和种植（As + P + B）的 VSSF-CW 的去除效率达到了约 95%，而未经改良（As + P）的 VSSF-CW 的去除效率约为 55%。未种植和改良的（As + B）VSSF-CW 的去除效率约为 70%。通过 SEM 显微照片证实，XZM 芽孢杆菌的共生关系显著（p ≤ 0.05）降低了香蒲中活性氧（ROS）和丙二醛（MDA）的积累，从而增加了植物的生长（增加了 2 倍）。在 As + P + B 系统中，还观察到吲哚乙酸（IAA）和砷在植物中的积累增加。该系统在连续 4 个循环后去除效率降低，48 小时被观察为最佳保留时间。FTIR 谱图表明，BCXZM 过滤器对砷的生物吸附涉及-N-H 键、羧酸、-CH 伸展的-CH 和-CH 羰基、-C-H、C-O-P 和 C-O-C、硫/硫醇和磷酸官能团。我们的研究首次报道了在混合 VSSF-CW 中同时进行砷的植物提取和生物吸附。建议将 BCXZM 有效地应用于 CW 中，以大规模进行受砷污染水的生物修复。
