Environmental Engineering Program, Guangdong Technion - Israel Institute of Technology, Shantou 515063, China; Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa 320003, Israel.
Environmental Engineering Program, Guangdong Technion - Israel Institute of Technology, Shantou 515063, China.
Sci Total Environ. 2022 Jan 1;802:149802. doi: 10.1016/j.scitotenv.2021.149802. Epub 2021 Aug 21.
Corncob powder possessing its superiority in environmental sustainability and cost, was approved with strong capability of being a replacement of biochar in facilitating the microbial carbonate precipitation process. In this study, the ureolytic bacterial strain Bacillus sp. WA isolated from a pre-acquired metal contaminated soil in Guiyu, China, was showed to be well attached on the surfaces of corncob powder, indicating the carrier's role as a durable shelter for bacterial cells. The efficient immobilization helped develop biochemical composite material (BCM) and proven to function better the calcite precipitation. Afterwards, the mechanism and multi-directional benefits of BCM in edaphic cadmium remediation were examined through pot experiment and compared with corncob powder/bacterial strain/nutrient media as control groups. Integrated lab-scale analyses emphasized the advantages of BCM by the maximum soil urease activity (up to 3.440 U/mg and increased by 214% in 28 days), maximal bacterial propagation (most abundant population in fluorescence microscopy), richest surface functional group (most remarkable OC bond and CO bond in FTIR result), notable calcite precipitation (clear calcite crystals on the surface of BCM compared to control group under SEM-EDS), and highest Cd immobilization rate (exchangeable Cd decreased by 68.54%), among all treatments. The pH and electroconductivity measurements additionally led to the mechanism of corncob powder and NBU promoting pre-existed ureolytic bacteria in soil, which demonstrated the added value of corncob to be fine carbon source and residence shelter for soil microorganism, revealing its potential in developing agricultural materials.
玉米芯粉末在环境可持续性和成本方面具有优势，被证明具有很强的替代生物炭的能力，能够促进微生物碳酸盐沉淀过程。在这项研究中，从中国贵屿预先获得的金属污染土壤中分离出的解脲细菌菌株 Bacillus sp. WA 被证明很好地附着在玉米芯粉末表面上，这表明载体作为细菌细胞的耐用庇护所的作用。有效的固定化有助于开发生化复合材料（BCM），并被证明在方解石沉淀方面效果更好。随后，通过盆栽实验研究了 BCM 在土壤镉修复中的作用机制和多方面的好处，并与玉米芯粉末/细菌菌株/营养培养基作为对照组进行了比较。综合实验室规模分析通过最大土壤脲酶活性（高达 3.440 U/mg，28 天内增加了 214%）、最大细菌繁殖（荧光显微镜下最丰富的种群）、最丰富的表面官能团（FTIR 结果中最显著的 OC 键和 CO 键）、明显的方解石沉淀（与对照组相比，BCM 表面有明显的方解石晶体，SEM-EDS 结果）和最高的 Cd 固定率（可交换的 Cd 减少了 68.54%），强调了 BCM 的优势。pH 和电导率测量进一步导致了玉米芯和 NBU 促进土壤中预先存在的解脲细菌的机制，这表明玉米芯作为土壤微生物的良好碳源和栖息地的附加值，揭示了其在开发农业材料方面的潜力。
