Sha Jia-Qi, An Jing, Wei Shu-He, Song He-Wei
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China.
Bioresour Technol. 2025 Oct;434:132775. doi: 10.1016/j.biortech.2025.132775. Epub 2025 Jun 4.
Cadmium (Cd) is widely distributed in contaminated water. Globally, substantial resources and energy are consumed annually to treat Cd-contaminated water, thereby intensifying carbon emissions and contributing to global climate change. Microbially induced carbonate precipitation (MICP) by cyanobacteria has the potential to become a low-carbon method for treating Cd-contaminated wastewater. This study demonstrated that the MICP reaction of Synechococcus sp., Synechocystis sp., and Microcystis aeruginosa could effectively achieve the low-carbon removal of Cd. Irregular spherical CdCO minerals with sizes ranging from 0.5 to 5.0 μm were produced during the MICP process. The removal rate and carbon sequestration amount of Synechococcus sp. were 97.13 ± 1.64 % and 0.101 ± 0.008 mg, respectively, which were significantly higher than those of Synechocystis sp. (47.52 ± 2.53 %, p < 0.01; 0.056 ± 0.001 mg, p < 0.01) and M. aeruginosa (45.73 ± 2.40 %, p < 0.005; 0.051 ± 0.002 mg, p < 0.01) when 10.00 mL of the supernatant was used to treat Cd with an initial concentration of 1.00 mM. On the one hand, Synechococcus sp. exhibited a higher pH (10.667 ± 0.311) and CO concentration (80.995 ± 2.500 mg·L), which facilitated the mineralization of Cd and inorganic carbon fixation. On the other hand, Synechococcus sp. had a higher cell density (OD: 1.451 ± 0.021) and chlorophyll-a concentration (5.262 ± 0.466 mg·L), promoting organic carbon fixation through enhanced cyanobacterial photosynthesis. This phenomenon could be attributed to the elevated transcription levels of key functional genes (including CcmO, CcmK, PsbA, PsaD) involved in CO concentration and photosynthesis processes. Cyanobacterial MICP reduces reliance on energy-intensive treatments, mitigating climate impacts. The integration of Cd remediation with carbon fixation offers a dual-benefit strategy for sustainable wastewater management, addressing hazardous metal pollution while contributing to global carbon neutrality goals.
镉（Cd）广泛分布于受污染的水体中。在全球范围内，每年为处理含镉污水要消耗大量资源和能源，从而加剧碳排放并导致全球气候变化。蓝细菌介导的微生物诱导碳酸盐沉淀（MICP）有潜力成为一种低碳的含镉废水处理方法。本研究表明，聚球藻属、集胞藻属和铜绿微囊藻的MICP反应能够有效实现镉的低碳去除。在MICP过程中产生了尺寸范围为0.5至5.0μm的不规则球形碳酸镉矿物。当用10.00 mL上清液处理初始浓度为1.00 mM的镉时，聚球藻属的去除率和碳固存量分别为97.13±1.64%和0.101±0.008 mg，显著高于集胞藻属（47.52±2.53%，p<0.01；0.056±0.001 mg，p<0.01）和铜绿微囊藻（45.73±2.40%，p<0.005；0.051±0.002 mg，p<0.01）。一方面，聚球藻属表现出较高的pH值（10.667±0.311）和CO浓度（80.995±2.500 mg·L），这有利于镉的矿化和无机碳固定。另一方面，聚球藻属具有较高的细胞密度（OD：1.451±0.021）和叶绿素a浓度（5.262±0.466 mg·L），通过增强蓝细菌光合作用促进有机碳固定。这种现象可归因于参与CO浓度和光合作用过程的关键功能基因（包括CcmO、CcmK、PsbA、PsaD）转录水平的提高。蓝细菌MICP减少了对能源密集型处理的依赖，减轻了气候影响。镉修复与碳固定的整合为可持续废水管理提供了一种双赢策略，既能解决有害金属污染问题，又有助于实现全球碳中和目标。
