National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an City, Shandong 271018, PR China.
National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an City, Shandong 271018, PR China.
Ecotoxicol Environ Saf. 2024 Aug;281:116608. doi: 10.1016/j.ecoenv.2024.116608. Epub 2024 Jun 19.
Water pollution caused by heavy metals is a major environmental problem, threatening water production, food safety, and human health. Cadmium (Cd) pollution is particularly serious because of food-chain biomagnification at toxic concentrations. Modified biochar is promising for heavy metal removal; however, efficient adsorbents for Cd removal are lacking. In the present study, a novel adsorbent, silica gel-modified biochar (SGB), was prepared and applied to treat sewage polluted by Cd. Through the batch adsorption experiments, it is known that SGB possessed outstanding Cd removal ability and recycleability. Furthermore, the adsorption behavior and mechanisms were analyzed by the application of kinetic and isotherm models. The maximum Cd adsorption capacity of SGB was 38.08 mg g, and after five recycling processes, the Cd removal rate was still 86.89 %. When the pH of the solution was 7.0, SGB showed the strongest Cd adsorption capacity (29.06 mg g). When competitive ions existed, biochar also had high Cd removal efficiency, although the effect of Pb was greater than those of Cu and Zn, indicating that SGB was applicable to complex polluted water. Additionally, the main Cd adsorption mechanisms by SGB were electrostatic interactions, π-π interactions, complexation, and co-precipitation. These results showed that SGB can effectively treat Cd-contaminated wastewater as a new adsorbent.
重金属造成的水污染是一个主要的环境问题，威胁着水的生产、食品安全和人类健康。由于食物链的生物放大作用，镉（Cd）污染尤其严重，处于有毒浓度。改性生物炭在重金属去除方面具有广阔的前景；然而，高效的 Cd 去除吸附剂仍然缺乏。在本研究中，制备了一种新型吸附剂，硅胶改性生物炭（SGB），并将其应用于处理受 Cd 污染的污水。通过批量吸附实验，可知 SGB 具有出色的 Cd 去除能力和可回收性。此外，还通过应用动力学和等温线模型来分析吸附行为和机制。SGB 的最大 Cd 吸附容量为 38.08mg/g，经过五次回收过程，Cd 的去除率仍为 86.89%。当溶液的 pH 值为 7.0 时，SGB 表现出最强的 Cd 吸附能力（29.06mg/g）。当存在竞争离子时，生物炭对 Cd 的去除效率也很高，尽管 Pb 的影响大于 Cu 和 Zn，但这表明 SGB 适用于复杂污染的水。此外，SGB 吸附 Cd 的主要机制是静电相互作用、π-π 相互作用、络合和共沉淀。这些结果表明，SGB 可以作为一种新型吸附剂有效地处理含 Cd 废水。
