Jeong Seok-Soon, Park Byung-Jun, Yoon Jung-Hwan, Kirkham Mary Beth, Yang Jae-E, Kim Hyuck-Soo
Department of Biological Environment, Kangwon National University, Chuncheon 24341, Republic of Korea.
Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.
Toxics. 2024 Apr 10;12(4):278. doi: 10.3390/toxics12040278.
A significant quantity of biologically produced sulfur (BPS) is generated as a by-product of chemical and biological desulfurization processes applied to landfill gas treatment. The beneficial upcycling of BPS has seen limited use in the environmental context. The effectiveness and underlying mechanism of BPS as an adsorbent for removing Hg from both solution and wastewater were elucidated based on experiments encompassing surface characterization, adsorption isotherms, kinetics, and thermodynamics. The BPS exhibited remarkable efficacy in removing Hg from solution, with the Langmuir model accurately describing the adsorption process and showing a maximum adsorption capacity of 244 mg g. Surface analysis through X-ray photoelectron spectroscopy and scanning electron microscopy revealed that Hg complexed with sulfide on BPS surfaces, forming stable HgS. The adsorbed Hg was strongly retained in BPS, with less than 0.2% of the adsorbed Hg desorbed by strong acids. Adsorption kinetics followed the double-exponential first-order model, showing an initial rapid adsorption phase wherein 75% of the initial Hg was removed within 5 min, followed by a slower adsorption rate. The thermodynamic parameters suggested that adsorption of Hg by BPS was a spontaneous and endothermic process. Additionally, BPS effectively removed Hg from wastewater, showing preference for Hg over other co-existing metals. These findings underscore the potential of BPS as an effective adsorbent for Hg removal from wastewater.
大量生物产生的硫（BPS）作为应用于垃圾填埋气处理的化学和生物脱硫过程的副产品而产生。在环境背景下，BPS的有益升级利用的应用有限。基于包括表面表征、吸附等温线、动力学和热力学在内的实验，阐明了BPS作为从溶液和废水中去除汞的吸附剂的有效性和潜在机制。BPS在从溶液中去除汞方面表现出显著效果，Langmuir模型准确描述了吸附过程，最大吸附容量为244 mg/g。通过X射线光电子能谱和扫描电子显微镜进行的表面分析表明，汞在BPS表面与硫化物络合，形成稳定的HgS。吸附的汞在BPS中被强烈保留，强酸解吸出的吸附汞不到0.2%。吸附动力学遵循双指数一级模型，显示出初始快速吸附阶段，其中在5分钟内去除了75%的初始汞，随后吸附速率较慢。热力学参数表明，BPS对汞的吸附是一个自发的吸热过程。此外，BPS有效地从废水中去除了汞，相对于其他共存金属，它对汞表现出偏好。这些发现强调了BPS作为从废水中有效去除汞的吸附剂的潜力。
