Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Sci Total Environ. 2021 Nov 10;794:148691. doi: 10.1016/j.scitotenv.2021.148691. Epub 2021 Jun 25.
Biochar-loaded Ce-enriched ultra-fine ceria nanoparticles (Ce-BC) were used as a novel nanostructured adsorbent for the removal of arsenate (As(V)) from aqueous solutions. The effect of cerium valence on As(V) adsorption and the mechanism of As(V) adsorption onto Ce-BC were investigated using batch experiments and a series of spectroscopy detection technologies. The adsorption isotherm data fitted with the Langmuir model, with maximum As(V) sorption capacity of 219.8 mg g at pH 5.0 and 25 °C. The adsorption kinetics fitted well with the pseudo-second-order model. Ce on the surface of Ce-BC plays an important role in the adsorption of As(V). The decrease in Ce concentration from 60.1% to 48.9% on the Ce-BC surface, significantly decreased the adsorption of As(V) on Ce-BC. Furthermore, a strong affinity between As(V) and Ce-enriched Ce-BC was revealed, resulting in irreversible adsorption. Most importantly, the adsorbed As(V) could further react with Ce of the ultra-fine cerium oxide nanoparticles in Ce-BC to form rod-like CeAsO precipitates. Through the novel adsorption-precipitation process, Ce-BC can be used to remove trace As(V).
负载铈的生物炭负载超细微晶氧化铈纳米颗粒 (Ce-BC) 被用作一种新型纳米结构吸附剂，用于从水溶液中去除砷酸盐 (As(V))。通过批量实验和一系列光谱检测技术研究了铈价态对 As(V)吸附的影响和 As(V)吸附到 Ce-BC 的机理。吸附等温线数据符合朗缪尔模型，在 pH 5.0 和 25°C 时最大砷酸盐吸附容量为 219.8mg/g。吸附动力学很好地符合准二级模型。Ce-BC 表面的 Ce 在 As(V)的吸附中起着重要作用。Ce-BC 表面的 Ce 浓度从 60.1%降至 48.9%，显著降低了 As(V)在 Ce-BC 上的吸附。此外，还揭示了 As(V)与富铈 Ce-BC 之间存在很强的亲和力，导致不可逆吸附。最重要的是，吸附的 As(V)可以进一步与 Ce-BC 中超细微晶氧化铈纳米颗粒中的 Ce 反应，形成棒状的 CeAsO 沉淀物。通过这种新型的吸附-沉淀过程，Ce-BC 可用于去除痕量的 As(V)。
