Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 S. Limestone, Lexington, KY 40536-0509, USA.
University of Nairobi, Department of Chemistry, P.O. Box 14538-00100, Nairobi, Kenya.
J Hazard Mater. 2019 Dec 15;380:120897. doi: 10.1016/j.jhazmat.2019.120897. Epub 2019 Jul 15.
Sorption of Congo Red (CR) and Malachite Green (MG) dyes currently used in pigments and clothing industries were investigated using brewers' spent grain (BSG) from a local brewery. Adsorption increased with a higher adsorbent weight and lower colorant concentrations. Accumulation of CR and MG was optimal at acidic pH and neutral pH respectively. Sorption decreased with an increase in temperature signifying an exothermic process. Batch adsorption data fitted better to Langmuir adsorption isotherm model and pseudo-second-order kinetics. Maximum monolayer coverage capacities (Q) were found to be 2.55 mg/g for MG and 36.5 mg/g for CR dye. Column studies using BSG were also conducted for both dyes. Fixed bed breakthrough was fast with an increase in dye concentration, adsorbent surface area, and flow rate and with a decrease in column depth. BSG are effective, simple in design and inexpensive adsorbing material from renewable sources.
采用本地啤酒厂的废啤酒糟（BSG）研究了目前用于颜料和服装工业的刚果红（CR）和孔雀石绿（MG）染料的吸附作用。吸附作用随着更高的吸附剂重量和更低的着色剂浓度而增加。CR 和 MG 的积累分别在酸性 pH 和中性 pH 下达到最佳状态。吸附随着温度的升高而降低，表明这是一个放热过程。批处理吸附数据更符合朗缪尔吸附等温线模型和伪二阶动力学。对于 MG 和 CR 染料，最大单层覆盖容量（Q）分别为 2.55 mg/g 和 36.5 mg/g。还对两种染料进行了 BSG 的柱研究。随着染料浓度、吸附剂表面积、流速的增加和柱深的减小，固定床的穿透速度很快。BSG 是一种有效的、设计简单的、从可再生资源中提取的廉价吸附材料。
