As a result of increasing population, developing technology, and growing industrial activity year by year, the release of heavy metals to the environment is continually increasing. Therefore, the treatment of heavy metals is of great importance for the protection of the environment. Lignocellulosic agricultural waste can be used as a versatile, adsorbent material for heavy metals. This article aims to evaluate experimental results on the behavior of various tea wastes for removal of Cr⁶⁺ under internal and external factors affecting adsorption properties. The effects of different parameters such as initial pH (2-7), adsorbent quantity (0.5-5.0 g/100 mL), stirring speed (50-300 rpm), contact time (5-120 minutes) were assessed. The suitability of Cr⁶⁺ adsorption to different isotherms and kinetics was also investigated. According to the CalcPlot3D, the order of the parameters that profoundly affect adsorption was pH > adsorbent dose > time > temperature > stirring speed. An assessment of ΔHº, ΔSº, ΔGº obtained during the adsorption process showed that waste black tea (WBT), waste green tea (WGT), waste rooibos tea (WRT) were applicable, spontaneous, endothermic for Cr⁶⁺. The maximum removal efficiency for Cr⁶⁺ was achieved under optimum conditions as 88%, 83%, and 73%. According to the data obtained, the equilibrium adsorption was observed to fit Langmuir. The maximum adsorption capacity for WBT, WGT, WRT was 9.14, 8.56, and 5.12 mg/g, respectively. The adsorption of Cr⁶⁺ on WBT, WGT, WRT was defined by pseudo-second-order. All results showed that raw WBT, WGT, WRT was environmentally friendly, low cost, an easily available adsorbent in removing Cr⁶⁺ from aqueous solution.

由于人口的增加，技术的发展以及工业活动的逐年增加，重金属向环境的释放不断增加。因此，重金属的处理对于保护环境非常重要。木质纤维素农业废料可用作重金属的多功能吸附材料。本文旨在评估各种茶废料在影响吸附性能的内部和外部因素影响下去除Cr ⁶⁺行为的实验结果。评估了不同参数的影响，例如初始pH（2-7），吸附剂量（0.5-5.0 g / 100 mL），搅拌速度（50-300 rpm），接触时间（5-120分钟）。Cr ⁶⁺的适用性还研究了对不同等温线和动力学的吸附。根据CalcPlot3D，影响吸附的参数顺序为：pH>吸附剂量>时间>温度>搅拌速度。对吸附过程中获得的ΔHº，ΔSº，ΔGº的评估表明，适用的废红茶（WBT），废绿茶（WGT），废茶子茶（WRT）是自发的，并且对Cr ^6+具有吸热作用。在最佳条件下，Cr ⁶⁺的最大去除效率达到88％，83％和73％。根据获得的数据，观察到平衡吸附适合朗缪尔。WBT，WGT，WRT的最大吸附容量分别为9.14、8.56和5.12 mg / g。Cr ⁶⁺的吸附在WBT，WGT，WRT上通过伪二阶定义。所有结果表明，原始的WBT，WGT，WRT环保，成本低廉，是从水溶液中去除Cr ⁶⁺的易用吸附剂。