Cocopeat is a cheap and easily available organic product. In this study, kinetics of hexavalent chromium [Cr(VI)] stabilization by cocopeat in three soils with different pH and organic carbon content, and the effects of influencing factors including ionic strength (0.03, 0.1 and 0.3 M KCl), temperature (10, 25 and 35 °C) and pH (5.2, 6.2 and 7.2) were investigated in a set of batch experiments by varying Cr(VI) and cocopeat concentrations. In this research, there was no possibility of spiking the soils with the same range of initial Cr(VI) concentration. Addition of Cr(VI) in higher levels masked the effect of soil on Cr(VI) reduction in a calcareous soil, while lower levels resulted in complete stabilization of Cr(VI) in a slightly acid soil. Cocopeat efficiently stabilized Cr(VI) in the soil suspensions within a few days. The time trend of Cr(VI) reduction was different in the three soil samples. The rate of Cr(VI) stabilization strongly increased with decreasing pH and increasing temperature, while remained unchanged with changes in ionic strength. Finally, the overall empirical pseudo-first order rate equation was determined to describe the reduction rate of Cr(VI) by cocopeat in soils.

中文翻译：

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Cocopeat修正的污染土壤中六价铬稳定化的动力学表征

Cocopeat是一种便宜且容易获得的有机产品。在这项研究中，钴酸铝在三种具有不同pH和有机碳含量的土壤中稳定六价铬[Cr（VI）]的动力学，以及影响因素的影响，包括离子强度（0.03、0.1和0.3 M KCl），温度（10 ，分别通过改变Cr（VI）和cocopeat的浓度，在一组分批实验中研究了温度（分别为25和35°C）和pH（5.2、6.2和7.2）。在这项研究中，不可能在相同的初始Cr（VI）浓度范围内掺加土壤。较高含量的Cr（VI）掩盖了土壤对钙质土壤中Cr（VI）还原的影响，而较低的含量导致Cr（VI）在弱酸性土壤中完全稳定。Cocopeat在几天内有效地稳定了土壤悬浮液中的Cr（VI）。三种土壤样品中Cr（VI）还原的时间趋势不同。Cr（VI）稳定化速率随pH值降低和温度升高而强烈增加，而随离子强度的变化保持不变。最后，确定了整体的经验拟一阶速率方程来描述土壤中共钴矿对Cr（VI）的还原率。