Author(s)

Chabi Dari Seidou¹, Tiejun Wang^1,2,3*, Mikouendanandi Mouendo Rahmat Brice Espoire¹, Yibin Dai¹, Yutao Zuo¹

¹Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China.
²Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station, Tianjin University, Tianjin, China.
³Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin, China.

This review synthesizes the methods for estimating the distribution coefficient (K_d) and provides a compilation of K_d values for five heavy metals (As, Pb, Cd, Cu, and Zn) based on research published in the last decade (2012-2021). We used the PRISMA method to ensure the transparency of the collected data. For mono-metal systems (MS), the K_d values ranged from 10^-2 to 10⁷ L/kg for Pb, from 10^-2 to 10⁶ L/kg for Cd, As, and Zn, and from 10^-2 to 10⁵ L/kg for Cu. In competitive systems (CS), the K_d values ranged from 10^-2 to 10⁵ L/kg for Cu, and 10^-2 to 10⁴ L/kg for Pb, Cd, and Zn, while no K_d value for As was reported under CS. It was found that the K_d values of heavy metals are affected not only by soil chemical and physical properties but also by the nature and characteristics of the metal involved along with experimental conditions. The totals references number of K_d data observation per element metal are represented as follows: Cd 35 (50%), Zn 35 (50%), Pb 33 (47.14%), Cu 33 (47.14%), and As 19 (27.14%). Overall, most research was done 1) on MS rather than CS, 2) on sorption rather than desorption, 3) on soil rather than sediments , and 4) most literature have reported the K_d values, derived from batch method than on column method. Despite significant progress over the past decade towards a better understanding of the variation in K_d values and the effect of factors influencing them to provide important parameters for predicting and controlling toxic metals in soils, additional research is still warranted to the complexity of underlying processes.

K_d Values, Heavy Metals, PRISMA, Sorption, Desorption

Seidou, C. , Wang, T. , Espoire, M. , Dai, Y. and Zuo, Y. (2022) A Review of the Distribution Coefficient (K_d) of Some Selected Heavy Metals over the Last Decade (2012-2021). Journal of Geoscience and Environment Protection, 10, 199-242. doi: 10.4236/gep.2022.108014.