A Comparative Study on Chemical Speciation of Trace Metals as a Function of Solution pH: A Multivariate Analysis and Simulation Approach

作者：Muhammad Shahid, Sana Khalid, Zeid A. ALOthman, Abdullah A. Al‐Kahtani, Camille Dumat, Behzad Murtaza · 发表于：Communications in Soil Science and Plant Analysis · 年份：2025 · DOI：10.1080/00103624.2025.2452160 · 被引用次数：5 · 研究领域：Heavy metals in environment、Arsenic contamination and mitigation、Selenium in Biological Systems

Biogeochemical activity of trace elements in the environment significantly relies on their chemical speciation. Solution pH influences the chemical speciation and biogeochemical activity of trace elements in the soil-plant continuum. The current study was conducted to simulate the influence of solution pH on chemical fractions of 11 trace elements (arsenic, lead, zinc, copper, chromium, cadmium, mercury, nickel, strontium, antimony, and selenium) using Visual Minteq, a chemical equilibrium model used for the calculation of metal speciation, sorption etc. Results delineated that pH-mediated variations in the chemical speciation of trace elements differed with their type. The results of the current study revealed a dominance of chemical trace element species at acidic (1–6), neutral (7.0), and alkaline (8–14) pH. Divalent trace elements (zinc, cadmium, copper, chromium, nickel, and lead) were the dominant species at acidic pH. However, mercury dominance has a narrow pH range (1–3), while strontium dominance has a wider pH range (1–13). Nitrate, sulfate, and phosphate fractions of trace elements also occurred at pH <8. However, at pH >8, trace elements existed in hydroxide (OH) fractions. In the case of arsenic (arsenite As3+ and arsenate As5+), selenium (selenite Se4+ and selenate Se6+), and antimony (antimonite Sb3+ and antimonate Sb5+), their dominant species get oxidized with increasing pH. Multivariate analysis was conducted for various metals for their dominance as a funct...