Diagboya Paul N, Olu-Owolabi Bamidele I, Adebowale Kayode O
Department of Physical Sciences, Landmark University, Kwara State, Nigeria.
Department of Chemistry, University of Ibadan, Ibadan, Nigeria.
J Contam Hydrol. 2016 Aug;191:99-106. doi: 10.1016/j.jconhyd.2016.04.005. Epub 2016 Apr 22.
Soil iron oxides (IOs) and organic matter (OM) play varying roles in pentachlorophenol (PCP) retention and mobility, but the extent and mechanism are still unknown. Therefore, in order to have a better understanding of the adsorption of PCP on soils, batch sorption studies were carried out on whole soils and soils selectively treated to remove IOs (IOR) and OM (OMR). The effects of pH, time, and temperature were investigated. Results showed that PCP sorption was temperature and pH dependent; sorption decreased as both temperature and pH increased. Sorption was partly surface adsorption and partly partitioning within voids of IOs components as revealed by the kinetics models. The surface adsorption was multi-layer in nature. Equilibria were faster in the IOR soils than the untreated and OMR soils. IOs played greater roles in PCP sorption than OM. Removal of soil components, especially the IOs, as experienced in soils plagued by soil erosion, may lead to increased risks of PCP pollution of environmental media especially the aquifer.
土壤中的铁氧化物（IOs）和有机质（OM）在五氯苯酚（PCP）的吸附和迁移过程中发挥着不同作用，但其程度和机制仍不明确。因此，为了更好地理解PCP在土壤上的吸附作用，对原状土壤以及经过选择性处理以去除铁氧化物（IOR）和有机质（OMR）的土壤进行了批量吸附研究。研究了pH值、时间和温度的影响。结果表明，PCP吸附取决于温度和pH值；随着温度和pH值升高，吸附量下降。动力学模型表明，吸附部分是表面吸附，部分是在铁氧化物组分孔隙内的分配作用。表面吸附本质上是多层的。IOR土壤中的吸附平衡比未处理土壤和OMR土壤更快。铁氧化物在PCP吸附中比有机质发挥着更大作用。在受土壤侵蚀影响的土壤中，去除土壤组分，尤其是铁氧化物，可能会增加PCP污染环境介质尤其是含水层的风险。
