Influence of Different Soil Conditioner on the Transfer and Transformation of Cadmium and Phthalate Esters in Soil

Abstract

This study examines the existing common form of soil pollution, combined organic and inorganic pollution. Cadmium (Cd) is the most important inorganic element in soil pollution. Due to the widespread use of plastic film, phthalates have become the main organic pollutants in soil. Pot experiments were conducted with purple soil from southwest China, and Chinese cabbage was used as a biological indicator. Different concentration gradients of Cd and diethylhexyl phthalate (DEHP) was used as foreign pollutants. The soil was treated with one of the six common soil conditioners, namely potassium feldspar powder, oyster shell powder, biological carbon powder (biochar), calcium, potassium carbonate, and calcium phosphate, to examine the effect of conditioners on cadmium morphology, DEHP content in contaminated soil, and cadmium and DEHP absorption in Chinese cabbage. The results showed that biochar is the optimal soil conditioner for the remediation of cadmium-phthalate composite pollution in purple soil. Subsequently, the effects of soil biochar content on cadmium pollution and phthalate ester migration were studied. Uncontaminated control soil, Cd-contaminated soil, and DEHP-contaminated soil were examined by pot experiments, and biochar treatments with mass fraction of 0%, 0.5%, 1%, 3%, and 5% added to cadmium contaminated soil were used to determine its influence on Cd morphology and DEHP content of contaminated soil.