[Effect of Citric Acid and Phosphorus Coexistence on Cadmium Adsorption by Soil].

In brown-red soil, the effect of phosphorus and citric acid co-existence on the adsorption of cadmium was studied using indoor experiments and isothermal equilibrium adsorption analysis. After treatment with different doses of phosphorus and citric acid, the fractions of cadmium were altered by varying dry and wet conditions. The results showed that:① Soil treated with 10 mg·L of CdCl solution showed no notable effect on cadmium adsorption when a low concentration of phosphorus was added (40 mg·L); however, higher a concentration of added phosphorus (80 mg·L) significantly increased cadmium adsorption (an increase of 78 g·kg and 7.

[Characteristics of Phosphorus Output Through Runoff on a Red Soil Slope Under Natural Rainfall Conditions].

The development of agriculture in the red soil sloping uplands has been increasingly restricted by low water availability, high temperatures, and low fertilizer use efficiency. Subsurface flow has a significant influence on runoff generation, nutrient loss, and soil erosion. The rainfall-runoff process makes it easy for nutrients on the sloping land to enter water bodies through subsurface flow mainly in the liquid phase, which may lead to environmental problems such as eutrophication and groundwater pollution.

[Effect of phosphate and organic acid addition on passivation of simulated Pb contaminated soil and the stability of the product].

Organic acids can improve the phosphorus availability, influence the immobilization of heavy metals in soil, and has very complicated function in phosphorus activation and heavy metal passivation. This research took simulated Pb contaminated soil as material, phosphate and citric acid as remediation matter, adopted BCR continuous extraction, 0.01 mol · L(-1) CaCl2 and toxicity characteristic leaching procedure (TCLP) to evaluate the remediation effect.