Immobilization of Cadmium by Molecular Sieve and Wollastonite Is Soil pH and Organic Matter Dependent

Abstract

The excessive cadmium (Cd) concentration in agricultural products has become a major public concern in China in recent years. In this study, two amendments, 4A molecular sieve (MS) and wollastonite (WS), were evaluated for their potential passivation in reducing Cd uptake by amaranth (Amaranthus tricolor L.) in six soils with different properties. Results showed that the responses of amaranth biomass to these amendments were soil-property-dependent. The effects of MS and WS on soil available Cd were in turn dependent on soil and amendment properties. The application of WS and MS at a dose of 660 mg·kg−1 Si produced the optimum effect on inhibiting Cd accumulation in amaranth shoots (36% and 34%, respectively) and did not affect crop yield. This was predominantly attributed to the marked increase in pH and exogenous Ca or Na, which facilitated the adsorption, precipitation, and complexation of Cd in soils. The immobilization effects of WS and MS were dependent on soil properties, where soil organic matter may have played an important role. In conclusion, MS and WS possess great potential for the remediation of Cd-contaminated acidic soils.

Absorption and Translocation Capacity of Cadmium in Papaya (Carica papaya L.) Plants With Addition of Organic Matter

“…Studies have reported that the application of 5% and 10% biochar to soil can reduce Cd, Zn, and Pb concentrations after 56 days of application (He et al, 2015). The use of manure and clay mineral amendments decrease Cd translocation from root to the wheat shoot (Hamid et al, 2019); while the addition of animal-derived organic matter can reduce Cd uptake by up to 38% in spinach crop (Sato et al, 2010); furthermore in amaranth shoots, it is possible to inhibit cadmium accumulation with the use of a combination of organic amendments (Dong et al, 2021). Hence the interest in finding the most viable strategies for agricultural producers, since heavy metals in soil can cause in addition to plant stress, alterations in growth and a reduction in crop yield (Nagajyoti et al, 2010).…”