Sulfur enhances iron plaque formation and stress resistance to reduce the transfer of Cd and As in the soil-rice system.

Sulfur plays an essential role in agricultural production, but few studies have been reported on how sulfur simultaneously impacts the transformation of cadmium (Cd) and arsenic (As) in the soil-rice system. This research selected two soils co-contaminated with both Cd and As, varying in acidity and alkalinity levels, to study the impacts of elemental sulfur (S) and calcium sulfate (CaSO) on the migration and accumulation of Cd and As by rice. Results indicated that two types of sulfur had a substantial (P < 0.

Cadmium, lead, and zinc immobilization in the soil using a phosphate compound with citric acid present.

Low molecular weight organic acids (LMWOAs) are common in rhizospheric soil and may impede the interaction between phosphate and metals. Thus, studying how phosphate compounds impact metal immobilization in rhizospheric soil using LMWOAs is crucial. An incubation experiment examined the effects of NaHPO (a P compound) (3%), various concentrations of citric acid (CA), and combinations of P and CA, on soil cadmium (Cd), lead (Pb), and zinc (Zn) immobilization using the European Community Bureau of Reference (BCR) sequential extraction method, CaCl extraction method, zeta potential, fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD).

Isotherm models for adsorption of heavy metals from water - A review.

Adsorption is a widely used technology for removing and separating heavy metal from water, attributed to its eco-friendly, cost-effective, and high efficiency. Adsorption isotherm modeling has been used for many years to predict the adsorption equilibrium mechanism, adsorption capacity, and the inherent characteristics of the adsorption process, all of which are substantial in evaluating the performance of adsorbents. This review summarizes the development history, fundamental characteristics, and mathematical derivations of various isotherm models, along with their applicable conditions and application scenarios in heavy metal adsorption.

Lead immobilization in soil using new hydroxyapatite-like compounds derived from oyster shell and its uptake by plant.

Protecting the natural environment and ecological systems from the inorganic pollutants such as lead (Pb) has highlighted the urgent need to develop new and effective approaches for this substance's immobilization in soil. In this study, new, low-cost, and eco-friendly hydroxyapatite (HAp)-like compounds were prepared by reacting oyster shell (Oys) with diammonium phosphate ((NH)HPO) (DAP) and calcium hydroxide (Ca(OH)) at 25-28 °C (OyOHr) and 100 °C (OyOHh). Furthermore, OyOHr and OyOHh were assessed for their effectiveness to immobilize Pb in soil and suppress Pb uptake by Indian spinach (Basella Alba L.

Cadmium, lead, and zinc immobilization in soil by rice husk biochar in the presence of low molecular weight organic acids.

Heavy metal immobilization using biochar (BC) is different from the usual soil incubation due to the low molecular weight organic acids (LMWOAs) in the rhizosphere and is an issue worth evaluating. Therefore, the impacts of rice husk BC (5%), tartaric acid, and oxalic acid, coupled with combinations of BC and tartaric acid/oxalic acid on the transformation of cadmium (Cd), lead (Pb), and zinc (Zn) among their geochemical forms, including their bioavailability in a metal-contaminated soil, were investigated in an incubation experiment. The application of BC, low concentration of tartaric acid (2 mmol kg soil) (TA2), and the combined BC plus a low level of tartaric acid (BC-TA2) markedly reduced the acid-soluble and available (CaCl-extractable) Cd, Pb, and Zn compared to control (CK) in which BC-TA2 was found to be the most effective treatment.

Effects of low molecular weight organic acids on Cu accumulation by castor bean and soil enzyme activities.

Chelating agents have been considered as an important phytoremediation strategy to enhance heavy metal extraction from contaminated soil. A pot experiment was conducted to explore the effects of low molecular weight organic acids (LMWOAs) on the phytoremediation efficiency of copper (Cu) by castor bean, and soil enzyme activities. Results indicated that the addition of all the three kinds of LMWOAs (citric, tartaric, oxalic acids) did not decrease the biomass of castor bean, despite the fact they reduced the concentration of chlorophyll-a in leaves compared to the control.

Variations of dissolved organic matter and Cu fractions in rhizosphere soil induced by the root activities of castor bean.

The root soil interaction affects metal bioavailability in the rhizosphere, thus impacting the uptake and accumulation of metals by plants. In this study, a greenhouse experiment using a root-bag technique for castor bean plants was conducted to determine the i) rhizosphere effect on the fractions of Cu, and ii) the characteristics of dissolved organic matter (DOM) in the rhizosphere soil. Results showed that the Cu concentration in the leaves, stems, and roots was 15.

Effect of rice straw, biochar and calcite on maize plant and Ni bio-availability in acidic Ni contaminated soil.

Metals that contaminate soil is one of the major problems seriously affecting sustainable agriculture worldwide. Nickel (Ni) toxicity to agricultural crops is a global problem. Mobility of heavy metals present in contaminated soil can be reduced by the amendment of soil passivators, which will ultimately reduce the risk of them entering the food chain.