[Preparation of Silicon-based Magnetic Biochar and Its Remediation Mechanism for Cd（Ⅱ） and As（Ⅲ） Co-contaminated Water].

Cadmium （Cd） and arsenic （As） often coexist in water and agricultural soils around mining areas, and it is difficult to remove them at the same time due to their opposite chemical behaviors. Therefore, this study employed a co-precipitation-pyrolysis method to synthesize silica-based magnetic biochar （SMB） materials for the remediation of water contaminated with both Cd and As. The optimization of preparation conditions involved introducing three different types of silicates （NaSiO, CaSiO,and SiO） into the biomass-magnetite mixture, followed by pyrolysis at various temperatures （300℃, 500℃, and 700℃）, and the optimal preparation conditions were determined based on the composite batch experiments.

[Passivation of Cadmium and Arsenic in Acidified Paddy Soil by Calcium Fertilizer with Biochar-ferromanganese Composites].

Due to the aggravation of atmospheric nitrogen and sulfur deposition and the unreasonable application of fertilizer, soil acidification is becoming increasingly serious. In heavy metal-contaminated soils, acidification not only seriously affects fertility but also the effectiveness and sustainability of conventional passivation remediation materials such as biochar. The application of calcium fertilizer may improve soil acidification, alleviate the aging of biochar materials in soil, and improve its remediation ability to composite polluted soil.

[Simultaneous Immobilization of Cadmium and Arsenic in Paddy Soils with Novel Fe-Mn Combined Graphene Oxide].

Novel Fe-Mn combined graphene oxide （GO-FM） material was produced and tested for its efficacy in remediating agricultural soil co-contaminated by Cd and As. In a 60-day soil incubation experiment， the remediation mechanism and immobilization effects of GO and GO-FM at different addition ratios （0.1%， 0.

[Using Biochar and Iron-calcium Material to Remediate Paddy Soil Contaminated by Cadmium and Arsenic].

In this study, iron-calcium material (FC) and hickory-cattail biochar (BC) were applied to prepare composite material (BF), which was used to repair the combined pollution of cadmium and arsenic in paddy soil to reduce the content of cadmium (Cd) and arsenic (As) in rice grain. Soil pore water, rhizosphere soil, bulk soil, rice plants, and root iron plaque samples were collected during the growth period of rice in a pot experiment to explore the effects and mechanism of FC, BC, and BF on the bioavailability of Cd and As in paddy soil and their contents in plants. The results showed that biochar could significantly ( < 0.

[Novel Insight into the Adsorption Mechanism of Fe-Mn Oxide-Microbe Combined Biochar for Cd(Ⅱ) and As(Ⅲ)].

A Fe-Mn oxide-microbe combined biochar (FM-DB) was prepared to simultaneously remove Cd(Ⅱ) and As(Ⅲ) contamination in an aqueous system. In the FM-DB, the best ratio of Fe-Mn oxide (FMBO) and carya cathayensis shell biochar (CCSB) was 3%+3%. The material had good acid resistance, mechanical strength, and mass transfer performance, and the maximum removal rates for Cd(Ⅱ) and As(Ⅲ) in the binary system were 77.

[Simultaneous Immobilization of Arsenic, Lead, and Cadmium in Paddy Soils Using Two Iron-based Materials].

Two iron-based materials, Fe-Ca composite (FeCa) and Fe-Mn binary oxide (FMBO), were applied to immobilize As, Pb, and Cd in heavy metal contaminated paddy soils. Seven kinds of paddy soil (tidal soil) contaminated by arsenic, lead and cadmium were collected from Shangyu, Shaoxing (SY), Foshan, Guangdong (FS), Shaoguan, Guangdong (SG), LiuYang, Hunan (LY), Ganzhou, Jiangxi (GZ), Dushan, Guizhou (DS), and Ma'anshan, Anhui (MAS). The effects of iron-based materials on the dynamic changes of As, Pb, and Cd concentration in soil solution, the stabilization efficacy of available As, Pb, and Cd in soil, and the effects of soil types and properties on stabilization efficacy were studied through soil incubation experiment.

Effects of magnetic biochar-microbe composite on Cd remediation and microbial responses in paddy soil.

There is growing global interest in the bioremediation of cadmium (Cd) using combinations of biochar and microorganisms. However, the interactions among biochar, introduced and indigenous microorganisms remain unclear. Accordingly, a 90 day microcosm experiment was conducted to investigate this by adding Bacillus sp.

A novel calcium-based magnetic biochar reduces the accumulation of As in grains of rice (Oryza sativa L.) in As-contaminated paddy soils.

The present study used calcium-based magnetic biochar (Ca-MBC), a novel material made through pyrolyzing rice straw impregnated with iron oxide (FeO) and calcium carbonate (CaCO) under oxygen-limited conditions, to reduce arsenic (As) accumulation in rice plants (Oryza sativa L.) through a 130-day pot experiment. The BCR (European Community Bureau of Reference) sequential extraction confirmed that Ca-MBC decreased the unstable fraction of As through transforming to the stable fraction at both tillering stage and maturity.

Zeolite-supported nanoscale zero-valent iron for immobilization of cadmium, lead, and arsenic in farmland soils: Encapsulation mechanisms and indigenous microbial responses.

Zeolite-supported nanoscale zero-valent iron (Z-NZVI) has great potential for metal(loid) removal, but its encapsulation mechanisms and ecological risks in real soil systems are not completely clear. We conducted long-term incubation experiments to gain new insights into the interactions between metal(loid)s (Cd, Pb, As) and Z-NZVI in naturally contaminated farmland soils, as well as the alteration of indigenous bacterial communities during soil remediation. With the pH-adjusting and adsorption capacities, 30 g kg Z-NZVI amendment significantly decreased the available metal(loid) concentrations by 10.

A novel calcium-based magnetic biochar is effective in stabilization of arsenic and cadmium co-contamination in aerobic soils.

This study developed a novel calcium-based magnetic biochar by pyrolysing rice straw mixed with calcium carbonate and iron oxide for stabilization of contamination of multiple metals. A 160-day incubation study was conducted to investigate its performance in stabilization of cadmium and arsenic co-contamination in soil. Both biochar and Ca-MBC treatments increased soil pH, decreased the bioavailability of cadmium.

Remediation of As(III) and Cd(II) co-contamination and its mechanism in aqueous systems by a novel calcium-based magnetic biochar.

A novel calcium-based magnetic biochar (Ca-MBC), made by pyrolyzing the mixture of rice straw, iron oxide (FeO) and calcium carbonate (CaCO), was developed in this study for remediation of co-pollution of arsenic and cadmium. Characteristics of the material showed that FeO and CaCO were adhered on the surface of biochar. The experiments on the effects of pH, adsorption kinetics and isotherm revealed that the Ca-MBC had a great ability to adsorb arsenic and cadmium within 0.