Scholarlink

Purpose <p>Developing an environmentally benign and cost-effective passivator for in-situ remediation of Cd-contaminated soil remains a global challenge. This study aimed to synthesize a novel passivator and apply it to three soils with different pH to investigate its passivation effect and mechanism on Cd-contaminated soil.</p> Materials and methods <p>Herein, a novel alkali/APTES-modified biochar (AP@BC) was synthesized by a cross-coupling reaction with γ-aminopropyl triethoxysilane (APTES) loaded on the surface of maize stalk-based biochar. Characterization and batch experiments were conducted to investigate the adsorption performance and mechanisms of AP@BC for Cd<sup>2+</sup>. Pot experiments were carried out to assess the impact of AP@BC on soil pH, bioavailable Cd (DTPA-Cd) and ryegrass biomass in acidic (AL), neutral (NH), and alkaline (BH) agricultural soils.</p> Results and discussion <p>The maximum adsorption capacity of AP@BC toward Cd<sup>2+</sup> was 78.57&#xa0;mg/g, which increased by 123.5% compared with pristine biochar. The Freundlich and Temkin equations satisfactorily fit the adsorption isotherm experimental data. Pot experiments revealed that the addition of AP@BC from 0.5 to 3% increased the pH of acidic and neutral soils while decreasing the pH of alkaline soils. Notably, the 3% treatment significantly reduced the DTPA-Cd contents in acidic, neutral, and alkaline soil by 8.00%, 22.45%, and 13.65%, respectively, compared to the control. And, ryegrass biomass increased most significantly in high-Cd-content soils (1.5–4.83 times for roots and 2.01–3.88 times for shoots). On the other hand, bioaccumulation and translocation coefficients decreased most in acidic soil (6.02-29.38% and 10.10-30.70%) compared to the control.</p> Conclusions <p>The introduction of -NH<sub>2</sub> to the surface of the biochar made it much better at adsorption ability. AP@BC reduced the Cd availability in three contaminated soils and most significantly in the acidic soil. It increased ryegrass roots and shoots biomass in high-Cd-content soil. The above results indicate that AP@BC is a promising passivator for the remediation of practical Cd-contaminated agriculture soil.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Amino-functionalized biochar enhanced Cd passivation in acidic, neutral and alkaline soils: effect and mechanism

  • 期刊论文

  • 发表日期：

    2025年4月25日

查看全文
  • Ling Jiang,
  • Siyi Zhang,
  • Samuel S. K. Gbon,
  • Zhen Wu,
  • Xiaoqiong Yue,
  • Jingyue An

摘要

Purpose

Developing an environmentally benign and cost-effective passivator for in-situ remediation of Cd-contaminated soil remains a global challenge. This study aimed to synthesize a novel passivator and apply it to three soils with different pH to investigate its passivation effect and mechanism on Cd-contaminated soil.

Materials and methods

Herein, a novel alkali/APTES-modified biochar (AP@BC) was synthesized by a cross-coupling reaction with γ-aminopropyl triethoxysilane (APTES) loaded on the surface of maize stalk-based biochar. Characterization and batch experiments were conducted to investigate the adsorption performance and mechanisms of AP@BC for Cd2+. Pot experiments were carried out to assess the impact of AP@BC on soil pH, bioavailable Cd (DTPA-Cd) and ryegrass biomass in acidic (AL), neutral (NH), and alkaline (BH) agricultural soils.

Results and discussion

The maximum adsorption capacity of AP@BC toward Cd2+ was 78.57 mg/g, which increased by 123.5% compared with pristine biochar. The Freundlich and Temkin equations satisfactorily fit the adsorption isotherm experimental data. Pot experiments revealed that the addition of AP@BC from 0.5 to 3% increased the pH of acidic and neutral soils while decreasing the pH of alkaline soils. Notably, the 3% treatment significantly reduced the DTPA-Cd contents in acidic, neutral, and alkaline soil by 8.00%, 22.45%, and 13.65%, respectively, compared to the control. And, ryegrass biomass increased most significantly in high-Cd-content soils (1.5–4.83 times for roots and 2.01–3.88 times for shoots). On the other hand, bioaccumulation and translocation coefficients decreased most in acidic soil (6.02-29.38% and 10.10-30.70%) compared to the control.

Conclusions

The introduction of -NH2 to the surface of the biochar made it much better at adsorption ability. AP@BC reduced the Cd availability in three contaminated soils and most significantly in the acidic soil. It increased ryegrass roots and shoots biomass in high-Cd-content soil. The above results indicate that AP@BC is a promising passivator for the remediation of practical Cd-contaminated agriculture soil.