Oxygen-containing groups on the surfaces of materials (i.e., –COOH and –OH) are vital to the adsorption of toxic metals. Acrylic acid is used as a green grafter to enhance the density of these groups in carbonaceous materials, whereas ammonium cerium nitrate is used as an initiator. Hydrochar (prepared via hydrothermal carbonization at 190 °C), biochar (generated via pyrolysis at 800 °C), and activated carbon (AC; generated via chemical activation with K₂CO₃ at 800 °C) derived from ginger residues are used as feedstock materials for the grafting process. Carbonaceous materials are characterized using scanning electron microscopy, X-ray photoelectron spectrometry, Brunauer–Emmett–Teller analysis, Fourier transform infrared spectroscopy, and zeta potential measurements. Cu²⁺, Cd²⁺, and Pb²⁺ are selected as adsorbates. Equilibrium adsorption experiments for the three metal ions on ungrafted and grafted carbonaceous materials are conducted at 25 °C and pH 5.0. Results indicated that the oxygen content in the grafted material is higher than that in the ungrafted material. Grafting can increase the number of OH and COOH functional groups on the carbonaceous materials, thus resulting in more metal ions being absorbed. The Langmuir maximum adsorption capacity (Q_max) of the carbonaceous materials for the toxic metal ions (mol/kg) is ranked in the order Cu²⁺ > Cd²⁺ > Pb²⁺. The amount of potentially toxic metal ions adsorbed on the ungrafted and grafted (abbreviated as G) materials are in the order hydrochar > AC > biochar. The Q_max values of hydrochar (72.8, 74.7, and 109.3 mg/g), biochar (53.6, 69.1, and 53.9 mg/g), AC (54.4, 73.1, and 101.8 mg/g), G-hydrochar (130.9, 146.0, and 271.4 mg/g), G-biochar (92.6, 143.6, and 153.6 mg/g), and G-AC (96.3, 146.1, and 259.1 mg/g) for the adsorbing metals (Cu²⁺, Cd²⁺, and Pb²⁺) are higher than that of commercial activated carbon (21.83, 22.13, and 25.15 mg/g, respectively). The adsorption capacity of the grafted hydrochar is restored after five adsorption–desorption cycles. The primary adsorption mechanisms are complexation and ion exchange.

材料表面的含氧基团（即 –COOH 和 –OH）对于有毒金属的吸附至关重要。丙烯酸用作绿色接枝剂以提高碳质材料中这些基团的密度，而硝酸铈铵用作引发剂。Hydrochar（通过 190 °C 的水热碳化制备）、生物炭（通过 800 °C 的热解产生）和活性炭（AC；通过 800 °C 的 K 2 CO 3 化学活化产生）_来自生姜_残渣用作接枝过程的原料。使用扫描电子显微镜、X 射线光电子能谱法、Brunauer-Emmett-Teller 分析、傅立叶变换红外光谱和 zeta 电位测量对碳质材料进行表征。铜选择²⁺、Cd ²⁺和 Pb ^{2+作为吸附物。}三种金属离子在未接枝和接枝碳质材料上的平衡吸附实验在 25 °C 和 pH 5.0 下进行。结果表明，接枝材料中的氧含量高于未接枝材料中的氧含量。接枝可以增加碳质材料上的 OH 和 COOH 官能团的数量，从而导致更多的金属离子被吸收。碳质材料对有毒金属离子(mol/kg)的Langmuir最大吸附量( Q _max )排序为Cu ²⁺ > Cd ²⁺ > Pb ²⁺. 吸附在未接枝和接枝（缩写为G）材料上的潜在有毒金属离子的量顺序为水炭>活性炭>生物炭。Hydrochar （72.8、74.7 和 109.3 mg/g）、biochar（53.6、69.1 和 53.9 mg/g）、AC（54.4、73.1 和 101.8 mg/g）、G-hydrochar（130.9 _、 146.0 和 271.4 mg/g）、G-生物炭（92.6、143.6 和 153.6 mg/g）和 G-AC（96.3、146.1 和 259.1 mg/g）用于吸附金属（Cu 2+ ^、 Cd ^{2 +}和 Pb ²⁺）高于商业活性炭（分别为 21.83、22.13 和 25.15 mg/g）。经过五个吸附-解吸循环后，接枝水炭的吸附能力得以恢复。主要的吸附机制是络合和离子交换。