The use of biochar for the removal of heavy metals from water has environmental benefits. In order to elucidate the potential application of highly functionalized biochar for the removal of Pb(II) in aqueous solution, maple wood biochar was oxidized using hydrogen peroxide. The pH values of oxidized biochar ranged from 8.1 to 3.7, with one set being adjusted to a pH of 7 as a comparison. It was found that oxidizing the biochars increased their Pb(II) adsorption capacity if the pH remained below 6 (strong oxidation), but decreased their Pb(II) adsorption ability above pH 6 (weak oxidation). After adjusting the pH of oxidized biochar to pH 7, the Pb(II) adsorption capacity further increased two to sixfold for oxidized biochars originally at pH 3.7–6. The adsorption characteristics of Pb(II) were well described by the Langmuir equation. Adsorption of Pb(II) was not fully reversible in water. Less than 6% of Pb(II) desorbed in water in two consecutive steps than was previously adsorbed, for biochars with a pH below 7, irrespective of oxidation. Recovery using an extraction with 0.1 M NaNO₃ increased from 0.7% to 32.7% of Pb(II) undesorbed by both preceding water extractions with increasing oxidation, for biochars with a pH below 7. Unextractable Pb(II) was lower at low oxidation but increased to 99.0% of initially adsorbed amounts at low pH, which indicated that the adsorption of Pb(II) on oxidized biochar is pH independent.

使用生物炭从水中去除重金属具有环境效益。为了阐明高功能生物炭在去除水溶液中Pb（II）方面的潜在应用，使用过氧化氢将枫木生物炭氧化。氧化生物炭的pH值范围为8.1至3.7，作为比较将一组pH值调整为7。已经发现，如果pH值保持在6以下（强氧化），氧化生物炭会增加其对Pb（II）的吸附能力，而在pH 6以上时会减弱其对Pb（II）的吸附能力（弱氧化）。在将氧化生物炭的pH值调节至7之后，Pb（II）的吸附能力对于最初在pH 3.7–6下的氧化生物炭的吸附能力进一步提高了2到6倍。Langmuir方程很好地描述了Pb（II）的吸附特性。Pb（II）的吸附在水中不是完全可逆的。对于pH低于7的生物炭，无论其氧化程度如何，在连续两个步骤中解吸的Pb（II）少于连续吸附的6％的Pb（II）。使用0.1 M NaNO萃取进行回收₃从0.7％提高到的Pb（II）的32.7％与具有pH增加氧化，生物炭为低于7不可提取的Pb（II）中，在低氧化低级undesorbed通过两个前述水提取，但提高到最初吸附量为99.0％在低pH值下，这表明Pb（II）在氧化生物炭上的吸附与pH无关。