Activated carbon has found key applications in the adsorption of polluted industrial dyes in water. In this work, macadamia husk biochar (MHC) was prepared using a household pyrolysis kiln before being activated with phosphoric acid (H₃PO₄) to obtain macadamia-husk-activated carbon (MHAC). A preliminary study was made on two activation conditions of MHC:phosphoric acid (w/v), 1:1 and 1:3, for the removal of malachite green (MG) dye. Analysis of experimental results revealed that the adsorption process was highly controlled by the time of contact, MHAC particle size, MHAC dosage and initial dye concentration. With the use of an MHAC particle size of 125–202 μm, an MHAC dosage of 6 g/l and a contact time of 120 min, the removal efficiency reached >99% at an MG concentration of 40 parts per million (ppm) before being degraded to around 75% at 70–80 ppm MG. Impregnation with zinc nitrate hexahydrate (Zn(NO₃)₂·6H₂O) on the MHAC surface could maintain a removal efficiency of >99% at all initial dye concentrations (40–80 ppm), so the maximum removal capacity increased to ∼130 mg/g.

中文翻译：

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家用热解窑澳洲坚果壳活性炭的吸附性能

活性炭在吸附水中受污染的工业染料方面有着重要的应用。在这项工作中，使用家用热解窑制备澳洲坚果壳生物炭（MHC），然后用磷酸（H ₃ PO ₄）以获得澳洲坚果壳活性炭（MHAC）。对MHC:磷酸(w/v)1:1和1:3两种活化条件进行了初步研究，以去除孔雀石绿(MG)染料。实验结果分析表明，吸附过程受接触时间、MHAC 粒径、MHAC 用量和初始染料浓度的高度控制。使用 125-202 μm 的 MHAC 粒径、6 g/l 的 MHAC 剂量和 120 分钟的接触时间，在 MG 浓度为 40 ppm (ppm) 的情况下，去除效率达到 >99%。在 70–80 ppm MG 时降解至 75% 左右。_{六水硝酸锌(Zn(NO 3} ) ₂ ·6H ₂浸渍O）在 MHAC 表面上可以在所有初始染料浓度（40-80 ppm）下保持 >99% 的去除效率，因此最大去除能力增加至~130 mg/g。