ABSTRACT Application of alkaline biochar has been proposed as an alternative to lime for remediation of acidic soils. However, questions remain as to how the reactions and fate of metals in acidic soils can be affected by biochar amendment. To find out how biochar addition might affect sorption-desorption behavior of zinc (Zn) in acidic soils, a soil with an initial pH value of 4.67 was treated with different levels [0 (control), 1%, 3%, and 6%] of biochar produced from pyrolysis of sugarcane bagasse at 600°C and incubated for 30 days under 80% of water holding capacity. At the end of the incubation period, important soil chemical properties were measured and batch isotherm experiments were performed to determine soil Zn sorption-desorption parameters. The results showed that the biochar-amended soils had higher pH values (up to 2.5 pH units), electrical conductivity (up to 2.66 times), and cation exchange capacities (up to 42%) relative to the un-amended acidic soil. Biochar addition also led to significant enhancements in soil exchangeable calcium, magnesium, sodium, and potassium cations. Both sorption and desorption isotherm experiments revealed the significantly higher capacity of the biochar-amended soils to retain Zn than that of the control. Moreover, the biochar-amended soils exhibited a higher affinity for Zn sorption than did the un-amended acidic one. It can be concluded that biochar derived from sugarcane bagasse could serve as a good amendment material to reclaim acidic soils and to reduce Zn mobility and toxicity in acidic metal-contaminated soils.

中文翻译：

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甘蔗渣生物炭：制备、表征及其对土壤性质和锌吸附-解吸的影响

摘要 碱性生物炭的应用已被提议作为石灰的替代品来修复酸性土壤。然而，关于生物炭改良剂如何影响酸性土壤中金属的反应和归宿的问题仍然存在。为了找出添加生物炭如何影响酸性土壤中锌 (Zn) 的吸附-解吸行为，对初始 pH 值为 4.67 的土壤进行了不同水平的处理 [0（对照）、1%、3% 和 6% ] 由甘蔗渣在 600°C 下热解产生的生物炭，并在 80% 的持水量下培养 30 天。在培养期结束时，测量重要的土壤化学性质并进行分批等温线实验以确定土壤 Zn 吸附-解吸参数。结果表明，经过生物炭改良的土壤具有较高的 pH 值（高达 2.5 pH 单位），相对于未改性酸性土壤的电导率（高达 2.66 倍）和阳离子交换容量（高达 42%）。添加生物炭还显着提高了土壤可交换的钙、镁、钠和钾阳离子。吸附和解吸等温线实验都表明，经过生物炭改良的土壤比对照土壤保留锌的能力显着更高。此外，生物炭改良的土壤比未改良的酸性土壤对锌的吸附表现出更高的亲和力。可以得出结论，从甘蔗渣中提取的生物炭可以作为一种很好的改良材料来回收酸性土壤并降低酸性金属污染土壤中锌的迁移率和毒性。添加生物炭还显着提高了土壤可交换的钙、镁、钠和钾阳离子。吸附和解吸等温线实验都表明，经过生物炭改良的土壤比对照土壤保留锌的能力显着更高。此外，生物炭改良的土壤比未改良的酸性土壤对锌的吸附表现出更高的亲和力。可以得出结论，从甘蔗渣中提取的生物炭可以作为一种很好的改良材料来回收酸性土壤并降低酸性金属污染土壤中锌的迁移率和毒性。添加生物炭还显着提高了土壤可交换的钙、镁、钠和钾阳离子。吸附和解吸等温线实验表明，经过生物炭改良的土壤比对照土壤保留锌的能力显着更高。此外，生物炭改良的土壤比未改良的酸性土壤对锌的吸附表现出更高的亲和力。可以得出结论，从甘蔗渣中提取的生物炭可以作为一种很好的改良材料来回收酸性土壤并降低酸性金属污染土壤中锌的迁移率和毒性。吸附和解吸等温线实验都表明，经过生物炭改良的土壤比对照土壤保留锌的能力显着更高。此外，生物炭改良的土壤比未改良的酸性土壤对锌的吸附表现出更高的亲和力。可以得出结论，从甘蔗渣中提取的生物炭可以作为一种很好的改良材料来回收酸性土壤并降低酸性金属污染土壤中锌的迁移率和毒性。吸附和解吸等温线实验都表明，经过生物炭改良的土壤比对照土壤保留锌的能力显着更高。此外，生物炭改良的土壤比未改良的酸性土壤对锌的吸附表现出更高的亲和力。可以得出结论，从甘蔗渣中提取的生物炭可以作为一种很好的改良材料来回收酸性土壤并降低酸性金属污染土壤中锌的迁移率和毒性。