获取海水中钙镁资源来制备改性木基生物炭吸附剂及其对水中磷的吸附

Acquisition of Calcium and Magnesium Resources from Seawater to Prepare the Modified Wood-Based Biochar Adsorbent and Its Adsorption of Phosphate from Water

摘要: 含CaO/MgO的改性木基生物炭(MCP-700)对水中磷具有良好的吸附性能。采用TG、XRD、SEM、EDX等手段表征了MCP-700制备后的化学组成、结构和微观形貌。考察了pH、投加量等因素对MCP-700吸附磷酸盐的影响。溶液pH明显影响MCP-700对水中磷的吸附量。结果表明，在pH = 4~9之间，MCP-700对磷酸盐的去除率都几乎达到100%。当投加量 ≥ 2.0 mg•L⁻¹，MCP-700对水中总磷的去除率大于95%。研究了温度为25℃，pH = 7，投加量为1 g•L⁻¹的情况下，MCP-700和Carbon-700对水中磷酸盐的吸附性能。根据Langmuir模型拟合，MCP-700和Carbon-700对水中磷酸盐的最大吸附量分别为9.75 mg P•g ⁻¹和1.29 mg P•g⁻¹，改性木基生物炭吸附性得到较大提升。本研究将为低成本改性木基生物炭去除水中磷酸盐提供科学依据和技术基础。

Abstract: The modified wood-based biochar (MCP-700) containing CaO/MgO exhibits excellent adsorption properties for removal of phosphate from water. TG, XRD, SEM and EDX were used to characterize the chemical composition, crystal structure and micro-morphologies of MCP-700. The effects of pH and dosage on phosphate removal by MCP-700 were investigated. The pH had obvious effect on the adsorption capacity. The adsorption on MCP-700 reached the 100% at pH of 4~9. The removal rate of total phosphate in water by MCP-700 is greater than 95% when the dosage ≥ 2.0 mg•L⁻¹. According to the Langmuir model, the maximum absorption capacity of MCP-700 and Carbon-700 were 9.75 mg P•g⁻¹ and 1.29 mg P•g⁻¹ at temperature of 25˚C (pH = 7 and dosage 1.0 g•L⁻¹). The adsorption capacity of modified wood based biochar was greatly improved. This study will provide the basis in theory and technique for the application of the low-cost modified wood-based biochar to remove phosphate in water.