To enhance the removal of phosphate and nitrate nutrients in wastewater with hard biochar, a two-step wet impregnation method was used to prepare a series of modified almond shell biochar (ASB) having different atomic ratios (x) of Mg/Al hydroxides (ASB-x). Several techniques (XRD, SEM/EDS, FTIR and $N_2$ adsorption/desorption) were used to characterize the structure and adsorption behavior of the adsorbents. The results showed that both Mg/Al hydroxides were successfully introduced onto the surface of ASB in the form of the low crystallinity Mg/Al-layered double hydroxide structure. Optimum adsorption rates for phosphate (47.5%) and nitrate (27.7%) were attained when x was equal to three (ASB-3). The specific surface area (4.51 m²$\mathbf{\cdot }$ g⁻¹) and total pore volume (0.023 cm ³$\mathbf{\cdot }$ g⁻¹) of ASB-3 were greater than those of ASB (2.18 m²$\mathbf{\cdot }$ g⁻¹, 0.012 cm ³$\mathbf{\cdot }$ g⁻¹). Adsorption kinetics and isotherm studies also showed that ASB-3 had an improved rate of adsorption, affinity and capacity for phosphate and nitrate. ASB-3 may provide a potential alternative to carbon-based adsorbents for the removal of phosphates and nitrates from aqueous solutions.

为提高含硬生物炭对废水中磷酸盐和硝酸盐营养物质的去除，采用两步湿法浸渍法制备了一系列具有不同原子比 (x) Mg/Al 氢氧化物 (ASB) 的改性杏仁壳生物炭 (ASB)。 -X）。多种技术（XRD、SEM/EDS、FTIR 和$N_2$吸附/解吸）用于表征吸附剂的结构和吸附行为。结果表明，两种 Mg/Al 氢氧化物均以低结晶度 Mg/Al 层状双氢氧化物结构的形式成功引入 ASB 表面。当 x 等于 3 (ASB-3) 时，磷酸盐 (47.5%) 和硝酸盐 (27.7%) 的最佳吸附率达到。比表面积 (4.51 m ²$\mathbf{\cdot }$g ^-1 ) 和总孔体积 (0.023 cm ³$\mathbf{\cdot }$g ^-1 ) ASB-3 大于 ASB (2.18 m ²$\mathbf{\cdot }$g ^-1 , 0.012 cm ³$\mathbf{\cdot }$g ^-1 )。吸附动力学和等温线研究还表明，ASB-3 对磷酸盐和硝酸盐的吸附速率、亲和力和容量均有所提高。ASB-3 可作为碳基吸附剂的潜在替代品，用于从水溶液中去除磷酸盐和硝酸盐。