聚丙烯酰胺改性生物质炭对盐碱化土壤盐分洗脱的影响

为了提升生物质炭对滨海盐碱土壤盐分的洗脱效率，以海兴县盐碱土为研究对象，利用聚丙烯酰胺(PAM)、小麦秸秆生物质炭(BC)、黏土矿物(M)等材料制备聚丙烯酰胺改性生物质炭(PAM-BC),通过室内模拟淋溶试验研究对比不同环境材料对盐碱土盐分的洗脱效果。结果表明，相比于CK处理，PAM、BC和PAM-BC、CaSO₄(CS)处理均显著增加土壤盐分洗脱量，其中PAM-BC处理下增幅最高，达到12.3%。进一步对淋洗液中主要盐分离子分析，添加PAM-BC显著促进土壤Na⁺和Cl^-的洗脱，增幅分别为11.0%～27.3%和17.8%～42.3%。主成分分析表明，PAM-BC增强对主要盐分离子的洗脱效果。土柱淋溶结束后，PAM-BC添加处理土壤全盐量比其他处理显著降低6.0%～16.7%。此外，土壤水分特征曲线表明，添加PAM-BC提升盐碱土壤的保水性。研究结果可为聚丙烯酰胺改性生物质炭应用于滨海盐渍化土壤的降盐改土提供理论依据。

Effect of Polyacrylamide-modified Biochar on Salt Elution of Saline-alkali Soil

In order to improve the water desalting efficiency of biochar on coastal saline-alkali soil,a granular biochar-polyacrylamide composite (PAM-BC) was obtained by blending biochar (BC),polyacrylamide (PAM),clay minerals in this study,while the effect of different environmental materials on the salt elution of saline soil from Haixing County was studied by a laboratory soil column simulation leaching experiment.The results showed that the treatments of PAM,BC and PAM-BC,CaSO₄(CS) significantly increased the elution amount of salt compared to CK,especially for the PAM-BC treatment with highest increase of 12.3%.The main salt ions in the eluent were further analyzed,the addition of PAM-BC significantly promoted the salt ions leaching of Na⁺ and Cl^- by 11.0%~27.3% and 17.8%~42.3% than other treatments,respectively.Principal component analysis indicated that PAM-BC addition enhanced the elution of major salt ions.The total salt content of soil under PAM-BC treatment was significantly decreased by 6.0%~16.7% compared to other treatments after the leaching of soil column.Moreover,the soil water characteristic curves indicated that PAM-BC promoted the water retention of saline-alkali soil.These findings can provide a theoretical basis for the application of PAM modified biochar in the salt reduction and soil improvement in coastal saline-alkali soil.