生物炭对四环素和铜复合污染土壤生菜生长及污染物累积的影响

通过生菜盆栽试验,研究四环素（TC）和铜（Cu）复合污染胁迫下施用不同生物炭（苹果枝条、玉米秸秆和谷子秸秆生物炭及其改性生物炭）对生菜生长的影响.结果表明,与CK相比,添加生物炭处理的生菜株高、根长、株鲜重和根鲜重均显著增加（P<0.05）.添加不同生物炭可以在不同程度上提高生菜生理指标中硝态氮、叶绿素和可溶性蛋白含量,降低丙二醛、脯氨酸含量以及过氧化氢酶活性,在幼苗期和成熟期生物炭对生菜生理指标的影响趋势一致.与CK相比,添加生物炭后生菜地上部和地下部的TC和Cu含量均有不同程度的降低,生菜地上部TC和Cu分别降低了2.49%~92.32%和12.79%~36.47%,地下部TC和Cu分别降低了12.53%~55.64%和22.41%~42.29%.相关性分析表明,生菜硝态氮、叶绿素和可溶性蛋白含量与生菜TC含量呈显著负相关,丙二醛、脯氨酸含量以及过氧化氢酶活性与生菜TC含量呈显著正相关,生菜抗性基因与TC含量呈显著正相关（P<0.05）.总体趋势上,改性生物炭对提高生菜生长及降低污染物累积的效果优于原生物炭,其中改性谷子秸秆生物炭的修复效果最佳.

Effects of Biochar on Growth and Pollutant Accumulation of Lettuce in Soil Co-contaminated with Tetracycline and Copper

Through lettuce potting experiments, the effects of different types of biochar (apple branch, corn straw, and modified sorghum straw biochar with phosphoric acid modification) on lettuce growth under tetracycline (TC) and copper (Cu) co-pollution were investigated. The results showed that compared with those under CK, the addition of biochar treatment significantly increased the plant height, root length, shoot fresh weight, and root fresh weight of lettuce (P < 0.05). The addition of different biochars significantly increased the nitrate nitrogen, chlorophyll, and soluble protein content in lettuce physiological indicators to varying degrees, while also significantly decreasing the levels of malondialdehyde, proline content, and catalase activity. The effects of biochar on lettuce physiological indicators were consistent during both the seedling and mature stages. Compared with those in CK, the addition of biochar resulted in varying degrees of reduction in the TC and Cu contents of both the aboveground and underground parts of lettuce. The aboveground TC and Cu levels decreased by 2.49%-92.32% and 12.79%-36.47%, respectively. The underground TC and Cu levels decreased by 12.53%-55.64% and 22.41%-42.29%, respectively. Correlation analysis showed that nitrate nitrogen, chlorophyll, and soluble protein content of lettuce were negatively correlated with TC content, whereas malondialdehyde, proline content, and catalase activity were positively correlated with TC content. The resistance genes of lettuce were positively correlated with TC content (P < 0.05). In general, modified biochar was found to be more effective in improving lettuce growth quality and reducing pollutant accumulation compared to unmodified biochar, with modified sorghum straw biochar showing the best remediation effect.