生物炭对四环素污染土壤微生物群落结构的影响及环境因子关联的剂量效应分析

Analysis of the dose-effect of biochar on the microbial community structure and environmental factors in tetracycline contaminated soils

为研究不同剂量生物炭对四环素污染的土壤的原位修复效果,本研究以甘蔗渣为原材料制备生物炭,并通过不同剂量的添加(1%、2%、3%,分别记作BC-1、BC-2、BC-3)明确了修复过程中四环素去除效率、土壤理化性质、酶活性和降解微生物的变化情况。结果表明:生物炭施入显著加速了土壤中四环素的降解,其中BC-2处理(79.50%)显著高于BC-3(62.50%)和BC-1(50.30%)处理。同时生物炭处理显著提高了土壤pH及有机质和腐殖质含量,在培养结束后,各处理的pH较CK(四环素污染土壤)分别提升了0.46、0.54、0.80,有机质分别提升了1.37、2.82、5.12 g·kg^(-1),腐殖质分别提升了4.48、6.55、5.21 g·kg^(-1)。生物炭处理显著提升了土壤脲酶、蔗糖酶、过氧化氢酶和脱氢酶活性,其中BC-2处理提升效果最好,较CK分别提升40.00%、183.30%、65.30%和157.10%。在生物炭处理中,具有降解作用的潜在降解菌Achromobacter(无色杆菌属)、Sphingomonas(鞘脂单胞菌属)、Stenotrophomonas(寡养单胞菌属)、Trichosporon(毛孢子菌属)、Shewanella(希瓦氏菌属)、Pseudomonas(假单胞菌属)和Klebsiella(克雷伯菌属)的丰度显著提升,其中BC-2处理对潜在降解菌丰度的促进效果最好。研究表明,生物炭可以通过改善土壤理化性质、提高酶活性、改变土壤微生物群落结构、促进潜在降解菌的相对丰度来加速土壤中四环素的去除。作为一种成本低、修复效果好的富碳材料,生物炭在四环素污染场地原位修复中具有巨大的应用潜力。

In order to study the in situ remediation effect of different doses of biochar on tetracycline contaminated soils,this study used bagasse as raw material to prepare biochar.The removal efficiency of tetracycline,soil physicochemical properties,enzyme activities and degradation microorganisms during the remediation process were determined by adding different doses(1%,2%,3%)of biochar.The results showed that biochar application significantly accelerated the degradation of tetracycline in the soil,and tetracycline contaminated soil+2%biochar(79.50%)was significantly higher than tetracycline contaminated soil+3%biochar(62.50%)and tetracycline contaminated soil+1%biochar(50.30%).The application of biochar significantly increased the pH of the soil and contents of organic matter and humus.After incubation,compared with tetracycline contaminated soil,tetracycline contaminated soil+1%biochar,tetracycline contaminated soil+2%biochar,and tetracycline contaminated soil+3%biochar resulted in significant increases in soil pH(0.46,0.54,0.80),organic matter(1.37,2.82,5.12 g·kg^(-1)),and humus(4.48,6.55,5.21 g·kg^(-1)),respectively.In addition,biochar treatment significantly increased soil urease,sucrase,catalase,and dehydrogenase activities,with tetracycline contaminated soil+2%biochar showing the best performance.In the biochar treatment,the abundance of tetracycline-potentially degrading bacteria,including Achromobacter,Sphingomonas,Stenotrophomonas,Trichosporon,Shewanella,Pseudomonas,and Klebsiella,were significantly increased,and tetracycline contaminated soil+2%biochar treatment had the best increasing effect on the abundance of potentially degrading bacteria.In conclusion,biochar enhances soil physiochemical properties,enzyme activity,and the abundance of potentially degrading bacteria and accelerates the biodegradation of tetracycline.As a carbon-rich material with low cost and good remediation effect,biochar has a great application potential in in situ remediation of tetracycline-contaminated sites.