【摘要】：為了提高秸稈固定化微生物對石油污染土壤的修復(fù)效果,開展腐植酸強化秸稈固定化微生物修復(fù)石油污染土壤的研究。本課題從以下四個方面展開實驗。(1)通過加入不同質(zhì)量腐植酸調(diào)節(jié)石油污染土壤中腐植酸含量,分析30d內(nèi)不同土樣中碳含量、氮含量、磷含量、含水率和酶活性的變化,研究腐植酸含量對石油污染土壤特性的影響。(2)在石油污染土壤樣品中分別接種相同濃度游離菌、固定化微生物,加入不同質(zhì)量腐植酸,調(diào)節(jié)土壤腐植酸含量分別為0mg/g(對照)、10mg/g、50mg/g、100mg/g、150mg/g,在28℃、50%濕度的恒溫恒濕培養(yǎng)箱中培養(yǎng)30d,每隔6d測定各土樣中的微生物數(shù)量、石油烴含量、脫氫酶含量,研究土樣中微生物數(shù)量變化趨勢、石油烴降解菌的生長情況、土著菌與游離菌、土著菌與固定化微生物之間相互作用。(3)采用單因素花盆實驗?zāi)M固定化微生物秸稈載體60d腐解情況,每隔15d測定土樣中腐植酸含量,考察含水率、溫度和pH三個單因素對秸稈載體腐解產(chǎn)生腐植酸含量的影響;采用BBD實驗進行響應(yīng)面優(yōu)化秸稈最佳腐解條件。(4)選取BBD實驗修復(fù)60d后的8個石油烴含量相近的花盆進行腐植酸強化固定化微生物修復(fù)實驗。設(shè)置對照實驗、強化修復(fù)實驗和對比實驗,研究秸稈載體最佳腐解條件和只考慮固定化微生物生長條件對石油污染土壤修復(fù)效果的影響。實驗結(jié)果表明:(1)土壤中腐植酸含量為100mg/g時,土壤蓄水性最佳,且在土壤含水率較低的水平下,最利于調(diào)節(jié)土壤中C/N和速效磷含量,以及多酚氧化酶和脫氫酶的生成,同時還可促進微生物對土壤H2O2的分解。(2)接種秸稈固定化微生物的土樣微生物量高于接種游離石油烴降解菌的土樣。當(dāng)土壤中腐植酸含量為100mg/g時,固定化后微生物在30d內(nèi)石油烴降解率菌可達(dá)48.2%,較不加腐植酸的土樣高7.2個百分點、較接種游離降解菌的土樣高11.3個百分點;腐植酸含量為100mg/g的土樣中脫氫酶活性較其他土樣的增長量和增長速率最大。(3)利用響應(yīng)面法得出固定化微生物秸稈載體腐解的最佳實驗條件為含水率32.5%、溫度27.3℃、pH 7.5,秸稈載體60d腐解產(chǎn)生腐植酸含量為763.08μg/g。(4)土壤初始石油烴含量為2.3%~3.0%時,將土壤腐植酸含量調(diào)節(jié)為100mg/g,并在最有利于秸稈載體腐解的環(huán)境條件下,30d石油烴降解率可達(dá)到27.6%,較在此環(huán)境條件下不加腐植酸的實驗組石油烴降解率高13.6個百分點,較只考慮微生物生長條件的實驗土樣高7.3個百分點。綜上所述,土壤中腐植酸含量為100mg/g,且在秸稈最佳腐解條件下,可起到強化秸稈固定化微生物對石油污染土壤的修復(fù)作用。
[Abstract]:In order to improve the remediation effect of straw-immobilized microorganism on petroleum-contaminated soil, humic acid enhanced straw-immobilized microorganism was carried out to repair petroleum-contaminated soil. The experiment was carried out from the following four aspects. (1) the changes of carbon content, nitrogen content, phosphorus content, moisture content and enzyme activity of different soil samples in 30 days were analyzed by adding humic acid of different quality to regulate the content of humic acid in petroleum-contaminated soil. The effects of humic acid content on the characteristics of petroleum-contaminated soil were studied. (2) the free bacteria of the same concentration were inoculated in the oil-contaminated soil samples, immobilized microorganisms, and humic acid of different quality was added to the soil samples. The humic acid content of soil was adjusted to 0mg/g (control), 10 mg / kg, 50 mg / kg, 100 mg / kg, 150 mg / g, respectively. The soil humic acid content was cultured in a constant temperature and humidity incubator at 28 鈩，

本文編號：2446306