氮磷养分对荧蒽污染土壤修复的应用研究

为探究污染土壤中氮、磷养分添加对土壤中多环芳烃(PAHs)去除的影响,通过室内土壤培养试验,以荧蒽为PAHs代表,研究外加氮磷(0、150、300、450、600 mg·kg^-1)对土壤中PAHs污染消减的影响,并通过污染土壤中外加氮磷对相关土壤酶活性的影响,探讨氮磷养分对土壤中荧蒽去除的机理。结果表明:外加氮磷有利于污染土壤中荧蒽的去除,外加氮磷可将土壤中荧蒽的半衰期缩短最多达78.4%。在100 mg·kg^-1荧蒽污染下,外加300 mg·kg^-1氮对土壤中荧蒽的消除速率常数提高了388.9%;外加150 mg·kg^-1磷对土壤中荧蒽消除速率常数提高了477.8%。外加氮磷可显著影响土壤中相关酶活性,外加磷能够显著提高土壤中脲酶活性和酸性磷酸酶活性;外加氮显著提高了低荧蒽污染土壤中酸性磷酸酶活性;外加氮磷均可显著提高土壤多酚氧化酶活性,多酚氧化酶活性的提高与土壤中荧蒽的去除具有显著正相关性。研究建议,污染黄棕壤中外加氮、磷的范围为150~300 mg·kg^-1,外加的氮磷通过有效改变污染土壤的酶活性,从而促进土壤中PAHs的去除。

Application of nitrogen and phosphorus in remediation of fluoranthene-contaminated soil

A soil culture experiment was conducted to investigate the effects of nitrogen and phosphorus on polycyclic aromatic hydrocarbons (PAHs) removal in polluted soil. In this experiment, fluoranthene was selected as a representative of PAHs. The concentrations of the added nitrogen and phosphorus were 0, 150, 300, 450 and 600 mg·kg^-1. The effects of nitrogen and phosphorus on soil enzyme activity, were accessed to examine the mechanism of fluoranthene removal. The results showed that the addition of nitrogen and phosphorus was beneficial to the removal of fluoranthene in contaminated soil; the half-life of fluoranthene in soil was shortened by up to 78.4%. In the contaminated soil with 100 mg·kg^-1 fluoranthene, the removal rate constant of fluoranthene was increased by 388.9% through the addition of 300 mg·kg^-1 of nitrogen and was increased by 477.8% through the addition of 150 mg·kg^-1 of phosphorus. The addition of nitrogen and phosphorus had certain effects on the activities of urease, phosphatase and polyphenol oxidase in soil. The activities of urease and acid phosphatase in soil were significantly increased by adding phosphorus. The acid phosphatase activity in soil contaminated with low fluoranthene was significantly increased by the addition of nitrogen. The addition of nitrogen and phosphorus could significantly increased the activity of polyphenol oxidase. An increase in polyphenol oxidase activity was significantly correlated with the removal of fluoranthene in soil. In conclusion, the optimal amount of nitrogen and phosphorus added in the polluted, yellow-brown soil is 150~300 mg·kg^-1, this can effectively change soil enzyme activities and promote PAHs removal.