甜菜-牧草体系对土壤中4种邻苯二甲酸酯的修复研究

通过室内盆栽试验,研究了甜菜与黑麦草、苜蓿、苏丹草分别间作及4种植物各自单作对土壤中邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸丁基苄基酯(BBP)和邻苯二甲酸(2-乙基己基)二酯(DEHP)4种邻苯二甲酸酯类(PAEs)的植物修复效果。结果表明:与空白对照相比,种植植物的修复效果更好;苜蓿单作与间作都有较好的修复效果,其中甜菜/苜蓿间作PAEs的去除率最高,可达66.48%;植物单作与间作相比,间作的修复效果高于单作,间作增强土壤中过氧化氢酶和磷酸酶的活性,从而促进了根际微生物对PAEs的降解;就单一污染物来说,DBP和DEHP在污染土壤和植物茎叶中的浓度较其他两种污染物高,两者在土壤中的去除率也较高,其中DEHP为最高,均可达50%以上,DBP的去除率也在40%以上;DEHP在植物茎叶中的生物富集系数明显较低,且单作低于间作,而DBP和BBP的生物富集系数较高。可选择苜蓿作为土壤中PAEs修复的一种高效修复植物,植物间作相对于单作有更好的修复效率,也可更高效地利用土地资源,因此可优先选择作为植物修复的一种种植模式。

Phytoremediation of 4 phthalic acid esters in contaminated soil by beet-grass system

A pot experiment was conducted to study the phytoremediation of 4 phthalic acid esters(DEP, DBP, BBP and DEHP) by different planting patterns with beet and 3 grasses(ryegrass, sudangrass and alfalfa) in contaminated soil. Greater reduction of phthalic acid esters was observed in treatments with plants than without plants, and in intercropping than monoculture. Alfalfa monoculture and intercropping both had better remediation effects than other plants did. Beet/alfalfa intercropping removed over 65% of PAEs. Intercropping enhanced the activities of catalase and phosphatase in soil, thus promoting the degradation of PAEs. In both soil and the shoots of the tested plants, DEHP and DBP had much higher concentrations than the other PAEs studied did. Their removal efficiencies were also higher, with DEHP greater than 50% and DBP over 40%. Bioconcentration factor(BCF) of DEHP was significantly low in the shoots of the tested plants, while that of DBP and BBP was high. Alfalfa could be used as a phytoremediator of phthalic acid esters in soil. Plant intercropping would provide greater remediation efficiency than monoculture.