Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin, 300191, China; School of Land and Environment, Shenyang Agriculture University, Shenyang, 110000, China.
School of Agriculture, Ludong University, Yantai, 264025, China.
Environ Pollut. 2018 Aug;239:118-128. doi: 10.1016/j.envpol.2018.03.091. Epub 2018 Apr 10.
Herein, we utilize sequential extraction and high-throughput sequencing to investigate the effects of nanomaterial additives on As volatilization from flooded soils. We reveal that maximum volatilization is achieved in the fourth week and is followed by stabilization. The extent of volatilization decreased in the order of control > nano-zerovalent iron >40-nm hydroxyapatite > nano-FeO > 20-nm hydroxyapatite > multilayer graphene oxide > high-quality graphene oxide. The most abundant forms of As in soil corresponded to As-Fe and Al oxides. In soil with low levels of As pollution, the contents of these species increased after treatment with graphene oxides but decreased after treatment with other nanomaterials, with an opposite trend observed for soil with high levels of As pollution. The addition of nanomaterials influenced the activity of soil enzymes, e.g., hydroxyapatites affected the activities of urease and alkaline phosphatase, whereas graphene oxides significantly impacted that of peroxidase (P < 0.05). The addition of nanomaterials (which can potentially inhibit microbial growth) affected As levels by influencing the amount of As volatilized from polluted soil. Moreover, As volatilization, enzyme activity, and As speciation were observed to be mutually correlated (e.g., volatilization was negatively correlated to peroxidase activity and the contents of amorphous crystalline hydrous oxides of As-Fe and Al).
在此，我们利用连续提取和高通量测序来研究纳米材料添加剂对淹水土壤中砷挥发的影响。我们发现，最大的挥发发生在第四周，随后是稳定化。挥发的程度按以下顺序递减：对照品>纳米零价铁>40nm 羟基磷灰石>纳米-FeO>20nm 羟基磷灰石>多层氧化石墨烯>高质量氧化石墨烯。土壤中砷的最丰富形式为砷-铁和铝氧化物。在砷污染水平较低的土壤中，在用氧化石墨烯处理后，这些物质的含量增加，但在用其他纳米材料处理后则减少，而在砷污染水平较高的土壤中则出现相反的趋势。纳米材料的添加影响了土壤酶的活性，例如，羟基磷灰石影响了脲酶和碱性磷酸酶的活性，而氧化石墨烯则显著影响了过氧化物酶的活性（P<0.05）。纳米材料的添加（可能会抑制微生物的生长）通过影响从污染土壤中挥发的砷量来影响砷水平。此外，还观察到砷挥发、酶活性和砷形态之间存在相互关联（例如，挥发与过氧化物酶活性和无定形结晶水合砷-铁和铝氧化物的含量呈负相关）。
