Mecozzi Roberta, Di Palma Luca, Merli Carlo
Dipartimento di Ingegneria Chimica, dei Materiali, delle Materie Prime e Metallurgia, Università di Roma La Sapienza, via Eudossiana 18, 00184 Rome, Italy.
Chemosphere. 2006 Mar;62(9):1481-9. doi: 10.1016/j.chemosphere.2005.06.011. Epub 2005 Aug 3.
Lab-scale experiments of in situ chemical oxidation (ISCO), were performed on soil contaminated with 100 mg kg(-1) of atrazine (CIET). The oxidant used was hydrogen peroxide catalysed by naturally occurring minerals or by soluble Fe(II) sulphate, added in aqueous solution. The oxidation conditions were: CIET:H2O2=1:1100, 2 PV or 3 PV reaction volume, Fe(II):H2O2=0, 1:22, 1:11. Stabilized (with KH2PO4 at a concentration of 16 g l(-1)) or non-stabilized hydrogen peroxide was used. The pH of the reagents was adjusted to pH=1 with sulphuric acid, or was not altered. Results showed that the addition of soluble Fe(II) increased the temperature of the soil slurry and the use of stabilized hydrogen peroxide resulted in a lower heat generation. The treatment reduced the COD of the soil of about 40%, pH was lowered and natural organic matter became less hydrophobic. The highest atrazine conversion (89%) was obtained in the conditions: 3 PV, Fe(II):H2O2=1:11 with stabilized hydrogen peroxide added in two steps. The stabilizer only increased H2O2 life-time significantly when soluble Fe(II) was added. Results indicate as preferential degradation pathway of atrazine in soil dechlorination instead of dealkylation.
对受100毫克/千克莠去津污染的土壤进行了原位化学氧化（ISCO）的实验室规模实验。使用的氧化剂是由天然矿物或添加到水溶液中的可溶性硫酸亚铁催化的过氧化氢。氧化条件为：CIET:H2O2 = 1:1100，2倍孔隙体积（PV）或3倍PV反应体积，Fe(II):H2O2 = 0、1:22、1:11。使用了稳定化（用浓度为16克/升的KH2PO4）或未稳定化的过氧化氢。用硫酸将试剂的pH值调节至pH = 1，或不改变。结果表明，添加可溶性Fe(II)会提高土壤泥浆的温度，使用稳定化过氧化氢会产生较低的热量。该处理使土壤的化学需氧量（COD）降低了约40%，pH值降低，天然有机物的疏水性降低。在以下条件下获得了最高的莠去津转化率（89%）：3倍PV，Fe(II):H2O2 = 1:11，分两步添加稳定化过氧化氢。仅在添加可溶性Fe(II)时，稳定剂才会显著延长H2O2的寿命。结果表明，土壤中莠去津的优先降解途径是脱氯而非脱烷基化。
