天然气开采压裂返排液污泥用于荒漠区植被修复的可行性

发布时间：2018-07-28 20:26

【摘要】：为解决中石化大牛地气田天然气开采压裂返排液污泥(采气污泥)难处理的困境,在测定采气污泥成分和运用地累积指数法(I_(geo))评估其环境风险的基础上,利用三种荒漠区常见植物[沙蒿(Artemisia desertorum)、黑麦草(Lolium perenne L.)和苜蓿(Medicago falcata L.)],通过设计采气污泥与荒漠区土壤配比,开展天然气开采压裂返排液污泥用于荒漠区植被修复的可行性试验研究.结果表明:(1)采气污泥中各污染物组分含量相对较低,w(Cr)、w(Cd)、w(Pb)分别为35.187、0.181、5.502 mg/kg,PAHs(多环芳烃类)未检出;w(OM)、w(TN)也较低,分别为1.46%、0.32%,盐分含量为1.2%.(2)重金属风险评估结果显示,Cr、Cd、Pb的I_(geo)值分别为-0.76、-8.69和-2.20,污染风险等级为清洁;Se和Ba的I_(geo)值分别为0.02和0.91,有轻度环境污染风险.(3)5%采气污泥处理能使土壤最大持水量、土壤保水能力和孔隙度分别提高了74.41%、14.29%和4.35%.(4)低浓度(2.5%)采气污泥处理能使沙蒿、黑麦草和苜蓿种子发芽率分别提高7.38%、3.61%和8.20%,高浓度(2.5%)采气污泥对种子萌发则表现为抑制作用.(5)根据采气污泥对沙蒿、黑麦草和苜蓿株高、根长和生物量的影响,确定采气污泥适宜施用量分别为≤5%、≤2.5%、≤2.5%.研究显示,采气污泥用于荒漠区植物修复是可行的,但适宜施用量较低,可采取去污染物和筛选耐性植物等技术来提高其用量.
[Abstract]:In order to solve the difficult problem of fracturing fluid sludge (gas recovery sludge) in natural gas mining in Daniudi gas field of Sinopec, the composition of gas recovery sludge and the assessment of environmental risk by using I _ (geo) method are determined. Using three common plants in desert region [(Artemisia desertorum), ryegrass] (Lolium perenne L.) And alfalfa (Medicago falcata L.), through designing the ratio of gas sludge and soil in desert area, the feasibility study of natural gas exploitation and fracturing back drainage sludge for vegetation restoration in desert area was carried out. The results showed that: (1) the content of each pollutant component in the gas recovery sludge was relatively low, and the (Pb) of w (Cr) / w (Cd) / w was 35.187 卤0.181 mg / kg and 5.502 mg / kg / kg respectively, and it was also lower than that of polycyclic aromatic hydrocarbons (PAHs) without the detection of polycyclic aromatic hydrocarbons (PAHs). The results of heavy metal risk assessment showed that the I _ (geo) values of Cr-CdCd-Pb were -0.76 ~ 8.69 and -2.20, respectively, and the I _ (geo) values of clean se and Ba were 0.02 and 0.91 respectively, and there was a slight environmental pollution risk. (3) 5% gas sludge treatment could cause pollution. Maximum soil water holding capacity, Soil water retention capacity and porosity were increased by 74.41% and 4.35%, respectively. (4) low concentration (2.5%) gas recovery sludge treatment could make Artemisia annua, Seed germination rate of ryegrass and alfalfa increased by 7.38% 3.61% and 8.20%, respectively, and high concentration (2.5%) of aerated sludge inhibited seed germination. (5) according to the effects of gas sludge on plant height, root length and biomass of Artemisia annua, ryegrass and alfalfa, It is determined that the appropriate application amount of gas recovery sludge is 鈮，

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