【摘要】：為解決中石化大牛地氣田天然氣開采壓裂返排液污泥(采氣污泥)難處理的困境,在測定采氣污泥成分和運(yùn)用地累積指數(shù)法(I_(geo))評估其環(huán)境風(fēng)險的基礎(chǔ)上,利用三種荒漠區(qū)常見植物[沙蒿(Artemisia desertorum)、黑麥草(Lolium perenne L.)和苜蓿(Medicago falcata L.)],通過設(shè)計采氣污泥與荒漠區(qū)土壤配比,開展天然氣開采壓裂返排液污泥用于荒漠區(qū)植被修復(fù)的可行性試驗研究.結(jié)果表明:(1)采氣污泥中各污染物組分含量相對較低,w(Cr)、w(Cd)、w(Pb)分別為35.187、0.181、5.502 mg/kg,PAHs(多環(huán)芳烴類)未檢出;w(OM)、w(TN)也較低,分別為1.46%、0.32%,鹽分含量為1.2%.(2)重金屬風(fēng)險評估結(jié)果顯示,Cr、Cd、Pb的I_(geo)值分別為-0.76、-8.69和-2.20,污染風(fēng)險等級為清潔;Se和Ba的I_(geo)值分別為0.02和0.91,有輕度環(huán)境污染風(fēng)險.(3)5%采氣污泥處理能使土壤最大持水量、土壤保水能力和孔隙度分別提高了74.41%、14.29%和4.35%.(4)低濃度(2.5%)采氣污泥處理能使沙蒿、黑麥草和苜蓿種子發(fā)芽率分別提高7.38%、3.61%和8.20%,高濃度(2.5%)采氣污泥對種子萌發(fā)則表現(xiàn)為抑制作用.(5)根據(jù)采氣污泥對沙蒿、黑麥草和苜蓿株高、根長和生物量的影響,確定采氣污泥適宜施用量分別為≤5%、≤2.5%、≤2.5%.研究顯示,采氣污泥用于荒漠區(qū)植物修復(fù)是可行的,但適宜施用量較低,可采取去污染物和篩選耐性植物等技術(shù)來提高其用量.
[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 鹵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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