天然气开采压裂返排液污泥对沙地植物的影响研究

发布时间：2018-07-11 15:11

  本文选题：采气污泥 + 风险评估　； 参考：《中国环境科学研究院》2017年硕士论文

【摘要】：随着我国能源结构变化,天然气开采量逐年递增,开采天然气过程中产生大量泥浆、岩屑及压裂返排液污泥等固体废弃物,目前处理技术方法为露天堆放,缺乏有效处理技术方法。为解决中石化内蒙古地区天然气开采压裂返排液污泥(简称:采气污泥)难处理的困境,参考城市污泥等固体废弃物处理处置方法,资源化利用是普遍认可度高的处理方式,其中污泥还田还林、园林土地利用是资源化主要方式之一。大量研究证实城市污泥能提高土壤养分含量,改良土壤结构,促进植物生长,但是对于采气污泥成分、改良土壤效果及对植物影响方面的研究鲜有报道。因此,本文以毛乌素沙地土壤、中石化内蒙古地区天然气开采压裂返排液污泥、鄂尔多斯市东胜区北郊水质净化厂生活污泥和3种植物(沙蒿(Artemisia desertorum)、黑麦草(LoliumperenneL.)和苜蓿(Medicago falcata L.)]为研究对象,利用盆栽试验,分别设置不同剂量采气污泥,C0作为对照,采气污泥施用量分别为2.5%、5%、10%、15%、20%,生活污泥施用量为固定值(10%)。研究采气污泥物质特性;采气污泥施入后沙地土壤物理和化学性质变化;采气污泥对植物生长影响;采气污泥+生活污泥对植物生长影响。试验结果如下:①采气污泥中重金属含量低,m(Cr)、m(Cd)和m(Pb)分别为35.19、0.18、5.5mg/kg,多环芳烃类(PAHs)未检出,有机质和总氮(TN)、总磷(TP)、总钾(TK)营养元素含量不高,分别为1.46%、0.32%、0.09%、0.15%,盐分含量为0.12%;重金属风险评估结果显示,Cr、Cd、Pb的Igeo值分别为-0.76、-8.69、-2.20,无污染风险,Se和Ba的Igeo值分别为0.02和0.91,有轻度环境污染风险。②采气污泥可以提高沙土最大持水量、增强土壤保水能力和增加沙土孔隙度,降低沙土容重。采气污泥施入量为5%时,土壤最大持水量、土壤保水能力和孔隙度分别相应提高了 74.41%、14.29%和 4.35%。③ 低浓度采气污泥(2.5%)处理能使沙蒿、黑麦草和苜蓿种子萌发率分别提高7.38%、3.61%和8.20%,高浓度污泥(2.5%)则表现为抑制作用。④从采气污泥对沙蒿、黑麦草和苜蓿株高、根长和生物量的影响,确定沙蒿、黑麦草和苜蓿相应污泥适宜施用量分别为≤5%、≤5%和2.5%;从采气污泥和生活污泥混合基质对沙蒿、黑麦草和苜蓿株高和生物量的影响,确定沙蒿、黑麦草和苜蓿相应污泥适宜施用量分别为≤10%、≤10%和5%。研究显示,荒漠区植物耐受采气污泥浓度较低,可采取去污染物和筛选耐性植物等技术来提高用量。
[Abstract]:With the change of energy structure in China, the amount of natural gas exploitation is increasing year by year. During the process of exploiting natural gas, a large number of solid wastes, such as mud, cuttings and fracturing fluid sludge, are produced. At present, the treatment technology is open-air stacking. Lack of effective processing techniques. In order to solve the difficult problem of refractory treatment of natural gas fracturing fluid sludge in Inner Mongolia region of Sinopec, referring to the disposal method of solid waste such as municipal sludge, resource utilization is a generally accepted treatment method. Among them, sludge returning to field and forest, garden land use is one of the main ways of resource utilization. A large number of studies have proved that urban sludge can improve soil nutrient content, improve soil structure and promote plant growth. However, there are few reports on the composition of gas recovery sludge, the effect of improving soil and the effect on plants. Therefore, in this paper, the soil of Maowusu sandy land, natural gas of Sinopec Inner Mongolia region, sewage sludge from fracturing fluid, sewage sludge from water quality purification plant in the northern suburb of Dongsheng District, Ordos City, and three kinds of plants (Artemisia desertorum), ryegrass (Loliumperenne L.) And Medicago falcata L.] In order to study object, pot experiment was used to set up different dosage of aerated sludge (C _ 0) as control. The amount of gas _ producing sludge was 2.5% and 10 ~ 10 ~ (15) ~ 20% respectively, and the amount of domestic sludge was fixed value (10%). The physical and chemical properties of soil in sandy land after aeration sludge application were studied. The effects of gas production sludge on plant growth and life sludge on plant growth were studied. The results were as follows: the contents of heavy metals were 35.19 ~ 0.185.5 mg 路kg ~ (-1), and the contents of organic matter, total nitrogen (TN), total phosphorus (TP) and total potassium (TK) were not high in the aerated sludge, the contents of heavy metals were 35.19 ~ 0.185.5mg / kg, respectively, and the contents of PAHs were not high, and the contents of organic matter, total nitrogen (TN), total phosphorus (TP) and total potassium (TK) were not high. The results of heavy metal risk assessment showed that the Igeo values of Cr-Cr-CdPh were -0.76- 8.69 ~ 2.20, the Igeo values of non-polluting se and Ba were 0.02 and 0.91, respectively, and the maximum water holding capacity of sandy soil was increased by using gas sludge with mild environmental pollution risk. Enhance soil water retention capacity and increase sand porosity, reduce sand bulk density. The maximum soil water holding capacity, soil water retention capacity and porosity were increased by 74.41% and 4.35.3% (2.5%), respectively. The germination rate of ryegrass and alfalfa seeds increased by 7.38% and 8.20%, respectively, and the high concentration sludge (2.5%) showed inhibitory effect on Artemisia annua, ryegrass and alfalfa plant height, root length and biomass. The appropriate amount of sludge applied in ryegrass and alfalfa was 鈮，

本文编号：2115613