本文關(guān)鍵詞： 納米羥基磷灰石 微生物 土壤 鎘 油菜　出處：《河北大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著現(xiàn)代農(nóng)業(yè)技術(shù)的快速發(fā)展以及農(nóng)藥化肥的不合理利用,在造成農(nóng)業(yè)減產(chǎn)、食品質(zhì)量安全下降的同時,土壤質(zhì)量問題日益嚴重。土壤污染尤其重金屬鎘污染問題相對突出。如何在當前確保農(nóng)業(yè)耕地紅線的前提下,保障農(nóng)產(chǎn)品和土壤環(huán)境安全成為農(nóng)業(yè)、環(huán)境及食品工作領(lǐng)域的重點關(guān)注話題。本文在大量文獻調(diào)研的基礎(chǔ)上,通過室內(nèi)模擬實驗探索了納米羥基磷灰石(NHAP)對重金屬鎘在土壤中淋溶特征的影響,明確了不同比例納米羥基磷灰石施加后土壤鎘含量和形態(tài)的轉(zhuǎn)化規(guī)律。在納米羥基磷灰石與微生物(枯草芽孢桿菌、白腐真菌)協(xié)同作用下,鎘在土壤和植株中的分布規(guī)律及植物根際土壤微生物種群變化。主要研究結(jié)果如下:1.納米羥基磷灰石(NHAP)對溶液中鎘離子的吸附率和解吸率隨時間延長、溫度上升均呈先升高后趨于穩(wěn)定;隨溶液pH升高,納米羥基磷灰石對鎘離子的吸附率快速上升后基本穩(wěn)定,解吸率隨pH升高后迅速降低,在pH為3時基本穩(wěn)定。2.通過模擬土柱實驗評價NHAP處理對污染土壤中Cd原位固定效果及形態(tài)變化規(guī)律。結(jié)果表明:NHAP的輸入增加了土壤的pH,而且土壤鎘經(jīng)NHAP鈍化穩(wěn)定化后由生物有效態(tài)向穩(wěn)定態(tài)轉(zhuǎn)化。土壤淋出液中鎘濃度經(jīng)不同模型擬合,拋物線擴散模型的R2最大,達到0.998,以此推斷在酸雨間歇淋失條件下,經(jīng)NHAP處理的鎘污染土壤50年后浸出液中鎘濃度不會對人體健康造成危害。3.室內(nèi)模擬盆栽實驗,研究納米羥基磷灰石的不同施加比例對鎘污染土壤的鈍化修復(fù)效果。結(jié)果表明:NHAP施加顯著增加油菜株高生物量,且隨NHAP施入量的增加,油菜中Cd含量顯著下降,施入量為0.2%、0.5%和1%時,分別比對照降低22.38%,36.25%和50.2%。NHAP施加可顯著提高土壤生物學(xué)質(zhì)量,與對照相比,NHAP處理鎘污染土壤過氧化氫酶、脲酶和堿性磷酸酶的活性顯著增加,且過氧化氫酶和堿性磷酸酶活性隨施加量的增加顯著提高。對比不同納米羥基磷灰石添加比例對植物、土壤修復(fù)效果,0.5%(W/W)的納米羥基磷灰石的施加比例為較優(yōu)修復(fù)處理。4.以0.5%(W/W)納米羥基磷灰石為修復(fù)基礎(chǔ),分別聯(lián)合枯草芽孢桿菌、白腐真菌,通過盆栽實驗,研究納米羥基磷灰石-微生物聯(lián)合作用對鎘污染土壤鈍化修復(fù)效果。結(jié)果表明,NHAP和微生物的聯(lián)合作用顯著提高了油菜株高生物量,油菜植株中Cd累積量顯著降低,各處理油菜植株中Cd含量分別比CK處理減少37.99%-57.04%。同時,由于油菜吸收量的降低,在植物-土壤體系鎘穩(wěn)定平衡的前提下,施加NHAP-微生物各處理土壤中鎘殘留量較對照提高7.01%-16.77%。BCR順序提取法分析表明NHAP與微生物聯(lián)合作用促進土壤Cd由交換態(tài)向Cd殘渣態(tài)轉(zhuǎn)化。分析土壤生物學(xué)質(zhì)量表明,NHAP與微生物聯(lián)合作用不同程度地提高了鎘污染土壤中過氧化氫酶、脲酶和堿性磷酸酶活性。而且,相較枯草芽孢桿菌和白腐真菌,NHAP施加對土壤中細菌種群豐富度和多樣性有顯著影響,鎘污染土壤加入NHAP后,群落豐富度和細菌多樣性均顯著增加,變形菌門、放線菌門等種群增多,有益菌Paenibacillus(類芽孢桿菌)等顯著增加,有害菌Gemmata(出芽菌屬)等顯著減少,使土壤向健康方向發(fā)展。綜上,本研究表明,納米羥基磷灰石對鎘污染土壤呈現(xiàn)較好的鈍化修復(fù)效果,土壤pH的升高與鎘離子形成磷酸鹽沉淀,降低了土壤中生物有效態(tài)鎘含量和濃度,且鎘污染土壤鈍化修復(fù)過程中納米羥基磷灰石與功能微生物呈現(xiàn)較好的協(xié)同作用,其吸附鈍化功能共同促進有效態(tài)鎘向穩(wěn)定態(tài)轉(zhuǎn)化,為中低濃度鎘污染土壤長期穩(wěn)定和可持續(xù)發(fā)展提供材料支持和技術(shù)補充。
[Abstract]:With the rapid development of fertilizer and pesticide is not reasonable use of modern agricultural technology, resulting in agricultural production, food safety and quality decline at the same time, the soil quality problems become more and more serious soil pollution. Especially the cadmium pollution problem is relatively prominent. How to ensure the premise of agricultural land in the red line under the protection of agricultural products and agricultural soil environmental security has become topic, focus on the environment and food field. In this paper, on the basis of literature research, through the indoor simulation experiment on the nano hydroxyapatite (NHAP) effect of cadmium on the leaching characteristics, clear the different proportion of nano hydroxyapatite and transformation of soil cadmium content and morphology after applying in nano hydroxyapatite and microbial. (Bacillus subtilis, white rot fungi) synergy, cadmium distribution and plant in the soil and plant rhizosphere Soil microbial population changes. The main results are as follows: 1. nano hydroxyapatite (NHAP) on the adsorption rate and desorption rate of cadmium ion in the solution with time, temperature rise were firstly increased and then tended to be stable; with the increase of solution pH, nano hydroxyapatite on the cadmium ion adsorption rate increased rapidly after the basically stable, with the desorption rate pH increased and then decreased rapidly when the pH is 3 stable.2. through soil column simulation experiment to evaluate NHAP treatment on the changes of fixed effect and morphology in Cd contaminated soil in situ. The results show that the input of NHAP increased soil pH, and soil cadmium by NHAP passivation after stabilization by biological effective state to a stable state transformation of soil leaching. The cadmium concentration in liquid by different fitting model, diffusion model R2 is the largest, reaching 0.998, in order to infer the intermittent leaching in acid rain conditions, the cadmium contaminated soil NHAP treatment after 50 years of leaching solution The Cd concentration in the.3. will not cause harm to human health indoor simulation and pot experiment, remediation effect of different proportion of applying nano hydroxyapatite passivation on the cadmium contaminated soil. The results showed that NHAP exerted significantly increased plant height and biomass, with the increase of NHAP application rate, Cd content in rape decreased significantly, the amount of applied for 0.2%, 0.5% and 1%, respectively, decreased by 22.38%, 36.25% and 50.2%.NHAP applied can significantly improve soil biological quality, compared with the control group, NHAP treatment of cadmium contaminated soil enzyme catalase, urease and alkaline phosphatase activity increased significantly, and the catalase and alkaline phosphatase activity increased with the increase of the amount increased significantly. Compared with different nano hydroxyapatite the proportion of plants, soil remediation, 0.5% (W/W) nano hydroxyapatite is applied as the optimal repair ratio of.4. to 0.5% (W/W) nano hydroxyapatite 鐏扮煶涓轟慨澶嶅熀紜，

本文編號：1450078