發(fā)布時間：2018-01-22 22:45

  本文關(guān)鍵詞： 垃圾填埋 滲濾液 固體垃圾 抗生素抗性基因 重金屬　出處：《華東師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：人類醫(yī)療、畜牧和水產(chǎn)養(yǎng)殖過程中抗生素的濫用將誘導(dǎo)環(huán)境中細(xì)菌產(chǎn)生抗生素抗性基因(Antibiotic Resistance Genes,ARGs)。作為一種新型環(huán)境污染物,ARGs在環(huán)境中的污染被認(rèn)為是對人類健康的又一種威脅,因而備受關(guān)注。近年來,關(guān)于城鎮(zhèn)污水、養(yǎng)殖廢水及污染土壤等環(huán)境中ARGs的研究較為廣泛,但對城市生活垃圾填埋過程中ARGs的研究還不夠充分。因此,研究填埋過程中滲濾液及固體垃圾中ARGs的分布及變化,探究其與環(huán)境因子之間的相關(guān)性,對掌握垃圾填埋過程中ARGs的變化規(guī)律以及ARGs的防控有理論和實際指導(dǎo)意義。本研究以采集自上海市黎明和老港生活垃圾填埋場中的滲濾液和固體垃圾樣品為研究對象,分別采用全自動間斷分析儀和電感耦合等離子光譜儀(ICP-AES)測定樣品中氮磷等理化指標(biāo)和常見重金屬含量,同時,采用實時熒光定量PCR(Quantitative Rea1-time PCR,qPCR)對磺胺類(sul1,sul2)、氨基糖苷類(aadA1,strB)、四環(huán)素類(tetM,tetQ)、大環(huán)內(nèi)酯類(ermB,wef4)、多重抗性基因(wexF)以及I類整合子基因(int//)等10種ARGs進(jìn)行定量分析。研究了不同介質(zhì)、不同填埋階段及不同季節(jié)的樣品中理化指標(biāo)、重金屬及ARGs的變化,并采用冗余分析(RDA)和雙變量相關(guān)分析對ARGs與環(huán)境因子的相關(guān)性進(jìn)行了研究。研究結(jié)果如下:(一)滲濾液中理化指標(biāo)、重金屬及ARGs的變化(1)滲濾液中COD、NH_4~+-N、TN和TP的濃度均隨著填埋時間的增長而減少,而NO3-N隨著填埋時間的增長而增加。8種重金屬(As、Cd、Cr、Cu、Mn、Ni、Pb、Zn)在所有滲濾液樣品中均有檢出,且重金屬總量隨著填埋時間的增長而減少,其中Pb和Zn的濃度最大,平均濃度分別為5.24±0.69mg/L和2.06±0.49 mg/L。(2)滲濾液中ARGs豐度總和隨著填埋時間的增長逐漸增多,除strB外其它9種目標(biāo)ARGs在老齡階段的豐度明顯高于新鮮階段(P0.05)。其中,Ⅰ類整合子基因intl1的豐度最高(2.36×107 copies/ngDNA),占整體的84%,其次為磺胺類和氨基糖苷類抗性基因。秋季滲濾液樣品的ARGs豐度總和比春季的高,且tetM、tetQ、wef4、ermB和wexF等5種ARGs在秋季的豐度明顯大于春季(P0.05)。(二)固體垃圾中理化指標(biāo)、重金屬及ARGs的變化(1)TN和TP均在填埋中期時的含量最大,在填埋后期的量最小,并且固體垃圾中TN的含量明顯高于TP(P0.05),兩者在秋季和春季樣品的含量沒有顯著差異(P0.05)。固體垃圾中的重金屬總量隨著填埋時間的增長逐漸減少,在三個填埋階段占比最高的三種元素為Cu、Mn和Zn,均占到總量的10%以上。除Mn外,其它7種目標(biāo)元素含量受季節(jié)影響不大。(2)填埋中期和初期的ARGs的豐度總量較高,填埋后期的最小,且與填埋初中期有顯著性差異(P0.05)。在所研究10種的ARGs中,int/1的豐度最大為1.65×107copies/ngDNA,占總體的92%。春季的ARGs豐度總和較秋季多1倍,差異主要體現(xiàn)在int/1上。(三)垃圾填埋場中ARGs與環(huán)境因子的相關(guān)性(1)滲濾液中intll及磺胺類ARGs(su/1和sul2)均與pH和TP有極顯著相關(guān)性(P0.01),大環(huán)內(nèi)酯類ARGs(mefA和ermB)均與TN有顯著相關(guān)性(P0.05),aadA1與NH_4~+-N有顯著相關(guān)性(P0.05)。此外,重金屬As和Ni均與intl1和sul2有顯著相關(guān)性(P0.05),而Cr與int/1和aadA1有顯著相關(guān)性(P0.05)。(2)固體垃圾中TN與int/1、aadA1、strB和wexF等4種ARGs有顯著相關(guān)性(P0.05),TP與sul1、/etM、tetQ和mefA等4種ARGs有顯著相關(guān)性(P0.05)。氨基糖苷類ARGs(aadA 和strB)均與Cd和Pb有顯著相關(guān)性(P0.05),大環(huán)內(nèi)酯類ARGs(ewA和ermB)均與Cr、Ni和Zn三種重金屬有顯著相關(guān)性(P0.05),并且均與Ni有極顯著相關(guān)性(P0.01),四環(huán)素類(tetM和tetQ)均與Cr有極顯著相關(guān)性(P0.01)。綜上,垃圾填埋過程中不論是滲濾液還是固體垃圾中均存在大量的ARGs,且隨著填埋時間的增長,固體垃圾中的ARGs濃度減少,而滲濾液中的濃度增加,因此老齡滲濾液中ARGs的防控至關(guān)重要。此外,垃圾填埋場中氮磷等理化指標(biāo)及重金屬影響著ARGs的變化,其中固體垃圾受環(huán)境因子影響較滲濾液大。
[Abstract]:Human health, abuse of antibiotics in animal husbandry and aquaculture in the process will induce the bacteria to produce antibiotic resistance genes in the environment (Antibiotic Resistance Genes, ARGs). As a new type of environmental pollutants in environmental pollution in the ARGs is considered to be a threat to human health, which attracted much attention. In recent years, the urban sewage study on ARGs, aquaculture wastewater and pollution of soil environment more widely, but the research on the process of ARGs landfill in the city is not enough. Therefore, the distribution and change of ARGs filtrate and solid waste in the landfill seepage process, explore its correlation with environmental factors, has theoretical and practical significance to master the variation ARGs landfill process and ARGs control. In this study, collected from Shanghai City dawn and old port life filtrate and solid waste landfill in infiltration The samples were used as the research object, automatic continuous analyzer and inductively coupled plasma atomic emission spectrometry (ICP-AES) determination of nitrogen and phosphorus in samples of common physicochemical indexes and heavy metal content, at the same time, by using real-time quantitative PCR (Quantitative Rea1-time PCR, qPCR) of sulfonamides (sul1, sul2), aminoglycosides (aadA1, strB), the tetracycline (tetM, tetQ), macrolides (ermB, wef4), multiple resistance genes (wexF) and class I integron gene (int//) of 10 species of ARGs were quantitatively analyzed. The effects of different media, physicochemical indexes of different filling stages and different seasons in the sample, and the variation of heavy metals ARGs, and the use of redundancy analysis (RDA) and bivariate correlation analysis of ARGs with environmental factors were studied. The results are as follows: (a) the physicochemical index of leachate infiltration, and the change of heavy metal ARGs (1) in the leachate COD, NH_4~+-N, TN and TP increased with the concentration of With the increase of landfill time decreased, while NO3-N increased with the increase of landfill time.8 heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) were detected in all samples of leachate infiltration, and the total amount of heavy metals decreased with the increase of landfill time, the concentration of Pb and Zn the maximum average concentrations were 5.24 + 0.69mg/L and 2.06 + 0.49 mg/L. (2) ARGs abundance in total infiltration filtrate gradually increased with the increase of landfill time, except strB 9 ARGs goals in the aging stage abundance was significantly higher than that of fresh stage (P0.05). The class I integron gene intl1 (the highest abundance 2.36 * 107 copies/ngDNA), accounting for 84% of the total, followed by sulfonamides and aminoglycoside resistance gene ARGs. The total abundance in autumn leachate samples than in spring, and tetM, tetQ, wef4, ermB and wexF 5 ARGs in the fall of abundance was significantly higher than that in spring (P0.05) (two) solid. Garbage In the physical and chemical indicators, changes of heavy metals and ARGs (1) the content of TN and TP are in the middle of the largest landfill in the landfill, the minimum amount of late, and the content of solid waste in TN was significantly higher than that of TP (P0.05), there was no significant difference in the content of autumn and spring two samples (P0.05). The total amount of heavy metals in solid in the garbage landfill gradually decreased with time increasing, in the three stage of landfill accounted for more than three kinds of elements was the highest in Cu, Mn and Zn, accounted for more than 10% of the total. In addition to Mn, other 7 kinds of target elements affected by season little. (2) the mid and early period of landfill ARGs the total abundance is higher, the minimum period of landfill, and there is a significant difference with the middle period of landfill (P0.05). In the study of 10 kinds of ARGs int/1, the maximum abundance is 1.65 * 107copies/ngDNA, ARGs 92%. of the overall total abundance in spring than in autumn 1 times, the difference is mainly reflected in the int/1. (three). 鍦懼～鍩嬪満涓瑼RGs涓庣幆澧冨洜瀛愮殑鐩稿叧鎬，

本文編號：1455934