本文主要研究内容
作者李志良(2019)在《湘江铜锈环棱螺耐受铅镉的适应机制研究》一文中研究指出:目的:通过研究分析湘江中游沉积物中Pb、Cd的总量和赋存形态的含量,湘江底栖铜锈环棱螺体内Pb、Cd的含量与分布情况,并对铜锈环棱螺中Pb、Cd含量与沉积物中Pb、Cd含量进行关联性研究,人工对铜锈环棱螺进行Pb、Cd胁迫试验,研究重金属胁迫下铜锈环棱螺体内过氧化氢酶和超氧化物歧化酶的变化情况,同时,分离纯化铜锈环棱螺肠道内耐Pb、Cd微生物,探讨铜锈环棱螺对重金属的耐受和解毒机制,揭示铜锈环棱螺对Pb、Cd的适应机制,以期为湘江重金属污染的生物修复与治理提供理论基础和技术支持。方法:本实验野外部分,于采样点采集常年位于水面以下的位置进行沉积物和铜锈环棱螺;沉积物经过烘干、粉粹、过筛后,使用湿法消解提取重金属总量,使用改进的BCR三步连续提取法,提取沉积物中重金属不同赋存形态含量;铜锈环棱螺经过3d的纯水驯养,吐尽泥沙,外壳清理干净后,分解为壳、外套膜、内脏团、足四部分,低温烘干、碾碎,使用湿法消解提取重金属;待测液使用石墨炉原子吸收光谱法测定溶液重金属的浓度,进而得到沉积物和铜锈环棱螺中重金属的浓度;胁迫实验分为Pb胁迫、Cd胁迫和Pb-Cd复合胁迫三组,每组又分为4个浓度,同时设立纯水饲养铜锈环棱螺为空白对照组,在第0d、2d、4d、6d、8d,从三个组的每个浓度中取铜锈环棱螺,测定CAT、SOD的活性;在第0d、2d、4d、6d、8d,在Pb、Cd单因子胁迫组最大浓度(Pb浓度0.4 mg/L,Cd浓度0.04 mg·L-1)中取5-8枚(约20g)铜锈环棱螺,对其软体部分进行重金属的提取测定,在第8d,将Pb、Cd单因子胁迫组最大浓度(Pb浓度0.4 mg·L-1,Cd浓度0.04 mg·L-1)中的剩余铜锈环棱螺全部转移至纯水中饲养,并于第10d、12d、14d、16d、18d,取5-8枚(约20g)铜锈环棱螺提取测定其软体部分重金属含量,计算得到铜锈环棱螺对Pb、Cd的生物半衰期。结果:1.湘江中游沉积物中Pb、Cd都有一定的积累,7个采样点沉积物中Pb浓度为29.105-94.675 mg·kg-1,Cd浓度为2.988-13.245 mg·kg-1,7个采样点Pb和Cd的分布具有显著相关性(p<0.01),说明个采样点的Pb、Cd的污染是一致的;对比《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618-2018),Pb浓度已低于农用地土壤污染风险筛选值,一般可忽略其产生的影响,7个采样点Cd浓度远远超出农用地土壤污染风险筛选值,且除车江镇外的6个采样点的Cd浓度超过了农用地土壤污染风险管制值,为风险管制值的1.16-3.31倍,土壤污染风险极其严重。2.沉积物中Pb、Cd的主要赋存形态有所不同,Pb主要是以Fe-Mn氧化物结合态存在于沉积物中,在七个采样点此形态占比为53.29%-79.80%,Cd主要以可交换态与碳酸盐结合态存在于沉积物中,占比为51.28%-66.25%;一般认为交换态与碳酸盐结合态对环境产生更直接的危害,因此Cd污染要远远高于Pb污染;虽然Pb、Cd在沉积物中主要赋存形态不同,但是通过对四种形态对应的关联性分析发现,Pb、Cd的B1、B2、B3三种形态具有相关性(p<0.05)。3.铜锈环棱螺体内Pb、Cd的分布具有很大的差异,Pb只在壳中检出,在其他组织器官中未检出,Cd主要分布在内脏团,七个采样点铜锈环棱螺内脏中Cd的浓度达到了12.825-34.375 mg·kg-1,占比40%以上,说明Pb在铜锈环棱螺体内易通过代谢进入壳中和体外,使其软体部位免受Pb累积的毒害,Cd也可通过代谢进入壳中和排出体外,但由于摄入量较高,使其无法通过代谢完全排出,从而在软体部分产生了高浓度的积累。分析铜锈环棱螺体内重金属含量,与沉积物中重金属总量和赋存形态的关联性发现,铜锈环棱螺体内的Pb、Cd与沉积物中的Pb、Cd总量和形态均无相关性(p>0.05),说明铜锈环棱螺与沉积物中重金属含量存在差异性。4.铜锈环棱螺在Pb、Cd和Pb-Cd复合胁迫下,体内CAT、SOD活性都出现了显著的上升,随着时间的增加,酶活性也随之增加,且在三组各对应的低、中、中高、高4个浓度中,CAT和SOD的变化情况基本据具有一致性(p<0.05),随着溶液中Pb、Cd浓度的升高,酶活性也随之升高,整体上看,酶活性上升速度Pb-Cd复合胁迫>Cd胁迫>Pb胁迫,说明Cd毒性要高于Pb,但在各胁迫组高浓度重金属胁迫下酶活性出现下降。表明,在一定范围内,可以通过CAT与SOD保护性酶活性的提高,以缓解Pb、Cd对螺造成的生物毒性;过高浓度的Pb、Cd胁迫下,酶活性下降,表明保护性酶活性的重金属毒性的缓解作用是有限的。5.在本实验条件下,Pb从铜锈环棱螺体内排出的表达式为CPb=e-0.0006t+1.0303,Cd从铜锈环棱螺体内排出的表达式为CCd=e-0.0005t-1.0985,从铜锈环棱螺排出Pb的生物半衰期(B1/2)为1155.245h,约为48.14d,排出Cd的生物半衰期(B1/2)为1386.294h,约为57.76d;铜锈环棱螺对Pb的生物半衰期比Cd的少9d,说明铜锈环棱螺对于Pb的代谢速率要比Cd的快,Cd比Pb更容易在铜锈环棱螺体内积累。6.铜锈环棱螺可以在高浓度Cd2+和Pb2+环境下正常存活,除了自身的代谢和耐受机制外,肠道菌群也参与其中,耐肠道中的微生物可以将一部分摄入消化道的Pb、Cd吸收,从而减少生物体对Pb、Cd的吸收,另外,微生物也会通过自身的代谢作用,改变重金属的价态,使Pb、Cd的毒性大大降低,降低了生物学吸收重金属后产生的毒性,从而保护了生物体的健康。结论:1.湘江中游沉积物中Pb、Cd重金属污染仍存在一定的生态风险,Cd重金属污染程度远远高于Pb重金属污染;2.铜锈环棱螺对Pb、Cd均具有富集和耐受能力,对Cd的富集能力远远高于Pb的富集能力;3.铜锈环棱螺在受到一定范围浓度Pb、Cd胁迫时体内的CAT、SOD的酶活性升高以降低Pb、Cd在体内产生的毒害作用。4.铜锈环棱螺对于Pb、Cd的代谢中,Cd的生物半衰期比Pb长,Cd更容易在铜锈环棱螺体内产生积累。5.铜锈环棱螺肠道菌群中存在多种耐受Pb、Cd的菌群,在Pb、Cd胁迫下可减少铜锈环棱螺受到的毒害。
Abstract
mu de :tong guo yan jiu fen xi xiang jiang zhong you chen ji wu zhong Pb、Cdde zong liang he fu cun xing tai de han liang ,xiang jiang de qi tong xiu huan leng luo ti nei Pb、Cdde han liang yu fen bu qing kuang ,bing dui tong xiu huan leng luo zhong Pb、Cdhan liang yu chen ji wu zhong Pb、Cdhan liang jin hang guan lian xing yan jiu ,ren gong dui tong xiu huan leng luo jin hang Pb、Cdxie pai shi yan ,yan jiu chong jin shu xie pai xia tong xiu huan leng luo ti nei guo yang hua qing mei he chao yang hua wu qi hua mei de bian hua qing kuang ,tong shi ,fen li chun hua tong xiu huan leng luo chang dao nei nai Pb、Cdwei sheng wu ,tan tao tong xiu huan leng luo dui chong jin shu de nai shou he jie du ji zhi ,jie shi tong xiu huan leng luo dui Pb、Cdde kuo ying ji zhi ,yi ji wei xiang jiang chong jin shu wu ran de sheng wu xiu fu yu zhi li di gong li lun ji chu he ji shu zhi chi 。fang fa :ben shi yan ye wai bu fen ,yu cai yang dian cai ji chang nian wei yu shui mian yi xia de wei zhi jin hang chen ji wu he tong xiu huan leng luo ;chen ji wu jing guo hong gan 、fen cui 、guo shai hou ,shi yong shi fa xiao jie di qu chong jin shu zong liang ,shi yong gai jin de BCRsan bu lian xu di qu fa ,di qu chen ji wu zhong chong jin shu bu tong fu cun xing tai han liang ;tong xiu huan leng luo jing guo 3dde chun shui xun yang ,tu jin ni sha ,wai ke qing li gan jing hou ,fen jie wei ke 、wai tao mo 、nei zang tuan 、zu si bu fen ,di wen hong gan 、nian sui ,shi yong shi fa xiao jie di qu chong jin shu ;dai ce ye shi yong dan mo lu yuan zi xi shou guang pu fa ce ding rong ye chong jin shu de nong du ,jin er de dao chen ji wu he tong xiu huan leng luo zhong chong jin shu de nong du ;xie pai shi yan fen wei Pbxie pai 、Cdxie pai he Pb-Cdfu ge xie pai san zu ,mei zu you fen wei 4ge nong du ,tong shi she li chun shui si yang tong xiu huan leng luo wei kong bai dui zhao zu ,zai di 0d、2d、4d、6d、8d,cong san ge zu de mei ge nong du zhong qu tong xiu huan leng luo ,ce ding CAT、SODde huo xing ;zai di 0d、2d、4d、6d、8d,zai Pb、Cdchan yin zi xie pai zu zui da nong du (Pbnong du 0.4 mg/L,Cdnong du 0.04 mg·L-1)zhong qu 5-8mei (yao 20g)tong xiu huan leng luo ,dui ji ruan ti bu fen jin hang chong jin shu de di qu ce ding ,zai di 8d,jiang Pb、Cdchan yin zi xie pai zu zui da nong du (Pbnong du 0.4 mg·L-1,Cdnong du 0.04 mg·L-1)zhong de sheng yu tong xiu huan leng luo quan bu zhuai yi zhi chun shui zhong si yang ,bing yu di 10d、12d、14d、16d、18d,qu 5-8mei (yao 20g)tong xiu huan leng luo di qu ce ding ji ruan ti bu fen chong jin shu han liang ,ji suan de dao tong xiu huan leng luo dui Pb、Cdde sheng wu ban cui ji 。jie guo :1.xiang jiang zhong you chen ji wu zhong Pb、Cddou you yi ding de ji lei ,7ge cai yang dian chen ji wu zhong Pbnong du wei 29.105-94.675 mg·kg-1,Cdnong du wei 2.988-13.245 mg·kg-1,7ge cai yang dian Pbhe Cdde fen bu ju you xian zhe xiang guan xing (p<0.01),shui ming ge cai yang dian de Pb、Cdde wu ran shi yi zhi de ;dui bi 《tu rang huan jing zhi liang nong yong de tu rang wu ran feng xian guan kong biao zhun (shi hang )》(GB 15618-2018),Pbnong du yi di yu nong yong de tu rang wu ran feng xian shai shua zhi ,yi ban ke hu lve ji chan sheng de ying xiang ,7ge cai yang dian Cdnong du yuan yuan chao chu nong yong de tu rang wu ran feng xian shai shua zhi ,ju chu che jiang zhen wai de 6ge cai yang dian de Cdnong du chao guo le nong yong de tu rang wu ran feng xian guan zhi zhi ,wei feng xian guan zhi zhi de 1.16-3.31bei ,tu rang wu ran feng xian ji ji yan chong 。2.chen ji wu zhong Pb、Cdde zhu yao fu cun xing tai you suo bu tong ,Pbzhu yao shi yi Fe-Mnyang hua wu jie ge tai cun zai yu chen ji wu zhong ,zai qi ge cai yang dian ci xing tai zhan bi wei 53.29%-79.80%,Cdzhu yao yi ke jiao huan tai yu tan suan yan jie ge tai cun zai yu chen ji wu zhong ,zhan bi wei 51.28%-66.25%;yi ban ren wei jiao huan tai yu tan suan yan jie ge tai dui huan jing chan sheng geng zhi jie de wei hai ,yin ci Cdwu ran yao yuan yuan gao yu Pbwu ran ;sui ran Pb、Cdzai chen ji wu zhong zhu yao fu cun xing tai bu tong ,dan shi tong guo dui si chong xing tai dui ying de guan lian xing fen xi fa xian ,Pb、Cdde B1、B2、B3san chong xing tai ju you xiang guan xing (p<0.05)。3.tong xiu huan leng luo ti nei Pb、Cdde fen bu ju you hen da de cha yi ,Pbzhi zai ke zhong jian chu ,zai ji ta zu zhi qi guan zhong wei jian chu ,Cdzhu yao fen bu zai nei zang tuan ,qi ge cai yang dian tong xiu huan leng luo nei zang zhong Cdde nong du da dao le 12.825-34.375 mg·kg-1,zhan bi 40%yi shang ,shui ming Pbzai tong xiu huan leng luo ti nei yi tong guo dai xie jin ru ke zhong he ti wai ,shi ji ruan ti bu wei mian shou Pblei ji de du hai ,Cdye ke tong guo dai xie jin ru ke zhong he pai chu ti wai ,dan you yu she ru liang jiao gao ,shi ji mo fa tong guo dai xie wan quan pai chu ,cong er zai ruan ti bu fen chan sheng le gao nong du de ji lei 。fen xi tong xiu huan leng luo ti nei chong jin shu han liang ,yu chen ji wu zhong chong jin shu zong liang he fu cun xing tai de guan lian xing fa xian ,tong xiu huan leng luo ti nei de Pb、Cdyu chen ji wu zhong de Pb、Cdzong liang he xing tai jun mo xiang guan xing (p>0.05),shui ming tong xiu huan leng luo yu chen ji wu zhong chong jin shu han liang cun zai cha yi xing 。4.tong xiu huan leng luo zai Pb、Cdhe Pb-Cdfu ge xie pai xia ,ti nei CAT、SODhuo xing dou chu xian le xian zhe de shang sheng ,sui zhao shi jian de zeng jia ,mei huo xing ye sui zhi zeng jia ,ju zai san zu ge dui ying de di 、zhong 、zhong gao 、gao 4ge nong du zhong ,CAThe SODde bian hua qing kuang ji ben ju ju you yi zhi xing (p<0.05),sui zhao rong ye zhong Pb、Cdnong du de sheng gao ,mei huo xing ye sui zhi sheng gao ,zheng ti shang kan ,mei huo xing shang sheng su du Pb-Cdfu ge xie pai >Cdxie pai >Pbxie pai ,shui ming Cddu xing yao gao yu Pb,dan zai ge xie pai zu gao nong du chong jin shu xie pai xia mei huo xing chu xian xia jiang 。biao ming ,zai yi ding fan wei nei ,ke yi tong guo CATyu SODbao hu xing mei huo xing de di gao ,yi huan jie Pb、Cddui luo zao cheng de sheng wu du xing ;guo gao nong du de Pb、Cdxie pai xia ,mei huo xing xia jiang ,biao ming bao hu xing mei huo xing de chong jin shu du xing de huan jie zuo yong shi you xian de 。5.zai ben shi yan tiao jian xia ,Pbcong tong xiu huan leng luo ti nei pai chu de biao da shi wei CPb=e-0.0006t+1.0303,Cdcong tong xiu huan leng luo ti nei pai chu de biao da shi wei CCd=e-0.0005t-1.0985,cong tong xiu huan leng luo pai chu Pbde sheng wu ban cui ji (B1/2)wei 1155.245h,yao wei 48.14d,pai chu Cdde sheng wu ban cui ji (B1/2)wei 1386.294h,yao wei 57.76d;tong xiu huan leng luo dui Pbde sheng wu ban cui ji bi Cdde shao 9d,shui ming tong xiu huan leng luo dui yu Pbde dai xie su lv yao bi Cdde kuai ,Cdbi Pbgeng rong yi zai tong xiu huan leng luo ti nei ji lei 。6.tong xiu huan leng luo ke yi zai gao nong du Cd2+he Pb2+huan jing xia zheng chang cun huo ,chu le zi shen de dai xie he nai shou ji zhi wai ,chang dao jun qun ye can yu ji zhong ,nai chang dao zhong de wei sheng wu ke yi jiang yi bu fen she ru xiao hua dao de Pb、Cdxi shou ,cong er jian shao sheng wu ti dui Pb、Cdde xi shou ,ling wai ,wei sheng wu ye hui tong guo zi shen de dai xie zuo yong ,gai bian chong jin shu de jia tai ,shi Pb、Cdde du xing da da jiang di ,jiang di le sheng wu xue xi shou chong jin shu hou chan sheng de du xing ,cong er bao hu le sheng wu ti de jian kang 。jie lun :1.xiang jiang zhong you chen ji wu zhong Pb、Cdchong jin shu wu ran reng cun zai yi ding de sheng tai feng xian ,Cdchong jin shu wu ran cheng du yuan yuan gao yu Pbchong jin shu wu ran ;2.tong xiu huan leng luo dui Pb、Cdjun ju you fu ji he nai shou neng li ,dui Cdde fu ji neng li yuan yuan gao yu Pbde fu ji neng li ;3.tong xiu huan leng luo zai shou dao yi ding fan wei nong du Pb、Cdxie pai shi ti nei de CAT、SODde mei huo xing sheng gao yi jiang di Pb、Cdzai ti nei chan sheng de du hai zuo yong 。4.tong xiu huan leng luo dui yu Pb、Cdde dai xie zhong ,Cdde sheng wu ban cui ji bi Pbchang ,Cdgeng rong yi zai tong xiu huan leng luo ti nei chan sheng ji lei 。5.tong xiu huan leng luo chang dao jun qun zhong cun zai duo chong nai shou Pb、Cdde jun qun ,zai Pb、Cdxie pai xia ke jian shao tong xiu huan leng luo shou dao de du hai 。
论文参考文献
论文详细介绍
论文作者分别是来自南华大学的李志良,发表于刊物南华大学2019-10-28论文,是一篇关于铜锈环棱螺论文,重金属论文,铅镉污染论文,适应机制论文,南华大学2019-10-28论文的文章。本文可供学术参考使用,各位学者可以免费参考阅读下载,文章观点不代表本站观点,资料来自南华大学2019-10-28论文网站,若本站收录的文献无意侵犯了您的著作版权,请联系我们删除。
标签:铜锈环棱螺论文; 重金属论文; 铅镉污染论文; 适应机制论文; 南华大学2019-10-28论文;