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1.
有机物生物降解动力学极限浓度(Sm in)是有机污染物生物降解过程能够达到的最低浓度,在废水生物处理中具有重要意义。研究了生物降解极限浓度的影响因素,分别探讨了基质浓度、微生物培养方式、第二基质以及污泥驯化等对生物降解极限浓度的影响及其规律。结果表明:基质浓度越低,Sm in越小;连续培养的微生物其Sm in比间歇培养的低,连续方式更适合于降解微量化学物质的微生物的培养;第二碳源对极限浓度的影响与污泥驯化与否有关,驯化污泥加入第二碳源后降解速率下降,而未驯化污泥则相反。这为废水生物高度净化提供了理论和实验依据。  相似文献   

2.
采用SBR反应器驯化中度嗜盐菌为主的活性污泥,高效处理高盐邻氯苯酚(2-CP)废水。不同盐度的驯化结果表明,当NaCl质量浓度为10~80g/L时,2-CP和COD的去除率均达到91%。当NaCl质量浓度为80g/L,2-CP质量浓度在1000mg/L以上时,去除率可以维持在98%,反应器达到最佳处理效果。在此条件下,活性污泥胞外聚合物(EPS)的含量最高达到142.6mg/g。随着盐度升高,EPS中的多糖含量也随之增加。采用显微镜和扫描电镜(SEM)观察,发现在高盐条件下,活性污泥中大部分微生物呈现球状,且菌群有自发聚集的趋势。16SrRNA基因文库分析表明,产碱杆菌是污泥中的优势菌群,它属于变形菌门。PCR扩增和测序分析2-CP降解途径的关键酶基因,发现羟化酶、氯代邻苯二酚1,2-双加氧酶和氯代邻苯二酚2,3-双加氧酶同时存在于活性污泥系统中,表明该活性污泥可能具有多样的2-CP降解途径。  相似文献   

3.
为探究三溴苯酚(TBP)在活性污泥系统中的降解过程,采用驯化活性污泥的方法,考察了初始浓度、pH、温度、外加碳源、重金属及络合剂对活性污泥降解三溴苯酚的影响。研究表明,当三溴苯酚质量浓度为10~50 mg/L时,降解过程符合零级动力学。活性污泥对三溴苯酚的比基质吸附速率qbd随pH增大而减小,且当pH为7.0~8.0时,有利于生物降解。苯酚和双酚A作为外加碳源时对三溴苯酚的降解产生抑制作用。Cu2+和Ni2+的存在也抑制了三溴苯酚的降解,且Ni2+的抑制效应要强于Cu2+。柠檬酸作为络合剂通过降低水相中游离金属离子的浓度可以减弱重金属对活性污泥的抑制作用,当Cu2+与柠檬酸物质的量之比为1:4时,Cu2+的抑制效应完全可以清除。  相似文献   

4.
研究了活性炭吸附双酚A(BPA)的规律、吸附特性和吸附处理效果。结果表明:吸附速度快,1 h达到平衡。吸附符合弗兰德利希公式,吸附常数K=191 m g/g,1n=0.239。吸附容量大,且受被吸附质浓度的影响小。当pH>9和有其他有机物存在时,因BPA发生电离和竞争吸附使吸附容量减小,吸附规律发生变化。但活性炭吸附可使BPA浓度降低到0.08 m g/L以下,是处理含BPA废水的一种有效方法。  相似文献   

5.
目的:观察滋阴泻火中药对环境内分泌干扰物辛基酚(OP)和双酚A(BPA)的拟雌激素活性的拮抗作用。方法:30只21天SD雌性大鼠分为3组:对照组(玉米油)、染毒组(OP 100mg/kg+BPA 100mg/kg)、治疗组(喂饲OP100mg/kg+BPA 100mg/kg+中药40mL/kg),每天灌胃1次,连续14天后检测子宫增重和子宫内膜ER的表达。结果:染毒组与对照组相比,子宫湿重、脏器系数、子宫内膜上皮细胞高度及平滑肌厚度、子宫内膜腺上皮高度,腺体数目及内膜ER蛋白表达均明显增高(P<0.05),治疗组与染毒组相比,治疗后上述指标显著降低(P<0.05)。结论:辛基酚和双酚A具有拟雌激素活性,滋阴泻火中药对辛基酚(OP)和双酚A(BPA)的拟雌激素活性的具有拮抗作用。  相似文献   

6.
双酚A对人早孕绒毛组织IGF1、TGFβ31、ADAM12表达的影响   总被引:1,自引:0,他引:1  
目的:研究双酚 A(BPA)水平与人早孕胰岛素样生长因子1(IGF1),转化生长因子β1(TGFβ1),以及解整合素样金属蛋白酶 12 (ADAMl2)表达的关系,探讨BPA 对绒毛组织可能带来的影响.方法:以 40 例早期妊娠 (6~8)周的新鲜绒毛组织进行体外培养,培养基中加入不同浓度的 BPA:A组为1000×1...  相似文献   

7.
目的:探讨双酚A(BPA)暴露水平以及BPA产生生殖毒性的潜在机制。方法:采用气相色谱质谱联用法检测新生儿(贵屿区153例为暴露组,濠江区47例为对照组)脐带血BPA浓度;实时定量RT-PCR法检测新生儿胎盘组织KiSS-1基因表达量。结果:暴露组脐带血BPA浓度(中位数6.4μg/L)显著高于对照组(2.8μg/L),暴露组胎盘组织KiSS-1基因相对表达量(中位数0.5)同样显著高于对照组(0.2),BPA浓度与KiSS-1表达量正相关(P<0.05);男性组该相关性更为显著(P<0.01)。结论:贵屿区人群已处于较高的BPA暴露水平,BPA有可能通过影响亲吻素的正常表达而干扰生殖内分泌系统。  相似文献   

8.
目的 :探讨双酚A(bisphenol A,BPA)对人前列腺癌PC-3细胞增殖和mi R-19表达的影响。方法 :不同浓度BPA处理人前列腺癌PC-3细胞,以雌二醇(E2)作为阳性对照,6 d后采用四甲基偶氮唑盐(MTT)法和Hoechst 33258荧光染色法测定BPA对PC-3细胞增殖的影响,real-time PCR检测mi R-19a和mi R-9b表达水平的变化,Western blot检测细胞中mi R-19的靶基因PTEN及细胞增殖相关基因p-AKT、AKT、PCNA和Cyclin D1的蛋白表达变化。结果:5×10-6~5×10-5 mol/L BPA显著促进PC-3细胞增殖,增加PC-3细胞中mi R 19a和mi R 19b的表达水平,降低PTEN表达并上调p-AKT、PCNA和Cyclin D1表达水平。结论:BPA可促进前列腺癌PC-3细胞增殖,其机制可能与BPA引起mi R-19表达上调有关。  相似文献   

9.
双酚A斑马鱼雄性生殖毒性的表观遗传学基础   总被引:1,自引:0,他引:1  
目的 从表观遗传学角度探讨双酚A(BPA)影响斑马鱼精子成熟与胚胎发育的机理.方法 将20 dpf斑马鱼幼鱼,暴露在乙醇(溶剂)对照、BPA0.5 mg/L、BPA1.5 mg/L至100 dph.选取各处理组雄鱼,荧光定量PCR检测性腺DNA甲基转移酶(DNMTs)表达量,免疫组化检测性腺全基因组甲基化水平,Western-blot、免疫组化检测性腺组蛋白3赖氨酸三甲基化(H3K9me3、H3K4me3、H3K27me3、H3K36me3)表达水平.各处理组雄鱼与正常雌鱼交配,观察胚胎期相关指标.结果 BPA处理组Dnmt1、Dnmt6、Dnmt7、Dnmt8 mRNA表达量明显升高,与对照组比较差别均具有统计学意义(P<0.05).BPA1.5 mg/L组中成熟精子DNA甲基化水平与H3K9me3水平均明显升高.与正常雌鱼交配,BPA 1.5 mg/组产卵量仅为对照组的63%±2.49%,12 h胚胎死亡率与对照组相比增加202.53%±6.21%,72 h胚胎畸形率与对照组相比增加399.08%±12.16%,差别均具有统计学意义(P<0.05).结论 双酚A诱导斑马鱼成熟精子DNA甲基化程度和组蛋白H3K9me3 表达水平增加,这些变化可能是BPA处理组后代胚胎发育异常的重要基础.  相似文献   

10.
目的:探讨双酚A(BPA)对成年小鼠睾丸组织的损伤作用,旨在阐明BPA对动物机体的生殖毒性及机制。方法:8W龄昆明小鼠,随机分为对照溶剂组(按体重比例玉米油灌胃)、低剂量组(100mg/kgBPA)、中剂量(200mg/kgBPA)、高剂量(400mg/kgBPA)4组,双酚A灌胃染毒4周后,取睾丸组织;免疫组化法检测CD95、CD95L蛋白的分布和表达。结果:与对照组比较,低剂量BPA不会导致睾丸组织内细胞CD95、CD95L蛋白的表达上调(P0.05);中、高剂量组睾丸组织内细胞CD95、CD95L蛋白表达上调,差异有统计学意义(P0.05)。结论:BPA会造成小鼠睾丸组织内凋亡调控基因CD95、CD95L表达上调,说明BPA的生殖毒性是激活了CD95蛋白死亡结构域,使之与其天然配体CD95L相结合结合,进一步激活CD95死亡受体信号通路所引起。  相似文献   

11.
Effect of salinity variations on the performance of activated sludge system   总被引:5,自引:0,他引:5  
Objective To investigate the influence of salinity variations on the performance of activated sludge systems, treating domestic wastewater. Methods The completely mixed reactor was used and operated in a batch-wise mode. The activated sludge taken from the Gaobeidian Wastewater Treatment Plant was used as a seeding sludge. Total organic carbon (TOC),oxygen uptake rate (OUR) and suspended solids (SS) were used as parameters to characterize the performance of the treatment systems. TOC was measured using a TOC-analyzer (TOC-5000, Japan). The OUR value was measured with a dissolved oxygen meter (YSI model-58). SS was measured gravimetrically. Results The TOC removal efficiency and the OUR value of activated sludge were not deteriorated when the NaCl shock concentration was less than 0.5 g/L. However, when the NaCl shock concentrations were up to 10g/t, and 20 g/L, the OUR of activated sludge was reduced by 35% and TOC removal efficiency was dropped by 30%, compared with the control experiment without NaCl shock loading. Conclusion The effect of NaCl shock loading on the activated sludge wastewater treatment system is dependant upon the NaCl concentrations and the degree of influence can be inferred through the change of substrate utilization rate at different shock NaCl loadings.  相似文献   

12.
Objective To investigate the performance of soil-slurry bioreactor used for remediating contaminated soil with 4-nitrophenol (4-NP). Methods The slurry bioreactor was used to degrade different concentrations of 4-nitrophenol with or without inoculating the acclimated activated sludge. HPLC system (Hewlett-Packard model 5050 with a UV detector) was used for the quantification of 4-nitrophenol. Results The indigenous microorganisms exhibited a little activity for simulated soil with 50 mg 4-NP/kg soil. However, at the concentration of 10 mg 4-NPkg soil, a considerable degradation occurred within two weeks. It appeared that nigh concentrations of 4-nitrophenol apparently produced an inhibitory effect on microbial activity. For system receiving 50 mg 4-NP/kg soil, the maximum rate of 4-NP degradation measured in the reactor inoculated with 25g sludge/kg soil was approximately 10 times nigher than the uninoculated reactor, suggesting that the degradation rate of 4-nitrophenol could be enhanced greatly by means of inoculating acclimated sludge. Conclusion The addition of sludge capable of degrading 4-nitrophenol can result in enhance the degradation rate of 4-nitrophenol.  相似文献   

13.
The biodegradation characteristics of di-n-butyl phthalate (DBP), an environmental endocrine disruptor, were studied by the method of dominant bacteria and immobilized microorganisms. Methods Taking DBP as the only carbon source to acclimatize the collected activated sludge, the concentration of DBP increased progressively in the process of acclimatization. Plate streaking was used to separate 1 strain of the degradation dominant bacteria after acclimatization. Better conditions to degrade DBP by the bacterium could be obtained through orthogonal experiments and the bacterium was identified. Then the acclimated activated sludge was made to immobilize the microorganism using polyvinyl alcohol as entrapment agent. The immobilized microorganism degraded DBP at different conditions. Results The appropriate conditions to degrade DBP by the dominant bacteria were: degradation time, 32 h; DBP concentration, 200 mg/L; rate of shaking incubator, 100 r/min; pH, 7 and temperature, 30℃. DBP could be degraded by more than 95% under such conditions. The bacteria were identified as pseudomonas. The proliferated immobilized microorganisms degraded DBP more effectively and more adapted to temperature and pH than the free acclimated activated sludge. Conclusion One strain of DBP degradation dominant bacteria was separated from the acclimatized activated sludge. It could grow with DBP as the only carbon source and energy, and degraded DBP effectively. After having been immobilized and proliferated, the dominant bacteria could keep a higher biological activity and degrade DBP more effectively than activated sludge.  相似文献   

14.
Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH_4NO_3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co~(2 ), Zn~(2 ), Ni~(2 ), Mn~(2 ) and Cu~(2 ) had an inhibitory effect on aniline degradation. Con  相似文献   

15.
Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment  相似文献   

16.
研究了Mn^2+对白腐菌(Phanerochanete chrysosporium)产生的过氧化物酶(MnP和LiP)活力的影响及胞内外酶在氯代酚化合物降解过程中的作用。结果表明:Mn^2+对MnP和LiP的活力有显著影响;白腐菌对相对分子质量低的有机化合物的降解主要在细胞内依靠胞内酶的作用进行,而胞外酶加快了降解速率;两种胞外酶MnP和LiP在降解过程中所起的作用不同,MnP起主要作用,LiP起次要作用。白腐茵对酚类化合物的基质亲和性较活性污泥低,适宜于高浓有机废水的预处理;白腐茵对毒性的忍受能力与活性污泥微生物相似,但处理方式和条件的改变可以提高其毒性忍受能力。  相似文献   

17.
针对地下水中常见的三氯乙烷(TCA)和二恶烷复合污染的去除问题,在升流式厌氧反应器中构建零价铁-厌氧活性污泥耦合体系,深入研究了耦合体系对TCA和二恶烷的降解特性,并对降解动力学及菌群多样性进行了分析,探究了耦合降解机制。研究表明,耦合体系极大地提高了TCA和二恶烷的降解率,使之分别达到97.5%和92.0%,且降解过程符合准一级反应动力学。TCA通过零价铁还原脱氯生成氯乙烷。最后通过研究零价铁腐蚀产物与微生物菌群结构得到了耦合降解机制。  相似文献   

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