硝化抑制剂的加量对生化需氧量值影响的探讨

BOD作为衡量水体受有机污染程度的重要指标,其反映的可生化降解性是其他参数无法替代的。在5日生化培养时间内,硝化作用的耗氧量取决于是否存在足够数量的能进行此种氧化作用的微生物,许多二级生化处理的出水和受污染较久的水体中,往往含有大量硝化微生物,因此测定这种水样时应抑制其硝化反应。通过对特定水体硝化抑制剂添加与否及加量多少对BOD5测定结果的影响,分析并探讨抑制特定水体硝化过程的最佳条件。在严格质量控制的基础上,对特定行业和环境水体的实际样品进行硝化抑制剂添加与否和加量及时间培养曲线等对比实验,通过所得到的比对数据以化学需氧量值与BOD5之间关系为基准,对硝化抑制剂的加量进行了探究。     

Enantioselective separation and zebrafish embryo toxicity of insecticide beta-cypermethrin

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between enantiomers.In this study,enantiomers of insecticide beta-cypermethrin (beta-CP) were separated on selected chiral column by HPLC,and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval assays.The enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism (CD) at 236 nm.Better separation could be achieved at lower temperature (e.g.,20°C) and with lower levels of polar modifiers.Pure enantiomers were obtained on Chiralcel OD.The CD spectra of enantiomers were recorded.By comparing the elution order with a previous similar study,the absolute configuration of beta-CP enantiomers was determined.The individual enantiomers were used in zebrafish embryo test,and the results showed that beta-CP enantioselectively induced yolk sac edema,pericardial edema and crooked body.The 1R-cis-αS and 1R-trans-αS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L,while the 1S-cis-αR and 1S-trans-αR induced no malformations at higher concentration (e.g.,0.3 mg/L).The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.     

鼎鑫煤化有限公司焦化废水处理工程实践

介绍了河北涉县鼎鑫煤化有限公司的焦化废水处理工程,详细论述了该工程所采用的"隔油+气浮+生化处理+脱色混凝"处理工艺,分析了DO、pH及温度等因素对运行效果的影响,并对该工程运行后的综合效益进行了分析.运行结果显示:系统出水的COD、SS、NH3-N、挥发酚、氰化物、硫化物、石油类质量浓度分别为140,100,20,0...     

Formation and cytotoxicity of a new disinfection by-product (DBP) phenazine by chloramination of water containing diphenylamine

Disinfection by-products (DBPs) in drinking water have caused worldwide concern due to their potential carcinogenic effects. The formation of phenazine from diphenylamine (DPhA) chloramination was studied and its cytotoxicities for two human cancer cells were also investigated. Phenazine was detected synchronously with the consumption of DPhA by chloramination, which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine (NDPhA) from DPhA chloramination. The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0, with phenazine as the main product for DPhA chloramination at lower pH, but higher pH favored the formation of NDPhA. Thus, solution pH is the key factor in controlling the formation of phenazine and NDPhA. Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine, although increasing the chloramine concentration could speed up the reaction rate of DPhA with chloramines. The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 (bladder cancer cell lines) and HepG2 (hepatic tumor cell lines) cells with IC50 values of 0.50 and 2.04 mmol/L, respectively, and T24 cells being more sensitive to phenazine than HepG2 cells. The IC50 values of phenazine, DPhA, and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA (IC50, 0.16 mmol/L), suggesting that phenazine in drinking water may have an adverse effect on human health.     

胶州湾北岸潮间带三-(2,3-二溴丙基)异氰脲酸酯和六溴环十二烷的分布水平

对胶州湾北岸潮间带底泥样品中三-(2,3-二溴丙基)异氰脲酸酯(tris-(2,3-dibromopropyl)isocyanurate,TBC)和六溴环十二烷(hexabromocyclododecanes,HBCDs)的3种同分异构体(α-HBCD、β-HBCD、γ-HBCD)的分布水平进行分析,结合索氏提取与Waters ACQUITY UPLC-MS-MS超高效液相色谱-质谱联用仪检测出TBC和HBCDs的3种同分异构体α-HBCD、β-HBCD、γ-HBCD,浓度范围分别为1.20~5.62 ng·g~(-1)(干重)、1.18~1.54 ng·g~(-1)(干重)、1.50~1.85 ng·g~(-1)(干重)、2.12~2.99 ng·g~(-1)(干重)。其中,TBC在河流入海口处的浓度较高,γ-HBCD占ΣHBCDs的比例(44.75%)最高,且相关性分析表明TBC和HBCDs可能有相似的污染来源。最近,斯德哥尔摩公约持久性有机污染物审查委员会(POPRC)将HBCDs列入POPs名单加以限制使用,这表明其具有一定的环境风险,未来可能对环境和人类健康造成的危害应该引起足够的重视。     

孕酮诱导非洲爪蟾卵母细胞生发泡破裂(GVBD)实验方法的优化及干扰物质筛查

非洲爪蟾卵母细胞生发泡破裂(GVBD)是生物学上研究卵细胞成熟过程及其机制的良好模型。由于GVBD受激素的调控,曾有研究将孕酮诱导的非洲爪蟾GVBD试验用于内分泌干扰物的筛查。通过预注射人体绒毛膜促性腺激素(HCG)提高非洲爪蟾卵母细胞对孕酮的敏感性、缩小个体差异,缩短试验时间等优化GVBD试验方法;并选用甲氧氯作为阳性参照物对优化的方法进行验证,最后用此方法研究了米非司酮、来曲唑、咪鲜胺3种化学物质对孕酮诱导GVBD的影响。结果发现,甲氧氯对GVBD的发生具有明显抑制作用,随着剂量的增加抑制作用增强,显示优化方法的可靠性。米非司酮作为孕酮受体拮抗剂,没有表现出抑制GVBD的效应,证明孕酮诱导爪蟾GVBD并非完全由孕酮受体(PR)介导。同时,来曲唑和咪鲜胺对孕酮诱导爪蟾GVBD没有影响,显示此两种物质在孕酮诱导GVBD过程中不具有内分泌干扰作用。     

应用黑斑蛙胚胎测试化学品发育毒性的方法

选择合适的尤其是本土生物种进行化学品生态毒性评估,对于各国化学品的环境管理十分重要.本文选择我国本土两栖种黑斑蛙的胚胎为试验生物,以半数致死浓度LC50、半数致畸浓度TC50、致畸指数TI及最小抑制生长浓度MCIG为终点指标,建立了黑斑蛙胚胎发育毒性试验方法.以五氯酚、视磺酸、氯化镉、重铬酸钾为测试物研究了方法的敏感性,并以五氯酚为测试物研究了方法的可重复性.结果显示:五氯酚、视磺酸、氯化镉和重铬酸钾对黑斑蛙胚胎的LC50分别为572.3 μg·L-1、54.8 μg·L-1、6.8 mg·L-1和97.5 mg· L-1.五氯酚、视磺酸和氯化镉对黑斑蛙胚胎的TC50分别为246.5 μg·L-1、18.7 μg· L-1和3.4 mg·L-1,TI分别为2.3、2.9和2.0,MCIG分别为160.0 μg· L-1、10.1 μg·L-1和2.4 mg·L-1.重复性试验发现,五氯酚的LC50、TC50、TI及MCIG的变异系数分别为12.6％、18.0％、23.0％和18.6％.与文献中非洲爪蟾胚胎试验的数据比较,这些数据显示黑斑蛙胚胎与非洲爪蟾胚胎对测试物的敏感性存在一定的差异,各个终点指标的变异系数相当.因此,本文建立的黑斑蛙胚胎发育毒性试验可以用于化学品的发育毒性评价,为我国化学品环境管理提供技术支持.     

换流站并联电容器保护跳闸分析及改进

针对换流站无功设备自动投切过程中发生的一起滤波器差动保护单套保护跳闸事件,基于并联电容器保护配置和交流滤波器选相合闸装置原理,对跳闸原因进行深入分析。分析结果表明:并联电容器选相合闸装置未在B相电压过零点合闸,同时并联电容器差动保护未躲过短时冲击电流,以及保护装置对高频电流过滤处理不充分是导致单套保护装置跳闸的根本原因。     

环糊精在环境污染治理中的应用分析

环糊精独特的结构特征使其在环境污染治理领域表现出越来越广泛的应用前景。主要综述了环糊精促进水体中有机污染物去除的应用研究,对土壤中污染物的修复应用研究,以及在其他环境污染治理方面的应用。展望了环糊精及其衍生物在环境保护等领域的应用前景。     

Allelochemicals of the invasive neophyte Polygonum cuspidatum Sieb. & Zucc. (Polygonaceae)

Polygonum cuspidatum Sieb. and Zucc., a traditional Chinese medicine is now a wide-spread invasive neophyte in Europe and America. The novel weapon hypothesis states that some invasive weed species owe part of their success as invaders to allelopathy mediated by some allelochemicals. Previous HPLC/UV/ESI-MS analysis showed that the constituents of the roots of P. cuspidatum from China were obviously different from the species collected in Switzerland (present as an invasive neophyte) with respect to piceatannol glucoside, resveratroloside and some proanthocyanidin. This work isolated these special constituents from the invasive plant and studied their allelopathy effect, as well as the related structures by the seedling and growing model of Lepidium sativum (garden cress, Brassicaceae). The results revealed that stilbenes as piceatannol glucoside, resveratroloside and proanthocyanidins as catechin, epicatechin from this plant were comparatively stronger allelochemicals than the reported allelochemical (−)-catechin, which may partly explain the invasive behavior of this plant in Europe.