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671.
为掌握湛江港临近海域养殖区贝类毒素的特征情况,近几年来,作者在多个采样点进行了样品采集,小白鼠生物法和高效液相色谱法的检测结果表明:(1)多种贝类体中检测出PSP,而DSP则更为普遍。(2)所检测的12种PSP成分在该海域均存在。不同的贝类,其毒素成分情况有所不同。PSP各成分有一定的季节性变化规律。消化腺中各毒性成分含量值相对较高。(3)PSP毒素值较低,未超标,仅在春秋季节检出。DSP毒素在各季节均存在,并有超标现象,从阳性率和超标率来看,秋季春季冬季。春秋季节应特别注意水产品的食用安全。(4)多处地区毒素含量值较高。 相似文献
672.
673.
给水系统中卡马西平含量测定方法的研究 总被引:1,自引:0,他引:1
文章用固相萃取与高效液相色谱结合的方法测定给水系统中痕量卡马西平的含量。考察了C18小柱的最佳洗脱条件,并且根据出峰时间选择了最佳的色谱条件:流动相为水(用磷酸调节pH至4)和甲醇(40∶60,V/V),温度为25℃,流速为1.0mL/min,检测波长为285nm。卡马西平浓度在0.2~2mg/L范围内线性关系良好,回归方程y=81.53258x-7.19487,加标回收率平均值为94.3%,RSD为2.7%(n=7)。用该方法测定实际水源水和自来水厂中间工段出水,简单易操作,结果准确。 相似文献
674.
A laboratory study was performed to assess the biodegradation of lube oil in bio-reactor with 304# stainless steel as a biofilm carrier.
Among 164 oil degrading bacterial cultures isolated from oil contaminated soil samples, Commaonas acidovorans Px1, Bacillus sp.
Px2, Pseudomonas sp. Px3 were selected to prepare a mixed consortium for the study based on the e ciency of lube oil utilization.
The percentage of oil degraded by the mixed bacterial consortium decreased slightly from 99% to 97.2% as the concentration of lube
oil was increased from 2000 to 10,000 mg/L. The degradation of TDOC (total dissolved organic carbon) showed a similar tendency
compared with lube oil removal, which indicated that the intermediates in degradation process hardly accumulated. Selected mixed
bacterial consortium showed their edge compared to activated sludge. Scanning electron microscopy (SEM) photos showed that
biofilms on stainless steel were robust and with a dimensional framework constructed by EPS (extracellular polymeric substances),
which could promote the biodegradation of hydrocarbons. The increase of biofilm followed first-order kinetics with rate of 0.216 g
glucose/(cm2 day) in logarithm phase. With analysis of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass
spectrometry (GC-MS) combined with removal of lube oil and TDOC, mixed bacterial consortium could degrade benzene and its
derivatives, aromatic ring organic matters with a percentage over 97%. 相似文献
675.
从实验室的废水生物处理反应器内的活性污泥样本,筛选出来一株以吡啶为唯一碳、氮源的脱氮副球菌(Paracoccus denitrificans),命名为W12;研究了温度、pH值、吡啶初始浓度和投菌量对W12降解吡啶的影响.结果显示,在试验温度范围内高温有利于W12降解吡啶;同时W12降解吡啶的最适pH值范围在7-9;吡啶初始浓度越大降解时间越长,且投菌量越大吡啶降解越快.此外还研究了W12菌上赋存的质粒特性.脉冲场试验表明,W12菌上2个质粒的大小分别为169 kb和182 kb,并通过质粒消除试验证实了质粒参与了编码吡啶降解基因. 相似文献
676.
Electrochemical incineration of dimethyl phthalate by anodic oxidation with
boron-doped diamond electrode 总被引:1,自引:0,他引:1
The anodic oxidation of aqueous solutions containing dimethyl phthalate (DMP) up to 125 mg/L with sodium sulfate (Na2SO4) as
supporting electrolyte within the pH range 2.0–10.0 was studied using a one-compartment batch reactor employing a boron-doped
diamond (BDD) as anode. Electrolyses were carried out at constant current density (1.5–4.5 mA/cm2). Complete mineralization was
always achieved owing to the great concentration of hydroxyl radical (.OH) generated at the BDD surface. The e ects of pH, apparent
current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization
and mineralization current e ciency were investigated systematically. The mineralization rate of DMP was found to be pH-independent
and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least
partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during
electrolysis determined by High Performance Liquid Chromatography (HPLC) revealed that DMP decay under all tested conditions
followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography-
Mass Spectrometry (GC-MS) and a general pathway for the electrochemical incineration of DMP on BDD was proposed. 相似文献
677.
678.
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. 相似文献
679.
低C/N比条件下高效生物脱氮策略分析 总被引:9,自引:1,他引:8
针对低C/N比污水传统生物脱氮碳源不足、脱氮效率不高,提出从充分利用碳源和减少生物脱氮碳源需求量两个方面,来实现高效生物脱氮.在充分利用碳源方面,介绍了好氧缺氧分段进水工艺、脉冲式SBR工艺等改进型生物脱氮工艺;在减少生物脱氮碳源需求量方面,介绍了短程硝化反硝化、厌氧氨氧化、完全自养脱氮等新型生物脱氮技术.并对这些技术和工艺的原理、优势、存在的问题以及应用情况进行了简要的分析. 相似文献
680.
针对目前水体中MCPA检测灵敏度不够,缺乏一种无需前处理、可直接上机、简单便捷方法的问题,以超高液相色谱串联质谱仪,建立了一种以电喷雾离子源ESI-为电离模式、MRM为监测模式、可直接进样测定水体中MCPA残留的方法。结果表明,最优方法条件为定量离子对199.0/140.9(m/z),流动相乙腈和水梯度洗脱,色谱柱Acquity UPLC HSS T3。在MCPA质量浓度为0.1~100μg/L范围内线性良好(R2=99.99%),检出限为0.006μg/L,定量限为0.018μg/L,是现有直接进样法的23~83倍,完全满足水体中MCPA的检测要求(<0.1μg/L)。在添加水平为1~100μg/L时,回收率为94.30%~105.60%,相对标准偏差为1.05%~3.61%,具有前处理简单、准确性高、精密度好、灵敏度高等优点。 相似文献