悬浮物对半滑舌鳎稚鱼的急性毒性效应

研究了不同浓度悬浮物对半滑舌鳎(Cynoglossus semilaevisG櫣nther)浮游阶段和伏底阶段稚鱼的急性毒性效应。实验结果表明,悬浮物对浮游阶段稚鱼的48 hLC50和96 hLC50(95%可信限)分别为588.2 mg/L(518.7~666.9 mg/L)和488.7 mg/L(428.6~557.2 mg/L),安全浓度(SC)为48.87 mg/L;水温(tw)为23℃时,对伏底阶段稚鱼的48 hLC50和96 hLC50(95%可信限)分别为3 034.6 mg/L(2769.8~3324.8 mg/L)和2117.2 mg/L(1932.1~2320.1 mg/L),SC为211.72mg/L;tw为26℃时,对伏底阶段稚鱼的48 hLC50和96 hLC50(95%可信限)分别为1684.0 mg/L(1543.4~1837.3 mg/L)和1657.1 mg/L(1522.7~1803.4 mg/L),SC为165.71 mg/L。     

基于可分离性指数的溢油图像定量分析

鉴于许多溢油监测技术都缺少量化指标,为了评价溢油监测方法,提出一种基于数学统计模型的评价指数——可分离性指数SI,通过对TM影像的处理,验证了利用油膜光谱曲线确定溢油监测通道的可行性,评价了几种图像增强的方法,得出高斯拉伸与直方图均衡化增强处理较佳,并经过反复试验建立数学描述性评价指标。结果证明该指数能够有效评价溢油监测方法。     

化工生产企业员工提高业务素质和安全技能的探讨

针对当前化工生产企业的安全现状,分析了化工生产企业当前存在的问题及其原因,并探讨了应对这些问题的相应对策,以促进员工业务素质和安全技能水平的提高,激发员工"关爱安全,关爱生命"的本能意识。     

Can phosphate compounds be used to reduce the plant uptake of Pb and resist the Pb stress in Pb-contaminated soils？

The effects of di erent phosphate-amendments on lead (Pb) uptake, the activities of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in cauliflower (Brassica oleracea L.) in contaminated soils with 2500, or 5000 mg P2O5/kg soil of hydroxyapatite (HA), phosphate rock (PR), single-superphosphate (SSP) and the mix of HA/SSP (HASSP) were evaluated in pot experiments. Results showed that the Pb concentrations in shoots and roots decreased by 18.3%–51.6% and 16.8%–57.3% among the treatments respectively compared to the control samples. The e ciency order of these phosphate-amendments in reducing Pb uptake was as follows: HASSPt HA > SSP t PR.With the addition of SSP, HA and the mix of HA/SSP, the SOD activity in shoot was reduced markedly (P < 0.05) compared with that in the control group. For example, the SOD activities in shoot by the treatments of HASSP, SSP, and HA in 5000 mg P2O5/kg were found to be only 51.3%, 56.2%, and 56.7%, respectively. Similar e ects were also observed on the level of MDA in the shoots with a decrease in 24.5%–56.3%. The results verified the inference that phosphate compounds could be used to reduce the plant uptake of Pb and resist the Pb stress in the plant vegetated in Pb-contaminated soils.     

Identification and characterization of the chromium（Ⅵ） responding protein from a newly isolated Ochrobactrum anthropi CTS-325

A Gram-negative, chromium(VI) tolerant and reductive strain CTS-325, isolated from a Chinese chromate plant, was identified as Ochrobactrum anthropi based on its biochemical properties and 16S rDNA sequence analysis. It was able to tolerate up to 10 mmol/L Cr(VI) and completely reduce 1 mmol/L Cr(VI) to Cr(III) within 48 h. When the strain CTS-325 was induced with Cr(VI), a protein increased significantly in the whole cell proteins. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis revealed that this protein was a superoxide dismutase (SOD) homology. The measured superoxide dismutase activity was 2694 U/mg after three steps of purification. The SOD catalyzes the dismutation of the superoxide anion (O₂^·−) into hydrogen peroxide and molecular oxygen. This protein is considered to be one of the most important anti-oxidative enzymes for O. anthropi as it allows the bacterium to survive high oxygen stress environments, such as the environment produced during the reduction process of Cr(VI).     

Characterization of organic matter in total suspended particles by thermodesorption and pyrolysis-gas chromatography-mass spectrometry

The organic matter in tropospheric aerosol plays an important role in atmospheric physical and chemical processes. The bulk of organic matter, representing a significant proportion of the total suspended particulate (TSP) mass, is bound to polymeric material whose structure and properties are largely unknown. Here we used thermodesorption gas chromatography/mass spectrometry (Td- GC/MS) to study organic compounds of low molecular mass and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to characterize the chemical structure of macromolecules in TSP samples collected in di erent seasons from di erent sites in Guangzhou. n-Alkanes, fatty acids and nitriles were the predominant compounds in the thermodesorption products, whereas aromatics, fatty acids, nitriles and n-alkanes/alkenes were the major compounds in the pyrolysates. The results indicated that aromatics were main units in macromolecules. The fatty acids and nitriles formed from carboxylic ammonium salts were detected in both thermodesorption products and pyrolysates at a certain concentration, indicating the importance of these compounds in TSP formation. The TSP source mainly determined the occurrence of compounds in samples from urban, suburban and forest sites, whereas the TSP source and formation process maybe controlled the seasonal variation in compounds detected. High levels of nitriles in summer samples from suburban and forest sites coincide with the release of ammonium from the land and of fatty acids from vegetation at these sites.     

污染河流悬沙与铜、锌污染相关性研究

通过对矿区选矿废水污染的河流水样和悬沙进行采样,分析悬沙、铜、锌质量浓度,探讨河流悬沙与铜、锌之间的相关关系,是有重要现实意义的.研究结果表明:河流水质铜超标严重,丧失了作为农业用水的使用功能.水中铜污染物量与悬沙量相关关系,锌污染物量与悬沙量相关关系都是极显著的.经过曲线回归方程拟合,锌污染物量与悬沙量之间的回归关系比铜污染物量与悬沙量之间的回归关系显著,有3个曲线方程较优,即:对数方程、二次多项式方程、三次多项式方程.据此,通过测定污染河流悬沙量可以粗略地估算水中锌污染物量.     

颗粒污泥接种UASB反应器处理废纸造纸废水的试验研究

采用颗粒污泥接种UASB厌氧反应器处理废纸造纸废水,对其可生化性及能降解程度进行研究。通过持续近2个月的运行实验可知：在进水CODCr质量浓度为2000—3000mg,L的情况下,COD容积负荷最高可达到20kg/（m3·d）左右,水力停留时间可缩短至4h,有机污染物的去除率稳定保持在80％-90％的范围内,并且运行稳定。     

我国生态城市建设的关键和对策

介绍了生态城市的内涵、生态城市建设的关键——社会生态化。结合我国国情,提出了建设生态城市的关键内容和对策。     

集约农区不同土地利用方式对土壤养分状况的影响

选择山东省寿光市,通过野外调查和室内分析,利用数理统计软件SPSS,系统分析不同土地利用方式下土壤养分的分布特征、变异情况及其相关性,研究集约农区不同土地利用方式对土壤养分状况的影响。结果表明,在不同土地利用方式下,各养分含量分布存在明显规律。有机质均值的分布特征是菜地水浇地果园旱地盐碱地;全氮、碱解氮、速效钾、速效磷和有效锌均值的分布特征是菜地果园水浇地盐碱地旱地;土壤pH值、交换性镁均值的分布特征为盐碱地旱地水浇地果园菜地;交换性钙在不同利用方式中的含量为盐碱地旱地水浇地菜地果园;有效硼为果园菜地盐碱地水浇地旱地;有效铁为菜地果园水浇地旱地盐碱地;有效铜和有效锰均为果园菜地水浇地盐碱地旱地。水浇地、菜地和果园在各养分含量上差异较小,旱地和盐碱地在各养分含量上较为相似。除pH值外,其它12种土壤养分在不同土地利用方式下变异系数均较高,其中以速效磷的变异系数最大。土壤养分中除了交换性镁、有效硼与其它各养分之间的相关性较低外,其它养分之间基本为显著或极显著相关,其中pH值与其它各土壤养分均呈现显著或极显著负相关,有机质与其它各土壤养分均呈现显著或极显著正相关。