深圳市社会经济发展与近岸水体富营养化关系研究(Ⅰ)

通过对深圳市近年来近海海域水体水质数据分析,研究和评价该海域水质演变趋势,并对这种趋势进行环境经济原因分析。得出以下结论:1.西部海域水体富营养化程度比较严重;2.深圳东、西部海域近年N:P值都远远超过16,属于严重的P缺乏型海域;3.深圳海域的大部分水质指标在1998年以后都有大幅上升的趋势,反映了深圳市近年向近海水体排放污染物量有加剧趋势;4.深圳市社会经济的发展加剧了近海水体的污染;5.深圳市人民生活水平近年有较大的提高,排放的生活污染造成环境危害远远大于工业污染。     

小麦细胞色素P450作为土壤污染生物标记物的研究

以小麦(Triticum acstivnm)为供试植物,建立了小麦细胞色素P450含量的测定方法.在此基础上,以草甸棕壤为供试土壤,菲为外源污染物,进行了菲污染暴露与P450含量的污染诱导量-效关系研究.比较了P450含量与超氧化物歧化酶(SOD)活性对污染诱导的敏感性.结果表明,当土壤菲浓度在1-8mg· kg-1范围内,P450总量分别为对照组的1.78,2.51,2.48和2.17倍,表现为诱导刺激效应,且P450含量与菲含量之间存在明显的剂量-效应关系(P=0.00).而同样浓度范围内,SOD活性变化与对照相比均无显著差异(P=0.168).     

AmOn一体化污水生物处理新工艺试验

主要介绍了AmOn一体化污水处理新工艺的试验研究。试验表明,AmOn一体化新工艺对CODCr去除和硝化、脱氮都有着较高的效率,出水的CODCr、NH3N、TN均可达到国家规定的排放标准,具有较好的应用前景和进一步深入研究的价值。但是该工艺除磷的效率不高,需进一步改进设备和工艺。     

New insights into eutrophication management: Importance of temperature and water residence time

Eutrophication and harmful cyanobacterial blooms threaten water resources all over the world. There is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management of lake eutrophication. The primary argument against the dual nutrients control of eutrophication is that nitrogen fixation can compensate the nitrogen deficits. Thus, it is of great necessary to study the factors that can significantly affect the nitrogen fixation. Due to the dif...     

小球藻对氨厂废水的净化及其叶绿素荧光变化

25℃、5 000 lx条件下,在微电脑培养箱中研究了普通小球藻对浓度分别为25%C、50%C、75%C、100%C的氨厂废水中COD和NH3-N的去除率.192 h后,COD去除率分别为84%、96.4%、97%和95.6%,NH3-N去除率分别为22.7%、4.9%、10.6%和0%,25%C、50%C、75%C和...     

多因素影响下SUFR系统除磷效果研究

在进水COD浓度控制在300～400 mg/L范围内,针对SRT、C/N和C/P 3个因素对TP的影响设计了正交实验,并在此基础上进行回归正交实验。实验结果显示：SRT、C/N、C/P 3个因素中SRT对厌氧释磷和好氧吸磷速率的影响最大,随着SRT的增大,系统除磷效率逐渐下降。C/N和C/P的增长使系统进水TN、TP浓...     

Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state ¹³C nuclear magnetic resonance spectroscopy (¹³C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants.     

Structural characterization and thermal stabilities of the isomers of the brominated flame retardant 1,2,5,6-tetrabromocyclooctane (TBCO)

1,2,5,6-Tetrabromocyclooctane (TBCO) is a commercial brominated flame retardant that is employed mainly as an additive in textiles, paints and plastics. Very little is known about its presence or behavior in the environment or its analysis. TBCO can exist as two diastereomers, the stereochemistries of which have not been previously reported. We have named the first eluting isomer, under HPLC conditions, as alpha-TBCO (α-TBCO) and the later eluting isomer as beta-TBCO (β-TBCO) when using an Acquity UPLC BEH C₁₈ column with methanol/acetonitrile/water as the mobile phase. The structural elucidation of these two isomers was accomplished by ¹H NMR spectroscopy, GC/MS, LC/MS and X-ray structure determinations. α-TBCO is (1R,2R,5S,6S)-1,2,5,6-tetrabromocyclooctane and β-TBCO is rac-(1R,2R,5R,6R)-1,2,5,6-tetrabromocyclooctane. As with some other brominated cycloaliphatic compounds, TBCO is thermally labile and the isomers easily interconvert. A thermal equilibrium mixture of α- and β-TBCO consists of approximately 15% and 85% of these isomers, respectively. Separation of the two diastereomers, with minimal thermal interconversion between them, is achievable by careful selection of GC-capillary column length and injector temperature. LC/MS analyses of TBCO also presents an analytical challenge due to poor resolution of the isomers on chromatographic stationary phases, and weak intensity of molecular ions (or major fragment ions) when using LC-ESI/MS. Only bromide ions were seen in the mass spectra. APCI and APPI also failed to produce the molecular ion with sufficient intensity for identification.     

Pteris vittata – Revisited: Uptake of As and its speciation, impact of P, role of phytochelatins and S

Pteris vittata is known to hyperaccumulate As but the mechanism is poorly understood. We found an increase of As concentration with increasing soil solution As concentrations, but P application had no impact, although plant P concentrations responded to different rates of P supply. As in fronds was dominantly (82–89%) present in the form of AsIII. In roots we detected 45% as AsIII which is higher than reported in previous studies and supports substantial As-reduction to take place in roots. We detected PC2/3GS–AsIII, PC2–GS–AsIII and (PC2)2–AsIII in increasing amounts with application of As. The total amount of PC was in the range reported previously and far too small to assign a significant role in As detoxification to PCs. The close correlation between S and As in fronds and the lack of data on sulphur uptake and metabolism indicates the need for a detailed investigation on sulphur nutritional status and As metabolism in P. vittata.     

1H-NMR-based metabolomic study on toxicity of methomyl and methidathion in fish

A ¹H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment.