溶剂萃取法提取电镀污泥浸出液中的铜

研究了N_(510)-煤油-H_2SO_4体系分离电镀污泥氨浸液中的Cu~(2+)的工艺过程,确定萃取铜的最佳工艺参数,以及负铜有机相反萃取较优工艺条件。研究结果表明,以N_(510)为萃取剂,经四级逆流萃取,铜的萃取效率达99％,共存的Ni~(2+)和Zn~(2+)损失量接近0,不影响后续有价金属的回收。铜在工艺过程中以铜盐CuSO_4·5H_2O或电解纯铜的形式得以回收,具有较高的经济效益。     

Sensitized photooxygenation of the fungicide furalaxyl

BACKGROUND: The photolysis of pesticides is of high current interest since light is one of the most important abiotic factors which are responsible for the environmental fate of these substances and may induce their conversion into noxious products. The action of light can also be mediated by oxygen and synthetic or naturally occurring substances which act as sensitizers. Our objective in this study was to investigate the photochemical behaviour of the systemic fungicide furalaxyl in the presence of oxygen and various sensitizers, and to compare the toxicity of the main photoproduct(s) to that of the parent compound. Previous reports on the direct photolysis of the pesticide demonstrated a very slow degradation and the only identified photoproducts were N-2,6-xylyl-D,L-alaninare and 2,6-dimethylaniline. METHODS: Solutions of furalaxyl in CH3CN were photooxygenate using a 500W high-pressure mercury lamp (through a Pyrex glass filter, lambda>300 nm) or a 650W halogen lamp or sunlight and the proper sensitizer. When sunlight was used, aqueous solutions were employed. The photodegradation was checked by NMR and/or GC-MS. The photoproducts were spectroscopically evidenced and, when possible, isolated chromatographically. Acute toxicity tests were performed on the rotifer Brachionus calyciflorus, the crustacean cladoceran Daphnia magna and the anostracan Thamnocephalus platyurus, while chronic toxicity tests (sublethal endpoints) comprised a producer, the alga Pseudokirchneriella subcapitata and the crustacean Ceriodaphnia dubia, as a consumer. RESULTS AND DISCUSSION: In the presence of both oxygen and sensitizer, furalaxyl underwent rapid photochemical transformations mainly to N-disubstituted formamide, maleic anhydride and a 2(5H)-furanone derivative. The formation of these products was rationalized in terms of a furan endoperoxide intermediate derived from the reaction of furalaxyl with active dioxygenated species (singlet oxygen, superoxide anion or ground state oxygen). The 2(5H)-furanone exhibited a higher toxicity than the parent compound. CONCLUSION: This work reports the first data on the photosensitized oxygenation of furalaxyl with evidence of the high tendency of the pesticide to undergo photodegradation under these conditions leading, among other things, to a 2(5H)-furanone, which is more toxic than the starting furalaxyl towards aquatic organisms. RECOMMENDATIONS AND OUTLOOK: Investigation highlights that the photolytic fate of a pesticide, although quite stable to direct photoreaction due to its low absorption of solar radiation at ground level, can be significantly influenced in the environment by the presence of substances with energy or electron-transfer properties as natural dyes, e.g. chlorophyll, or synthetic pollutants, e.g. polycyclic aromatic hydrocarbons (PAH).     

Effect of silica additive on the thermal stability of catalysts for NOx abatement

The aim of the plesent investigation was to study the effect of SiO₂ addition on the thermal deactivation of V₂O₅/WO₃/TiO₂ catalysts used for NOx pollution abatement. The results suggest that the degradation of the catalytic properties is strongly correlated to the structural ageing which is, in turn, mainly related to the anatase–rutile phase transformation and to the WO₃ phase segregation. The addition of SiO₂ strongly influences the temperature at which these phenomena occur. In fact, it was found that the introduction of this oxide stabilizes the material, retarding the collapse of surface area, and increases the temperature of the anatase to rutile phase transition.     

水中杀菌剂叶青双及其降解物的反相液相色谱测定

本文用反相液相色谱法测定水中叶青双及其降解物2-氨基5-巯基-1,3,4-噻二唑。平均回收率分别为91％和94％;对水样的最低检测浓度分别为2ppb和0.8ppb;叶青双与2-氨基-5-巯基-1,3,4-噻二唑的分离度为2.5。本法在柱效和灵敏度上比硅胶柱液相色谱法有明显的提高。     

GROUND WATER AS A SOURCE OF NUTRIENTS AND ATRAZINE TO STREAMS IN THE SOUTH PLATTE RIVER BASIN1

ABSTRACT: Concentrations of nitrite plus nitrate, ammonia, orthophosphate, and atrazine were measured in streams and ground water beneath the streams at 23 sites in the South Platte River basin of Colorado, Nebraska, and Wyoming to assess: (1) the role of ground water as a source of nutrients and atrazine to streams in the basin, and (2) the effect of land-use setting on this process. Concentrations of nitrite plus nitrate, ammonia, orthophosphate, and atrazine were higher in ground water than in the overlying streams at 2, 12, 12, and 3 of 19 sites, respectively, where there was not a measurable hydraulic gradient directed from the stream to the ground water. Orthophosphate was the only constituent that had a significantly higher (p ≤ 0.05) concentration in ground water than in surface water for a given land-use setting (range land). Redox conditions in ground water were more important than land-use setting in influencing whether ground water was a source of elevated nitrite plus nitrate concentrations to streams in the basin. The ratios of nitrite plus nitrate in ground water/surface were were significantly lower (p ≤ 0.05) at sites having concentrations of dissolved oxygen in ground water ≤ 0.5 mg/L than at sites having dissolved oxygen concentrations ≥ 0.5 mg/L. Elevated concentrations of ammonia or atrazine in ground water occurred at sites in close proximity to likely sources of ammonia or atrazine, regardless of land-use setting. These results indicate that land-use setting is not the only factor that influences whether ground water is a source of elevated nutrient and atrazine concentrations to streams in the South Platte River Basin.     

混合菌群FF降解染料效果及生物毒性变化

利用混合菌群FF降解偶氮染料活性黑5和蒽醌染料活性蓝19,通过检测一些常规指标,如脱色率、DOC(溶解性有机碳)去除率、UV254、比紫外吸收值SUVA(UV254/DOC)等来表征降解效果,进一步通过固相萃取方法进行前处理,采用SOS/umu(又称umu试验)和双杂交酵母法分别检测染料降解过程中遗传毒性和抗雌激素活性。结果表明,采用混合菌群FF,活性黑5和活性蓝19(150 mg/L)在35℃和p H=8.0条件下静置培养48 h后脱色率分别为82.5%和89.2%;DOC去除率低,分别为19.5%和13.0%;降解后UV254和SUVA均增加。遗传毒性检测表明,活性黑5本身无遗传毒性,降解过程中也无遗传毒性;活性蓝19本身无遗传毒性,降解24 h、48 h后在高浓缩倍数下出现遗传毒性。随着降解的进行,活性黑5和活性蓝19的抗雌激素活性均显著增加。     

碱氨蚀刻废液处理方法研究

论述了碱氨蚀刻废液处理方法的试验研究．研究包括碱法回收氢氧化铜，酸法回收胆矾和电解法回收金属铜等三种方法．     

Estimate of sea loading by pollutants originating from the littoral counties in the Republic of Croatia

The paper reviews the data of 10 yr of following up sewage (waste water) inflows of anthropological origin into the sea from all the coastal settlements in Croatia. In particular, we report the sea loading by biochemical oxygen demand (BOD₅), expressed by the inhabitant equivalent (I.E.), for seven littoral counties. We estimated the loading of a coastal sea area for each county separately. The objective was to avoid any over- or underestimation of amounts and significance of sewage inflows into the seawater. For this purpose, a precisely determined sea volume up to the 10 m isobath has been chosen. Because of the inadequate treatment of wastewater, the total loading of that maritime territory expressed in terms of i.e. was found to be 26% higher than expected from the actual number of inhabitants. However, daily input represents only 12‰ of the considered volume of the sea. Recipient spent only 0.7% of the disposable oxygen quantity in the sea.