Degradation of 2,4-dichlorophenol with a novel TiO2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process

Degradation of 2,4-dichlorophenol(2,4-DCP)was studied in a novel three-electrode photoelectrocatalytic(PEC)integrative oxidation process,and the factors influencing the degradation rate,such as applied current,flow speed of O_2,pH,adscititious voltage and initial 2,4-DCP concentration were investigated and optimized.H_2O_2 was produced nearby cathode and Fe~(2 )continuously generated from Fe anode in solution when current and O_2 were applied,so,main reactions,H_2O_2-assisted TiO_2 PEC oxidation and E-Fenton reaction,occurred during degradation of 2,4-DCP in this integrative system.The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process,while it was only 31% in E-Fenton process and 46% in H_2O_2-assisted TiO_2 PEC process.So,it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect.By the investigation of pH,it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.     

Di（2-ethylhexyl）phosphoric acid-coconut oil supported liquid membrane for the separation of copper ions from copper plating wastewater

Permeation of Cu(II) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(II), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconutoil has also been evaluated. High Cu(II) concentration in the feed leads to an increase in flux from 4.1 × 10-9 to 8.9 × 10-9 mol/(m2·s) within the Cu(II) concentration range 7.8×10-4-78.6×10-4 mol/L at pH of 4.0 in the feed and 12.4 × 10-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10-9 mol/(m2·s). The optimum conditions for Cu(II) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10-4 mol/L D2EHPA (membrane) in 0.5 (m pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(II) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(II). rane. It     

Comparative Salinity Tolerance of Three Indigenous Tropical Freshwater Cladoceran Species; Moinodaphnia Macleayi, Ceriodaphnia Rigaudii and Diaphanosoma Brachyurum

The acute salinity tolerance of three tropical freshwater cladoceran species, M. macleayi, C. rigaudii and D. brachyurum was determined. The existence of these species represented new records for Trinidad and Tobago, a tropical Caribbean island. It has a large oil based industry, in which, the primary effluent (saline produced water) is discharged directly into many freshwater systems. Cladoceran species are used routinely in temperate regions, to assess the impacts of chemicals and effluents in freshwater systems. However, relatively few studies have assessed the salinity tolerance of these organisms. Test organisms were assayed using seven salinity treatments (0, 1, 3, 5, 10, 15, 20, 25‰) prepared by volumetrically mixing natural filtered seawater with dilution water. C. rigaudii had a 48 h LC50 of 1.6‰, M. macleayi 1.5‰ and D. brachyurum <1‰. The CSmax (critical salinity maximum) for C. rigaudii and M. macleayi was 3‰ after 48 h, compared to 1‰ for D. brachyurum. There was no salinity value at which there was 100% survival. The resulting salinity response curve was a straight line which indicated that each species was intolerant of salt. Consequently, any of these can be considered as a representative freshwater organism for toxicity testing in Trinidad and Tobago.     

铅锌矿业废弃地草本植物重金属耐性研究

本文调查了四川甘洛铅锌矿废弃矿区和尾矿库区自然生长的15种草本植物，分析了其体内重金属（Pb、Zn、Cd）的含量，并对植物的重金属耐受性作了初步探讨。研究表明，在所采集的15种草本植物中，地上部分以小飞蓬对Pb、Zn、Cd的富集量最高；地下部分富集量则表现出较大的种间差异性，野烟对Pb的积累量最高，假酸浆对Zn的积累量最高，水蓼对Cd的积累量最高，但均未达到“超积累植物”的标准。     

FORMAL EDUCATION IN WILDLAND HYDROLOGY AND WATERSHED MANAGEMENT IN NORTH AMERICA1

ABSTRACT: A survey was made to determine the status of formal education in wildland hydrology by colleges and universities in the United States, Canada, and Mexico. As of December 1977 nine institutions offered the B.S. degree, 18 the M.S. degree, and 17 the degree of Ph.D. with a major or minor in watershed management, forest hydrology, or range hydrology. In addition, 8 other schools offer a minor in watershed management. The survey indicated 44 schools in the United States offer a total of 157 courses, five schools in Canada offer 24 courses, and 1 in Mexico offers one course in the related areas. The survey illustrated rapid growth in education programs and it is anticipated that growth will continue.     

Tolerance of Birch Stands of the Northern Transural Forest Steppe to Abiotic and Biotic Stress Factors

It is shown that both diffuse and complete drying of birch stands is due to the additive effects of meteorological factors (hydrothermal parameters of the first and second halves of the growing period) and tree defoliation by phyllophagous insects, with the former being of primary importance.     

Metal Contamination of the Natural Environment in Norway from Long Range Atmospheric Transport

Long range atmospheric transport is the most important sourceof contamination to the natural environment in Norway with manyheavy metals. Investigations based on aerosol studies, bulkdeposition measurements and moss analysis show that airborne transport from other parts of Europe is the major mode for supplyof vanadium, zinc, arsenic, selenium, molybdenum, cadmium, tin,antimony, tellurium, thallium, lead, and bismuth, whereas metalssuch as chromium, nickel, and copper are mainly derived from point sources within Norway and in northwestern Russia close tothe Norwegian border. Elements associated with long range transport show substantial enrichment in the humus horizon of natural soils in southern Norway, sometimes to levels suspected to cause effects on soil microbial processes. E.g. lead concentration values of 150–200 ppm are observed in the mostcontaminated areas in the south as compared to about 5 ppm inthe far north. Elements such as lead and cadmium also show enrichment in some terrestrial food chains. These elements alsoshow considerably elevated levels over background concentrationsin the water and sediment of small lakes in the southern part ofthe country. Retrospective studies based on ombrogenous peatcores indicate that long range transport has been a significantsource of heavy metal contamination in southern Norway for thelast couple of centuries. The deposition of most heavy metals inNorway has been considerably reduced over the last 20 yr, withthe exception of contributions in the north from Russian smelters.     

Incorporating the perceptual range of animals into connectivity models

The perceptual range of an animal towards different landscape elements affects its movements through heterogeneous landscapes. However, empirical knowledge and modeling tools are lacking to assess the consequences of variation in the perceptual range for movement patterns and connectivity. In this study we tested how changes in the assumed perception of different landscape elements affect the outcomes of a connectivity model. We used an existing individual-based, spatially explicit model for the dispersal of Eurasian lynx (Lynx lynx). We systematically altered the perceptual range in which animals recognize forest fragments, water bodies or cities, as well as the probability that they respond to these landscape elements. Overall, increasing the perceptual range of the animals enhanced connectivity substantially, both qualitatively and quantitatively. An enhanced range of attraction to forests had the strongest impact, doubling immigration success; an enhanced range of attraction to rivers had a slightly lower impact; and an enhanced range of avoidance of cities had the lowest impact. Correcting the enhancement in connectivity by the abundance of each of the landscape elements in question reversed the results, indicating the potential sensitivity of connectivity models to rare landscape elements (in our case barriers such as cities). Qualitatively, the enhanced perception resulted in strong changes in movement patterns and connectivity. Furthermore, model results were highly parameter-specific and patch-specific. These results emphasize the need for further empirical research on the perceptual capabilities of different animals in different landscapes and conditions. They further indicate the usefulness of spatially explicit individual-based simulation models for recognizing consistent patterns that emerge, despite uncertainty regarding animals’ movement behavior. Altogether, this study demonstrates the need to extend the concept of ‘perceptual ranges’ beyond patch detection processes, to encompass the wide range of elements that can direct animal movements during dispersal through heterogeneous landscapes.     

Managing Aquatic Species of Conservation Concern in the Face of Climate Change and Invasive Species

Abstract:  The difficult task of managing species of conservation concern is likely to become even more challenging due to the interaction of climate change and invasive species. In addition to direct effects on habitat quality, climate change will foster the expansion of invasive species into new areas and magnify the effects of invasive species already present by altering competitive dominance, increasing predation rates, and enhancing the virulence of diseases. In some cases parapatric species may expand into new habitats and have detrimental effects that are similar to those of invading non-native species. The traditional strategy of isolating imperiled species in reserves may not be adequate if habitat conditions change beyond historic ranges or in ways that favor invasive species. The consequences of climate change will require a more active management paradigm that includes implementing habitat improvements that reduce the effects of climate change and creating migration barriers that prevent an influx of invasive species. Other management actions that should be considered include providing dispersal corridors that allow species to track environmental changes, translocating species to newly suitable habitats where migration is not possible, and developing action plans for the early detection and eradication of new invasive species.