二氧化钛光催化降解处理染料废水

研究了TiO2的添加量，粒径大小，作用时间对3种染料废水脱色率的影响及TiO2薄膜对染料废水的处理效果。对于汽巴克染绿和直接大红染料溶液，适宜的TiO2添加量均为5g/L，紫外灯照射60min，其脱色率大于85％。对于阳离子红染料溶液，适宜的TiO2添加量为3g/L，其脱色率为83．5％。粒径小的TiO2作用效果优于粒径大的效果。在室温和适宜的TiO2添加量的条件下，随照射时间的延长，太阳光的光催化降解效果渐渐接近于紫外光的光催化降解效果。将TiO2薄膜固定在陶瓷睛上，有利于TiO2的重复使用。     

Carbon Storage in Tagus Salt Marsh Sediments

Seasonal variation of above ground and belowground biomass of Spartina maritima and Halimione portulacoides, decomposition rates of belowground detritus in litterbags, and carbon partitioning in plant components and sediments were determined in two Tagus estuary marshes with different environmentalconditions. Total biomass was higher in the saltier marsh from 7,190 to 6,593 g m^-2 dw and belowground component contributed to more than 90%. Litterbag experiment showed that 30 to 50% of carbonis decomposed within a month (decomposition rate from 0.024 to 0.060 d^-1). Slower decomposition in subsequent periods agrees with accumulation of carbon concentration in sediment. Atmospheric carbon annually transferred to the plant belowground biomass is stored more efficiently in sediments of Corroios than Pancas.     

EFFECTS OF DAM IMPOUNDMENT ON THE FLOOD REGIME OF NATURAL FLOODPLAIN COMMUNITIES IN THE UPPER CONNECTICUT RIVER1

ABSTRACT: Understanding the effects of dams on the inundation regime of natural floodplain communities is critical for effective decision making on dam management or dam removal. To test the implications of hydrologic alteration by dams for floodplain natural communities, we conducted a combined field and modeling study along two reaches in the Connecticut River Rapids Macrosite (CRRM), one of the last remaining flowing water sections of the Upper Connecticut River. We surveyed multiple channel cross sections at both locations and concurrently identified and surveyed the elevations of important natural communities, native species of concern, and nonnative invasive species. Using a hydrologic model, HEC‐RAS, we routed estimated pre‐and post‐impoundment discharges of different design recurrence intervals (two year through 100 year floods) through each reach to establish corresponding reductions in elevation and effective wetted perimeter following post‐dam discharge reductions. By comparing (1) the frequency and duration of flooding of these surfaces before and after impoundment and (2) the total area flooded at different recurrence intervals, our goal was to derive a spatially explicit assessment of hydrologic alteration, directly relevant to natural floodplain communities. Post‐impoundment hydrologic alteration profoundly affected the subsequent inundation regime, and this impact was particularly true of higher floodplain terraces. These riparian communities, which were flooded, on average, every 20 to 100 years pre‐impoundment, were predicted to flood at 100 ? 100 year intervals, essentially isolating them completely from riverine influence. At the pre‐dam five to ten year floodplain elevations, we observed smaller differences in predicted flood frequency but substantial differences in the total area flooded and in the average flood duration. For floodplain forests in the Upper Connecticut River, this alteration by impoundment suggests that even if other stresses facing these communities (human development, invasive exotics) were alleviated, this may not be sufficient to restore intact natural communities. More generally, our approach provides a way to combine site specific variables with long term gage records in assessing the restorative potential of dam removal.     

Simulating pesticide leaching and runoff in rice paddies with the RICEWQ-VADOFT model

There is a current need to simulate leaching and runoff of pesticide from rice (Oryza sativa L.) paddies for assessing environmental impacts on a valuable agricultural system. The objective of this study was to develop a model for determining predicted environmental concentration (PEC) in soil, runoff, and ground water through the linkage of two models, rice water quality model (RICEWQ) and vadose zone transport model (VADOFT), to simulate pesticide fate and transport within a rice paddy and underlying soil profile. Model performance was evaluated with a field data set obtained from a 2-yr field experiment in 1997 and 1998 in northern Italy. The predictions of amount of pesticide running off from the paddy field and accumulating in the paddy sediment were in agreement with measured values. Leaching into the vadose zone accounted for approximately 19% of the applied dose, but only a small amount of chemical (<0.1%) was predicted to reach ground water at a 5-m depth due to sorption and transformation in the soil. The permeability of the soil and the water management practices in the paddy field were shown to have a strong influence on pesticide fate. These factors need to be well characterized in the field if model predictions are to be successful. The combined model developed in this work is an effective tool for exposure assessments for soil, surface water, and ground water, in the particular conditions of rice cultivation.     

Case study: Building an ISO 14001-compatible EMS at Mead Coated Board,Mahrt Mill

Many companies are using ISO 14001 as a guide in formalizing their environmental management system (EMS). This article presents Mead Coated Board, Mahrt Mill's experiences in this process, which involved undertaking a gap analysis and developing the key elements and specific procedures that comprise the EMS. Specific issues addressed include the various techniques and approaches used for developing procedures based on the type and level of procedure required; the interaction between the consultants and the mill personnel; the methods for capitalizing on the experience and expertise of the consultant and the internal personnel to achieve the desired results and lessons learned in the process.     

Carrier detection of duchenne muscular dystrophy through analysis of dna from deciduous teeth of a dead affected child

The sister of a child affected by Duchenne muscular dystrophy (DMD) was referred for genetic counselling to assess the risk of her being a carrier. Her brother had died 15 years previously at the age of 8. There were no other affected males in the family. There were no methods for DNA investigation at the time of the child's death and the family had never been studied for linkage with polymorphic probes on the chromosomal region Xp21. The only tissue from which an assessment of the risk could be made by DNA linkage analysis was two of the child's deciduous teeth that the parents had kept. DNA was extracted using a protocol described for the recovery of ancient DNA from museum specimens and archaeological finds. Multiplex amplification did not reveal deletions in 19 exons spanning the hot-spot regions for deletions within the dystrophin gene in Xp21. Linkage analysis using three highly polymorphic microsatellites demonstrated that the sister had not received the X chromosome borne by her brother. These results show that DNA extracted from teeth is a reliable source for molecular diagnosis.     

Psychological reactions to fetoscopy: A controlled study

Twenty woman at risk of carrying a fetus with homozygous beta-thalassemia who underwent fetoscopy and a matched control group of pregnant women were administered the Symptom Questionnaire to evaluate changes in distress. Women who were offered fetoscopy had significantly more anxiety, depression, somatic symptoms and hostility than the control group. Psychological distress significantly decreased after the results of fetoscopy were communicated to the patient, and the decrease was similar in normal control women. Five other patients had a diagnosis of homozygous beta-thalassaemia and their pregnancies were terminated. Their psychological distress increased when they learned the outcome of fetoscopy, but decreased again after termination. Psychological reactions to fetoscopy and amniocentesis appear to be similar, yet women who undergo fetoscopy suffer from more psychological distress.     

The 1997 Kyoto Protocol: What Does It Mean for Project-Based Climate Change Mitigation?

The Kyoto Protocol effectively ends the Activities Implemented Jointly (AIJ) pilot phase. However, it is premature to conclude that Articles 6 and 12 of the Protocol vindicate joint implementation and successfully conclude the AIJ pilot phase. Rather, Articles 6 and 12 can be seen as part of the price developing countries felt they had to pay to obtain a Protocol. Debate over Articles 6 and 12 is likely to be as contentious as the JI/AIJ debates that preceded it. Indeed, the AIJ pilot phase has not answered many concerns posed by developing countries and other interest groups. While companies and countries participating in AIJ have had wide latitude to pursue almost any projects they wished, it remains to be seen how much of this flexibility will be preserved as Articles 6 and 12 become operational. This will determine whether the importance and cost-effectiveness originally predicted for the joint implementation concept comes to pass. A review of the JI and AIJ literature suggests many potential stumbling blocks to achieving large-scale and cost-effective emissions reductions through project-based mitigation efforts under the Kyoto Protocol. This paper identifies these stumbling blocks and systematically assesses their potential implications. The Greenhouse Gas Offset Cost Assessment and Decisionmaking Model (GGOCAD©) is used to qualitatively as well as quantitatively evaluate the importance of key criteria and methodological decisions under Articles 6 and 12. It is easy to develop scenarios in which project-based mitigation through Articles 6 and 12 would not be permitted to contribute substantially to achievement of countries’ obligations under Article 3. Overcoming the challenges facing project-based mitigation efforts is important to achieving the larger goals of the Kyoto Protocol.     

MtDNA population structure and gene flow in lingcod (<Emphasis Type="Italic">Ophiodon elongatus</Emphasis>): limited connectivity despite long-lived pelagic larvae

Lingcod, Ophiodon elongatus Girard, have a 3-month pelagic larval stage and are an important recreational and commercial species on the west coast of North America. Cytochrome-c oxidase I sequences from tissue samples were used to characterize population structure and infer patterns of gene flow from California to Alaska. No significant genetic structure was found when estimates of Wright’s F _ST (i.e., Φ_ST) were generated among all populations sampled. Nesting populations within regions, however, indicated that the inner coast of Washington State is distinct, a result corroborating previous allozyme work. Coalescent-based estimates of gene flow indicate that although migration can be high from an evolutionary perspective, nearly half of all comparisons among populations showed no gene flow in at least one direction. From an ecological perspective, moderate migration rates (Nm < 10) among most populations provide surprisingly limited connectivity at large (∼ 1,000 km) and small (∼100 km) spatial scales. Coalescent-based estimates also show that gene flow between the inner and the outer coasts is asymmetric, a result consistent with prevailing surface currents. Because the expected inter-locus variances for coalescent-based estimates of gene flow are likely large, future work will benefit from analyses of nuclear DNA markers. However, limited demographic connectivity on large spatial scales may help explain why stock recovery has been uneven, with greater recovery in the northern (87% rebuilt) than in the southern (24% rebuilt) fishery region, supporting a regional management strategy. These results suggest that despite a 3-month pelagic larval stage, some areas may be effectively closed with respect to both population dynamics and fishery management issues.     

Novel degradation products of the herbicide oxasulfuron identified by capillary electrophoresis – mass spectrometry

Two new intermediates rising from the photolytic reaction of the sulfonylurea herbicide oxasulfuron have been identified in aqueous environment. The higher concentrations of the two derivatives oxetan-3-yl 2-(formilsulfamoyl) benzoate and N-(4,6-dimethyl-pyrimidin-2-yl) formamide were reached within 8 h of UV-irradiation. Here we demonstrate that an optimal separation and analysis of such compounds can be achieved by using a novel analytical method based on “non-aqueous” capillary electrophoresis (CE) system joined to an electrospray ionisation-mass spectrometry equipment. Using such a separation method and a particular electrophoretic solution a high reproducibility of migration times and peak areas can be obtained.