Modeling the contribution of pig farming to pollution of the Thachin River

Rapid growth of the livestock production sector in South-East Asia during recent decades has led to a widespread degradation of ground and surface waters. The Thachin River Basin in Central Thailand serves as a case study for investigating the origins and pathways of nutrient loads produced by intensive pig farming. A mathematical material flow analysis is used to identify key nitrogen flows and the main parameters determining them. Scenarios of the potential for reducing these flows and achieving compliance with current discharge regulations are investigated. The results show that liquid waste discharged from large pig farms and directly discharged waste from small farms are the key nitrogen flows to the river system. The key driving forces are not only the treatment coverage and efficiencies but also the rate of reuse and recycling of the treated produc

Global renewable energies: a dynamic study of implementation time, greenhouse gas emissions and financial needs

The current worldwide energy consumption is largely dominated by non-renewable energies such as coal, oil and gas. For well-known reasons, this concept should be changed to a more sustainable one based on renewables. As learned from history, a transition from one energy system to another has always taken about 100years. A dynamic material flow model is developed to simulate some key elements for the implementation of renewable energy systems on a large scale. These key elements are the required industrial capacity, the energy and financial requirements and the impact on greenhouse gas mitigation. Results are presented for wind, photovoltaic, hydro, solar thermal, geothermal and biomass electrical energy systems. The comparison of two different implementation strategies, moderate ≈60years and fast ≈30years, shows that the implementation time is the only limitation, resulting in large production overcapacities. The energy and financial needs are not as critical. The implementation of renewables on a large scale would considerably reduce CO2 emissions by 2tons per person per year for a world population of 7billion peopl

Catalysis at Ciba-Geigy

After an introduction describing the significance and a short history of catalysis at Ciba-Geigy, the present role of the Catalysis Section within the Central Research Services is outlined. Its main activities are preparative services for the synthetic chemists in the fields of hydrogenation and high-pressure reactions, the development of catalytic processes and a research program in the fields of enantioselective catalysis, the modification of heterogeneous catalytic systems, acid-base catalysis and catalytic C–C-bond forming reactions. Because catalysis is considered by Ciba-Geigy to be a key technology, the main goal of its R+D program in catalysis is to create and maintain a reliable scientific and technical foundation for the optimal application of catalytic reactions throughout the company. Some results are presented that illustrate the work described above and an outlook on the opportunities of catalytic technologies in the fine chemicals industry is given

Material flow and economic analysis as a suitable tool for system analysis under the constraints of poor data availability and quality in emerging economies

Waste from electrical and electronic equipment or e-waste is increasingly processed in transitional or developing countries. The waste originates from both national consumption and waste imports. In these countries the e-waste processing and recycling is managed almost entirely by informal recycling businesses. Due to the application of inappropriate techniques, this sector bares high risks of environmental and occupational hazards and also looses valuable materials. Formal recycling industries have to compete with the informal businesses and simultaneously comply with environmental and occupational regulations. The presented model applies a dynamic stock-driven material flow model and an economic evaluation of gold and copper flows to the Indian personal computer (PC) recycling sector. The metal concentration per PC and value of these metals mainly determine the profits for recyclers. The study introduced threshold values for formal and informal gold and copper recycling according to their recycling cost per PC. At present level of metal concentration per PC and metal prices the formal sector will not become active. Two scenarios, one with double metal prices and a second with reduced threshold values for formal recycling, have been calculated. Also under theses scenarios the formal recycling sector will not overtake a majority of the recycling. The model proves that a stock-driven dynamic material flow model can be combined with an economic evaluation of material flows. The analysis included a calculation of error propagation and a sensitivity analysi

Dynamic Substance Flow Analysis as a Valuable Risk Evaluation Tool – A Case Study for Brominated Flame Retardants as an Example of Potential Endocrine Disrupters

Most studies of potentially hazardous substances focus on aspects of their occurrence and fate in the environment (monitoring and modelling studies) to estimate the environmental impact and the potential exposure of humans. In order to evaluate emission sources, to recognise environmental impacts at an early stage, and to take efficient legislative or technical measures, it is essential to know their behaviour in the anthroposphere as a function of time. So far, only very few investigations of this type exist for chemicals. In regular risk assessments, only rather limited knowledge is available concerning the behaviour of chemicals in the anthroposphere (production data, substance quantities in products, recycling rates, emissions occurring during use, etc.) or their lifecycle, and no information at all about their behaviour as a function of time. For this reason, it is these aspects that were investigated in a case study within the framework of the national research programme NRP50 for selected brominated flame retardants with endocrine-disrupting potential (pentabromodiphenyl ether, hexabromocyclododecane) or the potential to degrade to such substances (decabromodiphenyl ether). A dynamic substance flow analysis (SFA) model was performed for Switzerland for the time period 1980–2020. In this review paper (a) we present a summary of typical results (system overview, consumption trends/application patterns, anthropogenic stocks and their changes, emission trends including major sources and environmental fate), (b) we summarize the effectiveness of recent risk-reduction measures in Switzerland and (c) we indicate serious remaining data gaps and recommend further important measures for risk reduction. For the future, we suggest improving the knowledge of the lifecycle of chemicals such as brominated flame retardants by applying SFA as a suitable tool to weight the effect of substance flows with respect to environmental emissions, and to serve as the basis for planning actions and measures to reduce such emissions. This is in line with one major conclusion of the NRP50 consensus platform 'Brominated Flame Retardants'

Household analysis identifies water-related energy efficiency opportunities

Water heating accounts for around one third of household direct energy use. This energy demand is some four times greater than lighting. Here we use detailed monitoring and modelling of seven individual households to quantify major factors. Using normalized sensitivity results we demonstrate (i) high variability and (ii) a large and consistent influence of shower duration, flow rate, frequency and temperature along with hot water system efficiency, adult population, and the temperature of cold water. A 10% change in these factors influenced 0.1–0.9 kWh/hh-person.d, equivalent to a 2–3% of total household energy use. We draw on 5399 shower events from a further 94 households, and 491 shower temperature measurements to understand the scope for changes to the households. Individual parameters variation guided by these larger datasets demonstrated shower duration and flow rate offer most scope for change. The work helps guide city-scale analysis of household water-related energy demand. It also supports the tailoring of behavioural and technological water-efficiency programs towards those with strongest potential to influence energy. Strong interaction between parameters suggests that programs aiming to influence water-related energy need to be aware of how this interplay either amplifies, or diminishes, the intended energy savings

Method for analyzing trade-offs in biomass management in smallholder farming systems based on mass balance

In smallholder farming systems, especially in mountainous areas, households face trade-offs between meeting short-term human needs and ensuring long-term soil productivity. Improved biomass management can help break the downward spiral of overexploitation of natural resources, land degradation, and productivity decline, and support more sustainable use of marginal land. Mixed crop/livestock systems are often carefully balanced to minimize risks. Thus, when planning interventions, profound systems knowledge is crucial. However, the data required for system characterization are often scarce, and original field studies are thus necessary. The aim of this research, a case study in Tajikistan, was to improve systems understanding of the biomass cycle in crop/livestock systems in order to quantify the obstacles to the spread of sustainable land management technologies to farming households. It aimed to establish a database and methods of rapid data collection to quantify the stocks and flows of biomass, with a focus on mass balances, and to evaluate smallholders’ biomass management options and trade-offs. Data collection included household interviews, secondary literature, and reference data sets from global sources. Trade-off analysis focused on household-level self-supply of food, fodder, and fuel by farmers with different sizes of smallholdings, and their potential for on-farm recycling of organic matter. Results indicate that food self-supply by small and medium smallholders is insufficient and fodder sources are scarce. Fodder scarcity means that application of crop byproducts to soils is unlikely. Animal dung is largely used as fuel. Firewood needs exceed on-farm wood production, leading to deforestation. The approach presented facilitates an understanding of current and potential agricultural land interventions in the crop/livestock farming systems prevailing in mountainous areas

Long-term benefit-risk balance of drug-eluting vs. bare-metal stents in daily practice: does stent diameter matter? Three-year follow-up of BASKET

Aims To assess the long-term benefit-risk ratio of drug-eluting (DES) vs. bare-metal stents (BMS) relative to stent size. Methods and results All 826 consecutive BASKET (BAsel Stent Kosten-Effektivitäts Trial) patients randomized 2:1 to DES vs. BMS were followed after 3 years. Data were analysed separately for patients with small stents (<3.0 mm vessel/<4.0 mm bypass grafts, n = 268) vs. only large stents (≥3.0 mm native vessels, n = 558). Clinical events were related to stent thrombosis. Three-year clinical target-vessel revascularization rates remained borderline reduced after DES [9.9 vs. 13.9% (BMS), P = 0.07], particularly in patients with small stents (10.7 vs. 19.8%, P = 0.03; large stents: 9.5 vs. 11.5%, P = 0.44). Cardiac death/myocardial infarction (MI) rates (12.7 vs. 10.0%, P = 0.30) were similar, however, death/MI beyond 6 months was higher after DES [9.1 vs. 3.8% (BMS), P = 0.009], mainly due to increased late death/MI in patients with large stents (9.7 vs. 3.1%, P = 0.006). The results paralleled findings for stent thrombosis. Conclusion The clinical benefit of DES was maintained at no overall increased risk of death or death/MI up to 3 years. However, death/MI rates were increased in DES vs. BMS patients beyond 6 months, particularly in patients with large stents, paralleling findings for stent thrombosis. Thus, stent size seems to influence the 3-year benefit-risk ratio after DES implantatio

Sequential anti-cytomegalovirus response monitoring may allow prediction of cytomegalovirus reactivation after allogeneic stem cell transplantation

Background: Reconstitution of cytomegalovirus-specific CD3+CD8+ T cells (CMV-CTLs) after allogeneic hematopoietic stem cell transplantation (HSCT) is necessary to bring cytomegalovirus (CMV) reactivation under control. However, the parameters determining protective CMV-CTL reconstitution remain unclear to date. Design and Methods: In a prospective tri-center study, CMV-CTL reconstitution was analyzed in the peripheral blood from 278 patients during the year following HSCT using 7 commercially available tetrameric HLA-CMV epitope complexes. All patients included could be monitored with at least CMV-specific tetramer. Results: CMV-CTL reconstitution was detected in 198 patients (71%) after allogeneic HSCT. Most importantly, reconstitution with 1 CMV-CTL per µl blood between day +50 and day +75 post-HSCT discriminated between patients with and without CMV reactivation in the R+/D+ patient group, independent of the CMV-epitope recognized. In addition, CMV-CTLs expanded more daramtaically in patients experiencing only one CMV-reactivation than those without or those with multiple CMV reactivations. Monitoring using at least 2 tetramers was possible in 63% (n = 176) of the patients. The combinations of particular HLA molecules influenced the numbers of CMV-CTLs detected. The highest CMV-CTL count obtained for an individual tetramer also changed over time in 11% of these patients (n = 19) resulting in higher levels of HLA-B*0801 (IE-1) recognizing CMV-CTLs in 14 patients. Conclusions: Our results indicate that 1 CMV-CTL per µl blood between day +50 to +75 marks the beginning of an immune response against CMV in the R+/D+ group. Detection of CMV-CTL expansion thereafter indicates successful resolution of the CMV reactivation. Thus, sequential monitoring of CMV-CTL reconstitution can be used to predict patients at risk for recurrent CMV reactivation