Hội nghị khoa học lần thứ 20 = Proceedings of the 20th scientific conference Hanoi University of technology. Phân ban. Khoa học và công nghệ môi trường = Section. Environmental science and technology. Hanoi, 2006

Up one level

Next 7 items » [1] 2

A new process for the recovery of Zinc from electric arc furnace dust: In view of the resource conservation and recycling, a new process has been developed for the recovery of zinc from electric arc furnace (EAF) dust generated in the steel industry. The EAF dust contained zinc, lead and iron as major metallic values. The presence of chlorine and lead as major impurities in EAF dust adversely affect the purity during the recovery of zinc. Several works have been carried out world wide to recycle EAF dust, using pyro, hydro and the hybrid metallurgical processes. Initially a review has been made to see the feasibility of the process. A pyro-metallurgical process has been studied and optimized the parameters to recover zinc from EAF dust. In the developed process, the chlorine and lead contained in EAF dust were first removed from EAF dust by chlorination reaction. The 98.3% chlorine and 99.0% lead has been removed at the reaction temperature of 1223 K and the reaction time of 180 min in air. After the removal of lead and chlorine from the EAF dust, zinc was recovered from the residue using carbon reduction technique. Using the developed process, 99.6% zinc was recovered at the optimum condition, i.e., temperature 1323 K and reaction time 180 min. The 99.3% pure zinc was recovered from EAF dust by using developed eco-friendly process.
Analysing and selecting stack effective height formula in calculation of air pollution diffusion: Industrial development has brought economic growing but a lot of environmental issues as well. Factories' chimneys have discharged toxic gases and particular matters into atmosphere, caused air pollution and direct impacted to public health. Currently, Gauss model is usually used for determine ambient air pollution concentrations. However, the ambient concentrations of air pollutants depend so much on effective height of chimneys. From this point of view, authors aim to analysis and evaluate the formulas to determine effective height of chimneys in all conditions and compare with observation to suggest appropriate formula to apply for calculating air pollution diffusion in evaluating and predicting air environmental quality.
Analysing hidden energy flow in rice production section in Vietnam using input-output table: Input - output analysis for energy flows have been developing and is one of the best solutions for investigating macroscopic exchanges of both economy and energy. Since each element in the Leontief inverse contains both direct and indirect effects of any change in final demand, to separate those direct and indirect effects, the power series expansion is available. In this work, the changes of embodied energy intensity in Vietnam from 1996 to 2000 were analyzed using the structural decomposition and its power series expansion. The rice-processing sector, which is one of the important food processing sectors in Vietnam, is focused. By drawing diagrammatic map for the change of hidden energy flow, it is clarified that in the case of raising embodied energy intensity, cultivation sector and trade and repaired service sector are main contributors, and on the contrary, in the case of reducing embodied energy intensity, paper pulp sector is main contributor.
Application of Fenton technologies on the treatment of industrial wastewaters
Battery wastes - a recycled material source: Survey of waste cell - batteries commonly used in four urban and two sub-urban districts of Hanoi show that there is a considerable amount of the waste that is disposed into environment day by day and needs to be put under control. Total quantity of the waste is estimated to be about 240 tons of R6 cells and 600 tons of acid-lead batteries (used for motorcycles) per year. A technology process for recycling materials in the waste cells and batteries was proposed Results of verifying experiments at laboratory scale show that it is possible to extract targeting materials with purity meeting technical norms, and efficiency of over 85%. Recycling process's exhausted gas and wastewater treatment measures are also identified.
Behavior of estrogenic compounds in swinery waste treatment plant
Calculating energy generation, accummulation and reusing of methane from domestic wastes in Ho Chi Minh city: Methane (CH4) is an important and relatively long-lived greenhouse gas. Much of the global annual input of methane to the atmosphere is originated from anthropogenic and biosphere processes, particularly anaerobic bacterial fermentation. The decomposition of refuse in municipal landfills is believed to be one of the major components of the biogenic methane. Ho Chi Minh City is considered to be generated about 1,764,016 tones of MSW annually. 82.5% of which is collected and delivered to the landfills generating big amount of methane. Recovering this generated methane would reduce global warming, regional and local pollution and lessen the use of conventional fuels. This research is intended to estimate methane generation from MSW in Ho Chi Minh City and to enable waste managers to undertake a preliminary analysis of the potential for methane recovery and energy generation from solid waste.
Characteristics of leachate and status of leachate treatment technology in Vietnam: The rapid urbanization makes typical characteristics of municipal solid waste in Vietnamese landfill, among them leachate is the most important. In addition to these specific properties, strict standards for wastewater output have affected leach ate treatment technologies and the qualities of treated leach ate in Vietnam. Survey data of leachate quality and quantity shows that it is necessary to modify from step of landfill design and operation in order to minimize difficulties in leachate treatment to achieve Vietnamese and international environmental standards.
Copper adsorption through chitosan immobilized on sand to demonstrate the feasibility for in-situ soil decontamination
Distribution of heavy metal concentrations in the Nhue river basin
Effect of chloride on aniline oxidation by electro - Fenton process
Energy productivity in Vietnam between 1989-1996
Environmental impact assessment of sand exploiting activities in Dau Tieng lake
Environmental status in livestock farm (Ha Tay province)- research on treatment method by ozone technology: Odors and dusts generated from livestock farm are main pollutants for around environment of the farm. To research on odors and dusts treatment methodology by ozone application indicated that with concentration of 0.4 pap O3 can reduce from 25.8% to 55.3% total dusts generated from farm, reduce from 25.7% to 56.7% NH3. 80.5-90.3% H2S, 57.9-77.4% CH3-SH and 51.2%-70.2% CH3-CH2-SH The result of research showed that ozone application for odors and dusts treatment in livestock form is realizable and high applicability in Vietnam.
Establishing criteria to evaluate environmental pollution treatment technology in craft villages and small enterprises in Vietnam: Villages and the small enter pries in Vietnam are taking a crucial part of economy in during conversion structure process from agriculture to industry, small-scale industry and service. Particularly, in recent years when economy has changed from subsidize to market economic and a lot villages have restored and developed powerfully and also at the same time series of the small enter pries have came out. Not deny socioeconomic impacts that villages and small enter pries brought specially for society, however, the authors have also recognized environmental pollution burden not only was risk but also these have been become a burning issue, actually. Fundamental problems are how to treat environmental pollutions truly effective in the villages and small enter pries so that researching to bring out some types of technology to tackle environmental pollution in villages and the small enter pries are extra necessary. However, at present time do not have the detail criteria to assess the environmental pollution treatment technology for these production types in order to evaluate and choice what are the most feasible model and able to give the best effect.
Exploring the application of synthesized Zeolites for wastewater treatment
Exploring the capacity of laterite in heavy metal treatment (Ni (II) and Zn (II))
Improved septic tank - a feasible solution for decentralised wastewater treatment in Vietnam
Intergared modeling of resource - economy- environment: a sustainable approach method in higher education and research
New development of hydrometallurgical recycling studies
Pilot study environmental management audit in Machino Vietnam Company: Environmental Management Accounting (EMA) was acknowledged as the good accounting tool by the International Accounting Association. Using EMA, enterprises can clearly separate direct and indirect environmental costs in their balance table of receipts and expenditures for each product. It can be confirmed that this is a new accounting method that have not approached in Vietnamese enterprises. In this research, the price structure of three selected products of Machino Company was analyzed and re-counted in order to evidence the applied ability of EMA in Vietnam.
Polycyclic aromatic hydrocarbons associated with suspended particulate matter in Hanoi: Polycyclic aromatic hydrocarbons (PAHs) associated with airborne particulate matter in the dry season of Hanoi were monitored. Three sampling sites in the urban area of the city, namely Thuong Dinh, Bach Khoa and Chuong Duong were selected. 24 hour- samples of total suspended particulates (TSP) were collected on glass fibre filters using high volume samplers for a period of three months. Meteorological parameters such as wind direction and velocity, temperature, humidity were also measured every hour during sampling. Selected samples were Soxhlet extracted and then analyzed for 16 priority PAHs by GC/MS based on U.S. EPA method TO-13. Concentrations of particle - bound individual PAHs in the air as well as contents of individual PAHs in the suspended particulate matter at three sampling sites were obtained. Higher levels of total PAHs at Chuong Duong (traffic) site and dominant contents of benzo(b)fluoranthene in the airborne particulate matter were observed.
Prevention approach in hazardous wastes management in Nam Dinh province: Together with blooming process of industrial sector, industrial waste discharged to the environment has increased significantly. Among industrial waste, hazardous waste is critical important because its characteristics of extremely harmful to human health and environment. Applying preventive approach in hazardous waste management is an effective tool toward sustainable development. This paper will provide the results applied this approach in program named "Hazardous Waste Management in Nam Dinh" and prove effectiveness of the approach in sustainable industrial development.
Problems on decoloration of textile dyeing effluent: Wastewater from dyeing industry is characterized as a subject to high biochemical oxygen demand (BOD), chemical oxygen demand (COD) and contains large quantities of suspended solids (SS), which are generated from dyeing, scouring, bleaching, dyeing and printing. Textile effluent usually contains small amounts of dye that often colours receiving water bodies and is thus easily detectable. The reactive dyeing of cotton is a major contributor to the problem of coloured effluents. In this paper, the authors summarize various methods that remove colour from textile effluent.
Reduction of greenhouse gases (GHG) emission by improving energy use efficiency: This paper presents a number of examples of projects that have successfully applied cleaner production and energy efficiency methodology to reduce energy use and GHG emissions. The four companies belonging to four sectors being addressed in the project are ceramics, cement, paper and chemicals. The successful implementation of the project resulted in the annual coal consumption reduction of 7,223 tons, the annual DO consumption reduction of 279 tons, the annual electricity consumption reduction of 4,811.561 kwh and the cumulative GHG annual emission reduction of 22,626 tons CO2 during the period 2003-2005. This paper also discusses the role of energy efficiency in preventing pollution and reducing GHG gases, including energy savings potential and economic benefits. Lesson learned to cleaner production and energy efficiency are also discussed in this paper.
Study NO treatment by selected reduction method with propan and spinel niken aluminium catalyst: Results of activity test in C3H8-SCR-NO over two samples of nickel aluminate spinel, formed at 800 and 900oC were summarized, herein. Spinel calcined at 800oC, having larger BET surface area, exhibited higher activity for selective reduction of NO in a wide temperature range and at low temperatures. In the presence of SO2 the catalytic activity of these samples still remained relatively high. Based on TPD-C3H8, TPD-O2 analysis and measurements of NO conversion, the mechanism of the reaction was proposed with the aim to identify a role of O2 in this reaction.
Study on chlorine reduction ability of HCB by native microorganisms in Vietnam
Study on chromium (Cr) and cadmium (Cd) accumulation ability of mussel and snail to establish bioindicators assessing industrial wastewater quality: The possibility of Cr and Cd accumulation on mussel and snail is studied with mussel variety of Sinanodonta Modell and two snail varieties of Angulyara Rao and Sinotaia Hass in statically condition of lab. The researched concentration of Cr is 0.1 and 0.2 mg/l and that of Cd is 0.02 mg/l. The result shows that both mussel and snail can accumulate Cr and Cd. This accumulation ability depends on variety of living beings, heavy metal concentration in water and contact time. The research result provides that possibility of using mussel and snail as bioindicator for controlling industrial wastewater quality besides traditional methods.
Study on the effects of fish cage culture on the quality of water in Dau Tieng lake
Study on treatment of Ni, Zn, Cu, and Pb in nitrate medium by oyster covers: Conventional tannery wastewater treatment plants are coming under progressive pressure to increase their efficiency of operation, in order to achieve targets for economy, technique, and environment. In most cases, Tanning Toxicants usually give troubles to activated sludge processes. The best approach to toxicity detection for the activated sludge process is based on Sequencing Batch Reactor (SBR) to determine the specific kinetic parameters. The estimation of specific kinetic parameters for nitrification inhibition based on control DO, pH and ORP values present state of deferent load. The absolute values based on strategy were initiated by the fact that ORP and pH vary in certain range during an aerobic-anoxic cycle. The measured value is particularly important for treatment facilities, which are caused by toxicity of tanning toxicants for activated sludge process. In addition, they can be used to calibrate for validation by the simulation model, which are used such as the key parameters for calculation of SBR.