• Energy Research
• other engineering and technologies close
• 6. Clean water close
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AbstractA simple experiment for capillary sealed trap shows that leakage would occur only from the weakest point in the trap. As an extens ion of this concept, the sequestrated and accumulated CO2 in the structural high may happen to leak from the unexpected weak point near the top of sealing layer. On the other hand, if CO2 were sequestrated into the flank of tilted aquifer, CO2 in separate phas e would migrate upward within aquifer with no CO2 leakage into the sealing layer above and leaving some residual amount behind. According to this concept, the best location for sequestration of CO2 could be the flank of the structure rather than the top.

Abstract Uncertainties of cooling load may make cooling system oversized. Most of previous studies implement probabilistic-based uncertainty analysis, intending to achieve optimization and reliability simultaneously. However, how to reduce the load uncertainty has received little attention. This paper investigates the impact of water storage on the design of cooling system considering load uncertainty. Information entropy is used as a convergence index of load uncertainty and used to determine how many random simulations should to be performed. A cooling system configured with water storage (system B) and another system without water storage (system A as a comparation system) are investigated in this paper. In this paper, the configure of system A and system B are optimized respectively. The result shows that the capacity distribution of system A is consistent with the distribution of extreme loads. But, the capacity distribution of system B is more concentrated as the water storage can reshape the load curve. Water storage improves the flexibility of system B. Therefore, system B is more reliable and economical than system A.

Abstract The main purpose of salinity gradient solar ponds (SGSPs) is to store the maximum possible solar thermal energy. A well-established salinity and temperature gradients are the main points to achieved optimum storage efficiency. In this work, a high-fidelity model is developed using computational fluid dynamics (CFD) to simulate the SGSP behavior under hot climate regions. The model is able to simulate the double convective effect by solving Navier-Stokes and energy equations, simultaneously. Brines with different salinities (i.e. 10%,15, and 25%) are used to investigate their role on the developed salinity/temperature gradients. Simulation results show the successful establishment of the three zones (i.e. upper convective, non-convective, and lower convective) with relatively stable salinity and temperature gradients. However, injecting the lower convective zone (or storage zone) with 10% saline brine results in preserving the highest storage temperature of around 79.2°C after flow time of six hours.

Abstractwhatever the adoptod treatment system, the wastewater treatment is accompanied by production of large amounts of sludge which must be disposed. Several pathways exist lor the disposal of sewage sludge, but the choice must depend on the cost of installation, the result as an added value of the product and the possible impact of the chain retained on the environment To justify the choice of sludge recycling in agriculture, we will have to estimate the fertilizer value of sludge through the analysis of physico-chemica1 and microbiological parameters complying with regulations. Considering these parameters will detennine the worth of sludge,the environmental impact and precautions for use. For this purpose, we have to compare the sludge characteristics from three wastewater treatment plants (WIV) in the wilaya of Mascara, (west of Algeria), Mascara, Tizi and Ghriss. The results show that our overall sludge is rich in nutrients (N, P, K) but contains a hight concentrations in Nickel (Ni) of lIbout 8.6mg I kg prohably due to industrial waste. To enhance ille fertilizing power of the sludge in an agricultural field we recommend an additional treatment

AbstractThe theme of sustainable development has increasingly impacted the spheres of Brazilian society and has contributed to greater awareness to the need of natural resources conservation as well as issues on how to continue promoting socio-economic development of regions. One of the key issues for sustainable development is the generation of electricity with more use of renewable sources and, therefore, less environmental degradation. In this scenario, historically, Paraná State of Brazil has been one of the largest producers of electricity in the country, almost entirely from hydraulic source, due to the large existing river basin in the state. However, the use of this source in Brazil is declining due to depletion of water potential and also the pressure of society with respect to environmental, social and economic impacts caused by damming of rivers and flooding of cities and areas to form large reservoirs. To overcome these limitations, other sources have been studied and used, such as biomass and wind. Photovoltaic generation has been contemplated in Brazilian government policies only to supply electricity with off-grid systems in remote locations. However, due to the recent Resolution 482/2012 of ANEEL (Brazilian Electricity Regulatory Agency), which establishes rules for micro and mini-generation of electricity, it is possible that consumers install grid connected photovoltaic systems up to 1 MWp, as have been widely used in the urban environment installed or integrated on roofs as a form of distributed generation, particularly in Europe, where counts with installed capacity in GW range, while in Brazil it counts only with a few MW. Given this new perspective of growth of the Brazilian photovoltaic electricity generation this paper presents the potential of solar photovoltaic power generation in Paraná State, Brazil, with a comparative analysis with the potential presented by some European countries. The presented solar and photovoltaic maps uses irradiation data obtained from SWERA project (Solar and Wind Energy Resources Assessment), which was coordinated in Brazil by National Institute for Space Research (INPE). The results of this analysis can contribute to development of public policies related to projects and researches in photovoltaic aiming to spread the use of this renewable energy source in Paraná.

AbstractWith the lack of a management budget and weak policy for waste management of local communities in developing countries, especially for clusters that have the amount of garbage less than 5 tons per day, open dumping or open burning is the most common municipal solid waste (MSW) management, leading to severe impact on the environment. This study focuses on the sustainable development and eco-friendly waste management concept for these local communities. First, public participation campaigns with the 3R's concept (Reduced, Reuse and Recycle) must be launched to reduce and separate waste from households to be mixed with combustible waste, organic waste, and recycled waste. If the separation at the source is successful, the treated waste of about 2.5 tons is divided into wet and dry fractions. The wet fraction can be easily treated by conventional composting to produce soil conditioners and generate income for communities. The dry fraction must be treated by an incinerator. However, due to the high moisture content and low heating value of the waste, the incinerator needs to run with additional fossil fuel, causing high operating costs. Therefore, a novel hybrid incineration-gasification system has been introduced in this study to use Refuse Derived Fuel (RDF) prepared by dry fraction as feedstock to a downdraft gasifier. The producer gas generated from the gasifier can be used to substitute fossil fuel. This sustainable and eco-friendly model of waste management can be used as a prototype model for other rural areas in low or low-middle income countries.

Abstract Solar heating system has raised much attention due to the global energy shortage and environment pollution. The dynamic heat release performance of water tank (WT) with phase change materials (PCM) plays an important role in the operation of solar heating system, while seldom available literatures focused on this research topic. In this paper, an experimental system for heat release of the WT-PCM was established. The temperature variations of the water and the PCM during heat release of the WT-PCM and the traditional water tank were measured respectively, and their dynamic heat release performance were also analyzed based on the measured data. The results are as follows: the heat release of the WT-PCM can be divided into three phases: sensible heat before phase change, latent heat during phase change and sensible heat after phase change, and the water temperature will be temporarily heated after the sudden drop; the water supply temperature decline rate of both tanks will increase dramatically at the initial stage of heat release, when the PCM temperature is reduced to 50℃, the water supply decline rate of the WT-PCM is less than that of the traditional water tank, while when PCM is completely solidified, the water supply temperature decline rate of the WT-PCM is more than that of the traditional water tank. The heat release performance of the WT-PCM is much better than that of the traditional water tank. The research results can provide useful reference for engineering application of the WT-PCM.

AbstractThe microorganisms growth kinetics is determined by the physical and chemical characteristics of the environment in which they find themselves and multiply; It is therefore essential to understand the effect of these environmental factors to master cell multiplication and hence the pollution biodegradation. Respirometry has been used in recent years in the laboratory as an assessment technique of microbial activity and an effect detector of the contamination (presence of toxic, stress, increase or decrease in pH, temperature variation .) on bacterial respiration and hence on the biological waste water treatment plant. In this study respirometry has been used as a relatively quick and efficient means to detect the effect of the presence of a salt of up to 5g/l (low salt stress) on the degradation of carbon and nitrogen pollution and on bacterial floc aggregation.