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81.
This research article demonstrates biodiesel synthesis through the methanolysis of the oily contents (4.02 ± 0.27% w/w on dried basis) of Dictyota dichotoma collected from the coast of Hawksbay, Pakistan. The metal oxides (CaO, MgO, ZnO, and TiO2) used as nanocatalysts were refluxed (5% K2SO4), calcinated (850 °C) and characterized by Atomic Force Microscopy (AFM) which produced 93.2% w/w FAME (biodiesel) at relatively mild condition (5% catalyst, 65 °C, 3 h, 18:1 molar ratio) using CaO. Whereas, MgO, ZnO, and TiO2 produced 92.4%, 72.5%, and 31.8% w/w FAME, respectively at elevated condition (225 °C). Thus, CaO was considered to be the best catalyst among the others. This tri-phase reaction require continuous fast mixing and the yield depends on the reaction parameters like catalyst amount, temperature, reaction time and molar ratio (methanol: oil). The reusability of these heterogeneous catalysts simplified the purification step, reduced the waste generation and make the final product technically and economically viable. 相似文献
82.
Incorporating green and sustainable remediation analysis in coal combustion residuals (CCR) surface impoundment closure decision making 下载免费PDF全文
In response to new coal combustion residuals (CCR) disposal regulations, many coal‐fired utilities have closed existing unlined surface impoundments (SIs) that were traditionally used for disposal of CCR. The two primary closure options are closure‐in‐place (CIP), which involves dewatering and capping, and closure‐by‐removal (CBR), which includes excavation, transportation, and disposal of the CCR into a lined landfill. This article provides a methodology and a case study of how green and sustainable remediation concepts, including accounting for the life cycle environmental footprints and the physical risks to workers and community members, can be incorporated into the closure decision‐making process. The environmental impacts, occupational risks, and traffic‐related fatalities and injuries to workers and community members were calculated and compared for closure alternatives at a hypothetical site. The results demonstrated that the adverse impacts of the CBR option were significantly greater than those of the CIP option with respect to the analyzed impact pathways. 相似文献
83.
Aourell Mauffret André Rottiers Thomas Federle David C. Gillan Miriam Hampel Julian Blasco Ali Temara 《Environment international》2009,35(6):885-892
An innovative biodegradation test system was developed in order to fill the current gap for cost effective and environmentally relevant tools to assess marine biodegradability. Glass beads were colonized by a biofilm in an open flow-through system of seawater with continuous pre-exposure to Linear Alkylbenzene Sulfonate (LAS) (20 μg/L). Thereafter, such colonized beads were added as inoculum in different test systems. [14C]-LAS (5–100 μg/L) was added and primary and ultimate biodegradation were assessed. The bacterial density collected on the beads (109 bact./mL beads) was ca. 3 orders of magnitude higher than the typical seawater content. The LAS mineralization lag phase duration decreased from 55 to < 1 days and the mineralization extent increased from 53 to 90% as the colonized beads volume increased from 10 to 275 mL. This is the first demonstration of marine bacteria's ability to mineralize LAS. On the opposite, less than 13% LAS was mineralized in seawater only. The colonized beads possibly enhanced the probability to encounter the full degraders' consortium in a low volume of seawater (100 mL). 相似文献
84.
Himayatullah Khan 《Environment, Development and Sustainability》2009,11(2):293-305
Using survey-based data approach for modeling the demand for environmental goods/resources, this study estimates income and
price elasticities of demand for improved environmental quality of two National Parks in Northern Pakistan. The study uses
data from two studies. The estimates indicate that improved environmental quality effects can be described as a luxury and
an ordinary and price elastic service. Confidence intervals show however that the classification as a luxury is not statistically
significant. Income elasticities of willingness to pay are estimated for a broad range of environmental services. The study
finds that income and willingness to pay vary directly and significantly. The elasticity estimates, in general, are greater
than zero, but less than unity. The study concludes that environmental improvements are more beneficial to low-income groups
than for high-income groups.
相似文献
Himayatullah KhanEmail: |
85.
Himayatullah Khan Ehsan Inamullah Khadija Shams 《Environment, Development and Sustainability》2009,11(2):375-392
This study explores the interlinkages among population, environment and poverty and presents empirical evidence in a developing
country like Pakistan. It gives alternative views on population environment linkages. It explains poverty trap, market based
harmony, and dual effect of poverty on the basis of a link between population growth and natural resource degradation. In
addition, the paper also highlights social and political instability through population-poverty-environment spiral. It also
presents empirical evidence on population-environment-poverty nexus in Pakistan. It also compares environmental sustainability
index and human development index for selected Asian countries. The paper also gives scores for different components of environmental
sustainability index for Pakistan and compares these with India. The paper concludes that the causal relationship between
poverty and environment works in both directions, often through changes in GDP and population. Population stress does not
have any significant direct effect on all aspects of environmental status in Pakistan.
相似文献
Himayatullah KhanEmail: |
86.
Shadi Dayyani Chandra A. Madramootoo Peter Enright Guillaume Simard Apurva Gullamudi Shiv O. Prasher Ali Madani 《Journal of the American Water Resources Association》2009,45(3):779-792
Abstract: The hydrologic performance of DRAINMOD 5.1 was assessed for the southern Quebec region considering freezing/thawing conditions. A tile drained agricultural field in the Pike River watershed was instrumented to measure tile drainage volumes. The model was calibrated using water table depth and subsurface flow data over a two‐year period, while another two‐year dataset served to validate the model. DRAINMOD 5.1 accurately simulated the timing and magnitude of subsurface drainage events. The model also simulated the pattern of water table fluctuations with a good degree of accuracy. The R2 between the observed and simulated daily WTD for calibration was >0.78, and that for validation was 0.93. The corresponding coefficients of efficiency (E) were >0.74 and 0.31. The R2 and E values for calibration/validation of subsurface flow were 0.73/0.48 and 0.72/0.40, respectively. DRAINMOD simulated monthly subsurface flow quite accurately (E > 0.82 and R2 > 0.84). The model precisely simulated daily/monthly drain flow over the entire year, including the winter months. Thus DRAINMOD 5.1 performed well in simulating the hydrology of a cold region. 相似文献
87.
The current generation of Probabilistic Risk Analysis (PRA), particularly those for technical systems, does not include an explicit representation of the possible impacts of organization and management on the safety performance of equipment and personnel. There are a number of technical challenges in developing a predictive model of organizational safety performance. There is a need for a widely accepted and theoretically sound set of principles on which models of organizational influences could be developed and validated. As a result of a multidisciplinary effort, this paper explores the feasibility of developing such principles and proposes a set of principles for organizational safety risk analysis. Then, as a realization of the proposed modeling principles, a safety risk framework, named Socio-Technical Risk Analysis (SoTeRiA), is developed. SoTeRiA formally integrates the technical system risk models with the social (safety culture and safety climate) and structural (safety practices) aspects of safety prediction models, and provides a theoretical basis for the integration. A systematic view of safety culture and safety climate leaves an important gap in modeling complex system safety risk, and SoTeRiA, describing the relationship between these two concepts, bridges this gap. The framework explicitly recognizes the relationship among constructs at multiple levels of analysis, and extends the PRA framework to include the effects of organizational factors in a more comprehensive and defensible way. 相似文献
88.
Refaul Ferdous Faisal Khan Rehan Sadiq Paul Amyotte Brian Veitch 《Process Safety and Environmental Protection》2009,87(5):283-292
Event tree analysis (ETA) is an established risk analysis technique to assess likelihood (in a probabilistic context) of an accident. The objective data available to estimate the likelihood is often missing (or sparse), and even if available, is subject to incompleteness (partial ignorance) and imprecision (vagueness). Without addressing incompleteness and imprecision in the available data, ETA and subsequent risk analysis give a false impression of precision and correctness that undermines the overall credibility of the process. This paper explores two approaches to address data uncertainties, namely, fuzzy sets and evidence theory, and compares the results with Monte Carlo simulations. A fuzzy-based approach is used for handling imprecision and subjectivity, whereas evidence theory is used for handling inconsistent, incomplete and conflicting data. Application of these approaches in ETA is demonstrated using the example of an LPG release near a processing facility. 相似文献
89.
Hussein A. Kazem Ali H. A. Al-Waeli Miqdam T. Chaichan Asma S. Al-Mamari Atma H. Al-Kabi 《Environment, Development and Sustainability》2017,19(3):1041-1053
In the present paper, the optimum design of a PV system used to operate a water pumping system was determined for Oman. The system design focused on the environmental conditions of Sohar city. The implementation and measurement of the designed system are presented to prove the effectiveness of the proposed system. The results show that the system can provide the required power at peak hours, leading to a substantial reduction in the sizing of the PV system. Consequently, the investment capital costs 2400 USD, and the cost of energy is equal to 0.309 USD/kWh. Furthermore, the results indicate that the system annual yield factor is 2024.66 kWh/kWp and that the capacity factor is 23.05 %, which is encouraging since the latter is typically 21 %. The system capital cost and the cost of energy are worth comparing to a diesel generator. A comparison is made between the proposed system and several others in the literature. The comparison indicated that the system cost of energy is promising. 相似文献
90.
Ali Tighnavard Balasbaneh Abdul Kadir Bin Marsono 《International Journal of Sustainable Engineering》2017,10(3):176-184
The building sector has been regarded as a potential sector where there is large capacity to reduce the climate change effect. This study has proposed solutions to mitigate environmental impacts and achieve low CO2 emission from residential sector. Therefore, full life cycle assessment (LCA) has been run to assess the CO2 emission and its effect on the atmosphere and climate change. Based on the result, timber scheme is the best choice due to releasing less CO2 emissions to the atmosphere. However, house builders in Malaysia have almost completely neglected timber as a building material, with timber use as building components reduced to 5%. In this study, LCA Software was used to assess CO2 emissions from different wall construction. The alternative building scheme has been made by reinforce steel stud, wooden beam and timber wall (S8) to improve the scheme deficiency while releasing less CO2 emissions compared to other schemes. Therefore, S8 has a decreased CO2 effect by 85% less than precast concrete frame and 90% less than brick over their lifetime. (S8) increased the load bearing compared to conventional timber beam. Thus, new scheme S8 could be replaced by current scheme and promote more adjustable scheme for Malaysian housing. 相似文献