Recent Progress in Silane Coupling Agent with Its Emerging Applications

Journal of Polymers and the Environment - This paper presents the effects of silane coupling agent, which includes interfacial adhesive strength, water treatment, polymer composites and coatings...     

Performance evaluation of biodiesel from used domestic waste oils: A review

Global warming, high-energy demand and availability of new technologies are among the factors catalyzing the search for alternative sources of energy. Currently, there is renewed interest in obtaining energy from wastes hitherto meant for disposal. Increased costs of disposal and their attendant problems of heavy environmental loading are some aspects making the disposal option unattractive. These wastes are sources of energy and among the several sources of generating this energy are the waste-to-energy (WTE) categories with potentials for useable fuel production. The WTE materials are mainly used domestic waste oils (UDWOs), municipal solid waste (MSW), agricultural and industrial wastes. However, the latter wastes are not attractive as they consist of innumerable hazardous contaminants. The UDWOs are arguably a safe and cost effective source of useable fuel. Their conversion offers the merits of a reduction in greenhouse gas emission (GHG), enhancing fuel diversification and a qualitatively comparable energy output to fossil diesel fuels. Thus, UDWOs could significantly contribute towards achieving the 2020 and 2030 goals of substituting approximately 20% and 30% of petro-diesel with biofuels in US and EU, respectively. Moreover, attaining the forecasted annual production rate of 227 billion liters of biofuel by most active stakeholders in the biodiesel industry could be easily achieved.This review aims to analyze the performance of biodiesel fuels obtained from UDWO and to demonstrate the suitability of applying these fuels as substitutes to mineral diesel in various industries. Benefits of UDWO as a biodiesel feedstock were as well highlighted.     

Development of prolonged standing strain index to quantify risk levels of standing jobs

Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.     

Attributes of occupational injury among workers in the chemical industry and safety issues.

Case-study research was carried out with a view to find the attributes of occupational injury among workers in the chemical industry and to enhance safety issues. Injury data were collected and processed in terms of different variables, such as age, gender, skills, type of hazard, etc. Pareto analysis was then applied to find a pattern of occupational injury among the workers. The study revealed that 79.52% of the injured workers were in the 40-59 age group; 57.14% of accidents occurred during the 1st shift; 73.26% of accidents caused injury to hands, feet, chest to thigh, arms and eyes; and 70.93% of injuries were caused by pumps, carrying and lifting, vehicles, pipelines, valves, and grinding. Surprisingly, no one was injured in the group of temporary workers. The paper also provides specific suggestions followed by some action plans.     

Preparation and characterization of sorbents prepared from ash (waste material) for sulfur dioxide (SO2) removal

Sorbents synthesized from various types of ash (coal fly ash, coal bottom ash, oil palm ash, and incinerator ash) for flue gas desulfurization were investigated. The sorbents were prepared by mixing the ashes with calcium oxide and calcium sulfate using the water hydration method. The effects of various sorbent preparation variables, such as the hydration period, the ratio of calcium oxide to ash, and the amount of calcium sulfate, on the Brunauer-Emmett-Teller (BET)-specific surface area of the resulting sorbent were studied using a two-level full factorial design. The surface area of the sorbents obtained range from 15.4 to 122.1m²/g. Regression models were developed to correlate the significant variables to the surface area of the sorbents. An analysis of variance (ANOVA) showed that the model was significant at a confidence level of 95%. It was found that apart from all the individual variables studied, interactions between variables also exerted a significant influence on the surface area of the sorbent. From the activity test results, it was found that sorbents prepared from coal fly ash and oil palm ash have the highest SO₂ absorption capacity. Scanning electron microscope (SEM) analysis showed that the sorbent was composed of a compound with a high structural porosity, while an X-ray diffraction spectrum showed that calcium aluminum silicate hydrate compounds are the main products of the hydration reaction.     

Effects of floods on the use and condition of pit latrines in rural bangladesh

The severe floods of 1987 in Bangladesh had devastating effects on many development activities. Here, the use and condition of improved sanitation facilities (double pit water sealed latrines) during the 1987 peak flood period are presented. Two surveys on the use and condition of the latrines were carried out in May (pre-flood) and September (post-flood) 1987 in a rural area 60 km north of Dhaka, with a population of about 4500. General usage of the latrines by the population aged five years or more decreased from 88% to 78% ( p < 0.001) after the flood. Only 40% of the 343 latrines which were in use and had no damaged component at the time of the pre-flood survey still had no damaged components after the floods. Fencing was the component which suffered the most damage. It was the only component which was installed and maintained by the users, project staff being responsible for all other components. The estimated post-flood repair cost was approximately US $4.0 per latrine. Development of an affordable and durable fencing is recommended.     

Limitations of anthropometry during acute food shortages: high mortality can mask refugees' deteriorating nutritional status

Longitudinal comparison of anthropometric data from cross-sectional surveys is commonly used to assess nutritional status in relief operations. In a refugee camp in Sudan, assessment indicated a high level of childhood malnutrition, but nutritional status appeared relatively unchanged between cluster sample surveys in January (26.3% below 80% of median weight-for-height) and March 1985 (28.4% below 80% of median weight-for-height). However, in this interval, which was marked by irregular food supplies and relatively low energy (calorie) intake as well as by a high incidence of diarrhoeal disease and measles, nearly 13% of all children in the camp died. This deceptive appearance of stability in nutritional status in the face of high mortality may be explained by ongoing nutritional deterioration ("replacement malnutrition") among surviving children. These findings demonstrate that collection and analysis of mortality data are essential for the correct interpretation of anthropometric results during periods of uncertain food supply.     

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator,Pteris vittata L

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the compost-treated CCA soil was related to the increase of soil water-soluble As and As(V) transformation into As(III). Reduced As uptake in the ASC soil may be attributed to As adsorption to the compost. Chinese brake fern took up As mainly from the iron-bound fraction in the CCA soil and from the water-soluble/exchangeable As in the ASC soil. Without ferns for As adsorption, compost and phosphate amendments increased As leaching from the CCA soil, but had decreased leaching with ferns when compared to the control. For the ASC soil, treatments reduced As leaching regardless of fern presence. This study suggest that growing Chinese brake fern in conjunction with phosphate amendments increases the effectiveness of remediating As-contaminated soils, by increasing As uptake and decreasing As leaching.     

Measurement of wastewater treatment efficiency by fluorescence and UV absorbance

The degree of chemical treatment in terms of removal of organic matter from different wastewaters has been investigated by employing potassium ferrate (K₂FeO₄) and ozone in various combinations. The study was performed in both the batch and the continuous flow systems. The treatment efficiency was determined through three different methods, i.e., chemical oxygen demand (COD), fluorescence and ultraviolet (UV) absorption. Fluorescence and UV absorption techniques were employed due to their specificity in measurement of humic substances, aromatic compounds and heterocyclic systems, whereas COD is a general parameter for the estimation of total organic matter. Fluorescence and UV absorbance values were correlated with respective COD values.Abdul Bari is with the Department of ChemistryShaukat Farooq is with the Department of Civil Engineering