Fine route for an efficient removal of 2,4-dichlorophenoxyacetic acid (2,4-D) by zeolite-supported TiO2

Zeolites HY, Hbeta and HZSM-5 with different physico-chemical properties were chosen as support for TiO2 to illustrate their adsorption, dispersion and electronic structure in photocatalysis. The extent of TiO2 loading was monitored by XRD and BET surface area measurements. The adsorption capacity of HY zeolite was found to be high and hence chosen for further modification to continue the investigation. Photodegradation kinetics were carried out with 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. The extent of 2,4-D degradation on TiO2/HY loading revealed the importance of adsorption in photocatalysis. Mineralisation studies on all three zeolites with 1 wt.% TiO2 loading demonstrated the good dispersion properties of TiO2/HY. Its photocatalytic activity was found to be excellent with formulated 2,4-D. Comparison of relative photonic efficiencies demonstrated that supported photocatalysts exhibited higher activity than some of the commercial photocatalysts. The high activity of supported TiO2 is due to synergistic effects of improved adsorption of 2,4-D and efficient delocalisation of photogenerated electrons by zeolite support.     

Investigation of work-related musculoskeletal disorders among male kitchen workers in South India

Objective. This study aims to quantify the prevalence of work-related musculoskeletal disorders (MSDs) and risks among male kitchen workers in the catering industry. Method. Data were collected with the help of the Nordic musculoskeletal questionnaire and by direct observations. Results. In total, 114 male kitchen workers from various hostels of a college in South India were considered for this study. The average age and mean years of employment of the workers are 26.4 (SD 7.7) and 7.8 respectively. The statistical analysis carried out reveals that 67.5% of male kitchen workers reported MSDs during the past 12 months. The highest prevalence rate has been found in the lower back (65.8%) and shoulder region (62.3%). Among different categories of kitchen work analyzed, it is evident that chief cooks suffer more from MSDs (79.2%) than assistant cooks (74.3%) and kitchen aides (30.0%). Workers in the older group, i.e., ≥41 years, and workers with 6–10 years of experience suffer with higher risk of MSDs, i.e., 93.9% and 87.5%, respectively. Conclusion. The male kitchen workers who participated in this research were found to possess both MSDs and ergonomic hazards.     

Integrated techniques to identify groundwater vulnerability to pollution in a highly industrialized terrain, Tamilnadu, India

Investigation has been made to identify groundwater vulnerability to pollution by using geoelectric and hydrochemical investigations in an important industrial town Mettur located in Tamilnadu state of India. Schlumberger vertical electric soundings were carried out in 23 locations and groundwater samples collected from bore wells in the same locations. The resistivity value with <20 Ωm up to a depth of 36 m indicate contamination of groundwater in areas influenced by sewages from industries, domestic and agricultural practices in the central and southern part of the study area. The calculated specific conductance was noted higher than EC in central and southern part of the study area with low resistivity indicating the contaminated nature of groundwater. Concentrations of Ca, Na, Mg and K along with Cl, HCO(3), SO(4) and NO(3) were higher in certain locations when compared with WHO and ISI standards. The facies concept demarcated four groups based on the nature of groundwater contamination. The trace elements Fe and Pb were higher in locations confined to industrial zones and Zn and Cu were within the prescribed limit in all the samples.     

Site selection of check dams using geospatial techniques in Debre Berhan region,Ethiopia — water management perspective

Environmental Science and Pollution Research - Remote sensing and GIS technology were very helpful to determine an appropriate location of freshwater storage in Amhara, Ethiopia. The techniques...     

Agricultural solid waste for the removal of organics: adsorption of phenol from water and wastewater by palm seed coat activated carbon

Adsorption studies for phenol removal from aqueous solution on activated palm seed coat carbon (PSCC) were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dose and pH. Adsorption equilibrium was reached within 3 h for phenolic concentrations 10-60 mg l(-1). Kinetics of adsorption obeyed a first order rate equation. The percent removal remained constant over the pH range 4-9 for a phenolic concentration of 25 mg (l-1). The equilibrium data could be described well by the Freundlich isotherm equation. The adsorption of phenol on PSCC follows the film diffusion process. A comparative study with a commercial activated carbon showed that PSCC is two times more effective than commercial activated carbon. The studies showed that the palm seed coat carbon can be used as an efficient adsorbent material for the removal of phenolics from water and wastewater.     

Sorption of Cr(VI) from dilute solutions and wastewater by live and pretreated biomass of Aspergillus flavus

Sorption of Cr(VI) was carried out from dilute solutions using live and pretreated biomass in a batch mode. Effects of agitation time, adsorbent dosage and pH were examined. The autoclaved biomass that showed maximum adsorption capacity (Q(0)=0.335 mg g(-1)) was used as an adsorbent in column studies. The optimized flow rate of 2.5 ml min(-1) and bed height 10 cm were used to determine the effect of metal ion concentration on removal of Cr(VI). Applying the BDST model to calculate the adsorption capacity (N(0)) of column, which showed 4.56 x 10(-5), 7.28 x 10(-5), 6.89 x 10(-5), 3.07 x 10(-5), 2.80 x 10(-5)mg g(-1) for 4, 8, 12, 16 and 20 mg dm(-3) of Cr(VI), respectively. Batch sorption proved to be more efficient than the column sorption and hence batch sorption was used to remove Cr(VI) from a textile dyeing industry wastewater. The phytotoxic effect of treated and untreated wastewater was studied against Zea mays. Toxicity was reduced by 50% in the treated effluent.     

Electricity production using food waste: a review

Environmental Chemistry Letters - Conventional treatments of food waste such as incineration, landfilling, and composting require large land areas and induce contamination in&nbsp;air, soil,...     

Biosorption of Hg(II) Ions From Aqueous Solution Using the Aquatic Weed Water Hyacinth With Equilibrium and Kinetic Modeling

The potential for biosorption of Hg(II) ions from aqueous solutions using water hyacinth was studied. The effect of the retention period (0, 1, 3, 7, and 15 days), pH (3, 5, 7, and 9), initial concentration of Hg(II) ions (5, 10, and 15 mg/L), and organic loading rate (25, 50, and 75 percent) on biosorption were investigated. The physicochemical parameters were also analyzed at various concentrations of Hg(II) ions before and after treatment. The maximum biosorption rate was obtained at 15 days with the initial concentration of 10 mg/L at a pH of 7 and organic loading rate of 50 percent. The maximum biosorption capacity of both water hyacinth roots and shoots were 5.5 mg/L and 3.8 mg/L, respectively. The Hg(II) biosorption data were analyzed using the first‐ and second‐order kinetic models. Pseudo second‐order kinetics was considered the most appropriate model for predicting the biosorption capacity of both water hyacinth roots and shoots, and the modeled results were compared to the experimental results. Langmuir and Freundlich isotherms were used to evaluate the experimental data, and their constants were derived. Biosorption equilibrium data were best described by the Langmuir isotherm model followed by the Freundlich model. © 2013 Wiley Periodicals, Inc.     

Effect of additives on the stability of ethanol-diesel blends for IC engine application

The present research work was conducted on a compression ignition engine to assess the engine characteristics fueled with the blend of diesel and high-oxygenated additives such as ethanol. Ethanol does not easily blend with diesel. In order to attain a homogeneous mixture, a small amount of additive is added to the blend. Different additives were added to the blend to form a homogeneous mixture. Stability test was conducted on the blend to ensure prolonged homogeneity. The additives used for the test purpose were isopropanol, oleic acid, and ethylene acetate. From the stability results, it was found that oleic acid was the best additive which produces a better homogenous mixture for the blend of ethanol and diesel. One percentage of oleic acid is used as an additive to blend ethanol and diesel. The different combinations of blend ratios used for the test purpose were D90E10, D80E20, and D70E30. All the aforementioned blends have low cetane number because of ethanol, which was compensated by adding 1% DEE (diethyl ether) to all the blends. Experimental results exhibit that there is an improvement in the performance characteristics, such as brake thermal efficiency (BTE) and specific energy consumption (SEC), with the enrichment of DEE in ethanol-diesel blend. It is also noticed that the blend without DEE exhibited lower magnitude. This is mainly due to higher energy content and cetane number of DEE. Emission characteristics, like hydrocarbon (HC) and carbon monoxide (CO), were found to drastically increase with the increase in the ethanol concentration in the diesel blend. This is attributed to higher latent heat of vaporization (LHV) of ethanol present in the blend. Combustion pressure and heat release rate of the DEE-enriched ethanol blends were higher by 2.2 % and 2.4 %, respectively, when compared with their corresponding blends without DEE. This is a result of higher volatility of DEE which leads to better combustion.

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Performance analysis of crushed gravel sand heat storage and biomass evaporator-assisted single slope solar still

Environmental Science and Pollution Research - In this research work, the productivity, energy, exergy, and economic and enviro-economic performance in crushed gravel sand heat storage and biomass...