Speciation of selected heavy metals geochemistry in surface sediments from Tirumalairajan river estuary, east coast of India

Surface sediment samples from the Tirumalairajan river estuary were studied for grain size pattern, organic matter, and heavy metals (Fe, Mn, Zn, and Pb) using the sequential and bulk metal extraction methods to evaluate metal behavior. Ten surface sediment samples were collected during the monsoon and summer seasons of the year 2009. The observed orders of concentrations of heavy metals in the sediments were as follows: Fe?>?Mn?>?Zn?>?Pb. The results obtained from sequential extraction showed that, among the metals studied, a larger portion of the metals were associated with the residual phase, although they are available in other fractions. The low concentration of metals available in bioavailable phases indicated that the sediments of Tirumalairajan river estuary were relatively unpolluted. Correlation analysis was also carried out to understand the associations of metals in different phases with sand, silt, clay, and organic matter. To understand the risk of heavy metals to sediment-dwelling organisms, the data were compared with risk assessment code and sediment quality values using the screening quick reference table. The main source of metals to the estuary is from the irrigation field and its associated activities in the study area.     

Investigation of performance enhancement of solar still incorporated with Gallus gallus domesticus cascara as sensible heat storage material

In this research work, the conventional single slope still (CSS) with egg shells of breed Gallus gallus domesticus cascara as sensible heat storage (SHS) material are studied experimentally to enhance the yield. In this experimental investigation, the proposed single slope still (PSS) with SHS material was made in comparison with the CSS to evaluate the productivity of fresh water under the same ambient conditions. Comparatively, this PSS has higher thermal conductivity than the CSS. The yield obtained from the PSS is 2.46 L/m², while the yield from the CSS is 2.07 L/m². The average rate at which the rise of output fresh water obtained from the PSS is 18% more than the fresh water output obtained from the CSS. The daily energy efficiency of the PSS is 26.07%, and for the CSS, it is only 22.25%. The daily exergy efficiency of the PSS is 2.36%, and for the CSS, it is only 1.67%. Since using the egg shell will employ as organic waste management and modification in this still is economical, less initial, and maintenance cost.

     

A microscopic investigation of machining behavior in μED-milling process

The discussion presented in this work is about evaluation of physical behavior of μED-milling process based on channel shape, form and surface quality. μED-milling process is gaining lot of interest in recent times in micro manufacturing to generate complex shapes. Tool rotation and traverse which are not an inherent part of EDM process become important for μED-milling where it significantly influence the molten metal flow, debris flushing and redeposition. The effect of tool rotation not only disturbs the plasma but also affects the final shape and form of channel. Using scanning electron micrographs of μ-channel at different instant and conditions of machining, the physical nature of the process is understood and the results are presented. This study will provide a better understanding of the working phenomenon of μED-milling process.     

Organopesticides and fertility: where does the link lead to?

Environmental Science and Pollution Research - Organopesticides (OPs) are a group of various synthetic chemicals prevalently used in agriculture and homestead plantations. OPs were originally...     

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.

Graphical abstract

     

Phase behaviors,fuel properties,and combustion characteristics of alcohol-vegetable oil-diesel microemulsion fuels

Biofuels are being considered as alternatives to fossil-based fuels due to depletion of petroleum-based reserves and pollutant emission concerns. Vegetable oils and bioalcohols have proven to be viable alternative fuels both with and without engine modification. However, high viscosity and low energy content are long-term operational problems with vegetable oils and bioalcohols, respectively. Therefore, vegetable oil-based microemulsification is being evaluated as a method to reduce the high viscosity of vegetable oils and enhance the miscibility of alcohol and oil phases. Studies have shown that microemulsification with different alcohols lead to varying fuel properties depending on their structure. The overall goal of this study was to formulate microemulsion fuels with single and mixed alcohol systems by determining the effects of water content, alcohol branching structure and carbon chain length on phase behaviors, fuel properties, and emission characteristics. It was found that microemulsion fuels using certain alcohols displayed favorable stability, properties, and emission characteristics. Flames of fuels with linear short-chain-length alcohols had larger near-burner blue regions and lower CO and soot emissions indicating the occurrence of more complete combustion. In addition to alcohol effects, the effect of vegetable oils, surfactants, and additives on emission characteristics were insightful in pursuit of appropriate microemulsion fuels as cleaner burning alternatives to both No.2 diesel and canola biodiesel.