23 research outputs found
Comparative Assessment of Soil Quality at the Defence Establishments
The present study was carried out to adjudge the soil quality of two sites at the defence establishments in India. Various soil samples were collected from the surface and up to 20 cm depth (subsurface) as per apportioned gridding method. These samples were subjected to air drying for 15 days and were characterised for various parameters. The soil is clayey and loamy with granular blocky structure on both the sites. The pH ranged from 7.1 to 7.72 0.1 for site I and from 5.5 to 8.0 f 0.1 for site 11; salinity and bulk density ranged from 0.1 per cent to 8 per cent and from 1.2 glcm3 to 1.5 g/cm3, respectively and soil moisture was about 0.4 f 1 per cent for both the sites. Similarly, total Kjeldahl nitrogen ranged from 1100 mg kg-' to 1900 mg kg-' for site I and 1700 mg kg-' to 9000 mg kg ' for site I1 and total organic carbon ranged from 18 mg g-' to 75 mg g ' for both the sites. A good correlation between nitrate concentration and various explosive process activities has been observed which gives substantial evidence in terms of contamination of the soil. High performance liquid chromatography analysis, which shows varied concentrations of RDX-HMX, NB, DNB, DNT, and TNT in the respective ranges 0.003-2.300 rng g-1, 0.002-0.350 mg g~1, 0.002-0.550 mg g-1, 0.004-0.041 mg g-1 and 0.010- 0.050 mg g-1 for site 1 and 0.002 - 0.013 mg g-1, 0.005 - 0.350 mg g-1, 0.003 - 0.080 mg g-1, 0.001- 0.100 mg g-1, 0.0001- 0.044 mg g ~a1n d 6*10-6- 0.080 mg g-1 for sites I1 has also indicated the contamination of soil by nitro-organics. These results serve as a valuable database for an ongoing project on the development of phytoremediation technology to detoxify such sites
Green and energy-efficient methods for the production of metallic nanoparticles
In the last decade, researchers paid great attention to the concept of “Green Chemistry”, which aims at development of efficient methods for the synthesis of nanoparticles (NPs) in terms of the least possible impact on human life and environment. Generally, several reagents including precursors, reducing agents, stabilizing agents and solvents are used for the production of NPs and in some cases, energy is needed to reach the optimum temperature for reduction. Therefore, to develop a green approach, researchers had the opportunity to investigate eco-friendly reagents and new energy transfer techniques. In order to substitute the harmful reagents with green ones, researchers worked on different types of saccharides, polyols, carboxylic acids, polyoxometalates and extracts of various plants that can play the role of reducers, stabilizers or solvents. Also, there are some reports on using ultraviolet (UV), gamma and microwave irradiation that are capable of reducing and provide uniform heating. According to the literature, it is possible to use green reagents and novel energy transfer techniques for production of NPs. However, these new synthesis routes should be optimized in terms of performance, cost, product quality (shape and size distribution) and scale-up capability. This paper presents a review on most of the employed green reagents and new energy transfer techniques for the production of metallic NPs
Life cycle assessment of microbial 2,3-butanediol production from brewer’s spent grain modeled on pinch technology
Microbial production of 2,3-butanediol (BDO) has received considerable attention as a promising alternate to fossil-derived BDO. In our previous work, BDO concentration >100 g/L was accumulated using brewer’s spent grain (BSG) via microbial routes which was followed by techno-economic analysis of the bioprocess. In the present work, a life cycle assessment (LCA) was conducted for BDO production from the fermentation of BSG to identify the associated environmental impacts. The LCA was based on an industrial-scale biorefinery processing of 100 metric tons BSG per day modeled using ASPEN plus integrated with pinch technology, a tool for achieving maximum thermal efficiency and heat recovery from the process. For the cradle-to-gate LCA, the functional unit of 1 kg of BDO production was selected. One-hundred-year global warming potential of 7.25 kg CO2/kg BDO was estimated while including biogenic carbon emission. The pretreatment stage followed by the cultivation and fermentation contributed to the maximum adverse impacts. Sensitivity analysis revealed that a reduction in electricity consumption and transportation and an increase in BDO yield could reduce the adverse impacts associated with microbial BDO production
Pine-wood derived nanobiochar for removal of carbamazepine from aqueous media: Adsorption behavior and influential parameters
In recent years, application of biochar for removal of pollutants from aqueous solutions has been of interest due to favorable physicochemical properties and availability of feedstock. However, adsorption behavior has been reported only for raw and micro biochar particles and taking advantage of biochar nanoparticles, which offer superior specific surface area, did not receive any attention. The objective of this study was to investigate the adsorption efficiency of produced nanobiochar from pinewood. For this purpose, removal of carbamazepine (CBZ), a globally prescribed pharmaceutical, at very low concentrations (0.5–20 ppb) on as-produced nanobiochar with average particle size of 60 nm was studied. The results showed that nanobiochar can remove up to 95% of CBZ (74 μg CBZ/g nanobiochar) after 3 h contact time. Adsorption of CBZ on nanobiochar followed Freundlich isotherm model (R2= 0.9822) and pseudo-second order kinetic model (R2= 0.9994). It was found that increasing pH from 3 to 8 can enhance the adsorption efficiency by 2.3 folds. Also, due to the presence of surfactant in wastewater, the addition of Tween 80 as a model surfactant was studied in the range of 0 to 1 (Tween 80 to CBZ molar ratio) and the results showed that adsorption efficiency can be enhanced by 57%. Thus, the nanobiochar obtained from pinewood residues can be a promising sorbent for micropollutants
Diclofenac and its transformation products: Environmental occurrence and toxicity - A review
Diclofenac (DCF) is a prevalent anti-inflammatory drug used throughout the world. Intensive researches carried out in the past few decades have confirmed the global ubiquity of DCF in various environmental compartments. Its frequent occurrence in freshwater environments and its potential toxicity towards several organisms such as fish and mussels makes DCF an emerging environmental contaminant. At typical detected environmental concentrations, the drug does not exhibit toxic effects towards living organisms, albeit chronic exposure may lead to severe effects. For DCF, about 30–70% removal has been obtained through the conventional treatment system in wastewater treatment plant being the major primary sink. Thus, the untreated DCF will pass to surface water. DCF can interact with other inorganic contaminants in the environment particularly in wastewater treatment plant, such asmetals, organic contaminants and evenwith DCF metabolites. This processmay lead to the creation of another possible emerging contaminant. In the present context, environmental fate of DCF in different compartments such as soil and water has been addressed with an overview of current treatment methods. In addition, the toxicity concerns regarding DCF in aquatic as well as terrestrial environment along with an introduction to the metabolites of DCF through consumption as well as abiotic degradation routes are also discussed. Further studies are required to better assess the fate and toxicological effects ofDCF and its metabolites and must consider the possible interaction of DCF with other contaminants to develop an effective treatment method for DCF and its traces
Green and energy-efficient methods for the production of metallic nanoparticles
In the last decade, researchers paid great attention to the concept of “Green Chemistry”, which aims at development of efficient methods for the synthesis of nanoparticles (NPs) in terms of the least possible impact on human life and environment. Generally, several reagents including precursors, reducing agents, stabilizing agents and solvents are used for the production of NPs and in some cases, energy is needed to reach the optimum temperature for reduction. Therefore, to develop a green approach, researchers had the opportunity to investigate eco-friendly reagents and new energy transfer techniques. In order to substitute the harmful reagents with green ones, researchers worked on different types of saccharides, polyols, carboxylic acids, polyoxometalates and extracts of various plants that can play the role of reducers, stabilizers or solvents. Also, there are some reports on using ultraviolet (UV), gamma and microwave irradiation that are capable of reducing and provide uniform heating. According to the literature, it is possible to use green reagents and novel energy transfer techniques for production of NPs. However, these new synthesis routes should be optimized in terms of performance, cost, product quality (shape and size distribution) and scale-up capability. This paper presents a review on most of the employed green reagents and new energy transfer techniques for the production of metallic NPs
Development of adsorptive membranes by confinement of activated biochar into electrospun nanofibers
Adsorptive membranes have many applications in removal of contaminants, such as heavy metals and organic contaminants from water. Recently, increasing concentrations of pharmaceutically active compounds, especially antibiotics, such as chlortetracycline in water and wastewater sources has raised concerns about their potentially adverse impacts on environment and human health. In this study, a series of polyacrylonitrile (PAN)/activated biochar nanofibrous membranes (NFMs) with different loadings of biochar (0–2%, w/w) were fabricated using electrospinning. The morphology and structure of fabricated membranes was investigated by scanning electron microscopy, Fourier transform infrared and thermogravimetric analysis. The results showed that at 1.5% of biochar loading, the surface area reached the maximum value of 12.4 m2/g and beyond this loading value, agglomeration of particles inhibited fine interaction with nanofibrous matrix. Also, the adsorption tests using chlortetracycline showed that, under environmentally relevant concentrations, the fabricated adsorptive NFMs had a potential for removal of these types of emerging contaminants from water and wastewaters
Parámetros fenotípicos y genéticos de caracteres reproductivos en vacas Holstein en Túnez
Various factors influencing reproduction in dairy Holstein cows were
routinely evaluated and genetic parameters were estimated for four
traits to assess fertility of artificially inseminated cows: Calving to
first service interval (CFSI), calving interval (CI), calving to
conception interval (CCI) and number of services per conception (NSC).
Data used in this investigation consisted of records of insemination
and calving events on Tunisian Holstein cows. The data included records
from 1994 to 2003 in 150 herds. The aim of the study was to investigate
the effects of non-genetic factors on reproductive traits and estimate
their heritabilities. The factors examined were: month and year of
calving, herd, parity, and year-month of calving. The effect of month
and year of calving (or insemination), herd, parity and year-month of
calving were included in the model and were significant (P < 0.01)
except for the number of lactations that does not have an effect on the
NSC. A decreasing efficiency in cow fertility was observed over the
last years, with a longer day for first service interval. Heritability
for fertility traits was low ranging from 0.027 for NSC to 0.067 for
CI. The results suggested that more attention should be paid to herds
with too low fertility traits and that monitoring and intervention
schemes should be tested in research approaches.Se evaluaron de manera rutinaria diferentes factores que influyen en la
reproducción de las vacas lecheras Holstein y se estimaron los
parámetros genéticos de cuatro caracteres para evaluar la
fertilidad de las vacas inseminadas artificialmente: el intervalo de
parto a primer servicio (IPPS), el intervalo entre partos (IP), el
intervalo de parto a concepción (IPC) y el número de
servicios por concepción (NSC). Los datos utilizados en esta
investigación consistieron de registros de eventos de
inseminación y partos en vacas Holstein de Túnez. Los
registros fueron tomados desde 1994 hasta 2003 en 150 rebaños para
estudiar los efectos de factores no genéticos y estimar las
heredabilidades de los caracteres anteriormene señalados de
fertilidad. Los factores examinados fueron: mes y año de parto,
rebaño, paridad y año-mes de parto. El efecto del mes y
año de parto (o inseminación), rebaño, paridad y
año-mes de parto se incluyeron en el modelo y fueron
significativos (P <0,01) con excepción del número de
lactancias que no tiene un efecto sobre el NSC. Se observe una
eficiencia decreciente en la fertilidad de las vacas en los
últimos años, con un día más largo para el
intervalo del primer servicio. La heredabilidad para los caracteres de
la fertilidad fue baja en un rango de 0,027 para NSC a 0,067 para el
interval entre partos. Los resultados sugieren que debería
prestarse más atención a los rebaños con rasgos muy
bajos de fertilidad y que los esquemas de vigilancia e
intervención deberían ser evaluados con enfoques de
investigación
Cheese Whey as a Potential Feedstock for Producing Renewable Biofuels: A Review
Agro-industrial residues such as bagasse, pomace, municipal residues, vinasse and cheese whey are an environmental problem around the world, mainly due to the huge volumes that are generated because of the food production to satisfy the nutritional needs of the growing world population. Among the above residues, cheese whey has gained special attention because of its high production with a worldwide production of 160 million tons per year. Most of it is discarded in water bodies and land causing damage to the environment due to the high biological oxygen demand caused by its organic matter load. The environmental regulations in developing countries have motivated the development of new processes to treat transform cheese whey into added-value products such as food supplements, cattle feed and food additives. In addition, during the last decade, several processes and technologies have been developed to produce bioenergy through the biotechnological process using cheese whey as a potential feedstock. This review discusses the production of bioethanol, biohydrogen, biomethane and microbial lipid-biodiesel production using cheese whey as a potential substrate
Phenotypic and genetic parameters of reproductive traits in Tunisian Holstein cows
Various factors influencing reproduction in dairy Holstein cows were routinely evaluated and genetic parameters were
estimated for four traits to assess fertility of artificially inseminated cows: Calving to first service interval (CFSI), calving
interval (CI), calving to conception interval (CCI) and number of services per conception (NSC). Data used in this
investigation consisted of records of insemination and calving events on Tunisian Holstein cows. The data included records
from 1994 to 2003 in 150 herds. The aim of the study was to investigate the effects of non-genetic factors on reproductive
traits and estimate their heritabilities. The factors examined were: month and year of calving, herd, parity, and year-month
of calving. The effect of month and year of calving (or insemination), herd, parity and year-month of calving were included
in the model and were significant (P < 0.01) except for the number of lactations that does not have an effect on the NSC. A
decreasing efficiency in cow fertility was observed over the last years, with a longer day for first service interval.
Heritability for fertility traits was low ranging from 0.027 for NSC to 0.067 for CI. The results suggested that more attention
should be paid to herds with too low fertility traits and that monitoring and intervention schemes should be tested in
research approaches.Se evaluaron de manera rutinaria diferentes factores que influyen en la reproducción de las vacas lecheras Holstein y se
estimaron los parámetros genéticos de cuatro caracteres para evaluar la fertilidad de las vacas inseminadas artificialmente:
el intervalo de parto a primer servicio (IPPS), el intervalo entre partos (IP), el intervalo de parto a concepción (IPC) y el
número de servicios por concepción (NSC). Los datos utilizados en esta investigación consistieron de registros de eventos
de inseminación y partos en vacas Holstein de Túnez. Los registros fueron tomados desde 1994 hasta 2003 en 150 rebaños
para estudiar los efectos de factores no genéticos y estimar las heredabilidades de los caracteres anteriormene señalados de
fertilidad. Los factores examinados fueron: mes y año de parto, rebaño, paridad y año-mes de parto. El efecto del mes y año
de parto (o inseminación), rebaño, paridad y año-mes de parto se incluyeron en el modelo y fueron significativos (P <0,01)
con excepción del número de lactancias que no tiene un efecto sobre el NSC. Se observe una eficiencia decreciente en la
fertilidad de las vacas en los últimos años, con un día más largo para el intervalo del primer servicio. La heredabilidad para
los caracteres de la fertilidad fue baja en un rango de 0,027 para NSC a 0,067 para el interval entre partos. Los resultados
sugieren que debería prestarse más atención a los rebaños con rasgos muy bajos de fertilidad y que los esquemas de
vigilancia e intervención deberían ser evaluados con enfoques de investigación