Abstract: In the present study, an ecofriendly biocomposite namely calcium alginate immobilized Ammi Visnaga (Khella) extraction waste (SWAV/CA) was prepared by electrostatic extrusion method and used on the cadmium biosorption from aqueous phase with and without the assistance of ultrasound in batch conditions. The influence of low frequency ultrasound (37 and 80 KHz) on the cadmium biosorption kinetics was studied. The obtained results show that the ultrasonic irradiation significantly enhances and improves the efficiency of the cadmium removal. The Pseudo first order, Pseudo-second-order, Intraparticle diffusion, and Elovich models were evaluated using the non-linear curve fitting analysis method. Modeling of kinetic results shows that biosorption process is best described by the pseudo-second order and Elovich, in both the absence and presence of ultrasound.
Abstract: The present study investigated the protective effect of
thymoquinone (TQ), against cadmium-induced kidney injury in rats.
Cadmium chloride (1.2 mg Cd/kg/day, s.c.), was given for nine
weeks. TQ treatment (40 mg/kg/day, p.o.) started on the same day of
cadmium administration and continued for nine weeks. TQ
significantly decreased serum creatinine, renal malondialdehyde and
nitric oxide, and significantly increased renal reduced glutathione in
rats received cadmium. Histopathological examination showed that
TQ markedly minimized renal tissue damage induced by cadmium.
Immunohistochemical analysis revealed that TQ markedly decreased
the cadmium-induced expression of inducible nitric oxide synthase,
tumor necrosis factor-α, cyclooxygenase-2, and caspase-3 in renal
tissue. It was concluded that TQ significantly protected against
cadmium nephrotoxicity in rats, through its antioxidant, antiinflammatory,
and antiapoptotic actions.
Abstract: The study assessed the effectiveness of Pawpaw
(Carica papaya) wood in reducing the concentrations of heavy
metals in wastewater acting as a bio-sorbent. The following heavy
metals were considered; Zinc, Cadmium, Lead, Copper, Iron,
Selenium, Nickel and Manganese. The physiochemical properties of
Carica papaya stem were studied. The experimental sample was
sourced from the trunk of a felled matured pawpaw tree. Wastewater
for experimental use was prepared by dissolving soil samples
collected from a dump site at Owerri, Imo state of Nigeria in water.
The concentration of each metal remaining in solution as residual
metal after bio-sorption was determined using Atomic absorption
Spectrometer. The effects of pH and initial heavy metal concentration
were studied in a batch reactor. The results of Spectrometer test
showed that there were different functional groups detected in the
Carica papaya stem biomass. There was increase in metal removal as
the pH increased for all the metals considered except for Nickel and
Manganese. Optimum bio-sorption occurred at pH 5.9 with 5g/100ml
solution of bio-sorbent. The results of the study showed that the
treated wastewater is fit for irrigation purpose based on Canada
wastewater quality guideline for the protection of Agricultural
standard. This approach thus provides a cost effective and
environmentally friendly option for treating wastewater.
Abstract: The major environmental risk of soil pollution is the
contamination of groundwater by infiltration of organic and inorganic
pollutants which can cause a serious menace. To prevent this risk and
to protect the groundwater, we proceeded in this study to test the
reliability of a biosolid as barrier to prevent the migration of very
dangerous pollutants as ‘Cadmium’ through the different soil layers. In this study, we tried to highlight the effect of several parameters
such as: turbidity (different cycle of Hydration/Dehydration),
rainfall, effect of initial Cd(II) concentration and the type of soil.
These parameters allow us to find the most effective manner to
integrate this barrier in the soil. From the results obtained, we found a
significant effect of the barrier. Indeed, the recorded passing
quantities are lowest for the highest rainfall; we noted also that the
barrier has a better affinity towards higher concentrations; the most
retained amounts of cadmium has been in the top layer of the two
types of soil tested, while the lowest amounts of cadmium are
recorded in the bottom layers of soils.
Abstract: Cadmium oxide (CdO) nanoparticles have been
prepared by chemical coprecipitation method. The synthesized
nanoparticles were characterized by X-ray diffraction analysis
(XRD), scanning electron microscopy (SEM), transmission electron
microscopy (TEM), UV analysis, and dielectric studies. The
crystalline nature and particle size of the CdO nanoparticles were
characterized by Powder X-ray diffraction analysis (XRD). The
morphology of prepared CdO nanoparticles was studied by scanning
electron microscopy. The particle size was studied using the
transmission electron microscopy (TEM).The optical properties were
obtained from UV-Vis absorption spectrum. The dielectric properties
of CdO nanoparticles were studied in the frequency range of 50 Hz–5
MHz at different temperatures. The frequency dependence of the
dielectric constant and dielectric loss is found to decrease with an
increase in the frequency at different temperatures. The ac
conductivity of CdO nanoparticle has been studied.
Abstract: Household waste form a larger proportion of waste
generated across the state, accumulation of organic waste is an
apparent problem and the existing dump sites could be overstress.
Niger state has abundant arable land and water resources thus should
be one of the highest producers of agricultural crops in the country.
However, the major challenge to agricultural sector today is loss of
soil nutrient coupled with high cost of fertilizer. These have
continued to increase the use of fertilizer and decomposed solid waste
for enhance agricultural yield, which have varying effects on the soil
as well a threat to human livelihood. Consequently, vegetable yield
samples from poultry droppings, decomposed household waste
manure, NPK treatments and control from each replication were
subjected to proximate analysis to determine the nutritional and antinutritional
component as well as heavy metal concentration. Data
collected was analyzed using SPSS software and Randomized
complete Block Design means were compared. The result shows that
the treatments do not devoid the concentrations of any nutritional
components while the anti-nutritional analysis proved that NPK had
higher oxalate content than control and organic treats. The
concentration of lead and cadmium are within safe permissible level
while the mercury level exceeded the FAO/WHO maximum
permissible limit for the entire treatments depicts the need for urgent
intervention to minimize mercury levels in soil and manure in order
to mitigate its toxic effect. Thus, eco-agriculture should be widely
accepted and promoted by the stakeholders for soil amendment,
higher yield, strategies for sustainable environmental protection, food
security, poverty eradication, attainment of sustainable development
and healthy livelihood.
Abstract: This study focuses on the hydro-geology and chemical
constituents analysis of Ikogosi Warm Spring waters in South West
Nigeria. Ikogosi warm spring is a global tourist attraction because it
has both warm and cold spring sources. Water samples from the cold
spring, warm spring and the meeting point were collected, analyzed
and the result shows close similarity in temperature, hydrogen iron
concentration (pH), alkalinity, hardness, Calcium, Magnesium,
Sodium, Iron, total dissolved solid and heavy metals. The measured
parameters in the water samples are within World Health
Organisation standards for fresh water. The study of the geology of
the warm spring reveals that the study area is underlain by a group of
slightly migmatised to non-migmatised paraschists and meta-igneous
rocks. Also, concentration levels of selected heavy metals, (Copper,
Cadmium, Zinc, Arsenic and Cromium) were determined in the water
(ppm) samples. Chromium had the highest concentration value of
1.52ppm (an average of 49.67%) and Cadmium had the lowest
concentration with value of 0.15ppm (an average of 4.89%).
Comparison of these results showed that, their mean levels are within
the standard values obtained in Nigeria. It can be concluded that both
warm and spring water are safe for drinking.
Abstract: The ferrites ZnFe2O4, CdFe2O4 and CuFe2O4 are
synthesized in laboratory conditions using ceramic technology. Their
homogeneity and structure are proven by X-Ray diffraction analysis
and Mössbauer spectroscopy. The synthesized ferrites are subjected
to strong acid and high temperature leaching with solutions of H2SO4,
HCl and HNO3. The results indicate that the highest degree of
leaching of Zn, Cd and Cu from the ferrites is achieved by use of
HCl. The charging of five zinc sulfide concentrates was optimized using
the criterion of minimal amount of zinc ferrite produced when
roasting the concentrates in a fluidized bed. The results obtained are
interpreted in terms of the hydrometallurgical zinc production and
maximum recovery of zinc, copper and cadmium from initial zinc
concentrates after their roasting.
Abstract: Cadmium (II) (Cd) is one of the major toxic elemental
pollutants, which is hazardous for humans, animals and plants. γ-
Polyglutamic acid (γ-PGA) is an extracellular biopolymer produced
by several species of Bacillus which has been reported to be an
effective biosorbent for metal ions. The effect of γ-PGA on growth of
rice grown under laboratory conditions was investigated. Rice seeds
were germinated and then grown at 30±1°C on filter paper soaked
with Cd solution and γ-PGA for 7 days. The result showed that Cd
significantly inhibited the growth of roots, shoots by reducing root,
and shoot lengths. Fresh and dry weights also decreased compared
with control; however, the addition of 500 mg·L-1 γ-PGA alleviated
rice seedlings from the adverse effects of Cd. The analysis of
physiological traits revealed that Cd caused a decrease in the total
chlorophyll and soluble protein contents and amylase activities in all
treatments. The Cd content in seedling tissues increased for the Cd
250 μM treatment (P
Abstract: Nanotechnology has become the world attention in
various applications including the solar cells devices due to the
uniqueness and benefits of achieving low cost and better
performances of devices. Recently, thin film solar cells such as
Cadmium Telluride (CdTe), Copper-Indium-Gallium-diSelenide
(CIGS), Copper-Zinc-Tin-Sulphide (CZTS), and Dye-Sensitized
Solar Cells (DSSC) enhanced by nanotechnology have attracted
much attention. Thus, a compilation of nanotechnology devices
giving the progress in the solar cells has been presented. It is much
related to nanoparticles or nanocrystallines, carbon nanotubes, and
nanowires or nanorods structures.
Abstract: A field study was conducted to evaluate the efficacy
of lavender for phytoremediation of contaminated soils. The
experiment was performed on an agricultural fields contaminated by
the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. The
concentrations of Pb, Zn and Cd in lavender (roots, stems, leaves and
inflorescences) and in the essential oils of lavender were determined.
Lavender is a plant which is tolerant to heavy metals and can be
grown on contaminated soils, and which can be referred to the
hyperaccumulators of lead and the accumulators of cadmium and
zinc, and can be successfully used in the phytoremediation of heavy
metal contaminated soils. Favorable is also the fact that heavy metals
do not influence the development of the lavender, as well as on the
quality and quantity of the essential oil. The possibility of further
industrial processing will make lavender economically interesting
crops for farmers of phytoextraction technology.
Abstract: The concentrations of cadmium and lead in sewage
sludge samples were determined by Atomic Absorption
Spectrometric Method. Samples of sewage sludge were obtained
from three sewage treatment plants localised in Middle Region of
Libya (Misrata, Msallata and Tarhünah cities).
The results shows that, the mean levels of Cadmium for all regions
are ranges from 81 to 123.4 ppm and these values are higher than the
limitations for the international standard which are not registered
more than 50 ppm (dry weight) in USA, Egypt and the EU countries.
While, the lead concentrations are ranged from 8.0 to 189.2 ppm and
all values are within the standard limits which graduated between
(275–613) ppm.
Abstract: The aim of this study was to select the best strains of
Saccharomyces cerevisiae able to resist lead and cadmium. Ten
strains were screened on the basis of their resistance at different
concentrations of 0, 2, 4, 8, 12, 16, 20 and 24 ppm for Pb and 0, 0.5,
1, 2, 4, 6, 8 and 10 ppm for Cd. The properties of baker's yeast
quality were decreased by the increase of Pb or Cd in growth
medium. The slope values of yield, total viable cells and gassing
power of produced baker's yeast were investigated as an indicator of
metal resistant. In addition, concentrations of Pb and Cd in produced
baker's yeast were determined. The strain of S. cerevisiae FH-620
had the highest resistance against Pb and Cd and had the minimum
levels of both two investigated metals in produced baker's yeast.
Abstract: The concentration levels of six heavy metals (Cd, Cr,
Fe, Ni, Pb and Zn) and two mineral elements (Ca and Mg) were
determined in soil samples collected from the vicinity of two auto
mechanic workshops in Sabon-Gari, Kaduna state, Nigeria, using
Atomic Absorption Spectrometry (AAS), in order to compare the
gradation of their concentrations with distance and depth of soil from
the workshop sites. At site 1, concentrations of Lead, Chromium, Iron
and Zinc were generally found to be above the World Health
Organization limits, while those of Nickel and Cadmium fell within
the limits. Iron had the highest concentration with a range of 176.274
ppm to 489.127 ppm at depths of 5 cm to 15 cm and a distance range
of 5 m to 15 m, while the concentration of cadmium was least with a
range of 0.001 ppm to 0.008 ppm at similar depth and distance
ranges. In addition, there was more of calcium (11.521 ppm to
121.709 ppm), in all the samples, than magnesium (11.293 ppm to
21.635 ppm). Similar results were obtained for site II. The
concentrations of all the metals analyzed showed a downward
gradient with increase in depth and distance from both workshop sites
except for iron and zinc at site 2. The immediate and remote
implications of these findings on the biota are discussed.
Abstract: Water contamination by toxic compound is one of the serious environmental problems today. These toxic compounds mostly originated from industrial effluents, agriculture, natural sources and human waste. These studies focus on modification of multiwalled carbon nanotube (MWCNTs) with nanoparticle of calixarene and explore the possibility of using this modification for the remediation of cadmium in water. The nanocomposites were prepared by dissolving calixarene in chloroform solution as solvent, followed by additional multiwalled carbon nanotube (MWCNTs) then sonication process for 3 hour and fabricated the nanocomposites on substrate by spin coating method. Finally, the nanocomposites were tested on cadmium ion (10 mg/ml). The morphology of nanocomposites was investigated by FESEM showing the formation of calixarene on the outer walls of carbon nanotube and cadmium ion also clearly seen from the micrograph. This formation was supported by using energy dispersive x-ray (EDX). The presence of cadmium ions in the films, leads to some changes in the surface potential and Fourier Transform Infrared spectroscopy (FTIR).The nanocomposites MWCNTs-calixarene have potential for development of sensor for pollutant monitoring and nanoelectronics devices applications.
Abstract: Member States shall establish zones and
agglomerations throughout their territory to assess and manage air
quality in order to comply with European directives.
In Italy decree 155/2010, transposing Directive 2008/50/EC on
ambient air quality and cleaner air for Europe, merged into a single
act the previous provisions on ambient air quality assessment and
management, including those resulting from the implementation of
Directive 2004/107/EC relating to arsenic, cadmium, nickel, mercury
and polycyclic aromatic hydrocarbons in ambient air.
Decree 155/2010 introduced stricter rules for identifying zones on
the basis of the characteristics of the territory in spite of considering
pollution levels, as it was in the past. The implementation of such
new criteria has reduced the great variability of the previous zoning,
leading to a significant reduction of the total number of zones and to
a complete and uniform ambient air quality assessment and
management throughout the Country.
The present document is related to the new zones definition in
Italy according to Decree 155/2010. In particular the paper contains
the description and the analysis of the outcome of zoning and
classification.
Abstract: The recommended limit for cadmium concentration in
potable water is less than 0.005 mg/L. A continuous biosorption
process using indigenous red seaweed, Gracilaria corticata, was
performed to remove cadmium from the potable water. The process
was conducted under fixed conditions and the breakthrough curves
were achieved for three consecutive sorption-desorption cycles. A
modeling based on Artificial Neural Network (ANN) was employed
to fit the experimental breakthrough data. In addition, a simplified
semi empirical model, Thomas, was employed for this purpose. It
was found that ANN well described the experimental data (R2>0.99)
while the Thomas prediction were a bit less successful with R2>0.97.
The adjusted design parameters using the nonlinear form of Thomas
model was in a good agreement with the experimentally obtained
ones. The results approve the capability of ANN to predict the
cadmium concentration in potable water.
Abstract: Due to the determination of the pollution status of
fresh resources in the Egyptian territorial waters is very important for
public health; this study was carried out to reveal the levels of heavy
metals in the shellfish and their environment and its relation to the
highly developed industrial activities in those areas. A total of 100
shellfish samples from the Rosetta, Edku, El-Maadiya, Abo-Kir and
El-Max coasts [10 crustaceans (shrimp) and 10 mollusks (oysters)]
were randomly collected from each coast. Additionally, 10 samples
from both the water and the sediment were collected from each coast.
Each collected sample was analyzed for cadmium, chromium,
copper, lead and zinc residues using a Perkin Elmer atomic
absorption spectrophotometer (AAS). The results showed that the
levels of heavy metals were higher in the water and sediment from
Abo-Kir. The heavy metal levels decreased successively for the
Rosetta, Edku, El-Maadiya, and El-Max coasts, and the
concentrations of heavy metals, except copper and zinc, in shellfish
exhibited the same pattern. For the concentration of heavy metals in
shellfish tissue, the highest was zinc and the concentrations decreased
successively for copper, lead, chromium and cadmium for all coasts,
except the Abo-Kir coast, where the chromium level was highest and
the other metals decreased successively for zinc, copper, lead and
cadmium. In Rosetta, chromium was higher only in the mollusks,
while the level of this metal was lower in the crustaceans; this trend
was observed at the Edku, El-Maadiya and El-Max coasts as well.
Herein, we discuss the importance of such contamination for public
health and the sources of shellfish contamination with heavy metals.
We suggest measures to minimize and prevent these pollutants in the
aquatic environment and, furthermore, how to protect humans from
excessive intake.
Abstract: In recent decades with the development of technology
and lack of food sources, sewage sludge in production of human
foods is inevitable. Various sources of municipal and industrial
sewage sludge that is produced can provide the requirement of plant
nutrients. Soils in arid, semi-arid climate of central Iran that most
affected by water drainage, iron and zinc deficiencies, using of
sewage sludge is helpful. Therefore, the aim of this study is
investigation of sewage sludge and manure application on Ni, Pb and
Cd uptake by Savory. An experiment in a randomized complete block
design with three replications was performed. Sewage sludge
treatments consisted of four levels, control, 15, 30, 80 tons per
hectares; the manure was used in four levels of control, 20, 40 and 80
tons per hectare. Results showed that the wet and dry weights was not
affected by sewage sludge using, while, manure has significant effect
on them. The effect of sewage sludge on the cadmium and lead
concentrations were significant. Interactions of sewage sludge and
manure on dry weight values were not significant. Compare mean
analysis showed that increasing the amount of sewage sludge had no
significant effect on cadmium concentration and it reduced when
sewage sludge usage increased. This is probably due to increased
plant growth and reduced concentrations of these elements in the
plant.
Abstract: This article presents summary on preparation and
characterization of zinc, copper, cadmium and cobalt chromite
nanocrystals, embedded in an amorphous silica matrix. The
ZnCr2O4/SiO2, CuCr2O4/SiO2, CdCr2O4/SiO2 and CoCr2O4/SiO2
nanocomposites were prepared by a conventional sol-gel method
under acid catalysis. Final heat treatment of the samples was carried
out at temperatures in the range of 900−1200 ◦C to adjust the
phase composition and the crystallite size, respectively. The resulting
samples were characterized by Powder X-ray diffraction (PXRD),
High Resolution Transmission Electron Microscopy (HRTEM),
Raman/FTIR spectroscopy and magnetic measurements. Formation
of the spinel phase was confirmed in all samples. The average size of
the nanocrystals was determined from the PXRD data and by direct
particle size observation on HRTEM; both results were correlated.
The mean particle size (reviewed by HRTEM) was in the range from
∼4 to 46 nm. The results showed that the sol-gel method can be
effectively used for preparation of the spinel chromite nanoparticles
embedded in the silica matrix and the particle size is driven by the
type of the cation A2+ in the spinel structure and the temperature
of the final heat treatment. Magnetic properties of the nanocrystals
were found to be just moderately modified in comparison to the bulk
phases.