Biosorption is an effective method to remove toxic metals from wastewaters. In this
study biosorption of lead and chromium ions from solution was studied using
Citrobacter freundii and Citrobacter kosari isolated from industrial wastewater. The
experimental results showed that optimum grwoth temperature for both bacteria is 30oC
and the optimum pH is 7 &6 for C. freundii and C. kosari respectively. While the
optimum incubation period to remove Pb and Cr for C. freundii and C. kosari is 4 days
and 3days respectively. Also the biosorption of Pb and Cr in mixed culture of bacteria
and mixed culture of Pb and Cr was investigated. Result indicate that uptake of Cr and
Pb for C.freundii, C. kosari and in mixes culture of both bacteria is 58%, 53% and 82%
respectively for chromium in solution containing 1000ppm of Cr and 59%, 63% and
78% respectively for lead in solution containing 1000ppm of lead. But the uptake
decreases in solution containing both heavy metals lead and chromium.
There are still areas around the world suffer from severe shortage of freshwater supplies. Desalination technologies are not widely used due to their high energy usage, cost, and environmental damaging effects. In this study, a mathematical model of single-bed adsorption desalination system using silica gel-water as working pair is developed and validated via earlier experiments. A very good match between the model predictions and the experimental results is recorded. The objective is to reveal the factors affecting the productivity of fresh water and cooling effect in the solar adsorption system. The proposed model is setup for solving within the commercially-available software (Engineering Equation Solver). It is implemented to so
... Show MoreThe removal of COD from wastewater generated by petroleum refinery has been investigated by adopting electrocoagulation (EC) combined with adsorption using activated carbon (AC) derived from avocado seeds. The process variables influencing COD removal were studied: current density (2–10 mA/cm2), pH (4–9), and AC dosage (0.2–1 g/L). Response surface methodology (RSM) based on Box–Behnken design (BBD) was used to construct a mathematical model of the EC/AC process. Results showed that current density has the major effect on the COD removal with a percent of contribution 32.78% followed by pH while AC dosage has not a remarkable effect due to the good characteristics of AC derived from avocado seeds. Increasing current density gives be
... Show MoreEnvironmental exposures to lead remain a serious problem in the developing and industrializing countries. Children are the highest risk aged-group for lead poisoning. This study was designed to assess lead exposure in Al-Fallujah city by analyzing blood lead levels in children and adults and to explain the relationship between blood lead levels, hematological parameters and ferritin levels in the children. The study was performed on-(90) subjects, (65children and 25 adults).Venous blood samples were taken for estimation of hematological parameters, serum ferritin levels and blood lead levels. The children group was subdivided into four groups as: group (A) (low ferritin, low Hb), group (B) (low ferritin, normal Hb), group (C) (normal fer
... Show MoreCladophora and Spirulina algae biomass have been used for the removal of Tetracycline (TC) antibiotic from aqueous solution. Different operation conditions were varied in batch process, such as initial antibiotic concentration, different biomass dosage and type, contact time, agitation speed, and initial pH. The result showed that the maximum removal efficiencies by using 1.25 g/100 ml Cladophora and 0.5 g/100 ml Spirulina algae biomass were 95% and 94% respectively. At the optimum experimental condition of temperature 25°C, initial TC concentration 50 mg/l, contact time 2.5hr, agitation speed 200 rpm and pH 6.5. The characterization of Cladophora and Spirulina biomass by Fourier transform infrared (FTIR) indicates that the presenc
... Show MoreA series of adsorption laboratory experiments were conducted to study the sorption efficiency of bentonite in removal Cd from aqueous solutions. The bentonite was found to be a good receptive to the adsorption of Cd under specific laboratory conditions. The sorption capacity for Cd onto bentonite was investigated through the variation in pH and initial Cd2+ concentration. The sorption efficiency onto bentonite was examined as a function of pH, initial ion concentration, equilibrium reaction time and solid mass/ liquid volume ratio. The maximum sorption (%) of Cd from solutions were determined when solid to liquid ratio is 2 gm of bentonite versus 50 ml solution, the equilibrium reaction time is 50 minute at pH ranges from 5-7. The sorpti
... Show MoreBecause of the contaminants represented by heavy metals in the aquatic
environment have an adverse effects need to be addressed, therefore, a laboratory
simulation was conducted on Cd using kaolinite that collected from Ga’ara Formation
as considered as a natural sorbent material that can be used to remove heavy metals
from aqueous environments. Mineralogical study was conducted on kaolinite using
X-Ray diffraction (XRD), Scanning Electron Microscope (ESM) and Energy-
Dispersive X-ray Spectroscopy (EDS) for the purpose of investigating the microtexture.
It was found that kaolinite has pure phase of very fine grains with a very little
quantity of quartz and has a number of active sites for adsorption. Chemical an
Multi-drug resistance in Listeria monocytogenes is considered a major public health problem associated with foodborne outbreaks and causes high hospitalization and mortality rates. This study aimed to investigate the antimicrobial resistant genes among Listeria monocytogenes isolated from meat and clinical samples. Phenotypically, the isolates were tested for their susceptibility against the 12 most commonly used antimicrobials in veterinary and human therapy via the disc diffusion method, while conventional PCR was performed to study the presence or absence of 14 resistance genes predicted in L. monocytogenes isolates. The study established that 30(66.66%) of L. monocytogenes isolates showe
... Show MoreThe discharged water from tannery plants is main source for pollution of soil and groundwater, especially in Nahrawan area. Water samples is collected from 10 sites of wells, discharged water and from using water in different levels of tannery and 7 soil samples from different sites inside factories area and outside it. The results shown that pH for samples of wells and discharged water were within allowable limits between 6.5- 8.5, except the value of pH recorded in the discharged water sample (after the addition of calcium hydroxide) was 12.8, as well as reached the highest value of total dissolved salts (TDS) 7800 ppm in same samples. It also reached its highest value of electrical conductivity (EC) 8200 μS/cm. The results showed tha
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