ABSTRACT
Background: Iran is located within the dry and semi dry regions, thus almost 90% of the required water is secured via the use of groundwater. Owing to the increasing pollution of water resources, this study was performed to evaluate water quality pollution indices for heavy metals [As, Zn, Pb and Cu] contamination monitoring in Toyserkan Plain during spring and summer in 2012
Methods: a total of 20 ground water wells were chosen randomly. The samples were filtered [0.45 microm] and kept cool in polyethylene bottles. Samples were taken for the analysis of metals, the former was acidified with HNO[3] to pH lower than 2. Metal concentrations were determined using ICP-OES
Results: the results revealed that the mean values of contamination index [C[4]], heavy metal pollution index [HPI] and heavy metal evaluation index [HEI] in samples for spring season were -2.81, 9.74 and 1.20, respectively and were -2.67, 9.51 and 1.32, respectively in samples for summer season and this indicates low contamination levels. Comparing the mean concentrations of the evaluated metals with WHO permissible limits demonstrated a significant difference [P < 0.05]. Thus, the mean concentrations of the metals were significantly lower than the permissible limits
Conclusion: although the heavy metal pollution of the ground water in Toyserkan Plain is not higher than permissible limits, the irregular and long-term utilization of agricultural inputs, use of wastewater and sewage sludge in agriculture, over utilization of organic fertilizers and establishment of pollutant industries can threaten the ground water, and cause irreversible damages in this area
ABSTRACT
Background: the rapid increase in agricultural and industrial development has made heavy metal pollution a serious environmental problem and public health threat; therefore, removal of heavy metals from water is important. The current study prepared DNPH@SDS@Fe3O4 nanoparticles as a novel and effective adsorbent for removal of Hg [II] ions from an aqueous solution
Methods: a selective adsorbent for Hg [II] was synthesized by coating Fe3O4 nanoparticles with sodium dodecyl sulfate which was further functionalized with 2,4-dinitrophenylhydrazine [2,4-DNPH]. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy [FTIR], x-ray diffraction [XRD], scanning electron microscopy [SEM] and SEM-EDXSt. The effects of pH, dose of adsorbent and shaking time on adsorption capacity were investigated. The kinetics and equilibrium of adsorption of the metal ions were thoroughly studied
Results: SEM showed that the size of the nanoparticles was 20 to 35 nm. The maximum adsorption capacity for Hg [II] was 164.0 mg g-1 for an adsorbent dose of 0.04 g at pH 7.0, 25degreeC and the initial metal concentration was 25 mg L-1,which was greater than for most adsorbents previously examined for Hg[II] adsorption. Adsorption experimental data showed good correlation with the pseudo-second-order model and Langmuir isotherm model
Conclusion: the results indicated that the DNPH@SDS@Fe3O4 nanoparticles are an efficient adsorbent for removal of heavy metal from wastewater