Environmetal Engineering

Magnetic separation technology has been extensively used in the field of environmental problems, due to solving
difficulties resulted from filtration and centrifuging. In this study, powder activated carbon (PAC) was magnetized
by magnetite nanoparticles (Fe3O4@C) as an adsorbent for lead ions (Pb2+) from aqueous solution. The
characteristics of the modified PAC were analyzed by scanning electron microscopy, transmission electron
microscopy, X-ray diffractometry, Brunauer-Emmett-Teller surface area analysis, energy dispersive X-ray
spectroscopy and vibrating sample magnetometry. Batch adsorption experiments were conducted as a function of
pH, contact time, adsorbent dosage and initial Pb2+ concentration and solution temperature. The equilibrium
isotherm and kinetic models were used to evaluate the fitness of the experimental data. The maximum monolayer
adsorption capacity of Pb2+ was 71.42 mg/g at 50°C. It could also be shown that the sorption isotherms were well
described by the Langmuir equilibrium model. The kinetic of the adsorption process was found to follow the
pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible,
spontaneous and endothermic. Desorption experiments exhibited that the Fe3O4@C had a good potential in regard to
regeneration and reusability and is easily regenerated by HCl solution. The proposed adsorption process can be a
promising technique for Pb2+ removal from aqueous solutions and to be used in full-scale and industrial applications.

A great amount of industrial wastes are produced in Sweden every year. In 2008 there were 97.9 million tons of wasted generated, among which 93 million tons industrial waste were produced. 64.1% of industrial wastes were deposited in the landfill sites. Dust generation is one of the most important problems associated with industrial waste and landfills. The particulate dust emissions come from the industrial waste may contain heavy metal and produce environmental problems and potential health risks. Active and passive samplers, deposition pans are common equipment to collect dust samples. Real-time monitors use laser diffraction to recording continuous dust concentration. Dust emission from Malmberget mine in Sweden was analyzed as a case study. Dust was collected by NILU deposit gauge from 26 stations. Generally speaking the amount of dust fallout was decreasing with time because of implemented dust control methods., among all the measuring stations through the year, the maximum and the minimum value were 1284 g/100m 2 /30d and 9 g/100m 2 /30d. Two sources of dust generation were identified. The first was located close to the open pit, and the second near the current mining industrial center. The dust generation due to road construction was calculated. On the other hand dust generation was also closely related to weather conditions.