Military small arms shooting range (SASR) soils are heavily polluted by metals like copper, lead, antimony, and zinc. This study was carried out to define efficient operating conditions to solubilize these metals by a chemical leaching technique. The comparison of different leaching reagents (HCl, H2SO4, CH3COOH, and EDTA) has revealed that sulfuric acid leaching coupled with the addition of so...

In this paper, the leaching behavior of the major metals present in printed circuit boards waste is evaluated, aiming at its recycling by hydrometallurgy. Several leachants were compared (sulfuric, hydrochloric and nitric acids, at 2 M H concentration), at temperatures of 25oC and 90oC and 4 hours of reaction time. Sulfuric acid leaching was not very promising concerning metals dissolution bein...

Plant chemical defenses and escape from natural enemies have been postulated to select for dietary specialization in herbivorous insects. In field and laboratory bioassays, we evaluated the effectiveness of intact and chemically modified larval shield defenses of the generalist Chelymorpha alternans and the specialists Acromis sparsa and Stolas plagiata (Chrysomelidae: Cassidinae) against three...

In our study we showed the importance of holistic approach to evaluation of chemical stabilization using phosphate amendments, where all aspects of chemical treatments were observed. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil from the former zinc smelter area in the Celje re...

For the past 60 yr, chromate-copper-arsenate (CCA) has been used to pressure-treat millions of cubic meters of wood in the United States for the construction of many outdoor structures. Leaching of arsenic from these structures is a possible health concern as there exists the potential for soil and groundwater contamination. While previous studies have focused on total arsenic concentrations le...

Plant biomass harvested after heavy-metal phytoremediation must be considered as a hazardous waste that should be contained or treated appropriately before disposal or reuse. This study provides an evaluation of extractants for the removal of lead from Abutilon Theophrastus biomass. The research was carried out a leaching study to determine the lead-extraction efficiency of the different leacha...

The aim of this study was to evaluate relationship between shrinkage development and early solubility of two commonly used luting materials, a self-adhesive cement (GCem chemical and light cured) and composite resin (Tetric). Linear displacement, shrinkage forces and leaching of UDMA from specimens immersed in 75% ethanol/25% water were measured. The least amount of linear shrinkage (33.0±2.9 µ...

The intensification of the thiourea leaching of gold from goldsmith's waste (Košice, Slovakia) using mechanical activation as the pretreatment step. The leaching of “as-received“ sample in an acid thiourea solution resulted in 77 % Au dissolution, after mechanical activation 98 % of the gold was leached during 120 min. The activation was performed in an attritor using variable milling times. Th...

The recovery of precious metals from waste printed circuit boards (PCBs) is an effective recycling process. This paper presents a promising hydrometallurgical process to recover precious metals from waste PCBs. To simplify the metal leaching process, large pieces of PCBs were used instead of a pulverized sample. The chemical coating present on the PCBs was removed by sodium hydroxide (NaOH) tre...

The chemical composition and aluminum speciation of sludge incineration residue (SIR) were determined. Cementation of aluminum from sulfuric acid solution using SIR was studied. The results showed that acid-soluble inorganic aluminum was the predominant component in the sludge, and the total leached aluminum increased from 62.2% to 92.9% after incineration. Sulfuric acid dosage and reaction tim...