Soil water chemistry in forest soils over 20 years was studied at nine sites in southern Sweden. The aim was to investigate the recovery from acidification and the influence of strong sea salt episodes that occur in the region. All sites but one showed signs of recovery from acidification along with the reduced sulphur deposition, but the recovery progress was slow and the soil water was in mos...

Soil alkalinisation generally constitutes a major threat to irrigated agriculture in the semiarid regions of West Africa. The improvement of sodic soils is generally difficult and expensive. However, a recent study in the Niger valley in NIGER, reveals that a natural dealkalinisation is possible under natural conditions in a semi-arid climate. Transformation of non-saline sodic soil into brown ...

The leaching reaction kinetics of weathered crust elution-deposited rare earth with mixed ammonium salts was studied. The in uence of concentration of reagents and particle size of ore on leaching rate was investigated. The results showed that the di usion process and leaching rate could be improved by increasing reagents concentration and decreasing leaching owing rate and particle size. The l...

Drylands represent about one-third of the global land and mainly occur in Africa Asia. Because arid conditions, dryland soils are characterized by salt accumulation. Although salt-affected unsuitable for agriculture, some lands have been cultivated a long time. However, especially last decades, because increasingly warmer climatic conditions human migration toward favorable environments, progre...

Quasi-dynamic leaching characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from raw and solidified air pollution control (APC) residues were examined via a nine-time multiple leaching test. The effect of injected activated carbon in the APC residues on the PCDD/F leachability was also evaluated. When humic acid solution was used as a leachant, the leaching concentra...

In this study various leaching technologies were applied to extract heavy metals from sludge from the printed circuit board process. These methods included traditional acid extraction (TAE) and microwave assisted treatment (MAT). The target heavy metal was copper. Experiments were performed to determine the acid the leaching efficiency by changing operating conditions, including acid type and c...

A novel energy-saving hydrometallurgical recovery process for copper from electronic scrap employing the Cu(I)-ammine complex has been presented on the basis of a thermodynamic consideration. In order to experimentally explore the feasibility of the leaching stage in this process, the copper leaching behavior from a printed circuit board (PCB) in ammoniacal alkaline solutions has been investiga...

Remediation of heavy metal polluted sediment by extracting the metals with sulfuric acid can be performed as follows: abiotic suspension leaching, microbial suspension leaching, abiotic solid-bed leaching, and microbial solid-bed leaching. Abiotic leaching means that the acid is directly added, while microbial leaching means that the acid is generated from sulfur by microbes (bioleaching). Thes...

Glasses in lead-iron phosphate (LIP) system loaded with simulated nuclear waste, were melted in the temperature range750-950oC. Some of the LIP glasses were mixed with uranium salt. The pH determinations of the leachate solution at normal temperature show some interesting trends. Leaching study of these glasses with a maximum time period of 300 hrs. were conducted under Soxhlet distillation con...

This work describes a general method for the preparation of salt nanoparticles (NPs) made from an aqueous solution of ionic compounds (NaCl, CuSO(4) and KI). These nanoparticles were created by the application of ultrasonic waves to the aqueous solutions of these salts. When the sonication was carried out in the presence of a glass microscope slide, a parylene-coated glass slide, or a silicon w...