Soil organic matter (SOM) may give precious information about the age of soil landscapes and, thus, can contribute to decipher geomorphic surface dynamics. We tested five methods to isolate the oldest possible stable organic matter of 2 soil profiles developed on a Pleistocene morainic paragneiss substratum in an Alpine environment in northern Italy. Before and after the individual treatments, ...

Abstract In this research, a recycling process for palladium using “dry aqua regia,” which consists of iron(III) chloride–potassium chloride, was proposed. Palladium dissolved in and the recovered by leaching with potassium chloride solution added ammonium nitric acid. almost completely 3 h at 600 K, recovery ratio up to 80%. addition, dissolution coexistence platinum platinum-palladium alloy r...

A simplified scheme, combining aspects of the classical fire-assay with an atomic-absorption finish, is presented for the determination of gold and silver in ores and concentrates. The lead assay button is scorified to approximately 2 g and then parted in nitric acid. The filtrate is analysed by AAS for silver; the residue is dissolved in aqua regia and subsequently analysed for gold by AAS. Th...

We report an accessible and simple method of producing 'black silicon' with aspect ratios as high as 8 using common laboratory equipment. Gold was sputtered to a thickness of 8 nm using a low-vacuum sputter coater. The structures were etched into silicon substrates using an aqueous H2O2/HF solution, and the gold was then removed using aqua regia. Ultrasonication was necessary to produce columna...

Printed circuit boards (PCBs) are currently being dumped in landfills or incinerated which is causing a serious environmental harm in the form of toxic gases or leached hazardous compounds. PCBs contain high amounts of precious metals; about 20 wt% copper, 0.04 wt% gold, 0.15 wt% silver, and 0.01 wt% palladium. The extraction of these metals from PCBs is both profitable and environmentally wort...

The demand for palladium (Pd) has increased and this made it necessary to recover pure Pd from diverse secondary resources. To the small amount of Pd(II) present in spent electroplating solutions, is concentrated by cementation with zinc metal. In work, a hydrometallurgical process consisting leaching solvent extraction was developed cemented Pd. behavior Zn(II) synthetic HCl solution commercia...

ABSTRAK
 Perkembangan industri elektronik di Indonesia meningkat, maka begitu juga dengan limbah yang dihasilkannya. Salah satu bentuk adalah lempengan PCB (Printed Circuit Board). Logam seperti Au, Ag, dan Cu dapat ditemukan pada PCB, logam-logam tersebut dilakukan pemisahan metode leaching. Penelitian ini bertujuan untuk mengetahui pengaruh volume larutan HNO3 sebagai tahapan pre-leachin...

Due to its high refractive index, reflectance is often a problem when using Germanium for optoelectronic devices integration. In this work, we propose an effective and low-cost nano-texturing method for considerably reducing the reflectance of bulk Germanium. To do so, uniform V-shape pit arrays are produced by wet electroless chemical etching in a 3:1 volume ratio of highly-concentrated hydroc...