Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12. Ferrous sulfate, which is used for remediation of Cr(VI) contamination in wastewater and soils via reduction to Cr(III) and subsequent precipitation of iron(III)/chromium(III) hydroxide, has also been proposed for rem...

Recovering Y and Eu from waste phosphors using chlorination roasting followed by a water leaching process was investigated in this study. Firstly, by chlorination roasting and water leaching, Y and Eu elements present in waste phosphors were efficiently extracted into a leach solution. Secondly, the majority of the impurities in the solution can be removed by adjusting the pH to 4.5 using a Na2...

The filter cake, generated from the cold-purification stage in a zinc electrowinning plant and considered as a hazardous waste containing heavy metals, was characterized for its chemical and mineralogical compositions by inductively couple plasma-optical emission spectroscopy (ICP-OES), X-rays diffractometry (XRD) and scanning electron microscopyenergy dispersive X-rays spectrometry (SEM-EDS). ...

Leaching is an unavoidable phenomenon associated with the pesticide applications. Leaching of pesticide does not only indicate the efficiency of a pesticide molecule, but also degree of the environmental contamination. Leaching is the process by which a pesticide molecule enters the soil-water ecosystem. Hence, to access the leaching behavior of a pesticide molecule, various models are used glo...

The present paper addresses the leaching of hazardous contaminants from immersed and replenished materials and from granular materials flushed in a column. First, the leaching of an immersed material in contact with a limited volume of leachant is studied. The mass transfer from material to leachant is assumed to he inversely proportional to Jt (i.e. following the semiinfinite medium diffusion ...

The interaction between a medical device and a pharmaceutical solution it contacts may dictate solution safety and/or efficacy. Of specific concern is the ability of device components to leach into the contacting solution. As pharmaceutical solutions containing surfactants, co-solvents and solubilizing agents become more common, method's for assessing the extent of leaching are needed. In this ...

This study focused on the leaching process for the recycling of Li, Ni, Co, and Mn from the LiNixCoyMnzO2 (NCM) cathodes of spent lithium-ion batteries (LIBs). Eh–pH diagrams were used to analyze suitable leaching conditions. Operating variables, such as the concentration of H2SO4 (0.5–2.5 M), concentration of H2O2 (0–1 vol%), temperature (10–50 °C), stirring speed (400–800 rpm), and solid/liqu...

Effects of pH, D2EHPA, Cyanex® 302 and Cyanex® 272 on extractions of zinc, manganese and cobalt from a Zn-Mn-Co-Cd-Ni containing solution was comprehensively investigated at the room temperature. The addition of Cyanex® 302 indicated a left-shifting-effect on the extraction curve of zinc, a right-shifting-effect on the extraction curve of manganese and no effect on the extraction of cobalt. The...

Dairy manure has been linked to elevated phosphorus (P) levels in surface waters of Lake Okeechobee basin. Prevalent soils of the basin (Aquods) retain little P in sandy, quartz-dominated upper horizons, and lateral P transport is favored by high water tables. The stability of manure-derived P forms is thus an important factor in the Okeechobee basin and other regions where soil and hydrologic ...

The soil-plant system can act as a prevailing zone of pesticide dissipation in agroecosystems, which may influence leaching following rainfall events. Here we examined the contribution leaching, and degradation widely used anilide pesticides planted unplanted mesocosms with contrasting vineyard forest soils. were spiked at 25 mg/kg acetochlor, alachlor, S-metolachlor, butachlor metalaxyl, follo...