Contamination of Potentially Trace Metals in Aqaba and Eshidiya Phosphogypsum in Jordan

Contamination of As, Cd, Cr, Cu, Hg, Pb, Se, Zn and V in Jordan phosphogypsum by product has been determined. The aim of this study is to assess the potential of trace metals contamination caused by production plant of Aqaba and Eshidiya. Arsenic, Cr, Hg, Pb, Se and V have exhibited normal abundances where Cd and U had the highest enrichment factors of 16 and 4, respectively in Aqaba phosphogypsum and 18 and 1, respectively in Eshidiya phosphogypsum. In addition, the elements geo-accumulation index factor were calculated and found that As, Cd, Cr, Cu, Hg, Pb, Se, Zn V are unpolluted to moderately polluted, with the exception of Cd, it shows highly polluted. Arsenic, Cd, Cr, Cu and Zn show immobility to low mobility, whereas Se exhibits intermediate to high mobility. The results obtained in this study can be not worrying from the point of view of environmental safe use of phosphogypsum

Selectivity assessments of a sequential extraction procedure for potential trace metals' mobility and bioavailability in phosphate rocks from Jordan phosphate mines

A modified six-step sequential extraction procedure was used to fractionate and determine the following trace metals: U4+, As5+, Cd2+, Cr+2, Cu2+, Ni2+, Pb2+, Zn2+, and V5+ in three different phosphate rocks from mines in Jordan. The mean values of uranium in the samples investigated were 98 ± 6 mgkg-1, 92 ± 3 mgkg-1, 215 ± 6 mgkg-1, and 159 ± 13 mgkg-1, respectively. The sequential extraction results obtained showed that most of the U4+ in these samples was strongly bound with 87%, 93%, 97%, and 93% of the total content, respectively, remaining in the samples after the sequential extraction steps were performed. Hence, 13%-7% and 3%-7%, respectively, of the U4+ is distributed in the most labile form, indicating that the majority of the U4+ in these samples was highly incorporated within the apatite present in the samples. The aforementioned was in agreement with the XRD and SEM-EDX results obtained. The apparent mobility of U4+, As5+, Cd2+, Cr+2, Cu2+, Ni2+, Pb2+, Zn2+, and V5+ (using all six extraction steps) from the Al-Abied and Al-Hasa samples was as follows: As5+ (30.17%)> Cu2+ (6.55%)> Zn2+(4.34%)> Cd2+ (3.84%) Cr+2 (3.66%)> Pb2+ (2.57%)> V5+ (53%)> Ni2+ (1.71%)> U4+ (0.99%). The mobility of As5+, Cd2+, Cu2+, Cr+2, Ni2+, Pb2+, U4+, Zn2+, and V5+ (using all six extraction steps) from Eshidiya samples was as follows: As5+ (17.32%)> Cr+2 (4.84%)> Zn2+ (4.25%)> Pb2+ (4.19%)> Cu2+ (3.49%)> V5+ (1.42%)> Cd2+ (0.78) U4+ (0.09%)> Ni2+ (0%)

Mechanical activation on phosphogypsum: hydrosodalite system

The application of phosphogypsum in the production of binding materials is problematic because of phosphate, fluorine and other soluble impurities. These impurities influence the strength development of binding materials and during operating time can be released (efflorescence) from binding materials’ products. For these reasons, it is important to neutralize the above-mentioned impurities. The objective of the work was to investigate the neutralization process of the acid impurities of hemihydrate phosphogypsum (obtained from Kovdor apatite mine) with zeolite hydrosodalite. Mechanical activation together with the neutralizing zeolite additive was used in this research. Mechanical activation was carried out in a ball mill. Two types of samples were formed: one type with non-milled mixtures and the second type with milled mixtures. The additive of 0, 3, 5, and 10% of hydrosodalite was chosen. This paper describes the process of adsorbing of hazardous phosphate impurities by hydrosodalite. The compressive strength of phosphogypsum specimens with hydrosodalite additives subjected to mechanical treatment was higher as compared to the specimens without mechanical activation and additive of hydrosodalite. In this case pH values of milled mixture with hydrosodalite become neutral for these samples. It was determined that the mixture of phosphogypsum with hydrosodalite under mechanical treatment is an effective additive for neutralizing the acidic phosphogypsum mediumKauno technologijos universitetasVandens ūkio ir žemėtvarkos fakultetasVytauto Didžiojo universiteta