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Locally available apricot (Prunus armeniaca L.) shells classified as a waste product from fruit processing, were alkali activated in order to develop an efficient heavy metal ions sorbent for water purification. To examine the changes occurred after alkali treatment, raw (SH) and modified apricot shells (SHM) were thoroughly characterized in terms of their chemical composition and surface properties. Chemical analysis revealed that alkaline treatment causes the disintegration of hemicellulose (its content decreased from 19.2 to 3.5 %), which was in accordance with FTIR results. SEM micrographs and the mercury intrusion porosimetry revealed a larger surface area and porosity of SHM. Bohem's acid-base titration method indicated that the most of the SHM surface carboxylic groups were in sodium salt form and together with the pH of points of zero charge showed increase of surface alkalinity after modification. Treatment with NaOH enhanced the adsorption capacity by 154, 61 and 90 % for Cu 2+ , Zn 2+ and Pb 2+ , respectively. The amount of cations released from SHM was almost equal to the amount of adsorbed metal ions, suggesting ion exchange mechanism. The pseudo-second order kinetic indicated that the heavy metals cations were bound predominantly by complexation. In order to establish the effectiveness of the biosorbent in real wastewater sample, SHM was employed for cleaning-up of drain water emanating from atomic adsorption spectrophotometer. The SHM showed high removal efficiency towards multiple metal ions. The amounts of Fe, Pb, Cu and Cr ions were reduced by 97, 87, 81 and 80 %, respectively, while Ni and Zn amounts were reduced for 33 and 14 %. Used biosorbent SHM can be successfully regenerated with HCl (desorption > 95 %) and after regeneration biosorbent can be reused or it can be safely disposed.

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Phosphorus fertilizer contains contaminants that may increase the content in the soil and in plants. The relationship between soil P and soil uranium (U) was investigated to determine potential effects of P‐fertilizer use. This study is based on a long‐term experiment (38 years with 0, 15, and 30 kg fertilizer P ha–1 y–1) for beef production on grassland at Teagasc, Johnstown Castle, Wexford, Ireland and also on soils from a National Soil Database (NSD). The NSD soils were taken at fixed locations on a predetermined grid system at the density of one sample every 50 km2. Of the 1310 samples in the NSD, the 760 grassland mineral soils were selected for this study. The aim was to determine to what extent P fertilizer increases the content of U in the soil. The results showed that there was a small but significant increase in soil U in the high‐P treatments, which contained high levels of soil P, in the long‐term field experiment. The results from the NSD showed that there was not a significant relationship between extractable (Morgan's) soil test P (STP) and U. It is concluded that the use of chemical P fertilizer at normal rates used in agriculture in Ireland is not a major threat to U content of soil based on the results of this study. There was a significant relationship between total P and STP, in the NSD, with the latter making up approx. 1% of the former. Soil available P increased with soil pH, probably reflecting the use of chemical P fertilizer and lime on agricultural soils.

BACKGROUND: Lead is one of the frequent contaminants of industrial wastewater. Since it has been shown that aquatic plants can be used for the removal of heavy metals, herein Pb(II) biosorption by Myriophyllum spicatum and its compost were investigated. Effects of pH, ionic strength and contact time were analyzed using a batch experiment. Biomasses were characterized chemically and by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques.

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