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The objective of the present study was to investigate the impact of MgO 0.5 g/kg loaded in different organic waste materials on the properties of the modified biochars obtained. The waste materials included tea waste, wood waste, water chestnut peel, and pomegranate peel, which were used to create tea waste MgO-modified biochar (TWMgO-MBC), wood waste MgO-modified biochar (WSMgO-MBC), water chestnut peel MgO-modified biochar (WCMgO-MBC), and pomegranate peel MgO-modified biochar (PPMgO-MBC). All the MgO-modified biochars were prepared at 600 °C for 2 h and applied at 0.5 and 1% doses for the immobilization of Ni, Cu, Pb, and Cr in stone crushing and mining-polluted soil and the reduction in their uptake by pearl millet (Pennisetum glaucum) plant. The greatest fresh and dry biomasses were observed at 45.04% and 31.29%, respectively, with the application of TWMgO-MBC 1% in stone-crushing-polluted soil. The highest degree of immobilization of Ni (76.67%) was observed for the WSMgO-MBC 1% treatment, Cu (73.45%) for WCMgO-MBC 1%, Pb (76.78%) for WSMgO-MBC 1%, and Cr (70.55%) for WCMgO-MBC 1%, in comparison with the control. The maximum uptake of Ni, Cu, Pb, and Cr in the shoot of pearl millet was reduced by 78.43% with WSMgO-MBC 1%, 75.06% with WSMgO-MBC 1%, 90.81% with WCMgO-MBC 1%, and 85.71% with WSMgO-MBC 1% as compared with the control. The greatest reduction in Ni, Cu, Pb, and Cr in the root of pearl millet was observed at 77.81% with WSMgO-MBC 1%, 68.09% with WCMgO-MBC 1%, 84.03% with WCMgO-MBC 1%, and 88.73% with WCMgO-MBC 1%, in comparison with the control. The present study demonstrated that the TWMgO-MBC 1% treatment was highly effective for improving plant growth, while the WSMgO-MBC 1%, and WCMgO-MBC 1% treatments were found to be highly effective for immobilizing heavy metals in polluted soils, thus facilitating safe crop cultivation. Future studies should concentrate on the long-term application of MgO-modified biochars for the remediation of multimetal-polluted soils. [ABSTRACT FROM AUTHOR]

Cultural practices and control of diseases and insects are widely used for cultivation of Olea europea L. These are considered potential contaminants. Aim of this investigation lies in determination of concentrations of contaminants in several edible olive oils. All test samples were purchased in three consecutive seasons. They were analysed in compliance with standardized international protocols of wet digestion methods. Ion concentrations were determined in three replicates using method of inductively coupled plasma optical emission spectrometry. We have registered a positive correlation between storage time and heavy metals contents. It was particularly high in Iranian brands and varied significantly. Investigation results show that all obtained heavy metals contents in pepper-flavoured olive oil samples were significantly lower than in other samples. Considering the fungi-flavoured samples, levels of Pb and Cd were prominent and exceeded the maximum permissible level set in the majority of cases. The further monitoring is needed as all these metals are toxic and their detrimental effect becomes obvious only after several years of exposure.

The environmentally novel method of wastewater and effluent purification from heavy metal ions, utilizing home-made food waste bioadsorbent was studied. The initial concentration of heavy metals/metalloid such as Arsenic, Cadmium, Cobalt and Lead in the untreated effluents and treated by citrus peel (Grapefruit/orange and sour lemon peels) which treated by 2% coffee waste beans were analyzed. After especial times : 48, 72 hours and 1 and 2 weeks (by/ without stirring), final concentration of heavy metals in effluent samples were analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy. Batch adsorption experiments were carried out to evaluate the effects of adsorbent-dosage, contact time and ionic strength of solution on the adsorption of heavy metals onto bio-adsorbent that was simply gathered from household-food waste at room temperature and then dried at 80 C 0 and grind to specify sizes. The results revealed that the adsorbent content and percentage in the studied effluent solution played a major role in adsorption. The potential of adsorptive amount of Cd2+ in presence of biomass after 48 hours removed 98.9% and 100% removed the initial contents of Lead after 72 hours by stirring the waste water which shows efficiently, and environmentally method of purification of aqueous. Current study indicates that home-made wastes which are commercially available can be considered as an efficient adsorbent for removing toxic heavy metals in this novel method. [ABSTRACT FROM AUTHOR]

Hospital wastewater (HWW) is one of the largest sources of pharmaceutical release. The present paper proposes the sustainable and controllable hospital wastewater treatment method based on the photo-Fenton process using MnO2 and moving bed biofilm reactor (MBBR) treatment followed by ozonation process. The method has satisfactory removal rates of Ibuprofen and Ofloxacin˃90%. Evaluation of the optimum operational parameters such as hydraulic retention time (HRT), mixed liquor suspended solids (MLSS), ozone consumption (OC), time of ozone exposure (TOE), manganese oxide (MnO2) concentration (MOC) was carried out. It was established that the optimal performance occurred at following conditions – HRT (16–20 hours), MLSS (2500–3500 mg/L), OC (7–9 L/hrs), TOE (4–10 min) and MOC (1.9–2.7 mg/L). It is proposed for practical application to control the HWW in two stages. The first stage includes preliminary tests for evaluation of optimum MOC. The second stage is based on continuous evaluation of HRT and TOE using analytical modelling functions. [ABSTRACT FROM AUTHOR]