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This study is based to a new concept, to use maize stalk for specific sorption and recovery of Cu(II) and Fe(III) from synthetic solutions. Thus, the sorption properties of the biomass resulting from the recycling of the maize stalk that reached maturity (autumn) were studied. In the first stage, the sorption properties of the maize stalk were evaluated in batch system. Moreover, in terms of water quality improvement several key parameters that influence the sorption equilibrium were evaluated. The effect of contact time (0-120min) and cations initial concentration (investigated range: 0.05-0.4 mg/L) on biomaterial sorption capacity were assessed. Kinetic studies were performed taking into consideration the initial concentration of metallic cation. The experimental data were analyzed based on first order kinetic model, pseudo-second-kinetic model and Morris Webber kinetic model. The kinetics of sorption was in accordance with the pseudo - second - kinetic model as the correlation coefficients showed (R2=0.9940 for Cu(II) and R2=0.9999 for Fe(III)). Moreover the desorption study was evaluated with hydrochloric acid and have detected to be 63% and 89% for Cu(II) and Fe(III) when 4M HCl is used. The surface of the maize stalk loaded with Cu(II) and Fe(III) was characterized by various specific techniques such as FTIR-ATR, SEM, and TG. Experimental results revealed that cations sorption process takes place on the sorbent surface. The sorption rate of each metallic cation is controlled by the formation of chemical bonds with surface polar groups. Their presence on biomass structure, evidenced by FTIR-ATR analysis, explains the behavior of maize stalk as a weak ion exchanger acid.

Bisphenol A (BPA) � an endocrine disruptor, degradation was studied using the following systems: UV/H2O2 and UV/H2O2/TiO2. Optimum operating conditions were established for both studied systems and experimental results showed that the two systems could be successfully used for advanced degradation of BPA achieving degradation efficiencies for BPA of 99.99% in optimum working conditions. The two systems were compared and both advantages and disadvantages of each system were identified. Nine degradation intermediates were identified for BPA degradation in UV/H2O2/TiO2 system and a possible degradation pathway was proposed.

The objective of the present study was to evaluate the performance of the ultrafiltration process on the recovery of collagen solution constituents at laboratory scale, using a tangential flow filtration, with flat regenerated cellulose membrane (5000 Da). Also permeate flows were evaluated along with the physicochemical characteristics of the concentrates, the permeates and feed solutions. The regenerated cellulose membranes were morphological studied by electron microscopy and characterized by water solutions permeation at different pressures. Keywords: collagen, concentration, protein, purification, ultrafiltration

The influence of attached biomass bioreactor types on the denitrification process using a low-pitched groundwater containing nitrates was studied. Two types of fixed-bed and fluidized-bed biofilm reactors, equipped with expanded clay granular filler, with a particle size fraction of 2-5 mm were used. The nitrite and nitrate concentrations in the inflow and outflow of the two bioreactors were analytically determined. Based on the obtained concentration values, the denitrification rates were calculated, ranging between 1275�1387 g NO3-N/m3/day in the case of the fixed bioreactor and between 3390�3867 g NO3-N/m3/day in the case of the fluidized bed bioreactor.

Ifosfamide (IF) degradation from aqueous system via UV-Vis Fe-TiO2 system was studied for a photo catalyst dose of 200 mg/L and an irradiation time up to 240 min. IF degradation efficiency was monitored via Liquid Chromatography-Mass Spectrometry technique (LC-MS). Experimental photocatalytic tests were performed both in the absence and presence of 2-propanol and F- radicals� scavengers and the results proved that IF degradation occurs most likely in the bulk solution. Experimental results showed that degradation efficiencies for IF varied between 39.52% in the presence of 2-propanol and 70.70% in the scavengers� absence. Six degradation intermediates were identified using the same LC-MS technique and a three stage degradation pathway was proposed based on both available literature data and evolution of degradation intermediates peaks.