Boron is an element distributed widely in environment mainly in the form of boric acid or borate salts. Boron is an element of demand because of its use in many high technology materials. Moreover boron is an essential element for growth of plants, but may also result in toxicity when present in excessive amounts. As the range between a deficient and toxic amount of boron is very narrow, imbalances in boron nutrition are well-known. For the removal of boron from aqueous solutions, various methods exist which are chemical coagulation, adsorption, solvent extraction and ion exchange processes. In this study, an alternative, energy efficient and easily scalable membrane based method, polymer enhanced ultrafiltration (PEUF) was developed for removal of boron from aqueous boron solutions. PEUF process consists of two steps: complexing boron with a water soluble polymer then removing the complex by ultrafiltration. Previously, boron removal from aqueous solutions was studied in a continuous process with a commercial ligand, polyvinyl alcohol (PVA). In our study, three newly developed polymers, which are derivatives of N-methyl-D-glucamine (P1) and iminodipropylene glycol(P2 and P2G) were used as the boron complexing ligand. P1 and P2 are linear polymers, while P2G is cross linked version of P2. The pilot scale system utilized for the PEUF process accommodates a spiral wound cellulose cartridge with 10000 Da molecular weight cutoffs (MWCO). The effects of operating parameters on performance of PEUF were investigated. The experimental parameters studied are metal/polymer ratio (loading) (0.01-1), pH (7-10). Boron analyses of the samples were made by using ICP-AES. Maximum removal (retention) was 90.1 %. The permeate flux remained constant at around 20 L/m2.hr and was not affected by the operating parameters. Decrease in loading caused the retention of boron to increase. Also at high pH values, retentions were relatively higher. Results showed that PEUF could be a successful alternative method for removal of boron.

Διερευνήθηκε η δέσμευση/αποδέσμευση ιόντων Cu(II) ή/και αντίθετα φορτισμένων επιφανειοδραστικών ενώσεων από συμπολυμερή τύπου κτένας. Ο κεντρικός σκελετός ήταν το πολυ(ακρυλικό νάτριο), PANa, ενώ οι πλευρικές αλυσίδες ήταν το Πολυ(Ν,Ν-διμεθυλακρυλαμίδιο) και το πολυ(Ν-Ισοπροπυλακρυλαμίδιο). Η συμπλοκοποίηση των συμπολυμερών με τα ιόντα Cu(II)σε υδατικό περιβάλλον διερευνήθηκε με θολομετρία, ιξωδομετρία, φασματοφωτομετρία UV-Vis, δυναμική σκέδαση φωτός, ιχνηθέτηση με φθορίζοντες ιχνηθέτες και προσδιορισμό του ζ-δυναμικού. Σε επόμενο στάδιο διερευνήθηκε η δυνατότητα σχηματισμού τριμερών συμπλόκων ΡAΝa/Cu(II)/επιφανειοδραστικής ένωσης σε υδατικό περιβάλλον. Από τη φυσικοχημική μελέτη των συστημάτων σε συνάρτηση του pΗ, ελήφθησαν σημαντικές πληροφορίες σχετικά με τον ανταγωνισμό των δύο ειδών (ιόντα Cu(II)ή ιόντα επιφανειοδραστικής ένωσης) να σχηματίσουν σύμπλοκα με το PANa. Ως τελικό στάδιο, παρασκευάστηκαν αδιάλυτα στο νερό υβριδικά υλικά πολυμερούς/Cu(II)ή πολυμερούς/Cu(II)/επιφανειοδραστικής ένωσης. Έπειτα από διερεύνηση της συμβατότητας/αναμιξιμότητάς τους με εμπορικές μήτρες που χρησιμοποιούνται συνήθως στη βιομηχανία χρωμάτων, ορισμένα από αυτά ενσωματώθηκαν σε πραγματικά χρώματα. / The binding/release of Cu(II) ions or/and surfactants from comb-type copolymers was studied. The backbone was poly(sodium acrylate), PANa, whereas the side chains were poly(N, N-Dimethylacrylamide) and Poly9N-Isopropylacrylamide). The complexation of these copolymers with Cu(II) ions in water, was studied by turbidimetry, viscometry, UV-Vis fasmatophotometry, dynamic light scattering, fluorescense probing and ζ-potential. As a next step, the possible formation of ternary PANa/Cu(II)/surfactant complexes in water was studied. From the physiocochemical studies with pH, important information was taken as far as the competition of the two species (Cu(II) ions and surfactant) to form complexes with PANa is concerned. As a next step, water-insoluble hybrid polymer/Cu(II) or polymer/Cu(II)/surfactant materials were produced. After studies upon the compatibility/mischibility of the hybrid materials with matrices that are usually used in paints, some of the materials were incorporated to paints.