Enhancement of Separation Performances of a New Azoic Derivative From Industrial Water and the Posibility to Recover Its Complex as Nanomaterial

Abstract

In order to obtain new complexes of Fe(III) with multiple uses, their characteristics, important applications and also the obtaining conditions are studied. The obtaining conditions consist in mixing solutions of the same concentrations of ligand 2 amino-6-methoxy-benzothiazole sulphonic acid→1-naphtol-4-sulphonic acid with FeCl 3 . The solutions are mixed in molar ratios of 1:1, 2:1 and 3:1 (ligand to central metallic atom). For determining the molar ratio ligand:central metallic atom, the methods applied were: pH-metry, conductometry, UV-VIS spectrophotometry. Also, the stability constants for new obtained compounds were determined using Molar Ratio method (J.H.Yoe and A.L.Jones), Continuous Variation method (Job) and Harvay-Manning method. The stability of the new obtained compounds is studied by varying the pH of its solution. The values are K 1 = 2.56·10 6 L/mol for FeL 1 ; K 2 = 19.76·10 13 L/mol for Fe L 2 and K 3 = 30.03·10 32 L/mol for Fe L 3 . The higher value for stability is assigned to the compound with molar ratio 3:1 (ligand: metal) in the 1.5÷6.5 pH range. The maxim value for the absorbance was measured at λ max = 601 nm for FeL 1 , λ max = 601 nm for FeL 2 and respective λ max = 600 nm for FeL 3 . The studied complexes are very stable in the above-mentioned pH range and could be used for spectrophotometric determination of Fe(III) in visible domain. Another practical importance is represented by wastewater treatments by membranar separation. Thus, the separation process is improved by increasing the volume of these complexes in comparison with both ligand and Fe(III) and further the iron recovery by calcinations was accomplished.Key words: 2 amino -6 methoxy -benzothiazole sodium sulphonate→2-naphtol-6-sodium sulphonate as ligand, Fe(III) complex compounds, Fe 2 O 3 , purifying method through membrane, UV-VIS spectrometry