Removal of Lead, Cadmium, and Aluminum Sulfate from Simulated and Real Water with Native and Oxidized Starches

Abstract

The separation of toxic pollutants such as Pb2+, Cd2+, and Al3+ from water is a constant challenge as contamination of natural water bodies is increasing. Al3+ and especially Pb2+ and Cd2+ are ecotoxic and highly toxic for humans, even in ppb concentrations, and therefore removal below a dangerous level is demanding. Herein, the potential adsorber material starch, being ecofriendly, cheap, and abundantly available, was investigated. Thus, four different native starch samples (potato, corn, waxy corn, and wheat starch) and two oxidized starches (oxidized potato and corn starch) were comprehensively analyzed with streaming potential and charge density measurements, SEM-EDX, ATR-FTIR, 1H-NMR, and TGA. Subsequently, the starch samples were tested for the adsorption of Pb2+, Cd2+, and Al3+ from the respective sulfate salt solution. The adsorption process was analyzed by ICP-OES and SEM-EDX, and the adsorption isotherms were fitted comparing Langmuir, Sips, and Dubinin-Radushkevich models. Oxidized starch, for which chemical modification is one of the simplest, and also native potato starch were excellent natural adsorber materials for Al3+, Cd2+, and especially Pb2+ in the low concentration range, exhibiting maximum adsorption capacities of 84, 71, and 104 µmol/g for oxidized potato starch, respectively.

Ecological Sorption of Iron and Sulfate Ions onto Starch and Chitosan Biopolymer Blend

“…The elemental analysis of the studied samples was conducted, and the results are presented in Table 2. As expected, and in line with our previous work [9], starch contains no nitrogen, implying the absence of proteins. Both types of chitosans contain 7.51% and 7.49% nitrogen, respectively, because of the presence of amino groups into the chain.…”

“…As deduced in Figure 1a, the presence of the band at 1588 cm −1 is due to hydrogen bonding between the OH and NH3 + of chitosan and the OH group of starch [14,31]. Both spectra of the ps blend with chitosan and n.ps mixed with chitosan are congruent to the native potato starch spectrum, which is already published in our previous work [9], indicating that the modification of potato starch with chitosan did not change the chemical structure. However, the OH stretching attributed to chitosan shows a slight shift to 3320 cm −1 , and the peak related to the C=O of the amid I group at 1588 cm −1 was shifted to 1585 cm −1 , designating the presence of intermolecular hydrogen bonds (O…H-O and O…H-N) between starch and chitosan [32].…”

“…To gain further insight into the adsorption type and process, the Langmuir, Sips, and Dubinin-Radushkevich models were used to model the adsorption isotherms of Fe 2+/3+ and SO 4 2− ions, as described in our previous papers, for the purpose of maintaining consistency and comparability of the results [8,9]. The three fitting models are depicted in Figures S19-S21, and the fitting parameters are detailed in (Table 5, Table 6, Tables S11 and S12).…”

Polymer blends of poly(lactic acid) and starch for the production of films applied in food packaging: A brief review

“…447 About 15%-20% by weight of potato tubers is native starch, 448 with a granule diameter of 48 μm. 449 Native potato starch granules generally have a spherical and/or oval shape. [450][451][452][453] The amylose content found for potato starch was 24.78%, 454 25.03% 455 and 29.28%.…”

Removal of Iron, Manganese, Cadmium, and Nickel Ions Using Brewers’ Spent Grain

“…Multiple diverse bioadsorbers, such as lignocellulosic/plant materials such as rice husk, nut shells, potato peels, starch and olive stones have already been investigated [10][11][12][13][14][15][16][17]. An extremely efficient adsorber and flocculant for acidic water polluted with FeSO 4(aq) is the biopolymer chitosan.…”