@article{UnuabonahKolawoleAgunbiadeetal.2017, author = {Unuabonah, Emmanuel I. and Kolawole, Matthew O. and Agunbiade, Foluso O. and Omorogie, Martins O. and Koko, Daniel T. and Ugwuja, Chidinma G. and Ugege, Leonard E. and Oyejide, Nicholas E. and G{\"u}nter, Christina and Taubert, Andreas}, title = {Novel metal-doped bacteriostatic hybrid clay composites for point-of-use disinfection of water}, series = {Journal of Environmental Chemical Engineering}, volume = {5}, journal = {Journal of Environmental Chemical Engineering}, publisher = {Elsevier}, address = {Oxford}, issn = {2213-3437}, doi = {10.1016/j.jece.2017.04.017}, pages = {2128 -- 2141}, year = {2017}, abstract = {This study reports the facile microwave-assisted thermal preparation of novel metal-doped hybrid clay composite adsorbents consisting of Kaolinite clay, Carica papaya seeds and/or plantain peels (Musa paradisiaca) and ZnCl2. Fourier Transformed IR spectroscopy, X-ray diffraction, Scanning Electron Microscopy and Brunauer-Emmett-Teller (BET) analysis are employed to characterize these composite adsorbents. The physicochemical analysis of these composites suggests that they act as bacteriostatic rather than bacteriacidal agents. This bacterostactic action is induced by the ZnO phase in the composites whose amount correlates with the efficacy of the composite. The composite prepared with papaya seeds (PS-HYCA) provides the best disinfection efficacy (when compared with composite prepared with Musa paradisiaca peels-PP-HYCA) against gram-negative enteric bacteria with a breakthrough time of 400 and 700 min for the removal of 1.5 x10(6) cfu/mL S. typhi and V. cholerae from water respectively. At 10(3) cfu/mL of each bacterium in solution, 2 g of both composite adsorbents kept the levels the bacteria in effluent solutions at zero for up to 24 h. Steam regeneration of 2 g of bacteria-loaded Carica papaya prepared composite adsorbent shows a loss of ca. 31\% of its capacity even after the 3rd regeneration cycle of 25 h of service time. The composite adsorbent prepared with Carica papaya seeds will be useful for developing simple point-of-use water treatment systems for water disinfection application. This composite adsorbent is comparatively of good performance and shows relatively long hydraulic contact times and is expected to minimize energy intensive traditional treatment processes.}, language = {en} } @article{UnuabonahAgunbiadeAlfredetal.2017, author = {Unuabonah, Emmanuel Iyayi and Agunbiade, Foluso O. and Alfred, Moses O. and Adewumi, Thompson A. and Okoli, Chukwunonso P. and Omorogie, Martins O. and Akanbi, Moses O. and Ofomaja, Augustine E. and Taubert, Andreas}, title = {Facile synthesis of new amino-functionalized agrogenic hybrid composite clay adsorbents for phosphate capture and recovery from water}, series = {Journal of Cleaner Production}, volume = {164}, journal = {Journal of Cleaner Production}, publisher = {Elsevier}, address = {Oxford}, issn = {0959-6526}, doi = {10.1016/j.jclepro.2017.06.160}, pages = {652 -- 663}, year = {2017}, abstract = {New hybrid clay materials with good affinity for phosphate ions were developed from a combination of biomass-Carica papaya seeds (PS) and Musa paradisiaca (Plantain peels-PP), ZnCl2 and Kaolinite clay to produce iPS-HYCA and iPP-HYCA composite adsorbents respectively. Functionalization of these adsorbents with an organosilane produced NPS-HYCA and NPP-HYCA composite adsorbents. The pH(pzc) for the adsorbents were 7.83, 6.91, 7.66 and 6.55 for iPS-HYCA, NPS-HYCA, iPP-HYCA and NPP-HYCA respectively. Using the Brouer-Sotolongo isotherm model which best predict the adsorption capacity of composites for phosphate, iPP-HYCA, iPS-HYCA, NPP-HYCA, and NPS-HYCA composite adsorbents respectively. When compared with some commercial resins, the amino-functionalized adsorbents had better adsorption capacities. Furthermore, amino-functionalized adsorbents showed improved adsorption capacity and rate of phosphate uptake (as much as 40-fold), as well as retain 94\% (for NPS-HYCA) and 84.1\% (for NPP-HYCA) efficiency for phosphate adsorption after 5 adsorption-desorption cycles (96 h of adsorption time with 100 mg/L of phosphate ions) as against 37.5\% (for iPS-HYCA) and 35\% (for iPP-HYCA) under similar conditions. In 25 min desorption of phosphate ion attained equilibrium. These new amino-functionalized hybrid clay composite adsorbents, which were prepared by a simple means that is sustainable, have potentials for the efficient capture of phosphate ions from aqueous solution. They are quickly recovered from aqueous solution, non-biodegradable (unlike many biosorbent) with potentials to replace expensive adsorbents in the future. They have the further advantage of being useful in the recovery of phosphate for use in agriculture which could positively impact the global food security programme. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} }