Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 83Citation - Scopus: 90Packed Bed Column Dynamic Study for Boron Removal From Geothermal Brine by a Chelating Fiber and Breakthrough Curve Analysis by Using Mathematical Models(Elsevier Ltd., 2018) Recepoğlu, Yaşar Kemal; Kabay, Nalan; Yılmaz İpek, İdil; Arda, Müşerref; Yüksel, Mithat; Yoshizuka, Kazuharu; Nishihama, SyouheiIn this study, the performance of N-methyl-D-glucamine (NMDG) type functional group attached a novel boron selective chelating fiber adsorbent, Chelest Fiber GRY-HW, was investigated for boron removal from geothermal brine containing 10–11 mg B/L through a packed bed column. The effect of feed flow rate (Space Velocity, SV) on breakthrough capacity of Chelest Fiber GRY-HW was studied using various SV values (15, 20 and 30 h−1). The effect of SV on breakthrough capacity was particularly apparent when SV was decreased from 30 to 15 h−1. Yoon–Nelson, Thomas and Modified Dose Response (MDR) models were applied to the experimental data to estimate the breakthrough curves and model parameters such as rate constants and breakthrough times. The obtained results showed that the breakthrough curves were better described by Modified Dose Response (MDR) model than those described by Yoon-Nelson and Thomas models in each case. Also, the model estimations for adsorption capacity obtained by MDR model agreed well with the experimental results.Article Citation - WoS: 123Citation - Scopus: 131A New Methodology for Removal of Boron From Water by Coal and Fly Ash(Elsevier Ltd., 2004) Polat, Hürriyet; Vengosh, Avner; Pankratov, Irena; Polat, MehmetHigh levels of boron concentrations in water present a serious problem for domestic and agriculture utilizations. The recent EU drinking water directive defines an upper limit of 1 mgB/I. In addition, most crops are sensitive to boron levels >0.75 mg/1 in irrigation water. The boron problem is magnified by the partial (∼60%) removal of boron in reverse osmosis (RO) desalination due to the poor ionization of boric acid and the accumulation of boron in domestic sewage effluents. Moreover, high levels of boron are found in regional groundwater in some Mediterranean countries, which requires special treatment in order to meet the EU drinking water regulations. Previous attempts to remove boron employed boron-specific ion-exchange resin and several cycles of RO desalination under high pH conditions. Here, we present an alternative methodology for boron removal by using coal and fly ash as adsorbents. We conducted various column and batch experiments that explored the efficiency of boron removal from seawater and desalinated seawater using several types of coal and fly ash materials under controlled conditions (pH, liquid/solid ratio, time of reaction, pre-treatment, regeneration). We examined the effect of these factors on the boron removal capacity and the overall chemical composition of the residual seawater. The results show that the selected coal and fly ash materials are very effective in removing boron such that the rejection ratio of boron can reach 95% of the initial boron content under certain optimal conditions (e.g., pH = 9, L/S = 1/10, reaction time > 6 h). Our experiments demonstrated that use of glycerin enables regeneration of boron uptake into coal, but the boron uptake capacity of fly ash reduces after several cycles of treatment-reaction. The boron removal is associated with Mg depletion and Ca enrichment in the residual seawater and conversely with relative Mg enrichment and Ca depletion in the residual fly ash. We propose that the reaction of Ca-rich fly ash with Mg-rich seawater causes co-precipitation of magnesium hydroxide in which boron is co-precipitated. The new methodology might provide an alternative technique for boron removal in areas where coal and fly ash are abundant.