Ferda Gönen

Biosorption of phenol by immobilized activated sludge in a continuous packed bed: prediction of breakthrough curves

Abstract A continuous fixed bed study was carried out by using Mowital®B30H resin immobilized dried activated sludge as a biosorbent for the removal of phenol from aqueous solution. The effect of flow rate and inlet phenol concentration on the sorption characteristics of sorbent was investigated at pH 1.0. Data confirmed that the total amount of sorbed phenol and equilibrium phenol uptake decreased with increasing flow rate and increased with increasing inlet phenol concentration. Freundlich and Langmuir adsorption models have been used to represent the column equilibrium data. The results showed that the equilibrium data fitted both models within the concentration range studied. Four kinetic models; Adams–Bohart, Thomas, Clark and Yoon–Nelson models were applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. All models were found suitable for describing the whole or a definite part of the dynamic behavior of the column with respect to flow rate and inlet phenol concentration.

Biosorption of chromium(VI) ions by Mowital®B30H resin immobilized activated sludge in a packed bed: comparison with granular activated carbon

Abstract The potential use of Mowital®B30H resin immobilized dried activated sludge as a substitute for granular activated carbon for removing chromium(VI) was examined in a continuous packed bed column. The effect of operating parameters such as flow rate and inlet metal ion concentration on the sorption characteristics of each sorbent was investigated. From the batch system studies the working sorption pH value was determined as 1.0 for both sorbents and packed bed sorption studies were performed at this pH value. The total adsorbed quantities, equilibrium uptakes and total removal percents of chromium(VI) related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different flow rates and different inlet chromium(VI) concentrations for each sorbent. Data confirmed that the total amount of sorbed chromium(VI) and equilibrium chromium(VI) uptake decreased with increasing flow rate and increased with increasing inlet chromium(VI) concentration for both immobilized dried activated sludge and granular activated carbon systems. The results also indicated that the sorption process could only deal with lower flow rates and lower concentrations of chromium(VI) solutions if a high percentage removal was required for extended periods for both sorbents. The suitability of the Freundlich and Langmuir adsorption models to the column equilibrium data was also investigated for each chromium(VI)-sorbent system. The results showed that the equilibrium data for both the sorbents fitted the Langmuir model best within the concentration range studied.

Adsorption study on orange peel: Removal of Ni(II) ions from aqueous solution

Adsorption of Nickel(II) ions from aqueous solution onto a low cost adsorbent-orange peel was investigated to evaluate the effects of pH, initial nickel ion concentration and adsorbent dose on the removal of Ni(II) systematically. The optimal pH value for Ni(II) adsorption onto the orange peel was found to be 5.0. Greater percentage of metal ion was removed with decrease in the initial concentration of metal ion and increase in amount of adsorbent used. Adsorption data was modeled using the Langmuir and Freundlich adsorption. The adsorption kinetics was found to follow pseudo-second-order rate kinetic model, with a good correlation (r 2 > 0.99) and intra-particle diffusion as one of the rate determining steps. Thermodynamic parameters (ΔG°, ΔS° and ΔH°) for sorption system was determined at five different temperatures. Key words: Orange peel, heavy metal ion, adsorption, isotherms, kinetics.

Single and binary dye and heavy metal bioaccumulation properties of Candida tropicalis: use of response surface methodology (RSM) for the estimation of removal yields.

The single and binary effects of initial Remazol Turquoise Blue-G (RTBG) reactive dye and initial copper(II) concentrations on the dye or/and copper(II) bioaccumulation efficiency of C. tropicalis was investigated in 10 g l(-1) molasses sucrose containing growth medium at an initial pH value of 4.0 and optimized using response surface methodology (RSM). A 2(2) full factorial central composite design was successfully used for experimental design and analyses of the results. Two numerical correlations fitted to a second-order quadratic equation were obtained to estimate the responses of dye and copper(II) removal yields. The statistical analysis indicated that although relatively high accumulation efficiency of C. tropicalis was obtained for the single removal of dye and copper(II), individual uptake of both the components from binary mixture was affected negatively by the addition of other component up to 500 mg l(-1) due to inhibition caused by high concentrations of RTBG dye and copper(II). The optimum combination predicted via RSM confirmed that growing C. tropicalis was capable of bioaccumulating RTBG and copper(II) with the maximum yields of 59.2% and 21.3% in the growth medium containing 50 mg l(-1) RTBG and 50 mg l(-1) copper(II) together, respectively.

A comparative adsorption/biosorption of phenol to granular activated carbon and immobilized activated sludge in a continuous packed bed reactor

The potential use of Mowital B30H resin immobilized dried activated sludge as a substitute for granular activated carbon for removing phenol from aqueous solution was examined in a continuous packed bed reactor as a function of flow rate and inlet phenol concentration. The working sorption pH value was determined as 1.0 for both the sorbents, and packed bed sorption studies were performed at this pH value. The maximum specific uptakes, total adsorbed quantities, and total removals of phenol related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different flow rates and different inlet phenol concentrations for each sorbent. At the lowest flow rate of 0.8 mL/min and at the inlet phenol concentration of 500 mg/L, the maximum specific uptakes and total removals of phenol were 84.0 mg/g and 27.6%, respectively, for granular activated carbon and 9.0 mg/g and 9.3%, respectively, for immobilized dried activated sludge. Data confirmed that total removals of phenol decreased with increasing flow rate and inlet phenol concentration for both immobilized dried activated sludge and granular activated carbon systems.

Environmental Application of Telon Blue AGLF Adsorption on Sunflower Pulp: A Response Surface Methodology Approach and Kinetic Study

The adsorptive removal of Telon Blue AGLF (TB AGLF) from aqueous solution using sunflower pulp was studied. The effects of pH, adsorbent dose, temperature, and initial dye concentration on the adsorption capacity and the removal % of TB AGLF were investigated. Experimental results showed that sunflower pulp was excellent agroindustrial adsorbent with maximum dye removal efficiency of 97.22% for a very short time (under conditions of 100 mg L−1 initial dye concentration, pH = 3, °C, and 1 g L−1 of adsorbent dose). The binary effects of initial dye concentration and temperature on the adsorption properties of sunflower pulp were analysed by RSM and two model equations for predicting adsorption capacity and dye removal % of pulp because arbitrarily chosen initial dye concentration and temperature were developed by using response surface methodology (RSM). Experimental values of the adsorption capacity and dye removal % were in good agreement with the predicted values by the improved models. Adsorption experiments and kinetic regression results indicated that the experimental data were well defined with pseudo-second-order kinetic model.

ASİDİK BOYARMADDE İÇEREN TEKSTİL ENDÜSTRİSİ ATIKSULARINDAN ADSORPSİYON YÖNTEMİYLE RENK GİDERİLMESİ

Bu calismada, atiksulardan boyarmadde gideriminde yaygin olarak kullanilan adsorbentlere alternatif olabilecek yuksek giderim verimine sahip kitosan malzemesi kullanilmistir. Acid Blue 29(AB 29) boyarmaddesinin kitosan uzerine adsorpsiyonunda, pH, adsorbent derisimi(X), baslangic boyarmadde derisimi ve sicaklik gibi ortam parametrelerinin etkisi incelenerek proses icin en uygun degerler saptanmistir. Deneysel sonuclardan, adsorpsiyonun dengeye 15-20 dakikada ulastigi gozlenmistir. Bu denge surecinde en iyi adsopsiyon verimi pH=4, X=1.0g/L ile T=35°C degerlerinde elde edilmistir. Adsorpsiyon denge verilerinin Langmuir ve Freundlich izoterm modellerine uyumluluk durumu arastirildiginda, en iyi uyumun en yuksek regresyon katsayilarinin elde edildigi Langmuir modelinde gerceklestigi gozlenmistir. AB 29 boyarmaddesinin kitosana adsorpsiyonunun kinetic analizi amaciyla deneysel verilere yalanci birinci ve ikinci derece kinetik model uygulanmis, tum korelasyon katsayilarinin 0.99’dan buyuk olmasi, deneysel ve teorik degerlerin birbirine cok yakin cikmasindan dolayi adsorpsiyon kinetiginin ikinci derece kinetik modele oldukca iyi uyum sagladigi belirlenmistir. Sistem termodinamik acidan analiz edildiginde ise, adsorpsiyonda elde edilen negative ΔGo degerleri adsorpsiyonun kendiliginden gerceklestigini, adsorpsiyonun gerceklesmesi icin bir enerji engelinin olmadigini gostermistir. Yapilan calisma sonucunda boyarmadde gideriminde kitosanin diger adsorbentlere alternatif bir adsorbent olarak kullanilabilecegi dusunulmektedir.