Continuous Fixed-Bed Column Studies of Textile Effluent Treatment using Multi-Walled Carbon Nanotubes Originated from Rosmarinus officinalis Oil

A continuous adsorption study in a fixed-bed column was carried out using Multi-walled Carbon Nanotubes derived from Rosmarinus officinalis oil as an adsorbent for removing the textile dye Acid blue 40 from an aqueous solution. The adsorbent, MWNTs were prepared from Rosmarinus officinalis oil as a precursor to Fe/Mo catalyst supported on silica at 650 ºC under N2 atmosphere by spray pyrolysis process characterized by scanning electron microscopy, Transmission Electron microscopy, and Raman spectroscopy. The effects of adsorbent bed height (2–6 cm), initial ion concentration (20– 60 mg/L), and flow rate (10–30 mL/min) on the column performance were analyzed. The breakthrough curve was analyzed using the mathematical models of Thomas, Yoon-Nelson, and bed depth service time. The Thomas model at different conditions defined the behaviors of the breakthrough curves. The bed depth service time model showed good agreement with the experimental data. The high values of correlation coefficients (R2 0.9875) obtained indicate the validity of the bed depth service time model for the present column system.

Study of a fixed-bed column in the adsorption of an azo dye from an aqueous medium using a chitosan–glutaraldehyde biosorbent

A continuous adsorption study in a fixed-bed column was carried out using a chitosan–glutaraldehyde biosorbent for the removal of the textile dye Direct Blue 71 from an aqueous solution. The biosorbent was prepared from shrimp shells and characterized by scanning electron microscopy, X-ray diffraction, and nuclear magnetic resonance spectroscopy. The effects of chitosan–glutaraldehyde bed height (3–12 cm), inlet Direct Blue 71 concentration (15–50 mg l−1), and feed flow rate (1–3 ml min−1) on the column performance were analyzed. The highest bed capacity of 343.59 mg Direct Blue 71 per gram of chitosan–glutaraldehyde adsorbent was obtained using 1 ml min−1 flow rate, 50 mg l−1 inlet Direct Blue 71 concentration, and 3 cm bed height. The breakthrough curve was analyzed using the Adams–Bohart, Thomas, and bed depth service time mathematical models. The behaviors of the breakthrough curves were defined by the Thomas model at different conditions. The bed depth service time model showed good agreement with the experimental data, and the high values of correlation coefficients (R2 ≥ 0.9646) obtained indicate the validity of the bed depth service time model for the present column system.

TREATMENT OF FLUORIDE BEARING CONTAMINATED WATER USING SIMULTANEOUS ADSORPTION AND BIODEGRADATION IN A LABORATORY SCALE UP: FLOW BIO-COLUMN REACTOR BY JAVA PLUM SEED

ABSTRACTObjective: Here, we aimed for the treatment of fluoride bearing contaminated water using simultaneous adsorption and biodegradation in a biocolumnreactor by using java plum seed.Methods: We immobilized Acinetobacter baumannii bacteria on the java plum seed in the bio-column reactor. The water used contained a sample offluoride with concentration of 20 mg/L. The bed depth service time design model and empty bed residence time were used to analyze the performance thebio-column. We examined and observed closely the effect of different operating parameters such as flow rate of bed depth and initial concentration on thissimplified bio-column reactor design model. Desorption experiment was conducted to evaluate the possibilities of regeneration and to reutilize of media.Results: We observed that the bio-column reactor is capable to reduce the concentration of the pollutants in the effluent water below their permissiblelimit. Reduction in DO along the bed height of the reactor was also observed, which supports the aerobic nature of the bacteria.Conclusion: The experimental results were encouraging and indicate that java plum (Syzygium cumini) seed is a feasible option to use as a biosorbentto remove fluoride in the bio-column reactor.Keywords: Bio-reactor, Simultaneous adsorption and biodegradation, Flow rate, Acinetobacter baumannii MTCC 11451, Physicochemical adsorption,Bed depth service time, Empty bed residence time.

Fixed-Bed Column Study for Zn (II) Removal from Solution Using Raw Rice Husk

A fixed bed of raw rice husk was used for the removal of Zn (II) from aqueous solution. The material as adopted was found to be an efficient media for the removal of Zn (II) in continuous mode using fixed bed column. Different column design parameters like depth of exchange zone, flow rate and initial concentration were calculated. When conducted with Zn (II) concentration 10 mg.L-1 and flow rate 10 ml.min-1 with different bed depths such as 3, 6 and 9 cm, the equilibrium uptake was 3.366, 2.847 and 2.764 mg.g-1, respectively. The equilibrium uptake decreased from 2.802 to 1.975 mg.g-1 with increasing of flow rate from 5 to 15 mL.min-1 and increased from 2.764 to 3.798 mg.g-1 when initial concentration increased from 10 to 30 mg.L-1. The dynamics of adsorption process was modeled by bed depth service time (BDST), and indicating the validity of BDST model when applied to the continuous column studies.

Fixed-Bed Adsorption of Dyes on Bagasse Pith

The adsorption of a number of basic dyes on to bagasse pith has been studied using fixed-bed adsorption. Pith is a waste material produced from the crushed cane (depithing operation) during the extraction of sugar from sugar cane. The results show that pith can adsorb basic dyes and breakthrough curves are reported at various heights in the fixed beds. The bed depth service time model has been used to assess the results.

The Adsorption of Mixed Dyes (Acidic and Basic) on to Hardwood in a Fixed Bed

The adsorption of mixed dyes, Acid Blue and Basic Red, on to hardwood sawdust has been studied using the fixed bed technique. The influence of various parameters such as bed depth, solution flow rate and dye concentration were studied. The modified bed depth service time (BDST) model has been used to analyze the experimental data. In addition the empty bed residence time (EBRT) technique has been applied to optimize the adsorption process variables for either single or multi-component dyes.