Volcanic Rock Materials for Defluoridation of Water in Fixed-Bed Column Systems

Consumption of drinking water with a high concentration of fluoride (>1.5 mg/L) causes detrimental health problems and is a challenging issue in various regions around the globe. In this study, a continuous fixed-bed column adsorption system was employed for defluoridation of water using volcanic rocks, virgin pumice (VPum) and virgin scoria (VSco), as adsorbents. The XRD, SEM, FTIR, BET, XRF, ICP-OES, and pH Point of Zero Charges (pHPZC) analysis were performed for both adsorbents to elucidate the adsorption mechanisms and the suitability for fluoride removal. The effects of particle size of adsorbents, solution pH, and flow rate on the adsorption performance of the column were assessed at room temperature, constant initial concentration, and bed depth. The maximum removal capacity of 110 mg/kg for VPum and 22 mg/kg for VSco were achieved at particle sizes of 0.075–0.425 mm and <0.075 mm, respectively, at a low solution pH (2.00) and flow rate (1.25 mL/min). The fluoride breakthrough occurred late and the treated water volume was higher at a low pH and flow rate for both adsorbents. The Thomas and Adams–Bohart models were utilized and fitted well with the experimental kinetic data and the entire breakthrough curves for both adsorbents. Overall, the results revealed that the developed column is effective in handling water containing excess fluoride. Additional testing of the adsorbents including regeneration options is, however, required to confirm that the defluoridation of groundwater employing volcanic rocks is a safe and sustainable method.

Download Full-text

Adsorption of chloro-anilines from solution by modified peanut husk in fixed-bed column

Water Science & Technology ◽

10.2166/wst.2013.464 ◽

2013 ◽

Vol 68 (10) ◽

pp. 2158-2163 ◽

Cited By ~ 2

Author(s):

Shenglong Zhang ◽

Randi Zhang ◽

Wei Xiao ◽

Runping Han

Keyword(s):

Flow Rate ◽

Low Cost ◽

Fixed Bed ◽

Breakthrough Curves ◽

Ammonium Bromide ◽

Spectroscopy Analysis ◽

Time Model ◽

Fixed Bed Column ◽

Column Adsorption ◽

Critical Bed Depth

Natural peanut husk (NPH) modified with hexadecyl trimethyl ammonium bromide (CTAB) was used as adsorbent to remove 2,5-dimethoxy-4-chloroaniline (DMCH) from solution in a fixed-bed column. Fourier transform infrared spectroscopy analysis and X-ray fluorescence of NPH and modified peanut husk (MPH) showed that CTAB had been introduced onto the surface of NPH. The effects of flow rate and bed depth on breakthrough curves were studied. The Thomas model and the Yan model were selected to fit the column adsorption data and the results showed that the Yan model was better at predicting the breakthrough curves. The adsorption quantity was up to 6.46 mg/g according to the Yan model. The bed depth service time model was used to calculate the critical bed depth from experimental data and it was directly related to flow rate. As a low-cost adsorbent, MPH is promising for the removal of DMCH from solution.

Download Full-text

Adsorption of Sb(III) from Aqueous Solution by nZVI/AC: A Magnetic Fixed-Bed Column Study

Nanomaterials ◽

10.3390/nano11081912 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1912

Author(s):

Huijie Zhu ◽

Qiang Huang ◽

Mingyan Shi ◽

Shuai Fu ◽

Xiuji Zhang ◽

...

Keyword(s):

Flow Rate ◽

Fixed Bed ◽

Feed Solution ◽

Breakthrough Curves ◽

Contaminated Water ◽

Solution Ph ◽

Fixed Bed Column ◽

Ph Values ◽

Bed Height ◽

Bed Capacity

The effectiveness of nanoscale zero-valent iron(nZVI) immobilized on activated carbon (nZVI/AC) in removing antimonite (Sb(III)) from simulated contaminated water was investigated with and without a magnetic fix-bed column reactor. The experiments were all conducted in fixed-bed columns. A weak magnetic field (WMF) was proposed to increase the exclusion of paramagnetic Sb(III) ions by nZVI/AC. The Sb(III) adsorption to the nZVI and AC surfaces, as well as the transformation of Sb(III) to Sb(V) by them, were both increased by using a WMF in nZVI/AC. The increased sequestration of Sb(III) by nZVI/AC in the presence of WMF was followed by faster nZVI corrosion and dissolution. Experiments were conducted as a function of the pH of the feed solution (pH 5.0–9.0), liquid flow rate (5–15 mL·min−1), starting Sb(III) concentration (0.5–1.5 mg·L−1), bed height nZVI/AC (10–40 cm), and starting Sb(III) concentration (0.5–1.5 mg·L−1). By analyzing the breakthrough curves generated by different flow rates, different pH values, different inlet Sb(III) concentrations, and different bed heights, the adsorbed amounts, equilibrium nZVI uptakes, and total Sb(III) removal percentage were calculated in relation to effluent volumes. At pH 5.0, the longest nZVI breakthrough time and maximal Sb(III) adsorption were achieved. The findings revealed that the column performed effectively at the lowest flow rate. With increasing bed height, column bed capacity and exhaustion time increased as well. Increasing the Sb(III) initial concentration from 0.5 to 1.5 mg·L−1 resulted in the rise of adsorption bed capacity from 3.45 to 6.33 mg·g−1.

Download Full-text

Continuous fixed bed adsorption of Cu(II) by halloysite nanotube–alginate hybrid beads: an experimental and modelling study

Water Science & Technology ◽

10.2166/wst.2014.148 ◽

2014 ◽

Vol 70 (2) ◽

pp. 192-199 ◽

Cited By ~ 13

Author(s):

Yanyan Wang ◽

Xiang Zhang ◽

Qiuru Wang ◽

Bing Zhang ◽

Jindun Liu

Keyword(s):

Adsorption Capacity ◽

Flow Rate ◽

Fixed Bed ◽

Halloysite Nanotubes ◽

Fixed Bed Column ◽

Factors Affecting ◽

Bed Height ◽

Column Adsorption ◽

Fixed Bed Adsorption ◽

Adsorption Desorption

We used natural resources of halloysite nanotubes and alginate to prepare a novel porous adsorption material of organic–inorganic hybrid beads. The adsorption behaviour of Cu(II) onto the hybrid beads was examined by a continuous fixed bed column adsorption experiment. Meanwhile, the factors affecting the adsorption capacity such as bed height, influent concentration and flow rate were investigated. The adsorption capacity (Q0) reached 74.13 mg/g when the initial inlet concentration was 100 mg/L with a bed height of 12 cm and flow rate of 3 ml/min. The Thomas model and bed-depth service time fitted well with the experimental data. In the regeneration experiment, the hybrid beads retained high adsorption capacity after three adsorption–desorption cycles. Over the whole study, the new hybrid beads showed excellent adsorption and regeneration properties as well as favourable stability.

Download Full-text

Highly Effective Cow Bone Based Biocomposite for the Sequestration of Organic Pollutant Parameter from Palm Oil Mill Effluent in a Fixed Bed Column Adsorption System

Polymers ◽

10.3390/polym14010086 ◽

2021 ◽

Vol 14 (1) ◽

pp. 86

Author(s):

Adeleke A. Oyekanmi ◽

Mohammed B. Alshammari ◽

Mohamad Nasir Mohamad Ibrahim ◽

Marlia Mohd Hanafiah ◽

Ashraf Y. Elnaggar ◽

...

Keyword(s):

Correlation Coefficient ◽

Flow Rate ◽

Palm Oil ◽

Organic Pollutant ◽

Fixed Bed ◽

Palm Oil Mill Effluent ◽

Breakthrough Time ◽

Fixed Bed Column ◽

Column Adsorption ◽

Palm Oil Mill

The reduction of chemical oxygen demand (COD) from palm oil mill effluent (POME) is very significant to ensure aquatic protection and the environment. Continuous adsorption of COD in a fixed bed column can be an effective treatment process for its reduction prior to discharge. Adsorption capacity of bone derived biocomposite synthesized from fresh cow bones, zeolite, and coconut shells for the reduction in the organic pollutant parameter was investigated in this study in a fixed bed column. The effect of influent flow rate (1.4, 2.0, and 2.6 mL/min) was determined at an influent pH 7. The optimum bed capacity on the fabricated composite of surface area of 251.9669 m2/g was obtained at 1.4 mL/min at breakthrough time of 5.15 h influent POME concentration. The experimental data were fitted to Thomas, Adams–Bohart, and Yoon–Nelson models fixed bed adsorption models. It was revealed that the results fitted well to the Adams Bohart model with a correlation coefficient of R2 > 0.96 at different influent concentration. Adsorption rate constant was observed to increase at lower flow rate influent concentration, resulting in longer empty bed contact time (EBCT) for the mass transfer zone of the column to reach the outlet of the effluent concentration. In general, the overall kinetics of adsorption indicated that the reduction in COD from POME using a bone-biocomposite was effective at the initial stage of adsorption. The pore diffusion model better described the breakthrough characteristics for COD reduction with high correlation coefficient. Shorter breakthrough time compared to EBCT before regeneration indicated that the bone composite was suitable and effective for the reduction in COD from POME using fixed bed column adsorption.

Download Full-text

FIXED-BED COLUMN ADSORPTION OF FLUOROQUINOLONE ANTIBIOTIC FROM AQUEOUS SOLUTION ONTO SUGARCANE BAGASSE BIOCHAR

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/58/3a/14279 ◽

2020 ◽

Vol 58 (3A) ◽

pp. 93

Author(s):

Linh Thuy Nguyen ◽

Thuy Thi Pham ◽

Hanh Thi Nguyen ◽

Hoai Thu Dang ◽

Khai Manh Nguyen ◽

...

Keyword(s):

Sugarcane Bagasse ◽

Flow Rate ◽

Fixed Bed ◽

Column Experiment ◽

Maximum Adsorption Capacity ◽

Fixed Bed Column ◽

Initial Concentration ◽

Bed Height ◽

Column Adsorption ◽

Fluoroquinolone Antibiotic

The ability of the agricultural residue of sugarcane bagasse to serve as an absorbent material used to remove Ciprofloxacin, one of strong Fluoroquinolone antibiotic from aqueous solutions in fixed-bed columns was investigated. The properties of biochar sugarcane bagasse were characterized using scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy before and after modification. The results of fixed bed column experiment showed that the shape of the removal efficiency of CIP and exhaustion time was dependent on bed height, flow rate and initial concentration. The maximum adsorption capacity qo predicted from Thomas modelreached 0.955mg/g at the flow rate of 1mL/min, initial concentration of 15mg/L and bed height of 6cm. From Yoon-Nelson equation, 3.38 minutes was the time required for 50% exhaustion of 12cm bed height column with the flow rate 2mL/min and concentration 15mg/L. Thomas and Yoon-Nelson models were in good agreement with the experimental breakthrough curve data.

Download Full-text