Aqueous Solution In Fixed-bed Column Research Articles

Characterization and properties of manganese oxide film coated clinoptilolite as filter material in fixed-bed columns for removal of Mn(II) from aqueous solution

A new filter material, manganese oxide film coated clinoptilolite (MOFCC), was characterized and introduced to explore the effect in treating high concentration of manganese (1.71–2.12 mg L−1) from aqueous solution in fixed-bed column. Adsorption behavior of Mn(II) can be approximately described with the Langmuir isotherm. During the continuous 30 days filtration experiment, the removal rate of Mn(II) has maintained to be above 95.51%, the accumulated removal amount (806.42 mg) is much higher than the theoretical adsorption capacity (89.71 mg), which indicated that the removal of manganese by MOFCC includes both adsorption and auto-catalytic oxidation process, and it does not require a start-up period. SEM, EDS, XPS, XRD, ZETA potential and BET analyses were used to observe the surface properties of MOFCC. The manganese oxide film of MOFCC exhibits in clusters, apparently on occupied surface, the main component of the manganese oxide film is (Na0.7Ca0.3)Mn7O14·2.8H2O, the specific surface area of MOFCC is 38.76 m2 g−1, and the pore size is concentrated in the range of 3–40 nm, within the mesoporous range mesopores. pHpzc (point of zero charge) value is about 2.36. The characteristics of MOFCC make it an excellent manganese removal filter material for water treatment plant. Therefore, there is a long-term practical significance to develop new system for deep removal of manganese based on MOFCC.

Mitigation of toxic arsenic (V) from aqueous solution in fixed-bed column using functionally modified bio-polymer

The presence of arsenic in groundwater, eventually in drinking water, has been recognized as a serious community health problem due to its highly toxic nature, and therefore, its removal is highly essential. To enhance the adsorption capacity of chitosan for As (V), chitosan which is a natural biopolymer was modified by grafting with 2-Hydroxyethylmethacrylate (HEMA) and Sodium Styrene Sulfonate (SSS). Modified chitosan was characterized by SEM and FTIR spectroscopy. Maximum Removal percentage of As (V) was found to be higher (95%) at inlet concentration of As (V) 60 mg/L, flow rate 1 ml/min, pH 3.5, and bed depth 3 cm. The bed depth service time model and Thomas model are used to analyze the column data in terms of As (V) uptake rate and column capacities. Developed grafted adsorbent could be successfully regenerated using 0.1 M NaOH. Recycle studies suggested that maximum reusability of grafted polymer up to 8 cycles.

Removal of copper(II) from aqueous solution in fixed-bed column by carboxylic acid functionalized deacetylated konjac glucomannan

Carboxylic acid functionalized deacetylated konjac glucomannan (CADKGM) with regular cylinder shape was thermoplastically prepared by a single screw extruder. Thermoplastic deacetylated konjac glucomannan (TDKGM) using for preparation of CADKGM adsorbent showed good rheological processing properties with equilibrium torque of 13.1Nm and plasticizing time of 26s at 160°C, which was close to high density polyethylene (HDPE). The scanning electron micrograph results showed that CADKGM was porous inside the structure of the adsorbent. The removal of copper by CADKGM was studied in fixed-bed column. A comprehensive study was conducted to determine the breakthrough curves with varying bed heights, flow rates and initial concentrations. The breakthrough data gave a good fit to Thomas model. The consecutive adsorption–desorption cycles were applied to investigate the reusability of CADKGM. The adsorbed copper ions on CADKGM were easily desorbed by 0.01molL−1 HCl solution with desorption efficiency of 98%. The column capacity of CADKGM was not affected by an increase of reusable time.

Removal of disperse dye from aqueous solution in fixed-bed column by water treatment residuals

Removal of disperse dye from aqueous solution in fixed-bed column by water treatment residuals