Application of Polyacrylamide for Methylene Blue Removal from Aqueous Solutions

In this study the removal of methylene blue (MB) dye from aqueous solutions by polyacrylamide (PAA) as a potential adsorbent was reported. PAA was characterized using SEM and FTIR measurements. Batch adsorption experiments were performed as a function of the solution pH, contact time, solute concentration and temperature. Evaluation of the obtained data with isotherm studies indicated that the adsorption process was matched well with the Langmuir model. The maximum capacity of adsorbent for MB was 111.1 mg g−1. Kinetic studies were carried out on various kinetic models and the pseudo-second order kinetic model was fitted very well with experimental data. Moreover, the thermodynamic parameters indicated that the adsorption reaction was endothermic and spontaneous process

Removal of Heavy Metals from Industrial Wastewater by Sheep Gut Waste

Removal of toxic heavy metals from wastewater is an important environmental challenge. In this work, the Sheep Gut Waste (SGW) is used as a low-cost adsorbent for the removal of Pb2+, Fe3+, and Cu2+ from aqueous solutions and industrial wastewaters. Bath experiments were used to determine the best adsorption conditions. The effects of contact time, pH, initial metal concentration, and amount of adsorbent on the adsorption process were studied. The time required for the removal of metal ions was about two hour. Effective removal of metal ions was demonstrated at pH values of 4-8. The maximum adsorption capacities of Cu– SGW, Fe- SGW and Pb-SGW were 9.76 mmol g-1, 11.19 mmol g-1, and 3.01 mmol g-1, respectively. Metal adsorption onto SGW was evaluated by Langmuir and Freundlich isotherms. Results indicate that the Langmuir isotherm model is the most suitable one for the adsorption process using sheep gut waste

Original scientific paper Removal of Cu(II) from wastewater by waste tire rubber ash

Abstract: The influence of pH, adsorbent dose, initial Cu(II) concentration and contact time on the removal of Cu(II) from aqueous solution by the batch adsorption technique using waste tire rubber ash as a low-cost adsorbent was investigated. The adsorption equilibrium was achieved after 2 h at pH 4–6, the optimum for the adsorption of Cu(II) ions. A dose of 1.5 g/L of adsorbent was sufficient for the optimum removal of copper ions. The experimental data were analyzed by the Langmuir and Freundlich isotherms and the corresponding sorption constants were evaluated. The adsorption kinetics data were fitted by a first-order equation. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. The present study showed that waste tire rubber ash was capable of removing copper ions from industrial wastewater samples

Removal of Cu(II) from wastewater by waste tire rubber ash

The influence of pH, adsorbent dose, initial Cu(II) concentration and contact time on the removal of Cu(II) from aqueous solution by the batch adsorption technique using waste tire rubber ash as a low-cost adsorbent was investigated. The adsorption equilibrium was achieved after 2 h at pH 4–6, the optimum for the adsorption of Cu(II) ions. A dose of 1.5 g/L of adsorbent was sufficient for the optimum removal of copper ions. The experimental data were analyzed by the Langmuir and Freundlich isotherms and the corresponding sorption constants were evaluated. The adsorption kinetics data were fitted by a first-order equation. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. The present study showed that waste tire rubber ash was capable of removing copper ions from industrial wastewater samples

Preconcentration and determination of heavy metals in water, sediment and biological samples

In this study, a simple, sensitive and accurate column preconcentration method was developed for the determination of Cd, Cu and Pb ions in river water, urine and sediment samples by flame atomic absorption spectrometry. The procedure is based on the retention of the analytes on a mixed cellulose ester membrane (MCEM) column from buffered sample solutions and then their elution from the column with nitric acid. Several parameters, such as pH of the sample solution, volume of the sample and eluent and flow rates of the sample were evaluated. The effects of diverse ions on the preconcentration were also investigated. The recoveries were >95 %. The developed method was applied to the determination of trace metal ions in river water, urine and sediment samples, with satisfactory results. The 3δ detection limits for Cu, Pb and Cd were found to be 2, 3 and 0.2 μg dm−3, respectively. The presented procedure was successfully applied for determination of the copper, lead and cadmium contents in real samples, i.e., river water and biological samples

JSCS–3893 Short

Spectrophotometric determination of nitrite based on its catalytic effect on the reaction of nuclear fast red and potassium bromat

Nitrogen-modified nanoporous activated carbon from eucalyptus leaves for ultrasound-assisted removal of basic dyes using derivative spectrophotometric method

The nanoporous activated carbon (AC) was prepared from the eucalyptus leaves via chemical activation with KOH, then treated with nitric acid/ /urea (NOAC) and finally used as a new adsorbent for simultaneous ultrasound- assisted removal of basic red 46 (BR46) and basic yellow 13 (BY13) dyes from binary aqueous solutions. The NOAC nano-adsorbent was characterized with SEM, TEM, Raman, BET, FTIR, CHN, pHpzc and Boehm titration analysis. Both of the AC and NOAC samples had superior BET surface area of 2222 and 1572 m2 g-1 with average micropore volume of 0.81 and 0.50 cm3 g-1, respectively. First order derivative spectrophotometric method was used for analysis of BY13 in binary mixtures. Small amount of the adsorbent (30 mg) was capable to remove high percentage of dyes (>99 %) in a very short time (8 min). The adsorption of dyes follows the Langmuir isotherm and the pseudo- -second-order kinetics. The adsorption capacities of NOAC for single solutions of BR46 and BY13 were 1111 and 1250 mg g-1 as well as for binary solutions were 769 and 909 mg g-1, respectively. The adsorption thermodynamics were also explored. Exhausted NOAC was regenerated using HCl (2 M) and reused for five adsorption-desorption cycles with high performance

Combination of Experimental Design and Desirability Function as a Genuine Method to Achieve Common Optimal Conditions for the Adsorption of Pb(II) and Cu(II) onto the Poplar Tree Leaves: Equilibrium, Kinetic and Thermodynamic Studies

In this study, the ashes of poplar tree leaves are applied as an efficient, accessible and inexpensive biosorbent for the removal of heavy metals Pb2+ and Cu+2 in aqueous solutions. In the adsorption processes, the success of the ions removal highly depends on the level of several experimental factors such as pH, contact time, adsorbent dosage and temperature. Therefore, a genuine statistical experiment design method is required to achieve a common experimental conditions where both ions have been removed from aqueous solutions to a great degree. Here, this common optimal conditions are obtained by the combination of experimental design and desirability function methods. For a mixture of Pb2+ and Cu+2, the following optimal conditions were achieved: pH of 5.4, contact time of 23 min, adsorbent dosage of 0.14 g, and temperature of 280C; at 150 mg L-1 of Pb2+ and 120 mg L-1 Cu2+. The removal efficiencies of Pb2+ and Cu+2 were 92.8% and 94.9%, respectively, which verified the applicability of this biosorbent for the ions removal. Moreover, the equilibrium and kinetic behavior of the adsorption processes are investigated and then thermodynamic parameters, ΔG0(Kj mol-1), ΔH(Kj mol-1)0, and ΔS0 (Kj mol-1), are evaluated which reveal that both processes are endothermic and spontaneous

Graphene oxide-packed micro-column solid-phase extraction combined with flame atomic absorption spectrometry for determination of lead (II) and nickel (II) in water samples

<div><p>A sensitive and simple method has been established for simultaneous preconcentration of trace amounts of Pb (II) and Ni (II) ions in water samples prior to their determination by flame atomic absorption spectrometry. This method was based on the using of a micro-column filled with graphene oxide as an adsorbent. The influences of various analytical parameters such as solution pH, adsorbent amount, eluent type and volume, flow rates of sample and eluent, and matrix ions on the recoveries of the metal ions were investigated. Using the optimum conditions, the calibration graphs were linear in the range of 7–260 and 5–85 μg L⁻¹ with detection limits (3<i>S</i>_b) of 2.1 and 1.4 μg L⁻¹ for lead and nickel ions, respectively. The relative standard deviation for 10 replicate determinations of 50 μg L⁻¹ of lead and nickel ions were 4.1% and 3.8%, respectively. The preconcentration factors were 102.5 and 95 for lead and nickel ions, respectively. The adsorption capacity of the adsorbent was also determined. The method was successfully applied to determine the trace amounts of Pb (II) and Ni (II) ions in real water samples. The validation of the method was also performed by the standard reference material.</p></div