Development Of Low-cost Adsorbents Research Articles

Adsorption properties of Pb(II) and Cd(II) in acid mine drainage by oyster shell loaded lignite composite in different morphologies

A new idea to alleviate environmental pollution is the development of low-cost adsorbents using natural minerals and fishery wastes to treat high concentrations of heavy metal pollutants in acid mine drainage (AMD). Adsorbent morphology, adsorptive and regenerative capacity, and application potential are limiting factors for their large-scale use. Oyster shells capable of releasing alkalinity were loaded on the surface of lignite to develop two composite adsorbents with different morphologies (powdery and globular) for the treatment of AMD containing Pb(II) and Cd(II). The results show that the ability of the adsorbent to treat AMD is closely related to its morphologies. The pseudo-second-order kinetic model and the Langmuir model are suitable to describe the adsorption process of OS-M(P), and the maximum adsorption saturation capacities of Pb(II) and Cd(II) are 332.6219 mg/g and 318.9854 mg/g, respectively. The pseudo-second-order kinetic model and the Freundlich model are suitable to describe the adsorption process of OS-M(G). A synergistic result of electrostatic adsorption, neutralization precipitation, ion exchange and complex reaction is achieved in the removal of Pb(II) and Cd(II) by two morphologies of adsorbents. The regeneration times (5 times) and recovery rate (75.75%) of OS-M(G) are higher than those of OS-M(P) (3 times) and recovery rate (20%). The ability of OS-M(G) to treat actual AMD wastewater is still better than that of OS-M(P). OS-M(G) can be used as a promising environmentally friendly adsorbent for the long-term remediation of AMD. This study provides a comprehensive picture of resource management and reuse opportunities for natural mineral and fishery wastes.

Efficient adsorption of cationic and anionic dyes on Algerian natural phosphate

Adsorption is now recognized as an effective and economic method for wastewater treatment. Thus, in recent years, development of low cost adsorbent for dye loaded wastewater remediation has become an important area of research. Algerian phosphate was tested as an effective adsorbent for the removal of cationic dye methylene Blue (MB) as well as the anionic dye blue bezaktiv S-GLD 150 (BB) from synthetic wastewater. The phosphate was characterized by XRD, FT-IR, TGA, SEM, EDX and BET analysis. pHPZC analysis was performed to determine pH sensitive adsorptive removal of cationic and anionic dyes. Batch adsorption experiments of the dyes from aqueous solution were conducted, taking into account the influence of initial dye concentration (10–500 mg/L), adsorbent dosage (1–6 g/L), contact time (5–120 min) and solution pH ((2–12) ± 0.2). The experimental results show that, the adsorption was pH dependent with a high adsorption capacity of MB in basic range and high adsorption of BB in the acidic range. Experimental adsorption data were modeled by different equilibrium isotherms such as Langmuir, Freundlich, Redlich Peterson and Sips. The adsorption process fitted well to pseudo-second-order kinetics and the Langmuir model. The calculated maximum adsorbed quantity qmax of MB and BB were found 30.61 (mg/g) and 20.78 (mg/g) successively. The adsorption process was found to be exothermic in nature in the case of the MB and endothermic for BB. Accordingly; the phosphate has been shown to be a very efficient and low-cost adsorbent, and a promising alternative for eliminating dyes from industrial wastewater.

Insights of Montmorillonite Clay Nanocomposites for Adsorption of Toxic Colorant and Metals Ions from Wastewater: A Mini Review

The development of lowcost adsorbents is triggered often by not utilizing the costly starting material that pave the path for synthesizing cost comparative adsorbents for purpose of sequestration of toxic pollutants from water. Clay minerals are alternatives that are low-cost to activated charcoal due to their abundance presence, excellent textural properties, high specific surface area, strong chemical, and mechanical stability Pollution, in recent years has become an increasingly serious problem, leading to health issues in human and deteriorating environmental condition. Various remediation technologies are introduced so far, but adsorption regarded as important industrial technique for separation and purification of effluent media. This review paper showcases the importance of montmorillonite nanocomposites for the remediation of toxic contaminants from water. The preferred method of remediation is adsorption. It also emphasizes the recent development in the field of montmorillonite nanocomposites in sequestering different types of dyes and various heavy metals from water. Hence, this brief review authorises the various montmorillonite adsorbents conceivability towards water treatment.

Preparation and Characterization of Sludge-Based Magnetic Biochar by Pyrolysis for Methylene Blue Removal

The development of low-cost adsorbent is an urgent need in the field of wastewater treatment. In this study, sludge-based magnetic biochar (SMB) was prepared by pyrolysis of sewage sludge and backwashing iron mud without any chemical agents. The samples were characterized by TGA, XRD, ICP, Organic element analysis, SEM, TEM, VSM and BET. Characterization analysis indicated that the magnetic substance in SMB was Fe3O4, and the saturation magnetization was 25.60 emu·g−1, after the adsorption experiment, SMB could be separated from the solution by a magnet. The batch adsorption experiment of methylene blue (MB) adsorption showed that the adsorption capacities of SMB at 298 K, 308 K and 318 K were 47.44 mg·L−1, 39.35 mg·L−1, and 25.85 mg·L−1, respectively. After one regeneration with hydrochloric acid, the maximum adsorption capacity of the product reached 296.52 mg·g−1. Besides, the adsorption kinetic described well by the pseudo-second order model revealed that the intraparticle diffusion was not just the only rate controlling step in adsorption process. This study gives a reasonable reference for the treatment of sewage sludge and backwashing iron mud. The product could be used as a low-cost adsorbent for MB removal.

Humic acid attachment on chitosan-modified silica gel as an economical, efficient, and selective adsorbent for thorium and uranium removal

ABSTRACT A novel, low-cost adsorbent material was prepared by the immobilization of humic acid on a silica gel surface coated with cross-linked chitosan (SiChiHA). The adsorbent was developed to remove selectively of Th(IV) and U(VI) from aqueous solution, including their pre-concentration and separation from lanthanides and high salinity conditions. A simple waste-less humic acid immobilization method was shown to be successful based on FT-IR, SEM-EDS, and zeta potential characterization results. The adsorbent was found to be stable over a wide pH range, with the highest capacities obtained at pH 3.5 (Th(IV)) and pH 5 (U(VI)). Langmuir model calculations yielded a maximum capacity of 30.6 mg g−1 and 75.4 mg g−1 for Th(IV) and U(VI). The adsorption process was found to be rapid (half concentration was removed within 10 min) and best described by a pseudo-second order rate equation. Increasing NaCl concentration up to 2 mol L−1 or lanthanide concentration up to 100 times did not significantly affect the removal efficiency for either Th(IV) of U(VI). Both elements could be sequentially separated by elution with ammonium citrate and nitric acid, respectively. The adsorption-desorption experiment showed that the adsorbent could be used for at least five cycles without significant capacity loss. This study provides insight into the development of low-cost adsorbent with practical functionality, including separation and regeneration ability, the advantageous properties scarcely reported in low-cost adsorbent literature.

Development of low cost adsorbent from recycled polyethylene terephthalate for treatment of acephate contaminated water

Development of low cost adsorbent from recycled polyethylene terephthalate for treatment of acephate contaminated water

Facile Functionalization of Natural Peach Gum Polysaccharide with Multiple Amine Groups for Highly Efficient Removal of Toxic Hexavalent Chromium (Cr(VI)) Ions from Water.

The development of low-cost adsorbent with excellent adsorption property remains a big challenge. Herein, the functionalization of natural peach gum polysaccharide (PGP) with multiple amine groups for the removal of toxic Cr(VI) ions from water was studied. The obtained PGP-NH2 gel exhibited high-removal efficiency (>99.5%) toward Cr(VI) ions, especially with relatively low initial concentration of Cr(VI) ions (≤250 mg/L). The influences of pH, ionic strength, contact time, initial concentration, and temperature on the adsorption of Cr(VI) ions were systematically investigated. The PGP-NH2 gel showed rapid adsorption rate and could reach adsorption equilibrium within about 40 min. The Cr(VI) ion uptake process could be described by pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity of PGP-NH2 gel could reach 188.32 mg/g. Thermodynamic investigation results indicated the spontaneous and exothermic characteristic of the uptake process. Moreover, the PGP-NH2 gel also exhibited favorable reusability, and 135.52 mg/g of adsorption capacity was retained even after being reused for five times. Considering its low cost and superior uptake property, the PGP-NH2 gel holds a great promise for employing as an adsorbent to treat Cr(VI) ion-containing wastewater.

The development of low cost adsorbents from clay and waste materials: a review

Increased energy consumption due to industrial growth has increased the levels of carbon dioxide (CO2) emission being released into the atmosphere. CO2 emission is a type of greenhouse gas which is a major cause of global warming. Since the issue of CO2 emissions has drawn much attention in recent years, the development of CO2 capture technology has become a necessity. Although CO2 adsorbents are still at the early development stage, it has been suggested that CO2 adsorbents are the most effective technology in controlling CO2 emissions. Solid adsorbents have great potential as an alternative method to conventional adsorbents in adsorbing CO2. In this paper, low cost adsorbents including activated carbon, zeolites, mesoporous silica and clays are discussed in terms of adsorbent preparation methods and CO2 adsorption capacity. The low cost adsorbents are mainly derived from waste materials such as fly ash, steel slag, red mud, bagasses wastes and wood wastes. Besides that, natural resources such as clays have also been applied as low cost CO2 adsorbents. Surface modifications have also been applied to the low cost adsorbents, including metal ion exchange and amine impregnation to enhance CO2 adsorption capacity. In the last section, the current status of CO2 adsorbents is summarized and future trends are discussed briefly to predict the potential materials which can be applied as CO2 adsorbents.

Development of Low Cost Adsorbents from Agricultural Waste Biomass for the Removal of Sr(II) and Cs(I) from Water

For the purpose of remediating aquatic environment polluted by radioactive elements such as Cs(I) and Sr(II), two types of adsorption gels were developed using biomass wastes as feed materials: a Ca-type pectin based cation exchanger for the removal of Sr(II) prepared from orange waste and a polyphenol enriched bio-sorbent for Cs(I) prepared from tea leaves. The former was prepared by means of saponification of the methyl ester portion of orange pectin in orange juice residue using lime water. Due to the chemical similarity of Ca(II) and Sr(II), the Ca(II) ions in the saponified orange juice residue (SOJR) are easily replaced by Sr(II) during adsorption. The latter was synthesized by means of cross-linking condensation reaction with concentrated H2SO4. The adsorption of Sr(II) and Cs(I) increased with increasing pH of the solution, suggesting that these metal ions were adsorbed onto active sites of these bio-sorbents through a cation exchange mechanism. These modified biomass adsorbents were found to exhibit high adsorption capacities and fast adsorption rates for the tested metal ions. That is, the adsorption capacity of SOJR for Sr(II) was evaluated as 0.83 mmol/g whereas that obtained for the cross linked tea leaves (CTL) gel with regards to Cs was 1.22 mmol/g. In comparison to the adsorption capacities of other adsorbents, it was concluded that the SOJR and CTL displayed excellent potential for the adsorption of Sr(II) and Cs(I), respectively. Thus, the combined uses of SOJR and CTL gels can be expected to work as a promising alternative to remove radioactive Sr(II) and Cs(I) from polluted water.

Development of Low Cost Adsorbent from Cow Horn for the Biosorption of Mn (II), Ni (II) and Cd (II) Ion from Aqueous Solution

Development of low cost adsorbent from cow horn for the biosorption of Mn (II), Ni (II) and Cd (II) ion aqueous solution was carried out by batch adsorption experiment at 32°C. Parameters such as pH, contact time, metal ion concentrations as well as temperature were monitored. The residual concentration of Mn (II), Ni (II) and Cd (II) were determined using Atomic Absorption Spectrophotometer. The results revealed that maximum Ni (II) and Cd (II) ion removal occurred at pH of 6 while Mn (II) ion occurred at pH of 7 respectively. Langmuir and Temkin adsorption isotherm were used to describe the equilibrium data. The equilibrium data fitted well to Langmuir isotherm than Temkin isotherm. Thermodynamic investigation showed that standard Gibbs free energy (ΔGº) was positive indicating the feasibility and non-spontaneous of the process. The positive value of standard Enthalpy (ΔHº) implies that the reaction was endothermic and the negative standard Entropy (ΔSº) signifies decrease in the randomness at the solid/solution interface of the adsorbent during the adsorption process. The kinetic study revealed that adsorption of Mn (II), Ni (II) and Cd (II) could be best described by pseudo-second model. This study demonstrated that adsorbent developed from cow horn could be used as an alternative to commercial activated carbon in the removal of Mn (II), Ni (II) and Cd (II) ions from aqueous solution.

Invitro reduction, kinetic modelling and Optimisation of parameters for biosorption of Cr (VI) using an ecological sorbent

In this work extensive study has been carried out to understand the removal efficiency of chromium (VI) by a low cost sorbent material (lemon peel). Among the various techniques, adsorption is one of the most suitable methods which can be adopted to remove hazardous ions from water and waste water. The development of low cost adsorbent is essential for the benefit of the common people. Experiments were conducted in batch mode to know the removal efficiency of chromium (VI) as a function of size, pH, adsorbent dose, initial concentration and time. The removal efficiency of Cr(VI) was maximum at particle size of 0.46mm, pH-5, adsorbent dose of 2.5%, contact time 120 minutes from the aqueous solution having initial Cr (VI) concentration of 100 mg/L. From this study it is infer that the selected adsorbent is having high potential to remove Cr(VI) and other toxic metal which require further study. Keywords: Lemon peel, Chromium, Sorption, Isotherm, %removal.

Optimisation of sugar cane activated carbon for arsenic(V) and arsenic(III) removal from water

This paper addresses the development of low-cost adsorbents for removal of arsenic from water in support of mitigation programmes in low and middle income countries. Activated carbon (AC) is a well established water treatment technology, but has high cost and low selectivity in respect of arsenic. AC made from agricultural by-products is a low-cost alternative to coal-based AC. In this study, the preparation parameters of sugar-cane activated carbon (SCAC) were optimised for arsenic(V) and arsenic(III) adsorption. The effect of preparation parameters on arsenic removal was investigated with a 23 factorial experiment. SCAC was characterised by the pH of zero charge, surface area, pore width distribution, particle size distribution and imaging under scanning electron microscopy. Activation temperature (AT) has a profound effect on arsenic adsorption; arsenic(V) adsorption increased from 2.8% at an AT of 873 K to 87.6% at an AT of 1,173 K. The percentage of arsenic removal from water has a strong positive correlation with surface area, and a strong negative correlation with micropore/pore volume ratio and the percentage in volume of particles with a size of 60–2,000 μm. In conclusion, this research shows that low-cost AC can be manufactured for removal of target pollutants, such as arsenic, from water.

A comparative study on Pb(II), Cd(II), Cu(II), Co(II) adsorption from single and binary aqueous solutions on additive assisted nano-structured goethite

Development of low cost adsorbents for mitigation of toxic ions is one of the most important areas of research and development. Iron oxides especially in nano form have the potential for removing cations due to their structural properties. In the present work additive assisted nano structured goethite was synthesized at pH 3.0 and its cation adsorption behaviour was studied for Pb(II), Cd(II), Cu(II) and Co(II) from single and binary aqueous solutions. The contact time data for single cation adsorption followed pseudo second order kinetic model for all the four cations. The isothermic data was fitted to Langmuir and Freundlich models. The experimentally obtained maximum loading capacities were estimated as 109.2, 86.6, 29.15 and 37.25 mg/g of goethite for Pb(II), Co(II), Cd(II) and Cu(II) respectively from single cation containing solutions. Thermodynamic parameters were evaluated for the four metal ions. Adsorption behaviour from binary solutions was studied by keeping the concentration of Pb(II) at saturation concentration (500 mg/L) for its maximum uptake and varying the concentration of other metal ions (one at a time) in the range of 25 to 200 mg/L. The Pb(II) loading capacity increased in the presence of Cd(II) or Co(II) while it decreased in the presence of Cu(II) in the studied range of concentration variation. Maximum Pb(II) uptake was observed from Pb(II)-Cd(II) binary system (222 mg/L) with Pb II) and Cd(II) concentration as 500 and 200 mg/L respectively. An increase in the combined uptake capacities for Pb(II)-Cd(II) and Pb(II)-Co(II) binary systems were observed whereas a decrease was observed for Pb(II)-Cu(II) binary system. The synthesized goethite can be used effectively for cation removal from single/binary cation containing aqueous solutions. Keywords: Nano goethite; TEM, adsorption; cations; binary; kinetics International Journal of Engineering, Science and Technology, Vol. 2, No. 8, 2010, pp. 89-103

Copper and nitrophenol pollutants removal by Na-montmorillonite/alginate microcapsules

The use of renewable bioresources allows the development of low cost adsorbents that are versatile. In the present paper, the affinity and the removal capacity of montmorillonite/alginate microcapsules for a hydrophobic organic pollutant (4-nitrophenol) and an inorganic pollutant (copper) were evaluated. The physicochemical processes through sorption and kinetic experiments under different ratios of montmorillonite vs. alginate and initial contaminant concentrations were investigated. The total weight loss and diameter decrease during the drying process were 90–96% and 64%, respectively. A significant decrease in beads diameter, related to water elimination, has been observed during the first 24 h. Structural modifications that occur during the drying process were evaluated using thermal analysis. From correlation coefficients, the second-order equation depicts properly the adsorption of copper by the microbeads adsorption capacity increases to saturation with time; 3 and 6 h were needed to reach equilibrium on wet and dry mixed microcapsules. The pseudo-second order model properly depicts the adsorption process of 4-NP onto Na-mont and (Na-mont/SA) mixed microcapsules but failed to reproduce the data observed for the alginate beads. Isotherms data were fitted with good correlation using the Langmuir model; alginate and montmorillonite adsorption capacities ( q m /wet beads) agree with those obtained by various studies.

Adsorption of herbicides on coal fly ash from aqueous solutions

Development of low cost adsorbent for pesticide retention is an important area of research in environmental sciences. The present study reports the sorption potential of coal fly ash, a waste from power stations, for removal of metribuzin, metolachlor and atrazine from water. Batch sorption method was used to study the sorption of herbicides from water. The amount of herbicides sorbed increased with increase in the amount of fly ash in the suspension. The maximum capacity of the fly ash to adsorb metribuzin, metolachlor and atrazine was found to be 0.20, 0.28 and 0.38 mg/g by Freundlich equation and 0.56, 1.0 and 3.33 mg/g by Langmuir equation. Freundlich adsorption equation better explained the results of herbicides sorption in fly ash as regression coefficient ( R 2) values were higher from Freundlich equation than the Langmuir equation. Adsorption isotherms were L-type suggesting that the herbicide sorption efficiency of fly ash depend on the initial concentration of herbicide in the solution and maximum removal of herbicide was observed at concentrations less than 10 μg/ml. The results of this study have implications in using the fly ash for removal of these herbicides from industrial and agricultural waste water and can find use as a material in the preparation of biobeds to minimize environmental contamination from pesticide use.

Advances in water treatment by adsorption technology

Among various water purification and recycling technologies, adsorption is a fast, inexpensive and universal method. The development of low-cost adsorbents has led to the rapid growth of research interests in this field. The present protocol describes salient features of adsorption and details experimental methodologies for the development and characterization of low-cost adsorbents, water treatment and recycling using adsorption technology including batch processes and column operations. The protocol describes the development of inexpensive adsorbents from waste materials, which takes only 1-2 days, and an adsorption process taking 15-120 min for the removal of pollutants. The applications of batch and column processes are discussed, along with suggestions to make this technology more popular and applicable.