Maximum Sorption Efficiency Research Articles

Fabrication of electrospun ultrafine fibreous membrane and their application in paraben adsorption

Electrospinning provides a simple and versatile method for generating ultrafine fibers from a rich variety of materials that include polymers, composites, and ceramics. Find applications in various fields, including tissue engineering, filter media, reinforcement in nanocomposites, and micro/nano-electro-mechanical systems. In this study the polystyrene fibers in 10%, 20% and 30% (w/v) in THF: DMF solvents were characterized by ATR-FTIR, AFM and SEM. The obtained fibers exhibited a smooth surface with fine structures, emphasizing a ribbon-like morphology with bead-like features within the range of 3 µm to 5 µm in diameter. The aim of this study was to extract the parabens at optimized conditions such as pH, adsorbent dose, contact time and the elution of solvent. To examine the mechanism of adsorption kinetics, the two most commonly used kinetics models (pseudo-first order and pseudo-second order) were employed to test experimental data along with the Morris-Weber diffusion model. The obtained data showed that the maximum sorption efficiency obtained at pH 3.0, adsorbent dose optimized as 10 mg of fiber with time of 24 hours, the methanol was sufficient to elute paraben from fibers met. The experimental data of the adsorption followed by first-order reaction with a mass transfer-controlled diffusion mechanism

Kinetics, equilibrium and thermodynamics investigations of polypyrrole and polyaniline composites with Oryza sativa biomass for the removal of Nitenpyram insecticide

Abstract In this research, composite materials were prepared by combining polypyrrole (PPY) and polyaniline (PAN) with Oryza sativa (OS). These biocomposites were utilized for the adsorption of Nitenpyram (insecticide), from aqueous solutions. The study involved the optimization of various process variables including contact time, pH, adsorbent dose and initial Nitenpyram concentration. The maximum sorption efficiency of OS for Nitenpyram was observed at pH 2, biosorbent dose of 0.05 g, an initial Nitenpyram concentration of 125 mg/L and contact time of 30 min. To analyze the Nitenpyram adsorption process, the adsorption data for OS and its composites (OS-PPY and OS-PAN) were subjected to equilibrium isotherms and kinetics models (pseudo-first and pseudo-second-orders). The Langmuir isotherm and pseudo-second-order explained the Nitenpyram adsorption data. Furthermore, the feasibility of the adsorption was evaluated by employing thermodynamic studies. The outcomes of the study demonstrated the promising efficiency of the synthesized biocomposites for Nitenpyram removal, which was 37.03, 43.0 and 35.71 (mg/g) in the case of OS, OS-PPY and OS-PAN composites. These findings suggest that the composites have promising potential for the removal of pesticides from wastewater, contributing to the development of effective strategies for environmental remediation.

Removal of Zinc Ions from Aqueous Solutions with the Use of Lignin and Biomass Part II

Abstract In response to the trend toward sustainable management of by-products from the pulp and paper industry as well as plant waste, practical and economical methods are being developed to use them in a way that does not pose a threat to the environment. The main aim of the research was to study the possibility of using lignin and plant biomass as biosorbents for the removal of zinc ions from aqueous solutions. The secondary aim was to build an optimal multilayer system made of biosorbents selected during the research in order to obtain the highest sorption efficiency and to determine the best conditions of the sorption process. The effectiveness of zinc ion sorption was assessed using an appropriate combination of sorbents such as lignin, oat bran, rice husk, chitosan, pectin, sodium alginate, pine bark, coconut fiber and activated carbon, selected on the basis of literature data and the preliminary results of tests carried out using FTIR and AAS. The main component of the sorption system was lignin separated from black liquor. Results indicate that the best Zn sorption system was based on coconut fiber, lignin, and pine bark, for which the maximum sorption efficiency was 95%. The research also showed that the increase in the process temperature, the mass of biosorbents used and the alkaline pH are the factors that increase the efficiency of the sorption. It can be concluded that lignin and plant biomass can be used as ecological sorbents of zinc ions from water solutions. They are safe for the environment, produced from renewable sources, and are by-products or waste materials, which is part of the sustainable development and circular economy currently promoted in the EU.

Oil Removal from Polluted Seawater using Carbon Avocado Peel as Bio-Absorbent

Oil spills are a very dangerous occurrence for the marine ecosystem as the marine life-form's existence gets unnecessarily threatened. Since the exploration of oil from marine resources has become a must and oil spills end up occurring accidentally, as a result, it becomes important to employ various oil spill cleanup methods. The purpose of the current work was to evaluate the oil sorption capacity of dried carbonized avocado peel (AP) waste. AP was dried under the sun and microwaved to have the activated carbon AP. In this study, batch adsorption studies were conducted to remove different oil types (Crude oil, Diesel, Kerosene, and Gas oil) from polluted seawater using AP. The effect of various important parameters, namely, mixing time, adsorbent dose, oil dose, oil types, and reusability on the oil uptake, and their optimum conditions for maximum sorption efficiency was studied. Batch studies indicated that an adsorbent dosage of 7 g, mixing time of 20 minutes under a mixing rate of 45–50 revolutions/min, 1 g of oil and provides maximum oil removal efficiency in the present study. Based on the data fit result of the adsorption; the 7 g AP at 20 min (90%) had better oil retention than the 1.5 g (66%), 3 g (77%), and 5 g (82%) AP. The results indicated that the maximum oil adsorption percentage upon increasing the adsorbent dose (1.5 g, 3 g, 5 g, and 7 g peel) was 66-90% for Crude oil, 45-68% for Diesel, 35-56% for Kerosene, and 19-45% for Gas oil at 20 min using 1 gram oil. The results revealed that sorption capacity decreased as the oil got lighter. Increasing the oil dose reduce the adsorption capacity (Crude oil 90-66%, Diesel 64-45%, Kerosene 50-39%, and Gas oil 40-12%). The oil sorption capacities of the AP sorbents reduce gradually from 90-64% after 10 cycles, with about 72%, since the oleophilic nature of the peel surface was affected during the regeneration process. The kinetic data was analyzed for all adsorbent doses. The pseudo-first order kinetic model was found to agree well with then experimental data found. The result showed that AP biosorbent followed pseudo-first order kinetics. According to the results presented, the cheap efficient AP oil spill sorbent could be developed as a potential material to be used in seawater treatment for oil removal. The avocado carbon displayed excellent adsorption properties for the simulated seawater effluents containing oil.

Application of a new derivatives of traizole Schiff base on chromium recovery from its wastewater

ABSTRACT Interaction of 3-Amino-1 H–1,2,4-triazole with 4,4“-Dihydroxybenzil yielded 4,4”-((1E)-1,2-bis((1 H–1,2,4-triazol-3-yl)imino)ethane-1,2-diyl)diphenol. The adsorbent (TIHP) was made by subjecting the synthesized Schiff base to a phosphorylation reaction; its structure was validated by FTIR, TGA, 1HNMR, 13CNMR, GC-MS, and Phosphorus-31 nuclear magnetic resonance (31P-NMR). Chromium oxyanions (Cr(VI)) in water were successfully removed by using the newly synthesized adsorbent (TIHP). Many different variables, namely; the initial concentration of Cr(VI), the period of interaction, the temperature, the amount of the adsorbent dosage, and the pH of aqueous were tested via the batch technique. Maximum sorption efficiency were obtained at pH 2, 45 min contact time, 0.08 dose, at room temperature. When exposed to the proposed foreign ions, Cr(VI) desorption)‘s behavior modifies. The novel adsorbent had an extreme adsorption capability of 307.07 mg/g for Cr(VI) at ambient temperature. Adsorption isotherms could be explained by Freundlich’s isotherm model. The pseudo-second-order equation provided tight limits on the kinetic outcomes. Thermodynamic analyses confirm that the up taking process was spontaneous and endothermic.

Preparation of nitrogen-enriched pine sawdust-based activated carbons and their application for copper removal from the aquatic environment

In this research study, compressed pellets of pine wood sawdust were carbonized at a temperature of 600 °C and then physically activated at 800 °C to obtain activated carbons (ACs). Then, some of the samples were enriched with nitrogen by reaction with urea at 300 °C. The AC samples prepared in this way were examined for the removal of Cu(II) in adsorption processes. Pine wood sawdust is waste resulting from processing in the wood industry and is a promising material to be reused for metal ions recovery. For this purpose, firstly, the AC was characterized using several analytical methods, including ash content, elemental composition, TGA, specific surface area and pore diameter (BET), pore size distribution (BJH), micropore volume, the content of surface acidic and basic functional groups, pH, FTIR and SEM morphology. Secondly, these materials before and after modification with nitrogen were used in experiments on the adsorptive removal of Cu(II) ions from aqueous solutions. The influence of parameters, such as initial pH, adsorbent dosage, initial Cu(II) concentration and contact time on the process, was investigated. Thirdly, adsorption kinetics and sorption isotherms were analyzed. According to the research results, it was reported that maximum sorption efficiency was equal to 99.9 and 99.8% at pH 5 for activated carbon AC (TK6AF1/2) and nitrogen-modified activated carbon NMAC (TK6MAF1/2), respectively. This proves that the examined waste materials exhibit satisfactory sorption properties in relation to Cu(II) ions and can be used as low-cost adsorbents in industrial wastewater treatment processes. These studies are in line with current global trends in sustainable and circular economy. Future research may focus on performing adsorption processes of copper and other metals at various temperatures as well as dynamic flow, studying metal ion competition, performing regeneration to reuse the adsorbents, carrying out realistic wastewater studies and cost estimation of entire processes on a laboratory and industrial scale.

Facile synthesis and adsorption characteristics of a hybrid composite based on ethyl acetoacetate modified chitosan/calcium alginate/TiO2 for efficient recovery of Ni(II) from aqueous solution

Abstract In this study, chemical modification of chitosan has been carried out using epichlorohydrin as crosslinking agent and ethyl acetoacetate as a modifier to graft acetoacetyl moiety. The said organo-functionalization on chitosan and sodium alginate not only offered a novel support for TiO2 immobilization but also enhanced sorption performance for Ni(II) recovery from aqueous medium. So, a composite consisting of acetoacetyl moiety grafted chitosan, sodium alginate and titanium oxide (EAA-MCS/TiO2) was prepared and characterized by fourier transform-infra red (FT-IR) spectroscopy and scanning electron microscopy (SEM). The hybrid composite (3EAA-MCS/TiO2) which had TiO2 to EAA-MCS mass ratio of 20.0% by weight showed maximum sorption efficiency. The formulated sorbent was conditioned in the form of hydrogel beads for operation. Isothermal sorption and kinetics studies were performed at pH = 6.0 to configure the nature of sorption. Pseudo-2nd order rate expression better explained the sorption kinetics and chemisorption is the predominant mode of uptake. Langmuir adsorption model better explained the sorption process (R 2 ∼ 0.99) and maximum monolayer sorption capacity (q m ) at sorption/desorption dynamic equilibrium was computed as 403 mg/g at optimized pH.

Biosorbents for wastewater treatment

Biosorption is a promising technology for removing various pollutants from industrial wastewater, which consists in the use of secondary plant raw materials (e.g., agro-industrial waste) to solve environmental pollution problems. The purpose of this study is to evaluate the potential of nut shells as a biosorbent, to study the effect of alkaline modification of shells on their properties and to study the use of spent biosorbents as additives in cement. The influence of the fractional composition of the initial material on its sorption capacity and the influence of the modification of shells with alkaline solution on the properties of the obtained biosorbents are investigated. The yield of the final products was determined gravimetrically as the ratio of the mass of the product to the mass of the raw material. The sorption capacity was studied using model solutions. The concentration of sodium hydroxide solutions was determined by titration, and the cationic dye by spectrophotometric method. Methylene blue was used as a test dye. The studies have shown that the fractional composition of the material largely determines its sorption properties. Reducing the particle size of the nut shells leads to an increase in the sorption efficiency of methylene blue from 17.2% for the fraction with a size of 1.5-2.0 mm to 39.2% for the fraction with a size of 0.5-1.0 mm. The static exchange capacity increases by an average of 30 % for each subsequent fraction. To improve the sorption properties of the initial material, along with grinding, it is advisable to use chemical modification. The method of alkaline modification was used, which is accompanied by partial destruction of the aromatic component of raw materials and low molecular weight polysaccharides and by removal of extractives of different nature, which leads to the formation of a more porous structure. The maximum sorption efficiency of methylene blue (80 %) corresponds to the biosorbent obtained from nut shells (fractional composition 0.5-1.0 mm) by modifying with 5 % NaOH solution for 180 min at a temperature of 100 oC. Alkaline treatment significantly improves the adsorption capacity of the biosorbent to the cationic dye compared to the initial material. The sorption capacity of nut shells and biosorbent based on shells was studied as a function of pH of aqueous dye solution and duration of contact. It was found that pH of the aqueous solution had a significant effect on the sorption of the dye and the maximum value was reached at pH 6. This is due to the electrokinetic properties of the surface of lignocellulosic materials - the ability to change charge depending on pH (positive in acidic, negative in neutral and alkaline), due to the presence of different functional groups. The study of kinetics showed that the maximum rate of absorption of methylene blue corresponded to the first 30 minutes of contact. Sorption equilibrium is achieved within 240 minutes of contact. Sorption kinetics was also studied using pseudo-first and pseudo-second order models, as well as a diffusion model. The pseudo-second order kinetic model (R2 = 0.99) best describes the absorption kinetics of the cationic dye and suggests that the fixation of methylene blue on the surface of the biosorbent occurs due to various mechanisms. The problem of further use of spent sorption materials is no less important than the efficiency of sorbents in creating an effective integrated water treatment technology. Spent biosorbent was used as an additive to the composition of cement type I/500. The use of plant material in the amount of 5% will not lead to a significant deterioration of the physical and mechanical properties of cement. This indicates the prospects of such an approach in the utilization of spent sorbents. In further research, it is planned to investigate various modification options for plant materials for obtaining highly effective biosorbents of multipurpose function for the solution of environmental problems.

Methylene Blue Dye Removal from Aqueous Media Using Activated Carbon Prepared by Lotus Leaves: Kinetic, Equilibrium and Thermodynamic Study

In the present work, methylene blue was eliminated from aqueous solution using activated carbon prepared by lotus leaves. To perform the experiments, batch method was applied. Also, several analyses such as SEM, FTIR, EDAX and BET were done to determine the surface properties of the activated carbon. The results showed that the maximum sorption efficiency of 97.59% was obtained in initial dye concentration of 10 mg/L, pH of 9, adsorbent dosage of 4 g/L, temperature of 25 °C, contact time of 60 min and mixture speed of 400 rpm. Furthermore, the maximum adsorption capacity was determined 80 mg/g, which was a significant value. The experimental data was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, which the results showed that the pseudo-second order kinetic model could better describe the kinetic behavior of the sorption process. Also, the constant rate of the pseudo-second order kinetic model was obtained in the range of 0.0218-0.0345 g/mg.min. Moreover, the adsorption equilibrium was well described using Freundlich isotherm model. Furthermore, the thermodynamic studies indicated that the sorption process of methylene blue dye using the activated carbon was spontaneous and exothermic.

Highly Effective Adsorption Process of Ni(II) Ions with the Use of Sewage Sludge Fly Ash Generated by Circulating Fluidized Bed Combustion (CFBC) Technology.

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.

Adsorption of nickel ions from electroplating effluent by graphene oxide and reduced graphene oxide

Heavy metal pollution in the water bodies causes a serious threat to all living beings. Extended exposure of heavy metals such as nickel (Ni) ions causes cancer. Henceforth, the current study investigated the removal of Ni ions from the electroplating effluent using nanocomposites namely, Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) in the presence of various factors such as contact time, pH, agitation speed and sorbent dosage. Further, it was determined the rate kinetic model and adsorption equilibrium isotherms. The study also focused on comparing the removal efficiency of two nanocomposites. The maximum sorption efficiency were found to be 90.8% and 84.4% at optimized pH (8), contact time (180–1440 m), RPM (250–300) and adsorbent dosage (0.2 mg/L) for GO and rGO respectively. Furthermore, toxicity of treated and untreated effluent were tested against Phosphobacter and Azospirillium using GO and rGO and found that the treated effluent was non-toxic. The contribution of this study to agriculture in using recycled effluent for crop cultivation was being verified by seed germination of Lablab purpureus seeds watered with treated and untreated effluent. Finally we concluded that the results of treated water can be used for cultivation as there was healthy growth of plants.

Utilization of a Newly Developed Nanomaterial Based on Loading of Biochar with Hematite for the Removal of Cadmium Ions from Aqueous Media

In order to conserve the energy used for remediation of harmful metals from aqueous media, an adsorption process was performed. It is efficient and low-cost method with zero carbon emissions as compared to other methods. A hematite-based novel nanomaterial loaded onto biochar was utilized for the remediation of toxic cadmium metal ions from aqueous media. Saccharum munja has been employed as low-cost feedstock to prepare the biochar. Three adsorbents i.e., raw Saccharum munja (SM), Saccharum munja biochar (SMBC) and hematite-loaded Saccharum munja bichar (HLSMBC) were used in batch adsorption tests to study uptake of metal ions by optimizing the experimental parameters. Experimental data and calculated results revealed maximum sorption efficiency of Cd(II) removal was given by HLSMBC (72 ppm) and SMBC (67.73 ppm) as compared with SM (48.7 ppm). Among adsorption isotherms applied on work best fit for Cd(II) adsorption on SM was found for a Freundlich isotherm with high values of correlation coefficient R2 ≥ 0.9 for all sorbents and constant 1/n values between 0–1. Equilibrium results were evaluated using five different types of errors functions. Thermodynamic studies suggested feasible, spontaneous and endothermic nature of adsorption process, while, the ∆H parameter < 80 kJ/mol indicated physiosorption and positive ∆S values promoted randomness of ions with increase in adsorption process. Data fitted into type I of pseudo second order kinetics having R2 ≥ 0.98 and rate constants K2 (0–1). Desorption process was also performed for storage, conservation and reuse of sorbent and sorbate materials.

Адсорбция органических реагентов природным бентонитом, модифицированным полигидроксокомплексами алюминия и железа (III)

The effective nanostructured sorbents based on natural bentonite modified with aluminum and iron (III) polyhydroxocations were obtained. The elemental composition of the obtained sorbents was studied. The specific surface area was determined for the studied samples. It was shown that modified sorbents based on natural bentonite were nanostructured objects. IR spectroscopy showed that modification of natural bentonite led to the changes in its structural properties. While studying the sorption process on modified sorbents, it was found that the modification of bentonite with aluminum and iron (III) compounds using the “codeposition” method led to the increase in the sorption capacity of the obtained sorbents. The sorption properties of the obtained sorbents were tested in relation to a number of organic dyes of the anionic and cationic types. It was established that the maximum sorption efficiency was achieved for extracting cationic substances from water, including organic dyes.

Eggshell nano-particle potential for methyl violet and mercury ion removal: Surface study and field application

A nano-scale sorbent was produced from eggshell wastes for sorption of Hg(II) and methyl violet (MV) from aqueous solutions and real wastewaters. The properties of the nano-particles were fully determined using SEM, DLS, FTIR, XRD, BET, TGA, AFM, EDAX, mapping, and TEM analyses. The adsorbent structure mainly contained carbonate and silica. The effects of influential parameters including temperature, contact time, initial contaminants concentration, sorbent dose, and initial pH on the removal efficiency were investigated. The maximum sorption efficiency of Hg(II) and MV occurred at pH of 6 and 9 and temperatures of 25 °C and 55 °C, respectively. Freundlich model could be interpreted the equilibrium data of the sorption process of both contaminants. The maximum sorption capacity of Hg(II) and MV using eggshell nano-particles was obtained as 116.27 mg/g and 123.45 mg/g, respectively. The dynamic behavior of the process was studied using two kinetic models. The sorption system performance was also examined and t1/2 were determined as 4.34 min for Hg(II) and 4.97 min for MV. The sorption process of Hg(II) and MV was exothermic and endothermic, respectively. Effective sorption after seven cycles and successful treatment of landfill leachate and textile wastewater with eggshell nano-particles confirms its adequacy.

High Efficiency Mercury Sorption by Dead Biomass of Lysinibacillus Sphaericus-New Insights into the Treatment of Contaminated Water.

Mercury (Hg) is a toxic metal frequently used in illegal and artisanal extraction of gold and silver which makes it a cause of environmental poisoning. Since biosorption of other heavy metals has been reported for several Lysinibacillus sphaericus strains, this study investigates Hg removal. Three L. sphaericus strains previously reported as metal tolerant (CBAM5, Ot4b31, and III(3)7) were assessed with mercury chloride (HgCl2). Bacteria were characterized by scanning electron microscopy coupled with energy dispersive spectroscopy (EDS-SEM). Sorption was evaluated in live and dead bacterial biomass by free and immobilized cells assays. Hg quantification was achieved through spectrophotometry at 508 nm by reaction of Hg supernatants with dithizone prepared in Triton X-114 and by graphite furnace atomic absorption spectroscopy (GF-AAS). Bacteria grew up to 60 ppm of HgCl2. Non-immobilized dead cell mixture of strains III(3)7 and Ot4b31 showed a maximum sorption efficiency of 28.4 µg Hg/mg bacteria during the first 5 min of contact with HgCl2, removing over 95% of Hg. This process was escalated in a semi-batch bubbling fluidized bed reactor (BFB) using rice husk as the immobilization matrix leading to a similar level of efficiency. EDS-SEM analysis showed that all strains can adsorb Hg as particles of nanometric scale that can be related to the presence of S-layer metal binding proteins as shown in previous studies. These results suggest that L. sphaericus could be used as a novel biological method of mercury removal from polluted wastewater.

Application of Modified LECA in Removing Nickel from Wastewater

In the present study, lightweight expanded clay aggregate (LECA) coated with iron oxide was investigated as a low cost sorbent to remove from wastewater. Iron oxide coated LECA (IOCL) as a new sorbent was tested for its efficiency as sorbent using operational parameters such as contact time, the initial pH of the solutions, and sorbent dosage concentration in batch systems. The adsorption characteristics of the natural LECA and IOCL were investigated through scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), and X-ray diffraction (XRD) analysis. The maximum sorption efficiency was found to be 96% for IOCL at an initial pH of 6.0 and a sorbent dosage of 5 . The results revealed that the sorption kinetic data were well fitted to a pseudo second–order kinetic model. The experimental data showed that sorption was considerably high on IOCL and the new sorbent is an economical method for Ni (II) removal from effluents and aqueous media.

Removal of lead and phosphate ions from aqueous solutions by organo-smectite

Smectite has been modified using hexadecyltrimethyl ammonium bromide in an amount of double cationic exchange capacity. This alteration makes it possible to use organo-smectite as a sorbent to remove anionic forms. The experiment consisted of the interchangeable sorption of phosphate(V) and lead(II) by organo-smectite. Research was carried out with varying pH (2–5) and various concentrations (0.1–5 mmol/L). Organo-smectite with previously adsorbed lead ions removed more phosphate than the untreated organo-smectite. Experimental data show that lead is more likely to absorb on the organo-smectite than on the organo-smectite with previously adsorbed phosphate ions. It follows that the most effective use of the organo-smectite is through the sorption of first – Pb cations and then PO4 anions. With an increasing concentration of Pb(II) or P(V), the sorption efficiency increases. The maximum sorption efficiency of lead and phosphate ions is observed at pH 5. This enables the removal of harmful lead and phosphorus compounds from waste water and immobilizes them on the sorbent's surface. The alternating reactions of lead and phosphorus ions result in the crystallization of brompyromorphite Pb5(PO4)3Br.

Biosorpsi Ni2+ oleh Nannochloropsis Salina pada Medium Terpapar Ca2+

Research on biosorption of Ni2+ by N. salina in Ca2+ exposed medium has been done. This study aimed to determine the growth and efficiency of N. salina towards Ni2+ in Conwy Medium with addition of Ca2+. Exposure of mixed ions of Ni2+ 5 ppm and Ca2+ with variation of concentrations 10, 30, 50 ppm was conducted at the beginning of the growth of N. salina. The growth of N. salina was observed every day by counting the number of N. salina population using a microscope and haemocytometer. The concentration of metal ions after the exposure was determined by atomic absorption spectrophotometer. The growth of N. salina in medium with exposed metal ions is lower than the control. The maximum sorption efficiency of Ni2+ as a single ion is 55.2%. After exposure of mixed ions of Ni2+ and Ca2+ with variation of concentrations 10, 30, 50 ppm, the sorption efficiency of Ni2+ in sequents are 17.6%; 17.8%; and 19.6%; while the maximum sorption efficiency of N. salina towards Ca2+ are 5.1%; 7.1%; and 4.0% respectively.DOI :http://dx.doi.org/10.15408/jkv.v0i0.3153

Competitive and Noncompetitive Batch Sorption Studies of Aqueous Cd(II) and Pb(II) Uptake ontoCoffea canephoraHusks,Cyperus papyrusStems, andMusaspp. Peels

Coffea canephora,Cyperus papyrus,andMusaspp. were studied for competitive and noncompetitive removal of aqueous Cd2+and Pb2+. The optimal conditions were pH 4.5 and agitation time 3.0 hours. Biomass constituent ions showed no interference effects whereas cation exchange capacity values corresponded to the sorption efficiencies. XRD spectroscopy revealed surface oxygen and nitrogen groups that provide binding sites for metal ions. The maximum sorption efficiency ranges for metal ions in noncompetitive media were 95.2–98.7% forC. canephora, 42.0–91.3% forC. papyrus,and 79.9–92.2% forMusaspp. and in competitive sorption 90.8–98.0% forC. canephora, 19.5–90.4% forC. papyrus,and 56.4–89.3% forMusaspp. The Pb2+ions uptake was superior to that of Cd2+ions in competitive and noncompetitive media. In competitive sorption synergistic effects were higher for Cd2+than Pb2+ions. The pseudo-second-order kinetic model fitted experimental data with0.917≤R2≥1.000for Pb2+ions and0.711≤R2≥0.999for Cd2+ions. The Langmuir model fitted noncompetitive sorption data with0.769≤R2≥0.999; moreover the Freundlich model fitted competitive sorption data with0.867≤R2≥0.989. Noncompetitive sorption was monolayer chemisorption whereas competitive sorption exhibited heterogeneous sorption mechanisms.

Powdered Activated Lemon Peels as Adsorbent for Removal of Cutting Oil from Wastewater

AbstractBatch adsorption studies were conducted to remove cutting oil from wastewater using activated lemon (species Citrus x limon) peels. The effect of various important parameters, namely, pH, dose of adsorbent, contact time, mixing speed, and initial oil concentration, and their optimum conditions for maximum sorption efficiency were studied. Batch studies indicated that adsorbent dosage of 5 g/L, contact time of 70 min, mixing rate of 45–50 revolutions/min, and pH of 2 provides maximum oil removal efficiency in the present study. Results indicated that the kinetics of sorption of cutting oil on powdered activated lemon peels closely follows Freundlich isotherms. A scanning electron microscope micrograph of powdered activated lemon peels before and after adsorption is presented to prove that the oil has been adsorbed by the adsorbent.