Initial Lead Concentration Research Articles

Efficient Removal Lead (II) from the Environment by Adsorption Using Low-Cost Adsorbent Materials

Pollutants, particularly harmful heavy metals, are released into the environment, posing serious health risks to humans and other living species. The human body does not require lead, which is a toxic chemical. As a result, in order to eradicate or remove lead from the environment, a range of technologies must be used. The goal of this research was to use low-cost, high-efficiency adsorbent materials to adsorb lead (II) ions from aqueous solutions. Adsorption capacity, elimination percent, and batch adsorption settings are all discussed in this work. The adsorption capacity and percentage removal of lead from aqueous solutions by adsorption are affected by the initial concentration, pH, adsorbent dose, contact time, and temperature. The goal of this research was to use low-cost, high-efficiency adsorbent materials to adsorb lead (II) ions from aqueous solutions. The impacts of several parameters on the adsorption process such as pH, contact time, initial concentration of lead (II) ions, and temperature were examined. Therefore, lead (II) ions can be removed from the water body effectively using low-cost adsorbent materials.

Artificial neural network (ANN) approach for modeling of lead (II) adsorption from wastewater using a ragi husk powder

The main sources of lead in the environment are effluent industries such as electroplating, alloying, smelting, mining, refining, pigmenting, plastic manufacture, and metallurgical industries. A batch experiment as well as an Artificial Neural Network (ANN) coupled with a Genetic Algorithm model for the extraction of lead from wastewater was conducted. In the development of the ANN model, a tan sigmoid transfer function for input and a purelin for output layers have been employed. A feed-forward back propagation with a single layer was used with thirteen neurons in the hidden layer. The optimized process parameters, viz., pH, adsorbent dosage, and initial concentration of lead, have been obtained. Based on the regression coefficient value of R2 of 0.998, it was confirmed that the ANN model predicted data and the experimental value data were a perfect match. The maximum percentage removal of lead was obtained at optimum conditions by means of a pattern search algorithm in GA.

Closing the Loop: Dyeing and Adsorption Potential of Mulberry Wood Waste

ABSTRACT This study reports the successful transformation of mulberry wood waste into natural textile dye and adsorbent for Pb2+ ions from an aqueous solution. Fabrics of different chemical compositions were dyed using mulberry wood extract, whereas wool possessed the best appearance and color fastness to washing. Among differently dyed wool fabrics, those dyed with 15% extract for 5 h has the highest color strength (K/S = 11.24) and antioxidant activity (83.5%), and the best color and antioxidant activity fastness to washing, making it appropriate for protecting the skin from diverse damages by decelerating the effect of free radical. Moreover, it could be suggested that the binding mechanism proceeds via strong hydrogen bonds between wool surface carboxylate groups and characteristic phenolics found in the extract (dominantly taxifolin, oxyresveratrol, ellagic acid, and tannins). The mulberry wood solid parts separated after the extraction were further evaluated as adsorbents for Pb2+ ions. The highest lead removal was achieved at a solution pH of 5.5, while the equilibrium removal was reached after 4 h of contact time. At 20 mg/l initial lead concentration, the mulberry wood waste removal efficiency was 98.8%. The results of this study represent a step forward to a healthier, cleaner, and more sustainable society.

Adsorptive Capacity of Calcinated Hen Eggshell Blended with Silica Gel for Removal of Lead II Ions from Aqueous Media: Kinetics and Equilibrium Studies.

In this study, a description was given for the adsorbent CaSiO3 for allure proximate examination and determination like particle density, main part density, and porosity analysis. This is performed before management of batch adsorption experiments. Both kinetics and balance studies for the adsorbent were examined. The influences of various process parameters like lead concentration, pH, adsorbent dosage, and contact temporal length for process removal were explored. The removal efficiency of CaO from eggshell was enhanced to increase after mixing it with silica coagulate compared with added scholar's findings for the same limit. The maximum removal efficiency (99.58%) was obtained by limiting the pH, adsorbent dosage, initial lead concentration, and contact time at 4, 1.8 g, 35 g/L, and 140 minutes, respectively. Thus, blending CaO from eggshells with silica gel can increase the adsorption competency of CaO. Lead removal is well integrated into the Langmuir isotherm model with an equivalent factor of 0.991. The kinetic data of adsorption fit well into a pseudo-first-order model with a correlation coefficient of 0.90111. The pseudo-second-order model was the rate-determining step involved in the lead adsorption process for calcium silicate (CaSiO3) adsorbents.

Hierarchical 13X zeolite/reduced graphene oxide porous material for trace Pb (II) capturing from drinking water

The removal of lead in drinking water has attracted considerable attention of researchers in recent years, especially, the trace characteristic of lead is a challenge to water treatment. Herein, 13X zeolite/reduced graphene oxide composite material (13X-rGO) with hierarchically porous structure was successfully prepared using graphene oxide (GO) and 13X zeolite via a chemical reduction method and presented great performance for removing trace Pb(II) from drinking water. The influence of some important parameters including adsorbent dosage, contact time, initial lead concentration, coexisting competing ions, solution pH value, etc. on the removal of Pb(II) was systematically investigated. The composite material showed better adsorption properties compared with a single component and their physical mixture, confirming the synergistic effect of rGO and 13X zeolite on Pb(II) adsorption. The effluent lead concentration could be decreased to the level permitted by World Health Organization (WHO) (<10 ppb) within 30 s under calcium content of 20 ppm and initial lead concentration of 150 ppb. Simultaneously, the as-prepared 13X-rGO performed excellent adsorption capacity meeting WHO standard (6.07 mg/g), which was about 2.23 times that of single 13X zeolite (2.72 mg/g). In the presence of interfering ions, the lead concentration could still be reduced to safe drinking water standard. Moreover, the adsorbent could be effectively regenerated by saturated sodium chloride solution. Therefore, 13X-rGO can be introduced as a promising adsorption material for the purification of drinking water contaminated with trace lead owing to rapid adsorption, low cost and recycling potential. • 13X-rGO with hierarchically porous structure was prepared by a one-step green method. • 13X-rGO composite achieves the synergistic effect of rGO and 13X zeolite. • 13X-rGO exhibits rapid and selective adsorption ability for trace lead (II) in water. • 13X-rGO shows high adsorption capacity, low cost and recycling potential. • 13X-rGO shows significant potential for trace lead removal from drinking water.

Lead (II) removal from aqueous solution over Al-pillared bentonite as low-cost adsorbent and optimization

This study focuses on the optimization of lead ion (Pb2+) removal from aqueous solution by modified Aceh natural bentonite using response surface methodology (RSM). The modification process involves sodium ion (Na+) from NaCl intercalation and pillarization with aluminum ion (Al+) from AlCl3. The composition of natural and modified bentonite was examined via X-ray fluorescence (XRF). The surface area of the samples was characterized by Brunauer Emmett and Teller surface area (BET) analysis. In addition, the experiments were conducted based on Box-Behnken Design (BBD). Furthermore, adsorption characteristics were investigated as a function of three independent factors comprising bentonite mass (1.0–2.0 g), agitation time (30–200 min), and initial lead concentration (100–500 mg/l). Analysis of variance (ANOVA) depicted the influence of these variables is very significant. Also, optimization equations were developed for the natural, intercalated, and pillared samples. Based on the RSM model, the optimized conditions were found at 1.93 g bentonite mass, 176.42 min agitation time, 367.44 mg/l of its initial adsorbate concentrations viz. 250.264 mg/l (NB), 253.902 mg/l (IB), and 260.768 mg/l at approximately 1.00 desirability. Therefore, Pb2+ adsorption capacity onto the pillared bentonite (PB) appears greater compared to the intercalated and natural materials. Al-pillared bentonite appears to be a promising candidate for the adsorbent of Pb2+ from an aqueous solution.

Preparation of green synthesized copper oxide nanoparticles for efficient removal of lead from wastewaters

Green synthesis is a clean and eco-friendly process in which metal nanoparticles can be produced by the reaction between a metal salt solution and plant organ extract. In the present study, three copper oxide nanoparticles were green synthesized from the leaf extracts of astragalus (Astragalus membranaceus), rosemary (Salvia rosmarinus), and mallow (Malva sylvestris) as predominant plant cover in the study area was characterized. The effectiveness of three green synthesized nanoparticles in the adsorption of lead ions from polluted water was studied. According to the results, the removal efficiencies of the copper oxide nanoparticles synthesized from astragalus (A-CuO-NPs), rosemary (R-CuO-NPs), and mallow leaf extract (M-CuO-NPs) especially at the highest initial concentration of lead (1.5 mM), were 88.4%, 84.9%, and 69.6%, respectively. Probably due to the smooth morphology and more uniform configuration of the M-CuO-NPs, the changes between equilibrium adsorption (q e) and equilibrium concentration (C e) were more regular than those of the A-CuO-NPs and R-CuO-NPs. Therefore, the best fit of the data to the Langmuir and Freundlich isotherms belonged to the adsorption of lead onto the M-CuO-NPs. According to the results reported herein, the copper oxide nanoparticles synthesized from different plant covers are efficient adsorption agents for lead from wastewaters solution.

Removal of Lead Ions from Water Using Pellet Generated from Bacillus subtilis Isolated from Gold Mining Site in Niger State

Abstract&#x0D; This work concentrated on the isolation of lead tolerant strains of bacteria, identification of the isolated strain with the highest lead tolerance capacity using microgen identification kit. Also, the efficacy of the generated pellet (dead cell) in the bioremoval of lead from aqueous solutions was determined. A total of nine bacteria were isolated from soil collected from gold mining site in Kontagora metropolis, Niger State. Of the nine isolates, only Bacillus subtilis (KO1) possess high tolerance capacity for high levels of lead ions. The pellet generated from the Bacillus subtilis (KO1) strain was then used to adsorb lead ions from synthetic ion solutions. The isolate's removal efficiency was enhanced by optimizing several physical conditions (pH, temperature, initial lead concentration and contact time). The best optimized adsorption removal efficiency (&gt;90%) was found at pH 3, temperature 40oC with 100 mg/L of initial concentration of lead after 3 hours of treatment. The use of the pellet generated from eco-friendly Bacillus subtilis (KO1) has great potential and additional benefits in terms of lead removal.

Conversion of waste cooking oil into value-added emulsion liquid membrane for enhanced extraction of lead: Performance evaluation and optimization

This research study investigated the synthesis of environmentally benign green emulsion liquid membrane (GELM) employing waste cooking oil (WCO) as diluent. The emulsion was prepared using D2EHPA as the carrier, Span 80 as surfactant, and sulphuric acid as internal/stripping agent. The influence of nine operating variables namely, Span 80 concentration, D2EHPA concentration, shaking time, shaking speed, pH of the feed, treat ratio (TR), H2SO4 concentration, lead concentration in feed, and volume ratio of organic phase to aqueous phase (O/A) on the performance of lead extraction was studied. Plackett Burman design (PBD), was employed for the screening of variables. The Pareto analysis shows that six variables were the most significant variables at the confidence level of 95%. The selected variables were then screened applying Box-Behnken design (BBD). The optimum values of the variables were: D2EHPA concentration – 4.6 (v/v%), Span 80 concentration – 2.14 (v/v%), pH of the feed – 4.4, internal phase (H2SO4) concentration – 2 M, initial lead concentration – 173 ppm, phase ratio (O/A) – 1.3. At these optimum conditions, a maximum lead extraction of 97.39% was obtained. The mechanism for the extraction of lead was analyzed. Reuse and recycling of membrane phase show that the GELM can be recycled for 7 cycles without reduction in lead extraction efficiency. Kinetic analysis of lead extraction was performed using zero, first, and second-order model at optimum condition. The experimental data fitted well with first-order (R2 – 0.9653). Thermodynamic studies indicated that the extraction procedure is endothermic, spontaneous in nature.

Removal of Lead (Pb) From Aqueous Solutions Using Lignocellulose Nanofiber

The objective of this study was to investigate the removal of lead from aqueous solutions using Lignin-containing cellulose (LCNF) as natural adsorbent and advanced material in the batch system. The water sources contaminated with heavy metals, such as lead, have now become one of the major issues in the world due to non-degradability and huge adverse effects on the health of living organisms. X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) were used to analyze the physical, chemical, and structural properties of LCNFs. The parameters measured in the batch system included pH (4-9), adsorbent dosage (0.1-1 g), contact time (15-120 minutes), initial lead concentration (10-50 mg/L), and temperature (15-40°C). The data for each treatment were statistically studied by analysis of variance (ANOVA) and Duncan’s test. Based on the results, the optimal parameters were determined to be initial lead concentration of 10 mg/L, pH of 6, and adsorbent dosage of 0.3 g/L. The highest lead removal efficiency was achieved at 25°C. The system reached equilibrium at 60 minutes, and then there was little change in lead removal. The results of this study showed that LCNF, by removing more than 99% of lead from aqueous solutions, is a suitable adsorbent for removing lead from aqueous solutions.

Lead Removal From Simulated Wastewater Using Magnetite As Adsorbent With Box–Behnken Design

The current education explores the magnetite aptitude by way of adsorbent in eliminating lead metal from simulated wastewater (SWW). The effect of magnetite dose, initial lead concentration, pH solution, and Adsorption time on the elimination procedure remained explored. The adsorbent remained considered through different instrumental methods (FTIR, SEM, and surface area analyzer) and was rummage-sale aimed at the elimination of Pb2+ metals from SWW. It remained initiate that the lead elimination touched 88.9 % through 0.3 g magnetite dose,75 min,2 ppm original concentration of lead thru pH = 6 at room temperature. The limits of adsorption were strong-minded aimed at heavy metals adsorption utilizing Langmuir and Freundlich isotherms. The consequences deliver robust evidence to support the adsorption mechanism hypothesis.

Effective removal of heavy metals from industrial effluent wastewater by a multi metal and drug resistant Pseudomonas aeruginosa strain RA-14 using integrated sequencing batch reactor

Sequencing batch reactor (SBR) is useful in removal of both non-biodegradable and biodegradable contaminants from wastewater. The main aim of the present investigation was to evaluate the potential of biocatalyst strain RA-14 on heavy metal removal under SBR. The selected strain was screened from the soil sediment contaminated with heavy metals. It was able to survive at different (Hg2+, Pb2+, Zn2+, Cu2+, Cd2+ and Ni2+) heavy metals (>500 ppm). The bacterial strain RA-14 showed maximum bioaccumulation potential than other strains. Heavy metal resistance patterns of Pb2+ > Cu2 > Cd2+ > Hg2+, Ni2+ and Zn2 was observed. Strain RA-14 was resistant to penicillin–G, nalidixic acid, ceftazidime, cefotaxime, kanamycin and ampicillin. The results revealed that bioaccumulation activities were improved at pH 7.0 (83.2 ± 1.8%), 40 °C (89.34 ± 3%) and affected at higher pH values and temperature. The results showed that contact time and initial Lead concentration was also affected Lead accumulation. The heavy metal tolerant strain RA-14 was further investigated towards heavy metal removal in SBR. Heavy metal was removed in SBR within 10 h of hydraulic retention time. Heavy metal removal was high at 2 mg/L (0.33 mg/L Cu2+, 0.33 mg/L Hg2+, 0.33 mg/L Pb2+, 0.33 mg/L Zn2+, 0.33 mg/L Cd2+ and 0.33 mg/L Ni2+) heavy metals. Total nitrogen, biological oxygen demand (BOD) and chemical oxygen demand (COD) of treated water in SBR was removed and the removal efficacy was 91.3 ± 2.1%, 97.6 ± 3.3%, and 94.3 ± 4.4%, respectively in 10 h hydraulic retention time. However, the efficiency of BOD, COD and total nitrogen content removal was decreased, due to the reduced metabolic process of bacteria after 10 h. The SBR reactor proved to be an efficient method for the treatment of various heavy metals from the wastewater.

Characterization and Use of Char Produced from Pyrolysis of Post-Consumer Mixed Plastic Waste

In this work, the pyrolysis of post-consumer mixed plastic waste (polypropylene (PP), polystyrene (PS) and polyethylene film (PE)) is carried out. The solid product of the pyrolysis is characterized and tested for its use as adsorbent of lead present in aqueous media. The pyrolysis temperature has a great influence on the solid product yield, decreasing when the temperature increases. The highest yield to solid product obtained is from the pyrolysis of film at lower temperature (450 °C), reaching almost 14%. The results of product solid characterization reveal that the carbon, hydrogen and nitrogen content decreases with increasing pyrolysis temperature. Furthermore, both the ash and the volatile content are related to the pyrolysis temperature. The ash content is higher when the pyrolysis temperature is higher, while when the temperature increases, a solid product with lower volatile content is obtained. In respect to specific surface area, a higher pyrolysis temperature improves the properties of the solid product as an adsorbent. The adsorption capacity increases as the pyrolysis temperature increases, with the highest value of 7.91 mg/g for the solid obtained in the pyrolysis at 550 °C. In addition, adsorption capacity increases as the initial concentration of lead rises, reaching a maximum value close to 26 mg/g for an initial concentration of 40 mg/L. The Sips model is the one that best reproduces the experimental results of the adsorption process equilibrium study.

METODOLOGIA DE SUPERFÍCIE DE RESPOSTA PARA OTIMIZAÇÃO DA ADSORÇÃO DE METAIS PESADOS EM UMA SOLUÇÃO MULTI-METAIS POR PELLETS DE ZEÓLITAS DE BENTONITA-CAOLIM

Background: Heavy metals contamination of surface and groundwater is a major environmental problem. Clay minerals are porous and are efficient to adsorb metal ions. Amongst the available treatment technologies, adsorption is the most cost-effective, easy to operate, scalable, and replicable to remediate heavy metals from water solution. Aim: This study aimed to assess the adsorption performance of clay pellets of natural aluminosilicates, bentonite (29%), kaolin (4%) and zeolite (67%) to remove heavy metals from aqueous solutions. Methods: The effect of optimal operating conditions like contact time, adsorbent dose, pH, and heavy metals initial concentration has been studied. Kinetic and equilibrium studies were also performed. Adsorbents were characterized using FTIR analysis. Results and Discussion: Optimum values for contact time, adsorbent dose, pH, and initial concentration of lead, copper, and cadmium were; 240 min; 25 g/L; 4.3; and 4mg/L, 7 mg/L and 2 mg/L, respectively. The Langmuir isotherm was the best-fitted isotherm model for the three metals. Adsorption kinetics showed that the lead and copper adsorption followed the pseudo-second-order model while cadmium suited with the pseudo-first-order model. The selectivity of the pellets towards the metal ions was in the order of Pb &gt; Cu &gt; Cd. Conclusions: The new combination of bentonite-kaolinite-zeolite pellets worked well in tertiary wastewater treatment and successfully utilized as a natural adsorbent in multimetal solution. The results confirmed that the used clay pellets have better adsorption capacity than many other reported studies. Maximum adsorption capacity can be further increased by adjusting the calcination temperature and applying chemical treatments to the clay pellets before extrusion. The response surface analysis evaluated the predicted optimal values for the four operating factors.

RESPONSE SURFACE METHODOLOGY FOR OPTIMIZATION OF HEAVY METAL ADSORPTION IN A MULTIMETAL SOLUTION BY BENTONITE-KAOLIN-ZEOLITE PELLETS

Background: Heavy metals contamination of surface and groundwater is a major environmental problem. Clay minerals are porous and are efficient to adsorb metal ions. Amongst the available treatment technologies, adsorption is the most cost-effective, easy to operate, scalable, and replicable to remediate heavy metals from water solution. Aim: This study aimed to assess the adsorption performance of clay pellets of natural aluminosilicates, bentonite (29%), kaolin (4%) and zeolite (67%) to remove heavy metals from aqueous solutions. Methods: The effect of optimal operating conditions like contact time, adsorbent dose, pH, and heavy metals initial concentration has been studied. Kinetic and equilibrium studies were also performed. Adsorbents were characterized using FTIR analysis. Results and Discussion: Optimum values for contact time, adsorbent dose, pH, and initial concentration of lead, copper, and cadmium were; 240 min; 25 g/L; 4.3; and 4mg/L, 7 mg/L and 2 mg/L, respectively. The Langmuir isotherm was the best-fitted isotherm model for the three metals. Adsorption kinetics showed that the lead and copper adsorption followed the pseudo-second-order model while cadmium suited with the pseudo-first-order model. The selectivity of the pellets towards the metal ions was in the order of Pb &gt; Cu &gt; Cd. Conclusions: The new combination of bentonite-kaolinite-zeolite pellets worked well in tertiary wastewater treatment and successfully utilized as a natural adsorbent in multimetal solution. The results confirmed that the used clay pellets have better adsorption capacity than many other reported studies. Maximum adsorption capacity can be further increased by adjusting the calcination temperature and applying chemical treatments to the clay pellets before extrusion. The response surface analysis evaluated the predicted optimal values for the four operating factors.

Assessment of lead biosorption performance of spent Gelidiella acerosa (marine macro algae): Optimization, isotherm, kinetic, and column studies

AbstractIn this research, biosorption of Lead using spent Gelidiella acerosa from synthetic aqueous phase was studied in batch and fixed bed modes. Biosorbent was prepared from waste biomass of Gelidiella acerosa after extraction of agar as a model industrial waste recycle. The process efficiency and optimum lead uptake were evaluated by considering initial pH, lead concentration, and biosorbent dosage as process variables and contact time and temperature as fixed parameters. Central composite design of Response Surface Methodology was used to optimize process parameters and ANOVA showed that initial pH of lead solution significantly influences the biosorption. Interaction effects of different process parameters on process efficiency were analyzed with the help of surface response plots. The highest lead biosorption of 90.75% was noticed at optimum conditions of pH 5.15, initial lead concentration 27.35 mg L−1 and biosorbent dosage 0.04 g. Various kinetic equations were used to analyze the biosorption mechanism and found that metal binding is due to chemical reaction with multi stage mass transfer. Langmuir isotherm was found to be well fitted to equilibrium data. Column studies were also conducted to assess the suitability of the process to continuous operations. The most popular Thomas and Yoon nelson models were used to evaluate the fitness of column studies. Biosorbent was characterized using FTIR and SEM to determine surface functional groups and surface texture.

The effect of long-term freeze-thaw cycles on the stabilization of lead in compound solidified/stabilized lead-contaminated soil

The solidification/stabilization (S/S) method is a common technique for the remediation of soils polluted by heavy metal. This study, thus, evaluated the long-term effectiveness, in term of the stabilization of lead in the solidified/stabilized soils, under freeze-thaw cycles, which are important physical processes that lead to material weathering. Three types of compound binders were obtained by mixing the three most commonly used binders (cement, quicklime, and fly ash) in varying proportions for the remediation of lead-contaminated soils. The leachability, chemical forms, and microstructure characteristics of the solidified/stabilized samples after various numbers freeze-thaw cycles (i.e., 0, 30, 90, and 180 times) were examined by utilizing the toxicity characteristic leaching procedure (TCLP) test, chemical speciation analysis, and scanning electron microscopy (SEM). The results showed that the long-term freeze-thaw cycles lead to decreased leachate pH and increased lead concentration in the leachate. The larger the total mix quantities of cement and quicklime, the lower the concentration of lead was presented in the leachate, however, indicating that cement and quicklime are more effective in immobilizing lead ions than fly ash. Chemical speciation analysis revealed that the long-term freeze-thaw cycles did, however, reduce the content of carbonate-bound form lead while the quantity of the ion-exchange forms. SEM further confirmed the observed leaching characteristics and chemical speciation characteristics. In addition, it indicated that, at the same number of freeze-thaw cycles, high initial lead concentrations substantially delayed the hydration process of cement in solidified lead-contaminated soil.

Removal of Pb(II) from contaminated waters using cellulose sulfate/chitosan aerogel: Equilibrium, kinetics, and thermodynamic studies

In this study, the cellulose sulfate/chitosan aerogel (CCA) was prepared by chitosan and sulfonated cotton, and its efficiency was assessed for lead removal from contaminated waters. The adsorbent was determined by FESEM, EDS, FTIR, and BET analysis. The batch experiments were designed by Design-Expert software. At an initial lead concentration of 300 mg L−1, the contact time of 40 min, and the temperature of 26 °C, the maximum adsorption capacity and the removal efficiency were 137.8 mg g−1 and 91.9%, respectively. Also, the effect of ions including cations and anions at 100 mg L−1 was investigated, and it was found that the presence of anions does not have much effect on adsorption, but among cations, calcium and magnesium have the inhibitor effect on adsorption due to their double plosive. Adsorption isotherms were studied at different temperatures, and the kinetics of the reaction were investigated at different concentrations. Thermodynamic parameters indicated that the adsorption process was spontaneous, endothermic, and increasing irregularity at the adsorbent level. Adsorption recovery was performed five times adsorption and de-adsorption by hydrochloric acid 1 M washing and only 10% of adsorption capacity was decreased.

A study on effective adsorption of lead from an aqueous solution using Copper Oxide nanoparticles

In this work, the co-precipitation method was used to prepare copper oxide nanoparticles, which were found 21.6 nm in size, as calculated from the Debye-Scherrer equation. The prepared material was characterized using XRD and UV-Visible spectroscopy and further evaluated for its efficiency in adsorptive removal of Pb(II). To optimize the adsorption process was tried in the range: nanoparticle dosage (0.1-1 g/L), reaction time (0.5-2 hour), initial pH of the solution (2-6), and initial concentration of Lead (5-15 ppm). A linear fitting of equilibrium data to Langmuir and Freundlich isotherms was also explored and carried out. The results indicated that data obtained from the experiment fit better with the Freundlich isotherm model, attaining qmax for lead ions as 97 mg/g. Kinetic studies showed better fitting with a pseudo-second-order kinetic model signifying the mechanism of adsorption as chemisorption. The result advocate that synthesized adsorbent proved useful in adsorbing led from water.

Enhanced lead (II) removal with low energy consumption in an electrocoagulation column employing concentric electrodes: process optimisation by RSM using CCD

ABSTRACT The study aimed at complete elimination of lead with minimum energy consumption using electrocoagulation process employing concentric electrodes made of aluminium. The process was optimized using RSM for chosen variables: current intensity, initial pH, initial lead concentration and time. Quadratic models were generated and assessed using four factorial CCD. A significant quadratic regression model was obtained and validated using ANOVA. Complete removal was attained for optimised conditions having 6 pH, 0.3A current intensity, 41 mg/L initial Lead concentration,13 minutes of applied time duration using energy of 0.77 watt-hour per gram removal of lead. Adsorption followed pseudo Ist order kinetics with a good fitting of the Langmuir isotherm model. Overall process was well optimised with quite low operational cost of 0.00092 US $.