scholarly journals Adsorption of Cyanide from Cassava Wastewater Using Calcined and Activated Oyster Shell Ash

Author(s):  
Oto-Obong P. Akpan ◽  
B. R. Etuk

Calcined ash and activated ash adsorbents were prepared from oyster shell. The physico-chemical properties of the prepared calcined oyster shell ash (COSA) and activated oyster shell ash (AOSA) were obtained using ASTM standards and Sears method. The results show that AOSA is a better adsorbent for removal of cyanide from cassava wastewater than COSA. The adsorption of cyanide from cassava wastewater onto adsorbents (COSA and AOSA) was investigated as a function of pH, adsorbent dosage, contact time, temperature and initial cyanide concentration. The batch study reveals that the adsorption process is strongly pH dependent and maximum cyanide removal is found to occur at pH of 10. The highest percent removal of cyanide from cassava wastewater was found at contact time of 80 minutes and 30oC. The effect of temperature on the adsorption process shows a small increase in the percent cyanide removal followed by a large decrease which suggests physical adsorption as the adsorption mechanism. The percent cyanide removal efficiency decreases with increase in initial cyanide concentration and increases with increase in adsorbent dosage.

2019 ◽  
Vol 233 (2) ◽  
pp. 201-223 ◽  
Author(s):  
Khalida Naseem ◽  
Rahila Huma ◽  
Aiman Shahbaz ◽  
Jawaria Jamal ◽  
Muhammad Zia Ur Rehman ◽  
...  

Abstract This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.


2020 ◽  
Vol 12 (1) ◽  
pp. 167-177
Author(s):  
Ayuba Abdullahi Muhammad ◽  
Nyijime Thomas Aondofa

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment.


2021 ◽  
Author(s):  
Rachida Souidi ◽  
yasmina khane ◽  
Lahcen Belarbi ◽  
Smain Bousalem

Abstract In this work, the sawdust of vine wood (VW) was treated with sulfuric acid and used to adsorb methylene blue (MB) from aqueous solutions via a batch adsorption process. The characteristics of the adsorbent were determined by various analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) and Brunauer−Emmett−Teller (BET) N2 adsorption−desorption isotherms. The effects of various experimental parameters including sulfuric acid concentration, particle size of the adsorbent, pH of the solution, contact time, initial concentration, adsorbent dosage and temperature on adsorption of MB by activating sawdust were systematically investigated. The experimental results showed that the adsorption efficiency was increased with contact time and adsorbent dosage. The maximum removal efficiency was found after 180 min of solid/liquid contact with adsorbent doses of 1 g/l for sawdust. The isotherm and kinetic experimental data for MB adsorption on VW sawdust were best-fitted by Langmuir models and Pseudo-second-order, respectively. The calculated values of the entropy (ΔS°), enthalpy (ΔH°) and Gibbs energy (ΔG°) indicated that the adsorption process was exothermic in nature. These results suggest that the activated sawdust can be employed as a low-cost and environmentally friendly adsorbent for the treatment of wastewaters containing dyes.


2020 ◽  
Vol 40 (3) ◽  
pp. 22-28
Author(s):  
Angel Villabona Ortíz ◽  
Candelaria Nahir Tejada-Tovar ◽  
Rodrigo Ortega Toro

The effect of temperature on the adsorption of Cr (VI) was determined with waste materials from the agroindustry, such as palm bagasse and plantain peels, by determining the thermodynamic parameters which allow to establish the mechanisms that control the process. The methodology included an initial preparation of the biomass, its characterization, and subsequent adsorption tests by setting the initial concentration of the metal to 100 ppm, a particle size of 0,5 mm, a biomass amount of 0,325 g, pH 2, and a volume of 100 mL. The process temperature varied between 303,15, and 352,15 K. The concentration of the remaining metal in the solution was performed using the diphenyl carbazide colorimetric method through a UVVis spectroscopy at a wavelength of 540 nm. The results show that the effect of temperature does not present a defined trend for palm bagasse, whereas it is linear for adsorption using plantain peels. Furthermore, the process of adsorption of Cr (VI) with palm bagasse is more favorable at higher temperatures, since it is a spontaneous process with a physical adsorption mechanism. On the other hand, the adsorption process with plantain peels is thermodynamically feasible at temperatures from 40 to 55 °C and not spontaneous at higher temperatures. Also, a physicochemical adsorption mechanism was evinced. It is concluded that the use of the studied materials is possible in the removal of the Cr (VI) ion in aqueous solutions.


2020 ◽  
Author(s):  
Fola Temilade Akinhanmi ◽  
Edwin Andrew Ofudje ◽  
Idowu Abideen Adeogun ◽  
Aina Peter ◽  
Joseph Mayowa Ilo

Abstract The presence of heavy metals in polluted water is known not only to cause stern harm to marine organisms but also to terrestrial plants and animals including human beings. This research applied low-cost and environmental benign adsorbent primed from waste orange peel (OP) for the removal of Cd(II) ions from aqueous solution via batch adsorption process. The surface properties of the orange peel powder were studied using Scanning Electron Microscopy (SEM), X-ray spectroscopy (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Operational conditions like temperature, contact time, sorbent dosage, solution pH and initial adsorbate concentration were investigated. The utmost uptake of Cd(II) ion was obtained at a contact time of 120 mins, initial metal concentration of 240 mg/L, adsorbent dosage of 0.04 g/L, temperature of 45 °C and solution pH of 5.5. Equilibrium results showed that the orange peel adsorbent has an adsorption capacity of 128.23 mg/g as obtained from the Langmuir isotherm. The adsorption kinetics data followed a pseudo-first-order kinetic model with correlation coefficient (R2) >0.9 and low standard % error values. The adsorption process was found to be endothermic in nature with enthalpy of 0.0046 kJ mol−1 and entropy of-636.865 Jmol-1K-1 respectively. Results from the optimization study indicated that higher adsorbent dosage and lower Cd(II) ion concentration increased the percentage of Cd (II) ion removal. Thus, orange peel could be used in the removal of Cd(II) ion from aqueous solutions.


2020 ◽  
Vol 45 (6) ◽  
Author(s):  
K. A. ABDULSALAM ◽  
B. H. Amodu ◽  
O. K. Fakorede ◽  
J. M. Adelowo ◽  
A. P. Onifade ◽  
...  

One of the most problematic groups of water pollutants is dye, a main constituent of textile industrial wastewater, which is carcinogenic. Therefore, this research delved into adsorption of dyes from textiles and wastewater using acid-treated as an adsorbent. The adsorbent was prepared by functionalizing the pod of carob with concentrated H3PO4. The effects of operational parameters such as adsorbent dosage, contact time, initial concentration of dye and temperature were studied and optimized using central composite design of design of experiment (DOE). The effects of process parameters (contact time, concentration, adsorbent dosage and temperature) on the dye adsorption were determined and optimized. It was observed that the colour removal efficiency increased with an increase in adsorbent mass and contact time. The adsorption process is endothermic as the percentage removal increases with temperature. The optimum contact time, concentration, adsorbent dosage and temperature were found to be 60oC, 9.74hr, 10ppm, and 5g respectively for the maximum decolorization.


2016 ◽  
Vol 6 (3) ◽  
pp. 377-388 ◽  
Author(s):  
Ibrahim Umar Salihi ◽  
Shamsul Rahman Muhamed Kutty ◽  
Muhamed Hasnain Isa ◽  
Nasir Aminu

Pollution caused by heavy metals has become a serious problem to the environment nowadays. The treatment of wastewater containing heavy metals continues to receive attention because of their toxicity and negative impact on the environment. Recently, various types of adsorbents have been prepared for the uptake of heavy metals from wastewater through the batch adsorption technique. This study focused on the removal of zinc from aqueous solution using microwave incinerated sugarcane bagasse ash (MISCBA). MISCBA was produced using microwave technology. The influence of some parameters such as pH, contact time, initial metal concentration and adsorbent dosage on the removal of zinc was investigated. The competition between H+ and metal ions has affected zinc removal at a low pH value. Optimum conditions for zinc removal were achieved at pH 6.0, contact time 180 min and adsorbent dosage of 10 g/L, respectively. The maximum adsorption capacity for the removal of zinc was found to be 28.6 mg/g. The adsorption process occurred in a multilayered surface of the MISCBA. Chemical reaction was the potential mechanism that regulates the adsorption process. MISCBA can be used as an effective and cheap adsorbent for treatment of wastewater containing zinc metal ions.


Author(s):  
Salaudeen Abdulwasiu Olawale ◽  
Abdulrahman Wosilat Funke ◽  
Aliyu Haruna Dede ◽  
Abudukadiri Habeeb

This study was carried out to examine the adsorption isotherm (Langmuir, Freundlich, Temkin, and Dubinin Radushkevich adsorption isotherm) of Pb(II) and Cu(II) in order to determine the  maximum adsorption capacity of chicken feather, CF. Equilibrium sorption of Pb(II) and Cu(II) using homogeneously sized Chicken Feather (CF) was carried out and the physico-chemical properties of the feathers were determined. Results revealed that the maximum biosorption capacity of Pb(II) and Cu(II) by the chicken feather from Langmuir isotherm model were 79.36 and 61.92 mg/g respectively. Separation factor RL were 0.195 and 0.018 indicating a favourable adsorption process. Mean free energy (E) from Dubinin Radushkevich isotherm model were 1.291 and 0.102 KJ/mol for Pb(II) and Cu(II) respectively, indicating a physical adsorption process. Negative standard Gibbs free energy (ΔG) obtained indicated that the Pb(II) biosorption process was spontaneous and thermodynamically feasible.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Hadi Dehghani ◽  
Amir Hessam Hassani ◽  
Rama Rao Karri ◽  
Bahareh Younesi ◽  
Mansoureh Shayeghi ◽  
...  

AbstractIn the present study, the adsorptive removal of organophosphate diazinon pesticide using porous pumice adsorbent was experimentally investigated in a batch system, modelled and optimized upon response surface methodology (RSM) and artificial neural network-genetic algorithm (ANN-GA), fitted to isotherm, kinetic and thermodynamic models. The quantification of adsorbent elements was determined using EDX. XRD analysis was utilized to study the crystalline properties of adsorbent. The FT-IR spectra were taken from adsorbent before and after adsorption to study the presence and changes in functional groups. The constituted composition of the adsorbent was determined by XRF. Also, the ionic strength and adsorbent reusability were explored. The influences of operational parameters like pH, initial pesticide concentration, adsorbent dosage and contact time were investigated systematically. ANN-GA and RSM techniques were used to identify the optimal process variables that result in the highest removal. Based on the RSM approach, the optimization conditions for maximum removal efficiency is obtained at pH = 3, adsorbent dosage = 4 g/L, contact time = 30 min, and initial pesticide concentration = 6.2 mg/L. To accurately identify the parameters of nonlinear isotherm and kinetic models, a hybrid evolutionary differential evolution optimization (DEO) is applied. Results indicated that the equilibrium adsorption data were best fitted with Langmuir and Temkin isotherms and kinetic data were well described by pseudo-first and second-order kinetic models. The thermodynamic parameters such as entropy, enthalpy and Gibbs energy were evaluated to study the effect of temperature on pesticide adsorption.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
M. Muhammad ◽  
Moonis Ali Khan ◽  
T. S. Y. Choong

Adsorption ofβ-carotene on mesoporous carbon coated monolith (MCCM) from methyl ester as a solvent was investigated. Kinetics and thermodynamics parameters have been evaluated. Maximumβ-carotene adsorption capacity was 22.37 mg/g at 50 °C. Process followed Langmuir isotherm. The adsorption was endothermic and spontaneous. Contact time studies showed increase in adsorption capacity with increase inβ-carotene initial concentration and temperature. Pseudo-second-order model was applicable to the experimental data. The value of activation energy confirmed physical adsorption process.


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