scholarly journals Kinetic and isotherm modeling of adsorption of dyes onto rice husk carbon

2013 ◽  
Vol 12 (2) ◽  
pp. 190-196 ◽  

Rice husk carbon (RHC) has the ability to adsorb the dyestuff from aqueous solution. It may be useful low cost adsorbent for the treatment of effluents, discharged from textile industries. The effectiveness of RHC have been tested for the removal of colour from the wastewater samples containing three dyes namely crystal violet, direct orange and magenta. Effect of various parameters such as agitation time, pH, temperature, adsorbent dose and concentration have been investigated in the present study. The adsorption of dyes have been best described by pseudo first order mechanism and Freundlich adsorption isotherms. The rate constant of adsorption (Kad) have been determined, which are found to be 6.8 x 10–3, 8 x 10–3 and 10 x 10–3 min–1 for crystal violet, direct orange and magenta respectively. Similarly the Freundlich constants related to the adsorption capacity (Kf) are found to be 0.74, 0.44 and 0.68 g l–1 and intensity of adsorption (n) are found to be 0.41, 0.73 and 0.33 mg g–1 for above dyes respectively.

2011 ◽  
Vol 356-360 ◽  
pp. 1289-1292
Author(s):  
Dan Fu ◽  
Yi He Zhang ◽  
He Li Wang ◽  
Feng Zhu Lv

In this paper, the adsorption properties of TNT on Rice husk active carbon (RHAC) were investigated. The effects of contact time was examined. Kinetic data obtained at different concentrations were conducted using Lagergren’s pseudo first-order, pseudo second-order and diffusion models. The regression results showed that the adsorption kinetics was more accurately represented by pseudo second-order model. The study indicates that there is significant potential for RHAC as an adsorbent material for TNT removal from wastewater.


2020 ◽  
Vol 3 (6) ◽  
pp. 857-870
Author(s):  
Shagufta Zafar ◽  
Muhammad Imran Khan ◽  
Mushtaq Hussain Lashari ◽  
Majeda Khraisheh ◽  
Fares Almomani ◽  
...  

AbstractThe present study investigates the removal of copper ions (Cu (II)) from aqueous solution using chemically treated rice husk (TRH). The chemical treatment was carried out using NaOH solution and the effect of contact time (tc), adsorbent dosage (Dad), initial Cu (II) concentration ([Cu]i), and temperature (T) on the percentage removals of Cu (II) (%RCu) were investigated. Different analytical techniques (FTIR, SEM, and EDX) were used to confirm the adsorption (ads) of Cu (II) onto the TRH. The ads kinetics was tested against pseudo-first-order (PFO) and pseudo-second-order (PSO) models as well as Langmuir and Freundlich isotherms. Treating RH with NaOH altered the surface and functional groups, and on the surface of RH, the ionic ligands with high electro-attraction to Cu increased and thus improved the removal efficiency. The %RCu decreased by increasing the [Cu]i and increased by increasing the ct, Dad, and T. Up to 97% Cu removal was achieved in ct of 30 min using Dad of 0.3 g [Cu]i of 25 mg L−1 and T = 280 K. The ads of Cu on TRH is endothermic, spontaneous, follows Langmuir isotherms, and exhibited a PSO kinetics. Moreover, the TRH was successfully regenerated and used for further adsorption cycles using 1 M HNO3.


2013 ◽  
Vol 842 ◽  
pp. 187-191
Author(s):  
Guang Fu Xu ◽  
Zhao Xi Shen ◽  
Rui Xin Guo

As an agricultural waste available in large quantity in China, Orange peel was utilized as low-cost adsorbent to remove furadan from aqueous solution by adsorption. Pseudo-first-order, second-order models and intraparticle diffusion model were applied to analyze experimental data and thus elucidated the kinetic adsorption process. The high values of correlation coefficients showed the data conformed well to the pseudo-first-order rate kinetic model over the initial stage of the adsorption processes. The plots were not linear over the whole time range, implying that more than one process affected the adsorption: the first one representing surface adsorption at the beginning of the reaction and the second one was the intraparticle diffusion at the end of the reaction. The results in this study indicated that orange peel was an attractive candidate for removing furadan from the aqueous solution.


2013 ◽  
Vol 49 (1) ◽  
pp. 101-111 ◽  
Author(s):  
R. M. Lattuada ◽  
M. C. R. Peralba ◽  
J. H. Z. Dos Santos ◽  
A. G. Fisch

2020 ◽  
Vol 21 (2) ◽  
pp. 1-6
Author(s):  
Noor Abdul Ameer Mohammed ◽  
Abeer I. Alwared ◽  
Mohammed S. Salman

The reactive yellow azo dye (λmax = 420 nm) is widely utilized for textile coloring due to its low-cost stability and tolerance properties. Treatment of dye-containing wastewater by traditional methods is usually inadequate because of its resistance to biological and chemical degradation. From this research, the continuous reactor of an advanced oxidation method supported the use of H2O2/TiO2/UV to remove the coloration of the reactive yellow dye from the discharge. At constant best conditions obtained from the batch reactor tests pH=7, H2O2 dosage = 400 mg/l and TiO2=25mg/l , the aqueous solutions were tested in the continuous reactor at different dye concentration and different flow rates . The maximum removal efficiency was found to be 91.552% obtained at the flow rate 5 l/h, also the results of decomposition information proved that method was pseudo-first-order kinetics.  


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongxue Qi ◽  
Xianjun Niu ◽  
Haipeng Wu ◽  
Xiuping Liu ◽  
Yongqiang Chen

To investigate the adsorption behavior of Cu (I)-MOF material for chromium (VI) in water, the parameters of influencing adsorption were optimized and found as follows: the optimal pH was 6 for the adsorption of Cr (VI) by the Cu (I)-MOF, the optimal amount of adsorbent was 0.45 g·L−1, and the adsorption saturation time was within 180 min. Subsequently, the kinetics results were fitted by four models such as pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. Among them, the adsorption of chromium (VI) was more inclined to the pseudo-first-order model (Radj2 = 0.9230). Then, the isotherm data were fitted by Langmuir and Freundlich models. The results indicated that Langmuir isotherm was the excellent match model (Radj2 = 0.9827). It belongs to a monolayer adsorption, and the maximum adsorption capacity was 95.92 mg·g−1. Subsequently, the thermodynamic parameters of the adsorption were calculated as follows: enthalpy change (ΔHθ) was −8.583 kJ·mol−1, entropy change (ΔSθ) was −8.243 J·mol−1 K−1, and the Gibbs function change (ΔGθ) was less than zero in the temperature range of 288–328 K, indicating that the reaction was spontaneous. Finally, both the spectra of infrared and XPS supported the adsorption mechanism that belonged the ion exchange. The spectra of XRD and SEM images shown that the structure of Cu (I)-MOF remained stable for at least 3 cycles. In conclusion, Cu (I)-MOF material has a high adsorption capacity, good water stability, low cost, and easy to prepare in large quantities in practical application. It will be a promising adsorbent for the removal of Cr (VI) from water.


2014 ◽  
Vol 567 ◽  
pp. 20-25 ◽  
Author(s):  
Taimur Khan ◽  
Mohamed Hasnain Isa ◽  
Malay Chaudhuri ◽  
Raza Ul Mustafa Muhammad ◽  
Mohamed Osman Saeed

The aim of the study was to prepare potentially cheaper carbon for the adsorptive removal of Nickle [Ni (II)] from aqueous solution. The adsorption capacity of the prepared carbon to remove Ni (II) from aqueous solution was determined and adsorption mechanism was investigated. Rice husk carbon was prepared by incineration in a muffle furnace. The incinerated rice husk carbon (IRHC) was characterised in terms of surface area, micropore area, micropore volume, average pore diameter and surface morphology. Adsorption of Ni (II) by IRHC was examined. The influence of operating parameters, namely, pH, initial concentration and contact time on adsorption of Ni (II) by IRHC was evaluated. Batch adsorption tests showed that extent of Ni (II) adsorption depended on initial concentration, contact time and pH. Equilibrium adsorption was achieved in 120 min, while maximum Ni (II) adsorption occurred at pH 4. Langmuir and Freundlich isotherms were studied and the equilibrium adsorption data was found to fit well with the Langmuir isotherm model. Langmuir constants Q° and b were 14.45 and 0.10, and Freundlich constants Kf and 1/n were 4.0 and 0.26, respectively. Adsorption of Ni (II) by IRHC followed pseudo-second-order kinetics. Being a low-cost carbon, IRHC has potential to be used for the adsorption of Ni (II) from aqueous solution and wastewater in developing countries.


2018 ◽  
Vol 7 (3) ◽  
pp. 844
Author(s):  
Yentaria Juli Wijaya ◽  
R Rinita ◽  
Felycia Edi Soetaredjo ◽  
Suryadi Ismadji

Nitrobenzene is one of organic compound that usually contained in industrial wastewater, which is toxic. Nitrobenzene can be found in the chemical and pesticides industry. Nitrobenzene, which also known as nitrobenzol, is dangerous organic chemical for organism because can cause death. Organic waste in aqueous solution are usually removed by adsorption. In the adsorption process, adsorbent that usually used are carbon active and organic adsorbent. Neem leaf one of organic adsorbent that effective used in the adsorption process because it has a low cost dan easy to get. In this adsorption process, neem leaf used as a adsorbent. Neem leaf powder characterization with Boehm’s titration and proxymate analysis, which contain moisture content, water content, carbon, and volatile matter. Isoterm adsorption process of  nitrobenzene is appropriated with Freundlich equation and Langmuir equation. And the result of kinetic adsorption is appropriated with pseudo first order and pseudo second order. From the experimenal result, it can be seen that adsorption of nitrobenzene by neem leaf powder is using Langmuir equation in isoterm adsorption and follow pseudo first order in kinetic adsorption.Keywords : Adsorption, neem leaf powder, nitrobenzeneAbstrakNitrobenzene merupakan salah satu zat organik yang biasanya terkandung dalam limbah industri dimana Nitrobenzene sangat sulit diolah sebelum dibuang karena sifatnya yang sangat kompleks. Limbah yang mengandung nitrobenzene ini dapat ditemukan pada industri pestisida, sabun, dan farmasi. Nitrobenzene yang juga disebut nitrobenzol, merupakan bahan kimia organik yang berbahaya bagi mahluk hidup karena dapat menyebabkan kematian. Adsorpsi adalah salah satu cara yang dapat digunakan untuk mengatasi limbah nitrobenzene ini. Dalam proses adsorpsi, bahan penyerap yang umum digunakan adalah karbon aktif dan bahan penyerap organik. Daun intaran merupakan salah satu dari bahan penyerap organik yang efektif digunakan dalam proses adsorpsi karena biayanya yang murah dan mudah didapat. Pada penelitian ini, daun intaran digunakan untuk menyerap zat organik nitrobenzene. Karakterisasi bubuk daun intaran sendiri dilakukan dengan titrasi Boehm dan analisa proximat yang meliputi kandungan abu, air, karbon, dan volatile matter. Proses isoterm adsorpsi nitrobenzene ini disesuaikan dengan persamaan Freundlich dan persamaan Langmuir, sedangkan hasil kinetika adsorpsi disesuaikan dengan menggunakan pseudo first order dan pseudo second order. Dari hasil percobaan, didapatkan hasil bahwa proses adsorpsi nitrobenzene dengan menggunakan bubuk daun intaran ini mengikuti persamaan Langmuir pada isoterm adsorpsinya dan mengikuti persamaan pseudo first order pada kinetika adsorpsinya.Kata Kunci : Adsorpsi, bubuk daun intaran, nitrobenzene


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