Preparation of activated carbons from walnut shells via vacuum chemical activation and their application for methylene blue removal

Yang, Juan; Qiu, Keqiang

doi:10.1016/j.cej.2010.09.019

Cited by 417 publications

(116 citation statements)

References 35 publications

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“…This means that the removal of SP increases with coagulant loading depending on a particular pH range and stirring time. 90.0% maximum removal was achieved at 100mg/L and stirring time of 25min at pH 2 [27]. As shown in these plots, increased SP removal was observed with increasing coagulant dosage and pH values.…”

Section: Test For Significant Of Regressionmentioning

confidence: 49%

“…However, an increase in both factors beyond the optimum region results in a decrease in the removal efficiency for the two coagulants [28]. Coagulant dosage higher than 100mg/L, the SP removal begin to decrease in all coagulation pH, this implies restabilization of the particles due to overloading [27]. From the plots, low pH value indicates improved coagulation and SP removal.…”

Section: Test For Significant Of Regressionmentioning

confidence: 99%

See 1 more Smart Citation

Optimizing bio-coagulants for brewery wastewater treatment using response surface methodology

Okolo¹,

Nnaji²,

Oke³

et al. 2018

Nig. J. Tech.

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Coag-flocculation process was used to treat brewery effluent stream with Detarium Microcarpum seed powder (DMSP) and oyster dried shell powder (ODSP) as coagulants. The proximate analyses of the coagulants were obtained using AOAC standard method. Percentage moisture, ash, fat, crude protein, crude fiber and carbohydrate content were determined for both coagulants. Jar test experiments were employed for the coag-flocculation process and response surface methodology (RSM) optimize the process. A box-Behnken design (BBD) of Design Expert 6.0.8, implementing RSM was used to evaluate the effects and interactions of three factors: coagulant dosage, pH and stirring time on the treatment efficiency. The optimal conditions obtained were coagulant dosage of 100.53mg/L, pH of 2.001 and stirring time of 24.47mins with 90.44% solid particle (SP) removal (desirability value of 1.0) and coagulant dosage of 104.19mg/L, pH of 3.34 and stirring time of 27.54 with 96.55% SP removal (desirability value of 1.0) for DMSP and ODSP, respectively. These agree reasonably with the experimental optimum for both coagulants. A determination coefficient, R 2 , of 97 and 98%; F-value of 45.8056 and 55.3045; and prob.-value of 1.92E-07 and 2.39E-07 for DMSP and ODSP respectively were used to evaluate the model adequacy.RSM has been demonstrated to be appropriate approach for the optimization of this process.

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Section: Test For Significant Of Regressionmentioning

confidence: 49%

Section: Test For Significant Of Regressionmentioning

confidence: 99%

Optimizing bio-coagulants for brewery wastewater treatment using response surface methodology

Okolo¹,

Nnaji²,

Oke³

et al. 2018

Nig. J. Tech.

View full text Add to dashboard Cite

show abstract

“…However, both activated carbons had the highest iodine adsorption (approximately 480 mg/g) at a carbonization temperature of 700 C. Also, the average iodine adsorption of the 2 types of activated carbon that were carbonized at 600 C was 330 mg/g, which was significantly higher than that of activated carbon that was produced at 800 C and 900 C (average 210 mg/g). High temperature adversely affects carbon structure, because the heat shrinkage of the carbon structure decreases the surface area and pore volume (Hayashi et al, 2000;Yang and Qiu, 2010). As shown in Figure 1, the increase in carbonization time did not improve iodine adsorption.…”

Section: Effect Of Carbonization Time and Temperaturementioning

confidence: 69%

Production of granular activated carbon from food-processing wastes (walnut shells and jujube seeds) and its adsorptive properties

Bae

Kim

Chung

2014

Journal of the Air & Waste Management Association

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Commercial activated carbon is a highly effective absorbent that can be used to remove micropollutants from water. As a result, the demand for activated carbon is increasing. In this study, we investigated the optimum manufacturing conditions for producing activated carbon from ligneous wastes generated from food processing. Jujube seeds and walnut shells were selected as raw materials. Carbonization and steam activation were performed in a fixed-bed laboratory electric furnace. To obtain the highest iodine number, the optimum conditions for producing activated carbon from jujube seeds and walnut shells were 2 hr and 1.5 hr (carbonization at 700 C) followed by 1 hr and 0.5 hr (activation at 1000 C), respectively. The surface area and iodine number of activated carbon made from jujube seeds and walnut shells were 1,477 and 1,184 m 2 /g and 1,450 and 1,200 mg/g, respectively. A pore-distribution analysis revealed that most pores had a pore diameter within or around 30-40 Å, and adsorption capacity for surfactants was about 2 times larger than the commercial activated carbon, indicating that waste-based activated carbon can be used as alternative.Implications: Wastes discharged from agricultural and food industries results in a serious environmental problem. A method is proposed to convert food-processing wastes such as jujube seeds and walnut shells into high-grade granular activated carbon. Especially, the performance of jujube seeds as activated carbon is worthy of close attention. There is little research about the application of jujube seeds. Also, when compared to two commercial carbons (Samchully and Calgon samples), the results show that it is possible to produce high-quality carbon, particularly from jujube seed, using a one-stage, 1,000 C, steam pyrolysis. The preparation of activated carbon from food-processing wastes could increase economic return and reduce pollution.

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“…Usually, to study these properties the most used techniques are microscopies in general. Scanning Electron Microscopy (SEM) is the most applied in the study of the morphology of ACs (Guo and Lua 2000;Phan et al 2006;Saka 2012;Tay et al 2009;Tseng and Tseng 2005;Yang and Qiu 2010) (Fig. 1b).…”

Section: Morphological Analysismentioning

confidence: 99%

Activated carbons for applications in catalysis: the point of view of a physical-chemist

Lazzarini

2017

Rend. Fis. Acc. Lincei

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This paper is a concise review on the principal physical-chemical techniques available to investigate the structural and surface properties of activated carbons (ACs) for catalytic applications. The same activated carbon has been characterized by an incredible amount of techniques: Solid State-Nuclear Magnetic Resonance, X-Ray Powder Diffraction and Raman spectroscopy for structural characterization, X-ray Photoelectron Spectroscopy, Inelastic Neutron Scattering and FT-IR spectroscopy for surface analysis, instead. The main goal is to discuss the advantages and disadvantages of all the techniques and to propose a multi-technique approach that should help in avoiding misinterpretations, as often found in the specialized literature.

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Preparation of activated carbons from walnut shells via vacuum chemical activation and their application for methylene blue removal

Cited by 417 publications

References 35 publications

Optimizing bio-coagulants for brewery wastewater treatment using response surface methodology

Optimizing bio-coagulants for brewery wastewater treatment using response surface methodology

Production of granular activated carbon from food-processing wastes (walnut shells and jujube seeds) and its adsorptive properties

Activated carbons for applications in catalysis: the point of view of a physical-chemist

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