Walnut shell treated with citric acid and its application as biosorbent in the removal of Zn(II)

Segovia-Sandoval, Sonia Judith; Ocampo-Pérez, Raúl; Berber-Mendoza, M.S.; Leyva‐Ramos, Roberto; Jacobo‐Azuara, Araceli; Castillo, Nahúm Andrés Medellín

doi:10.1016/j.jwpe.2018.06.007

Cited by 60 publications

(28 citation statements)

References 34 publications

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“…Therefore, there existed an electrostatic interaction between the protonated CR ions and negatively charged groups of CAB. The band at 3,446 cm −1 corresponded to -N-H-stretching vibration and 1,610 cm −1 was assigned to -N=N-stretching in the structure of CR, which diminished after CAB adsorption, while the peaks at 1,176 and 1,048 cm −1 assigned to S=O stretching (Sonia et al, 2018) also diminished. Hence, chances of hydrogen bonding or esterification may exist between the functional electronegative groups on CR such as -NH 2 , -N=N-, -SO 3 , -OH, and -COOH groups of CAB.…”

Section: Ft-irmentioning

confidence: 96%

“…The bands at 3,613 and 3,419 cm −1 corresponding to -OH stretching vibration of adsorbed water and hydrogen bonding between water molecules and Si-O surface, respectively (Zhang et al, 2014). The new adsorption band in CAB at 1,732 cm −1 was assigned to C=O symmetrical stretching, which obviously related to carboxyl groups of CA (Sonia et al, 2018). The main binding modes of CA on bentonite are as follows: (1) Esterification reaction between bentonite and CA.…”

Section: Ft-irmentioning

confidence: 99%

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Citric Acid Modified Bentonite for Congo Red Adsorption

et al. 2019

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Raw bentonite (RB) was chemically modified by citric acid (CA) to obtain a low-cost and environment-friendly citric acid incorporated bentonite (CAB) adsorbent, which was applied for the adsorptive removal of Congo Red (CR). The effect of adsorbent dosage, contact time, ionic strength, surfactant, and pH on adsorption was investigated. Adsorption equilibrium data fitted well with Langmuir model while the Langmuir adsorption capacity of CR on CAB reached up to 384 mg•g −1. Furthermore, CR adsorption on CAB followed pseudo-second kinetic model while intra-particle diffusion was not the only rate-limiting step as determined from intra-particle diffusion model investigation. RB and CAB were characterized by XRD, FT-IR, and BET techniques. A proposed mechanism for the adsorption of CR over CAB suggested the chemical adsorption phenomenon is mainly controlled by chelation, hydrogen bonding, and fixing.

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Section: Ft-irmentioning

confidence: 96%

Section: Ft-irmentioning

confidence: 99%

Citric Acid Modified Bentonite for Congo Red Adsorption

et al. 2019

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“…Regarding the determination of active sites present on the surface of coffee pulp, the Boehm methodology exposed by Boehm (1994, cited in Segovia et al, 2018) was used [17], in which we seek to quantify the concentration (µmol × g −1 o mmol × g −1 ) of the basic sites and total acids by volumetric acid base by regression. Therefore, to neutralize the total active sites of basic character, 0.100 g of agricultural residue (CP or PP) in a beaker was weighed and added 25 mL of a HCl solution 0.010 M; in relation to the neutralization of the total acid-active sites, these exclusively quantified the carboxylic, phenolic and lactonic groups, which were determined by measuring the previous amount of the residue and 25 mL of a 0.010 M NaOH solution was added.…”

Section: Determination Of the Zero Charge Point (Ph Pzc ) And Active mentioning

confidence: 99%

“…On the other hand, with the above data we propose the adsorption mechanism to explain the removal of Cr (VI) in the Synthetic Residual Waters. For this, it should be noted that the optimum pH obtained for this removal according to number 3.3 was 2.0 pH units, in this condition the species of Cr (VI), according to Rollinson (1973, cited in Acosta et al, 2010) [24] is in the aqueous solution as (HCrO 4 ) − , (Cr 2 O 7 ) −2 , (CrO 4 ) − and that the pH pzc was 3.95 indicating that the load of the surface of the CP is positive with respect to the optimum pH of 2.0, which is lower than the zero load point of the CP [17]; for this reason, the removal occurs by electrostatic interactions, as illustrated in Figure 5:…”

Section: Total Active Sites Ph Pzcmentioning

confidence: 99%

Coffee Pulp: A Sustainable Alternative Removal of Cr (VI) in Wastewaters

et al. 2019

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Currently, agricultural waste is proposed as a sustainable alternative in the removal of heavy metals present in industrial wastewater, to fulfill some of the goals proposed in the Sustainable Development Goals stated for the 2030 Agenda, in particular in Sections 3.9 and 6.9. Considering this context, the coffee pulp (Castilla variety) of Caldas municipality (Colombia) was used in study for the removal of one of the most toxic chemical species of chromium: Cr (VI). Therefore, the agricultural residue was subjected to a bromatological characterization, determination of the lignocellulosic composition and elucidation of characteristic organic functional groups by IR spectrophotometry. Additionally, the optimal parameters for contaminant removal were identified, regarding particle size, biomass quantity, optimum pH, stirring time, temperature, adsorption kinetics, zero charge potential (pHpzc) and adsorption isotherms, to analyze the kinetic model that fitted the process, the explanation of the possible adsorption mechanism between the contaminant, the surface of the coffee pulp and the capacity of maximum adsorption, respectively. Finally, the innovation of the research is discussed considering two criteria: First, when a mixture was made in different proportions between two agricultural residues (coffee pulp and plantain pseudostem) to show if there was an increase in the removal of the contaminant under the same optimal conditions found experimentally; and the second criterion, the comparison of the maximum adsorption capacity, with the percentages of removal carried out by other authors using the pulp of unmodified coffee.

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“…The World Health Organization (WHO) has cataloged thirteen heavy metals as toxic, among which is Zn [1]. This metal, of atomic number 30, with oxidation states −2, 0, +1, +2, and +3 [2,3], has multiple applications at the industrial and laboratory level, among which are car parts, electronic equipment, light machine tools, metal coating, glass manufacturing, matches, glues, paint manufacturing, varnishes, ceramics, medications, sunscreen, deodorants, electrodeposition, toys, and batteries [4,5]. When the concentrations of this element are high, it can generate health problems, entering through three exposure routes (inhalation, ingestion, and contact).…”

Section: Introductionmentioning

confidence: 99%

Removal of Zn(II) in Synthetic Wastewater Using Agricultural Wastes

Aguilar

Miranda

Miller

et al. 2020

Metals

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In the present investigation, results obtained from the process of the biosorption of Zn(II) in synthetic wastewaters are presented, using three agricultural wastes (coffee pulp, banana pseudo-stem, and corncob). Firstly, the percentage of lignin and cellulose for each material was determined. Then, using the free software XLSTAT, the waste with the highest removal for this metal was selected and, after this, the optimum pH, kinetics, adsorption isotherm, and point of zero charge (pHpzc) were found. Finally, a comparison with other lignocellulosic materials derived from banana, corn, and coffee crops was carried out. According to the results obtained, coffee pulp was the material that showed a high removal compared to the other two (63.58%), for which the optimum pH was 5.0 units. The kinetic model, which was adjusted to the process of biosorption, was the pseudo second order of Ho and McKay, which in turn presented an isotherm of Langmuir’s linearized model where the maximum adsorption capacity with that waste was 13.53 mg × g−1, obtained with a particle size of 180 µm, contact time of 90 min at 100 RPM, temperature of 25 °C, and pHpzc 3.95 units. Lastly, the authors state that this type of agricultural waste can be used as a green technology in the treatment of wastewater, particularly in the removal of the aforementioned pollutant, in order to fulfill goals 3.9 and 6.9 of the Sustainable Development Goals of the 2030 Agenda; to the level of challenge of the research, the authors propose for the future to carry out the implementation of this type of waste, without chemical modification, in the treatment of wastewater for the removal of the mentioned pollutant in a pilot study with different wastewaters and industries.

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Walnut shell treated with citric acid and its application as biosorbent in the removal of Zn(II)

Cited by 60 publications

References 34 publications

Citric Acid Modified Bentonite for Congo Red Adsorption

Citric Acid Modified Bentonite for Congo Red Adsorption

Coffee Pulp: A Sustainable Alternative Removal of Cr (VI) in Wastewaters

Removal of Zn(II) in Synthetic Wastewater Using Agricultural Wastes

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