Adsorption of Rhodamine B by Coconut Shell Activated Carbon

A study of basic and reactive dyes removal from synthetic and industrial wastewater by electrocoagulation process

In order to reuse the waste fabric and develop a novel textile-based adsorbent for heavy metal removal, the waste silk fabric was modified by tannic acid (TA) and the prepared adsorbents were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analysis. The removal of Cd(II), Cu(II), and Ni(II) ions from aqueous solutions was investigated using the modified silk fabric (TA-SF) under various conditions and the adsorption behavior of heavy metal ions was compared with the original silk fabric. The results showed that the maximum metal adsorption amounts reached 100% in 10 min. The adsorption isotherm models were demonstrated using Langmuir, Freundlich, and Temkin isotherm models, and the adsorption of TA-SF to Cd(II), Cu(II), and Ni(II) were well fitted with Langmuir isotherm than Freundlich and Temkin isotherm model. Moreover, the adsorption kinetics was well fitted with to the pseudo-first-order and pseudo-second-order kinetic models, and adsorption kinetics indicated that the former model was better suited than the latter. For 60 mg/L initial concentrations of Cd(II), Cu(II), and Ni(II) at pH 9.0, the adsorbents' maximum adsorption capacity was 8.03 mg g−1, 7.42 mg g−1, and 7.47 mg g−1, respectively. Within 5 min, the absorbed metal ions on TA-SF could mostly be desorbed. Moreover, TA-SF can adsorb heavy metal ions from dyeing aqueous solution, showing its capability of simultaneous removal of heavy metal and waste dyes. The results suggest that the lower-cost TA-SF could be an effective adsorbent for removing heavy metals from industrial wastewater.

Among many environmental pollutants, dyes releasing from industries play a major role in contaminating the aquatic environment. Most of the dyes are non biodegradable, stable and carcinogenic due to their synthetic nature and aromatic structure. Therefore it is necessary to reduce the pollution load including decolourization of industrial effluents before disposal. Though the adsorption on to commercial activated carbon is a promising method, it is expensive. The present study was carried out to investigate the possibility of using a low cost adsorbent for the removal of carcinogenic dye, Rhodamine B in a more effective manner. Three different forms of sawdust, formaldehyde treated sawdust (SD), base treated sawdust (BTSD) and acid activated charred sawdust (AASD) were prepared and used for the removal of Rhodamine B from an aqueous solution. Batch experiments were carried out to investigate the potential efficiency of the three forms of sawdust to remove Rhodamine B from the aqueous solution as a function of the initial Rhodamine B concentration, Contact time and temperature. Equilibrium was found to be attained at about 30 min, 50 min and 60 min respectively for SD, BTSD and AASD. Based on Langmuir isotherms, the maximum adsorption capacity was found to be 319.5 mgg-1 at 60˚C for AASD among three different forms of sawdust. Various isotherms and kinetic models were fitted to describe the adsorption process and the activation parameters were evaluated in all three types of sawdust. Kinetic data of all three types of sawdust were well fitted for the second order rate model. Based on Langmuir, Frendlich and D-R isotherms, a better adsorption capacity was obtained for the AASD adsorbent compared to SD and BTSD. Thermodynamic parameters suggest that the adsorption of Rhodamine B onto all three type of adsorbent is spontaneous and the process is physisorption. SEM images revealed that AASD has more porous and irregularities in the surface which makes it a better adsorbent. IR spectral data reveal the disappearance of many functional groups in AASD adsorbent compared to SD and BTSD. Keywords: Rhodamine B, Kinetics, Equilibrium, Iisotherms, Modified jackwood sawdust

At present, graphite is commonly used as the carbon source in Al 2 O 3 ‐C refractory. However, graphite resources are limited and belong to the category of nonrenewable resources. Coconut shell is a biomass material with low cost, low impurity, and high reactivity, and also belongs to renewable resources. Therefore, the research for using coconut shell carbon as a substitution for graphite in Al 2 O 3 ‐C refractory has great significance. In this work, the coconut shell was firstly carbonized at 200–1000°C in flowing argon, and the microstructure of the carbonized coconut shells was investigated. Then the carbonized coconut shell powder was introduced into Al 2 O 3 ‐C refractory instead of graphite, and the effect of carbonized coconut shell on mechanical properties and microstructure evolution of materials was investigated. The results show that the carbonized coconut shell has porous structures, composed of amorphous carbon and disordered micro‐graphite with many defects, endowing its high reactivity. Compared with graphite, the carbonized coconut shell promotes the Si and Al to in situ formation of nonoxide ceramic whiskers (SiC, Al 4 C 3 , and AlN), which play a strengthening and toughening role in the materials. When graphite is replaced by 1 wt% carbonized coconut shell, the residual strength ratio of samples increased from 81.8% to 90.2%, and that of the hot modulus of rupture increased from 17.53 MPa to 18.47 MPa.

Adsorption of dye from industrial effluent before discharge into the environment has become a major challenge to the food, pharmaceutical, textile, photographic and cosmetic industries. This has led scientists to the search for suitable green solutions. Carbonized and zinc chloride activated Arachis hypogaea (groundnut husk) in a 1:1 ratio was used as an adsorbent for the removal of Rhodamine B from aqueous solution. The adsorbent was characterized by ash content, bulk density, moisture content, pH, Iodine number, surface area and functional group analyses. Key parameters such as initial pH, initial concentration of Rhodamine B dye, temperature and contact time were investigated. The equilibrium data obtained were correlated with Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. It was found that both the Freundlich and Langmuir isotherms fit well to the data. The Langmuir isotherm model best describes the uptake of Rhodamine B onto zinc chloride activated groundnut husk biochar with R2 > 0.997. Maximum Rhodamine B. dye removal was observed at a pH of 11.0, with an adsorbent dosage of 1.0 g, a contact time of 125 min, an initial dye concentration of 20 mg/L and a temperature at 315 K. The efficiency of zinc chloride activated groundnut husk biochar for Rhodamine B removal was 99.55% for dilute solutions at 50 g/L. The Fourier Transform Infrared (FTIR) spectra recorded before and after activation showed the numbers of functional groups available for Rhodamine B. molecules to bind onto in the studied adsorbent. The kinetic data were best described by the pseudo-first-order and pseudo second-order models, while the thermodynamic studies indicated a spontaneous and endothermic nature in the adsorption of Rhodamine B by the zinc chloride modified groundnut husk. This research clearly details an innovative approach to utilizing carbonized and zinc chloride-activated Arachis hypogaea (groundnut husk) as an eco-friendly adsorbent for the removal of Rhodamine B from industrial effluents.

Mechanical Properties of Activated Carbon (AC) Coconut Shell Reinforced Polypropylene Composites Encapsulated with Epoxy Resin

Abstract. The purpose of this research is to make activated carbon from coconut shell carbon and examine its use in adsorbing metals in acid mine drainage; to study the types of activators; to determine the optimum mass for the efficiency of reducing the concentration of Cu2+ metal and Mn2+ metal (percent removal) using the activated carbon from coconut shell carbon; and to determine the adsorption of isothermal model. Based on the results of the study, it is concluded that activated carbon could be made from coconut shell carbon with 20% H3PO4 chemical activation. Before being activated, it was made by heating at a temperature of 300°C for 2 hours. The best activated carbon in terms of metals adsorption in acid mine drainage was in a mass of 4 grams with each percent removal of 57.62% for Cu metal and 91.37% for Mn metal. Data analysis of the effect of concentration on adsorption capacity used the Langmuir and Freundlich isotherm equations. The Langmuir equation for the adsorption of Mn metal obtained the maximum adsorption capacity (qmax) of 15.16 mg/g; KL=73.09 mol/L and R2=0.9568. Meanwhile, the adsorption of Cu metal obtained the maximum adsorption capacity (qmax)=4.73 mg/g; KL=73.14 mol/L and R2= 0.9304. In Freundlich's equation, on the adsorption of Mn metal, the resulting KF=15.14 mol/L; R2=0.9129, while on the adsorption of Cu metal, the resulting KF=.72 mol/L; R2= 0.9092. Based on the data, the adsorption isotherm curve more closely follows the Langmuir isotherm model (adsorption takes place in one layer (monolayer).

Chlorinated polyfluoroalkyl ether sulfonates (F-53B) were often used as mist suppressants in the chrome plating industry, resulting in the large discharge of F-53B-containing electroplating wastewater into the aquatic environment. Due to the high toxicity of F-53B, increasing attention has been paid to its efficient removal from wastewater. In this study, three nano-activated carbons were successfully prepared from coconut shell carbons by a simple one-step KOH activation method. The nitrogen adsorption/desorption experiments showed that the synthesized coconut shell activated carbons possessed a well-developed nano-pore structure, which was favorable for the adsorption of F-53B. The results suggested that the adsorption of F-53B on the coconut shell activated carbons followed pseudo-second-order kinetics and was better fitted in the Langmuir isotherm, indicating that the adsorption of F-53B was mainly controlled by chemical adsorption and was mainly monolayer adsorption. Theoretical calculation results revealed that the faster adsorption rate of F-53B on CSAC_800 than on CSAC_600 and CSAC_700 could be contributed to the lower adsorption energy of F-53B on CSAC_800 and the higher self-diffusion coefficients of F-53B in CSAC_800. The higher adsorption capacity of CSAC_800 (qm = 537.6 mg·g−1) for F-53B than that of CSAC_600 (qm = 396.83 mg·g−1) and CSAC_700 (qm = 476.19 mg·g−1) could be attributed to the higher specific surface area and larger number of adsorption sites of CSAC_800. The results of this study demonstrate that coconut shell activated carbons with a well-developed nano-pore structure are an effective adsorbent for F-53B removal and have a good application prospect.

Synthesis & characterization of acid-activated sago pulp biochar as an adsorbent of rhodamine B dye has been carried out. This study aims to synthesize & characterize sago pulp biochar activated with HCl 1 M & H3PO4 0,214 M solutions & to assess its ability as an adsorbent of rhodamine B dye. This biochar is produced through a pyrolysis method with a combustion temperature of 700 °C for 2 hours. The results of the pyrolysis biochar were then activated with HCl 1 M & H3PO4 0,214 M acid solvents & then analyzed the effect of contact time, pH, & initial concentration on its ability to adsorb rhodamine B dye. Characterization using Fourier Infrared (FTIR) showed the presence of alkene groups & aromatic groups (C=C) & bonds (CO) & (CC) which play an important role in the adsorption process. The results of the water content of BAS, BAS/HCl & BAS/H3PO4 produced were 2.57%, 4.47% & 5.06% which met the requirements of SNI 06-3730-1995. The results of the surface area test showed BAS/H3PO4 with the largest surface area of 0,520 m2/g & BAS of 0,452 m2/g while the smallest surface area was BAS/HCl of 0,445 m2/g. The study of the effect of pH & contact time on the adsorption capacity of rhodamine B showed that the optimum adsorption capacity of pure sago pulp biochar (BAS) at neutral pH with a contact time of 15 minutes, BAS/HCl at acidic pH with a contact time of 180 minutes, & BAS/H3PO4 at alkaline pH with a contact time of 60 minutes. Based on the analysis results, the adsorption process of rhodamine B on biochar follows the Langmuir & Freundlich isotherms with maximum adsorption capacities for BAS, BAS/HCl, & BAS/H3PO4 of 4.285 mg/g, 4.834 mg/g, & 3.934 mg/g, respectively.

The use of dyes in the textile industry has a negative impact, namely water pollution if the waste is discharged directly into the river or not treated properly. Liquid waste from the textile industry generally still contains dyes that are harmful to living things and the environment. In this study the dye adsorption method was used by using modified activated carbon from the coconut shell with the addition of the active site Fe 2 O 3 . Characterization and activity testing of iron / porous oxide activated carbon adsorbent will be carried out. The type of porous activated carbon used is coconut shell carbon with micropore characters. The stages of this study consisted of the impregnation process of iron oxide on porous carbon, the methylene blue adsorption process and the characterization of the resulting adsorbent. Based on the research that has been done, it can be concluded that the adsorption of Fe 2 O 3 / coconut shell activated carbon is very effectively applied for the absorption of dye wastewater. The adsorption capacity of methylene blue increased with increasing concentrations of loading of active sites of Fe and the percentage of adsorption capacity in the 180 minute reaction was 89.8% with the loading of iron oxide / coconut shell adsorbent 2%. In addition, from the results of the adsorbent activity test with variations in the mass addition of the adsorbent it can be concluded that the mass increase of the adsorbent significantly affected the yield of blue methylene adsorption.

ABSTRAK Tempurung kelapa ialah endokarp buah kelapa yang merupakan limbah dari kelapa. Contoh produk olahan tempurung kelapa yang terkenal merupakan karbon aktif. Pada tempurung kelapa mengandung senyawa kimia selulosa (34%) sehingga dapat menghasilkan karbon dengan pigmen berwarna hitam jika dipanaskan. Pigmen ini dapat dijadikan bahan utama penyusun tinta spidol yang ramah lingkungan. Tujuan penelitian ini adalah untuk mengetahui pengaruh variasi massa sampel karbon tempurung kelapa dan gum arab terhadap karakteristik tinta spidol whiteboard. Di bawah penelitian ini ada dua tahapan diawali dengan proses pembuatan karbon tempurung kelapa. Dan pada tahap kedua, tinta diuji karakteristiknya yaitu uji densitas, uji viskositas, uji pH dan uji pigmen tinta. Variasi sampel karbon tempurung kelapa dan gum arab yaitu sampel A (5 g : 5 g), B (7 g : 7 g), C (9 g : 9 g). Hasil penelitian mendapatkan pengaruh dari variasi karbon tempurung kelapa dan gum arab yaitu nilai densitas dan viskositas mengalami kenaikan dan pH mengalami penurunan serta mendapatkan tinta optimum pada sampel C (9 g : 9 g) yaitu mempunyai nilai densitas 1,0722 gr/cm3, nilai viskositas 3,4844 poise, nilai pH 8,39 yang bersifat basa serta menghasilkan warna hitam pekat. Kata kunci : Karbon Tempurung Kelapa, Pigmen, Tinta Spidol ABSTRACT The coconut shell is the endocarp of the coconut fruit which is the waste of the coconut. An example of a well-known coconut shell processed product is activated carbon. The coconut shell contains the chemical compound cellulose (34%) so it can produce carbon with a black pigment when heated. This pigment can be used as the main ingredient for eco-friendly marker ink. The purpose of this study was to determine the effect of variations in the mass of coconut shell carbon samples and Arabic gum on the characteristics of whiteboard marker inks. Under this research, two stages begin with the process of making coconut shell carbon. In the second stage, the characteristics of the ink were tested, namely the density test, viscosity test, pH test and ink pigment test. Variations in the samples of coconut shell carbon and gum arabic are samples A (5 g: 5 g), B (7 g : 7 g), C (9 gs : 9 g). The results of the study were influenced by variations in coconut shell carbon and gum Arabic, namely the density and viscosity values ​​increased and the pH decreased and obtained the optimum ink in sample C (9 g: 9 g), which had a density value of 1.0722 gr/cm3, viscosity value 3.4844 poise, a pH value of 8.39 which is alkaline and produces a deep black color Keywords : Coconut Shell Carbon, Pigment, Marker Ink

Kinetics and equilibrium adsorption study of lead(II) onto activated carbon prepared from coconut shell.

ABSTRACTIn the present study, microwave treated Salvadora oleoides (MW-SO) has been investigated as a potential biosorbent for the removal of toxic methyl violet dye. A batch adsorption method was experimented for biosorptive removal of toxic methyl violet dye from the aqueous solution. The effect of various operating variables, viz., adsorbent dosage, pH, contact time and temperature on the removal of the dye was studied and it was found that nearly 99% removal of the dye was possible under optimum conditions. Kinetic study revealed that a pseudo-second-order mechanism was predominant and the overall process of the dye adsorption involved more than one step. Hence, in order to investigate the rate determining step, intra-particle diffusion model was applied. Adsorption equilibrium study was made by analyzing Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) adsorption isotherm models and the biosorption data was found to be best represented by the Langmuir model. The biosorption efficiency of MW-SO was also compared with unmodified material, Salvadora oleoides (SO). It was found that the sorption capacity (qmax) increased from 58.5 mg/g to 219.7 mg/g on MW treatment. Determination of thermodynamic parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) confirmed the spontaneous, endothermic and feasible nature of the adsorption process. The preparation of MW-SO did not require any additional chemical treatment and a high percentage removal of methyl violet dye was obtained in much lesser time. Thus, it is in agreement with the principles of green chemistry. The results of the present research work suggest that MW-SO can be used as an environmentally friendly and economical alternative biosorbent for the removal of methyl violet dye from aqueous solutions.

Removal of dye from synthetic textile wastewater using agricultural wastes and determination of adsorption isotherm

Ozonation of aqueous Bomaplex Red CR-L dye in a semi-batch reactor