Determination of rice husk activated Carbon capacity in adsorption of Cu Metal from Sasirangan liquid waste based on isotherm model

The process of manufacturing Sasirangan - a traditional fabric of South Kalimantan - has an impact that affects environmental pollution, namely the dyeing process of the fabric. The synthetic dyes used contain heavy metals and one of those toxic metals is copper (Cu). This study aims to determine the adsorption capacity of rice husk activated carbon adsorbent by adjusting the adsorption pattern based on isotherm models as the treatment to sasirangan liquid waste. The method consists of three stages: preparation of adsorbent by carbonization process, chemical and physical activation, then continued by adsorption process of Cu metal with carbon from rice husks with variations of adsorbent dose (2, 4, and 6 grams). This treatment was conducted by batch process. In this reseach, the adsorption capacity of rice husk adsorbent towards heavy metal Cu in sasirangan liquid waste was determined from the equilibrium state with the Langmuir isotherm equation and Freundlich isotherm equation. Based on isothermal studies of adsorption data, the correlation coefficient values obtained from the isotherm model approaches are: for dose of 2 grams adsorbent, Langmuir R2 = 0.9991 and Freundlich R2 = 0.9981; for dose of 4 grams adsorbent, Langmuir R2 = 0.9992 and Freundlich R2 = 0.9989; for dose of 6 grams adsorbent, Langmuir R2 = 0.9990 and Freundlich R2 = 0.9986. The results of investigation indicate that adsorption data correlated well with Langmuir isotherm model.

Adsorptive removal of methyl orange and methylene blue from aqueous solutions with Acacia crassicarpa activated carbon

In this study, activated carbon prepared from Acacia crassicarpa barkwas prepared and studied for the potential development of low-cost, carbon-based adsorbents that remove industrial dyes from aqueous solutions. Various spectroscopy techniques and surface analyses were used to characterize the adsorbents. The adsorption of methyl orange (MO) and methylene blue (MB) onto the material was investigated under optimal experimental conditions including temperature, adsorbent dosage, and initial concentration of chemicals. The Langmuir isotherm model was observed to fit the adsorption data well. The maximum adsorption capacities predicted by the Langmuir isotherm were found to be 10.36 mg.g-1 for MO and 15.34 mg.g-1 for MB. The adsorbents were better able to remove the cationic dye than the anionic dye. The results of this study will be useful for future scale-up production of low-cost adsorbents using Acacia crassicarpa for the removal of cationic and anionic dyes.

Modelling of pure CO2 and flue gas sorption data on South African coals using Langmuir, Freundlich, Temkin, and Extended Langmuir isotherm models

Greenhouse gases (GHGs) have sharply increased over the past four decades due to intensifying industrial activities; as a result, the earth has been faced with global warming in which the major contributor is the anthropogenic carbon dioxide (CO 2 ) emissions. Carbon sequestration in unmineable coal seams has been proposed as one of the most attractive technologies to mitigate CO 2 emissions in which CO 2 is stored in the microporous structure of the coal matrix in an adsorbed state. The CO 2 adsorption process is hence considered one of the more effective methodologies in environmental sciences. Thus, adsorption isotherm measurements and modelling are key important scientific measures required in understanding the adsorption system, mechanism, and process optimization in coalbeds. In this paper, three renowned adsorption isotherm models were employed including Langmuir, Freundlich, and Temkin for pure CO 2 adsorption data, and the Extended-Langmuir model for multicomponent, such as flue gas mixture-adsorption data as investigated in this research work. The adsorption data was acquired from a high-pressure volumetric sorption system (HPVSS) experiment involving two South African coal samples from Ermelo and Somkhele coalfields with pure CO 2 and synthetic industrial flue gas to simulate emissions that are representative of a typical coal-fired power plant (12% CO 2 , 5.5% O 2 , 82% N 2 , 0.38% SO 2 , and 0.12% NO 2 ). The adsorption data was measured on 10 g samples with a mean size of 2 mm at temperatures ranging from 30 ºC to 60 ºC and pressure up to 9.0 MPa using the HPVSS. The statistical evaluation of the goodness-of-fit was done using three (3) statistical data analysis methods including correlation coefficient (R 2 ), standard deviation ( σ ), and standard error (SE). The Langmuir isotherm model conventionally fits the pure CO 2 gas experimental data better than Freundlich and Temkin. The Extended Langmuir gives best experimental data fit for the flue gas.

Heavy Metals Adsorption on Cellulosic Materials from Agricultural Waste

Adsorption technique has been known to be a very effective method for treatment of heavy metals polluted wastewater, with the advantages of specific affinity, simple design and being user-friendly. However, the high cost of activated carbon commonly used as the adsorbent makes it necessary to explore the use of cheap cellulosic adsorbents. In this study, the adsorptive property of sugarcane bagasse (SB) and orange mesocarp (OM) was investigated. The cellulosic adsorbents were used for the sorption of lead and zinc ions from aqueous solutions. The effects of varying adsorbent dose, varying contact time and initial metal ion concentration on adsorption process of the metals were studied. The results show that both adsorbents (though waste materials) are viable for removal of metals from wastewater. Moreover, SB had higher sorption capacity for zinc (12.95 for SB and 12.68 for OM) while OM had higher sorption capacity for lead (9.90 for OM and 9.48 for SB) at optimum dosage. The isothermal studies shows that for lead adsorption, experimental data best fitted the Langmuir isotherm for both adsorbents (R2 of 0.9574 for OM and 0.98 for SB) while the data for zinc adsorption best fitted into Freundlich isotherm with SB (R2 of 0.9565)and Langmuir isotherm for OM(R2 of 0.814).

Heavy Metals Adsorption on Cellulosic Materials from Agricultural Waste

Adsorption technique has been known to be a very effective method for treatment of heavy metals polluted wastewater, with the advantages of specific affinity, simple design and being user-friendly. However, the high cost of activated carbon commonly used as the adsorbent makes it necessary to explore the use of cheap cellulosic adsorbents. In this study, the adsorptive property of sugarcane bagasse (SB) and orange mesocarp (OM) was investigated. The cellulosic adsorbents were used for the sorption of lead and zinc ions from aqueous solutions. The effects of varying adsorbent dose, varying contact time and initial metal ion concentration on adsorption process of the metals were studied. The results show that both adsorbents (though waste materials) are viable for removal of metals from wastewater. Moreover, SB had higher sorption capacity for zinc (12.95 for SB and 12.68 for OM) while OM had higher sorption capacity for lead (9.90 for OM and 9.48 for SB) at optimum dosage. The isothermal studies shows that for lead adsorption, experimental data best fitted the Langmuir isotherm for both adsorbents (R2 of 0.9574 for OM and 0.98 for SB) while the data for zinc adsorption best fitted into Freundlich isotherm with SB (R2 of 0.9565) and Langmuir isotherm for OM (R2 of 0.814).

Treatment of Bilge Water by Fenton Oxidation Followed by Granular Activated Carbon Adsorption

Due to its high oil content, the discharge of bilge water from ships is one of the most important pollutants in marine ecosystem. In this research, we investigated the treatment of bilge water for Haydarpasa Waste Collection Plant by Fenton oxidation followed by granular activated carbon (GAC) adsorption. We applied the following optimum operational conditions for Fenton oxidation: [Fe2+]: 6 mM; [H2O2]: 30 mM; and the ratio of [Fe2+]/[H2O2]: 1/5. Adsorption was performed in the effluent sample of Fenton oxidation. The effects of different adsorption periods, adsorbent concentrations, temperature, and pH were examined. Additionally, Freundlich and Langmuir isotherm models were applied. We obtained the following optimum operational conditions: 24 h, 2 g of GAC L−1, 20 °C, and pH = 6. We observed an 89.5 ± 1.9% of Chemical Oxygen Demand (COD) removal efficiency under these conditions. Data generated from the experiments fit both isotherm models well, though we preferred the Langmuir isotherm model to the Freundlich isotherm model because the former’s regression coefficient (0.90) was larger than that reported for the Freundlich isotherm model (0.78). The potential to treat bilge water by Fenton oxidation followed by granular activated carbon is promising for the Haydarpasa Waste Collection Plant.

HIGH ENTROPY ALLOWS A BETTER AFFINITY BETWEEN METAL IONS AND ACTIVATED CARBON FIBRES

Recent numerical approaches to extracting metal species using carbonaceous materials have de facto stimulated an interest in the field of microextraction, but theoretical observations inspired by randomness changes have been elusive. In this contribution, we present the degree of randomness using Cu (II) and Pb (II). Here, activated carbon fibres were employed as the skeleton adsorbent, providing scientific insights via the aqueous phase. Coupled isotherms of Langmuir and Freundlich were represented to unravel the aforementioned thermodynamics. Findings revealed that the Langmuir isotherm best described the equilibrium state and the trend was in accordance with the energy computation. The maximum microextraction performance was 84.75 mg/g and 102.04 mg/g for Cu (II) and Pb (II), respectively. Under all circumstances, there was a high randomness change as the microextraction performance increased.

Removal of radioactive cesium from liquid waste by zeolite

A radioactive fluid waste polluted with cesium-137 from Al-Tuwaitha site -south of Baghdad-Iraq is used in this paper. Commercial zeolite is used as a sorbent material in the present work for the removal of radioactive cesium-137. The removal efficiency for radioactive liquid was 96.43 % with 2 h mixing time, 0.04 g sorbent mass and pH=6.8 and at room temperature. The Freundlich and Langmuir isotherm models were found to represent the experimental results well and these results are more consistent with Freundlich model than Langmuir model.

A Simple One-Step Modification of Shrimp Shell for the Efficient Adsorption and Desorption of Copper Ions

Removing toxic heavy metal species from aqueous solutions is a point of concern in our society. In this paper, a promising biomass adsorbent, the modified waste shrimp shell (MS), for Cu (II) removal was successfully prepared using a facile and simple one-step modification, making it possible to achieve high-efficiency recycling of the waste NaOH solution as the modification agent. The outcome shows that with the continuous increase in pH, temperature and ion concentration, the adsorption effect of MS on Cu (II) can also be continuously improved. Adsorption isotherm and adsorption kinetics were fitted with the Langmuir isotherm model and the pseudo-second-order model, respectively, and the maximum adsorption capacity of Cu (II) as obtained from the Langmuir isotherm model fitting reached 1.04 mmol/g. The systematic desorption results indicated that the desorption rate of Cu (II) in the MS could reach 100% within 6 min, where HNO3 is used as the desorption agent. Moreover, experiments have proven that after five successive recycles of NaOH as a modifier, the adsorption capacity of MS on Cu (II) was efficient and stable, maintaining tendency in 0.83–0.85 mmol/g, which shows that waste NaOH solution can be used as a modification agent in the preparation of waste shrimp shell adsorbent, such as waste NaOH solution produced in industrial production, thereby making it possible to turn waste into renewable resources and providing a new way to recycle resources.