Activated Charcoal Adsorption Research Articles

Utilization of Coffee Grounds as an Adsorbent in Reducing the Levels of Naphthol Dyes of Weaving Industry Wastewater

Naphthol dye is one of the synthetic dyes contained in weaving industry waste. One method that can be used to reduce the disadvantageous effects of these substances is by adsorption using activated charcoal adsorbent from coffee grounds. This research aims to determine the character of activated charcoal from coffee grounds and the effect of adsorbent dosage and stirring time on the adsorption of naphthol dye levels. Making activated charcoal from coffee grounds goes through 3 stages, namely the dehydration stage, carbonization stage at 350 oC for 3.5 hours, and activation stage using a 0.1 M HCl activator for 48 hours. The characterization of activated charcoal obtained complies with SNI 06-3730-1995 with results of water content of 3.74%, ash content of 2.12%, and iodine adsorption capacity of 758.29 mg/g, and functional group testing was carried out by varying the adsorbent dosage at 0.125; 0.250; 0.500; 0.750; 1 g (per 100 mL sample) and stirring time for 10; 20; 30; 40; 50 minutes. From the research results, it was obtained the best adsorbent dose and mixing time were 0.5 g and 40 minutes with adsorption efficiency of 98.68% and 99.63%.

Efektifitas arang aktif tongkol jagung dalam menurunkan emisi kendaraan bermotor berbahan bakar ganda

Emission reduction through after treatment processes has become one of the options to minimize the adverse effects of two-wheeler emissions. Activated charcoal adsorbents have been proven effective in reducing emissions to a certain extent. In this study, corn cob charcoal activated with a 15% NaCl solution serves as the adsorbent. The adsorbent used is shaped into particles with a mesh size of 10. The adsorbent is placed in the modified motorcycle muffler. Testing is conducted on two-wheeled vehicles operated using the dual-fuel method, where biogas and pertalite are used as fuels. With this method, fuel concentrations are obtained significantly smaller compared to vehicles without emission reduction methods. Testing is carried out for 2 hours to determine the durability of the adsorbent in absorbing exhaust gas emissions. Based on the test results, where data collection is conducted every 10 minutes, the concentrations of emissions including hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2) initially decrease and then rise again after several minutes. This indicates that the adsorbent effectively reduces emissions in a relatively short duration. However, the effectiveness of corn cob activated charcoal in reducing these three emissions varies, with the adsorbent showing good performance in reducing HC

Adsorption study of methylene blue dye using activated carbon prepared from waste palm fiber.

The study investigated the utilization of waste palm fiber as an adsorbent for methylene blue (MB) removal. The waste palm fiber was treated by a series of steps to prepare an activated charcoal adsorbent. The adsorption process of MB on the activated charcoal was modeled using the Box-Behnken design (BBD) in the response surface methodology (RSM). Adsorbent mass, solution pH, temperature, and time were selected as factors, while removal efficiency and adsorption capacity were chosen as responses. Both models were significant with correlation factors of 0.85 and 0.99 for removal efficiency and adsorption capacity, respectively. Optimal conditions for MB removal were achieved at an initial pH of 7, an adsorbent dose of 0.05 g/L, and a contact time of 30 min, resulting in a 99% removal efficiency. The adsorption of MB using the activated charcoal indicates the physical nature of the reaction.

Utilization of Ketapang Seed Shells in Reducing Pb(NO<sub>3</sub>)<sub>2</sub> Metal Levels by Adsorption Process

Industrial wastes such as lead metal can cause serious problems because of their toxic nature and can pollute the environment. To reduce levels of lead metal, you can use a natural adsorbent from activated charcoal on the outer shell of ketapang seeds. The ketapang tree is a type of plant that is often found in the surrounding environment because it is used as a shade for the many falling ketapang seeds making waste in the environment to reduce environmental pollution from the falling ketapang can be used as an adsorbent because it contains cellulose and carbon elements. One alternative to reduce lead levels using adsorbents is through the adsorption process which is the process of adsorption of a solid or liquid that involves physical, chemical and electrostatic interactions between the adsorbate and the adsorbent on the surface of the adsorbent. The adsorption process using activated charcoal adsorbent is one of the most frequently used non-polar adsorbents because it has better adsorption power and surface area than other types of adsorbents. This study aims to determine the influencing variables and the optimum condition of the natural adsorbent from the activated charcoal of the outer shell of ketapang seeds on decreasing levels of metal Pb (NO3)2. The research method used is an experimental method with a two-level factorial design. The results showed that the adsorption temperature was the most influential variable in this study with an optimum yield presentation of 66.77%. The activated charcoal produced has a water content of 8%, ash content of 5.2% and an absorption capacity of methylene blue of 698 mg/g.

Adsorption Isotherms and Kinetics Studies on Adsorption of Malachite Green onto Activated Charcoal from Aqueous Solution

The article presents low-cost activated charcoal as an adsorbent in the adsorption process for the removal of malachite green from aqueous solution by batch process. To find the optimum condition of the process, contact time, shaking rate, concentration of malachite green, and concentration of activated charcoal were examined. The malachite green was removed up to 98.9%. The adsorption isotherms were studied to check the performance of the adsorbent. Langmuir, Freundlich, Temkin, Hill De Boer, and Dubinin-Radushkevich adsorption isotherms were studied and compared to which one was suitable in the process. The adsorption process with the activated charcoal adsorbent followed suitably with the order of the Dubinin-Radushkevich > Langmuir > Hill De Boer> Temkin > Freundlich models. According to a kinetic study, the adsorption process was second order. In thermodynamic studies, we obtained negative values of ΔG, ΔS, and ΔH. The negative ΔH and ΔS values suggest that enthalpy contributes more than entropy in producing negative ΔG values. The negative ΔG values of malachite green adsorptions indicate that is a favorable and spontaneous process. The negative value of ΔH ensures the adsorption process is characterized as chemical adsorption and exothermic. The negative ΔS value indicates that randomness decreases at the solid–solution interface during the adsorption of MG by activated charcoal. The surface morphology of the Activated charcoal ensured the adsorption process. The results indicate that the adsorption process is exothermic, spontaneous, and favorable. So, activated charcoal might be useful for removing the malachite green dye from the aqueous solution.

Pesticides’ low-cost removal from polluted groundwater using charcoal from “Salix mucronata” trees activated by gold nitrate

ABSTRACT Used pesticides result in soil pollution, which potentially seep into groundwater, posing risks to human and animal health. The current study examines the use of a new cheap material for removing four commonly used pesticides from polluted groundwater before use for drinking. These pesticides are Malathion, Methomyl, Abamectin, and Thiamethoxam. Activated charcoal obtained from the trunk of “Salix mucronata” trees is introduced for removing these pesticides by surface adsorption. Activation treatment using gold-nitrate solution is introduced to enhance the charcoal adsorption capacity, because removal of pesticides is difficult due to their large-sized molecules and lack of obvious surface electrostatic charges. Physical and chemical properties of the studied pesticides and the activated charcoal were determined. Batch experiments tested the effects of solution pH, contact time, dose of charcoal, and initial concentrations on the charcoal adsorption capacity. Langmuir adsorption linear isotherm test was done to use for the prediction of adsorption behavior. Fixed-bed column experiments tested clean-up of polluted water using charcoal filter under steady flow. Gold-nitrate activated charcoal adsorption capacities were almost three times higher than other charcoals for the same pesticides at the same initial concentrations. Maximum adsorption capacities achieved in the current study were 16.17, 14.59, 9.55, and 8.99 mg/g, respectively, at the initial concentrations of 50.0 mg/l. Meanwhile, treatment times in steady-flow fixed-bed columns were much lower compared to other studies. Preparation cost of gold-nitrate activated charcoal in the current study was lower than other adsorbents. The charcoal introduced in this study is recommended for use in low-cost removal of pesticides from polluted groundwater on the national scale, including small treatment units for rural communities with limited facilities.

Innovative Production of Highly Nutritive Value Margarine from Refined Fish Oil by-Products of Lemuru Fish (Sardinella Lemuru) Canning Industry – A Novel Approach through Activated Charcoal Adsorbent

Innovative Production of Highly Nutritive Value Margarine from Refined Fish Oil by-Products of Lemuru Fish (Sardinella Lemuru) Canning Industry – A Novel Approach through Activated Charcoal Adsorbent

Adsorption Of Methylene Blue Using Active Charcoal From Empty Fruit Bunch (EFB)

Research on the adsorption of methylene blue by activated charcoal from Empty Fruit Bunch (EFB) has been carried out. This study aimed to synthesize activated charcoal from EFB, characterize it, and use it as an adsorbent for methylene blue. Activated charcoal was synthesized by carbonation in a furnace at 300oC for 1 hour. Chemically, activation was carried out by immersion in HCl solution for 24 hours. Characterization was carried out by proximate test, determination of functional groups using Fourier Transform Infrared (FT-IR), and determining material shape with X-Ray Diffraction (XRD). The study of activated charcoal adsorption as methylene blue adsorbent was carried out by treating variations in contact time, adsorbent weight, and concentration. The results of the proximate test with the parameters of surface area, moisture content, and ash content were 162.12 m2/g, 0.52%, and 5.27%, respectively. The results of the FT-IR characterization test showed an aromatic C–H, C=C and C–O. Based on the results of characterization with XRD giving a pattern at a diffraction angle of 2 20 - 30o, it was seen that there was a wide peak, which indicated that it had an amorphous structure. The optimum conditions for methylene blue adsorption occurred at a contact time of 40 minutes, and the adsorbent weight was 0.1 g for 10 mL of 50 ppm methylene blue. The adsorption of methylene blue followed the Freundlich isotherm adsorption pattern and had a maximum adsorption capacity of 8.92 mg/g.

Efficient removal of PAHs from peanut oil using coconut shell-based activated charcoal decorated by cationic (CTAB), anionic (SDS), non-ionic surfactant (Triton X-100)

The coconut shell-based activated charcoal was decorated by three different electronegativities of surfactants (CTAB, SDS, and Triton X-100) through the impregnation method, and the decorated activated charcoal adsorbents were used for the removal of PAHs from peanut oil, respectively. The influence of surfactant decoration on the adsorption and detoxification effect of coconut shell-based activated charcoal was discussed. The thermodynamic and kinetic behaviors of PAHs adsorption on the surfactant-modified activated charcoal were investigated, and the adsorption mechanism was analyzed in-depth. Notably, the prepared modified coconut shell activated charcoal could not only remove more than 90% of PAHs from the peanut oil but also keep the cytotoxicity of the treated peanut oil low. Meanwhile, the detoxification procedure has little effect on the nutritional quality and flavor of the peanut oil. The results of this fundamental study demonstrate that the low-cost surfactant-modified coconut shell-based activated charcoal was effective and feasible.

Effect of Filtration Methods of Various Types of Adsorbents on the Quality of Coconut Shell and Kusambi Liquid Smoke as Raw Materials for Processed Meat Smoking

In this study, there were two groups, namely liquid smoke of kusambi and liquid smoke of coconut shells with various treatments of adsorbent filtration with 3 replications. There are three kind of treatment for each liquid smoke groups, first is liquid smoke without filtration process with adsorbent, liquid smoke with zeolite adsorbent treatment, liquid smoke with silica adsorbent treatment, and liquid smoke with activated charcoal adsorbent treatment. Analysis of variance showed that different types of liquid smoke and different adsorbent filtration had a very significant effect (P0.01) on antioxidants, total acid, specific gravity, tar, phenol content, pH, salinity, TDS, total yield, L* and b* color, hedonic color and smokey scent in the resulting liquid smoke. Analysis of variance showed that the different types of liquid smoke had no significant effect (P0.05), but the filtration treatment with different adsorbents had a very significant effect (P0.01) on viscosity. And the analysis of variance also showed that the different types of liquid smoke and the filtration of different adsorbents had no significant effect (P0.05) on the color a* of the resulting liquid smoke. The differences in the types of liquid smoke and the treatment of liquid smoke filtration with adsorbents had a very significant effect (P0 .01) on antioxidant, total acid, specific gravity, tar, phenol content, pH, salinity, TDS, total yield, L* and b* color, hedonic color, and smoke aroma in the liquid smoke produced. However, the different types of liquid smoke did not have a significant effect on the resulting viscosity (P0.05) and the different types of adsorbents in the liquid smoke filtration process had a very significant effect on the viscosity (P0.01). Meanwhile, the different types of liquid smoke and the different types of adsorbents in the liquid smoke filtration process did not have a significant effect on the value of the color a* or the reddish color of the liquid smoke (P0.05).

Arang Kulit Biji Kakao (Theobroma cacao L) sebagai Adsorben untuk Menurunkan Kadar Asam Lemak Bebas pada Pembuatan Biodiesel dari Minyak Jelantah

Indonesia as one of the largest producing and exporting countries of crude palm oil (CPO). However, Indonesia still has not utilized the potential of the waste that generated by using CPO as cooking oil, namely used cooking oil. The high content of free fatty acids (FFA) in used cooking oil will cause the saponification reaction and interfere the processing into biodiesel. Cocoa bean shell charcoal (Theobroma cacao L) has a K2CO3 content similar to its commercial product, and contains some traces of silicates and sulfates so that it can increase the efficiency of reducing free fatty acids. In this study, tests were carried out to reduce FFA levels in used cooking oil using charcoal from cocoa bean husks activated with HCl, varying the concentrations of 6, 8 and 10 Molar, as well as the temperature treatment during the process of mixing used cooking oil with activated charcoal adsorbent, which was 75 , 100, and 150°C. The best FFA reduction results were found in the A3T2 reactor which reached 80%, where the best HCl concentration was 10 Molar and the temperature of the mixing process with the adsorbent was 100°C and produced a biodiesel yield of 75%. The quality of the biodiesel produced complies with SNI 7182-2015 standards, 867 kg/m3 of density, 0.5 mg KOH/g of acid number, 1.52 cSt of kinematic viscosity, 48.081 MJ/kg of calorivic value and 143.99%- mass of methyl ester content.

Combination of Biogas-dual Fuel Engine Method and Activated Charcoal Adsorbent to Minimize Emissions from Two-wheeler

Two-wheelers emissions have been reduced by using sustainable fuels, mainly biogas, in conjunction with adsorbents made from corncob charcoal. Biogas is obtained by purifying biogas from fermented cow dung. In addition, activated charcoal adsorbents obtained from corn cobs are used in the biogas purification process. This process yields biogas with a methane concentration of 93.4%. Purified biogas is then mixed with liquid fuel. Therefore, this study employs the dual fuel combustion method, in which liquid fuel serves as the pilot fuel. The experiment was conducted by introducing biogas at a rate of 1 L/minute and without load at a constant engine speed of 900 rpm. The findings demonstrate a strong synergy between biogas and activated carbon adsorbents in significantly reducing CO and HC emissions. Notably, the adsorbent's capacity to adsorb exhaust emissions improves as the concentration of NaCl activator in activated charcoal increases. HC emissions can be reduced by up to 20%, while CO emissions can be reduced by up to 5.6%. However, CO emissions show an increase, particularly during biogas combustion. Yet, this increase is reversed when combined with activated charcoal adsorbent. The NaCl activator has been proven to widen charcoal pores effectively, enhancing absorption efficiency.

Development of A Hybrid Method by Integrating Electrocoagulation Countinous System with Activated Charcoal Adsorption to Treat Sago Wastewater

Wastewater from the sago industry can pose a risk of pollution because it contains chemicals such as high organic matter content, fiber, 4% unextracted starch, nitrogen solution, and cyanoglucoside which are difficult to degrade in the environment. Sago wastewater is generally acidic, has foul smells, and has a high solids concentration. In this study, a hybrid method using electrocoagulation continuous system and activated carbon adsorption was developed to decrease organic and inorganic contaminates which considered importand environmental concern. These two methods have the advantages of simple equipment, easy operation, low efficiency, and short reaction time. The flow rate will affect the pause time of the sample in the reactor. The longer the pause time, feeding will lead to an increase in the level of turbidity that can be lowered. Industrial wastewater variations in the initial analysis then carried out the electrocoagulation process in a continuous system with a container capacity of 1680 mL with an electrode distance of 2 cm, a voltage of 18 volts, and wastewater into a container with a flow rate of 1 mL/, 2 mL/second, 3 mL/ sec, 4 mL/sec, and 5 mL/sec. In addition, the waste is directly into a container containing charcoal. The parameters studied were COD, BOD, TSS, TDS, KMnO4, DO, pH, DHL, and Al concentration analysis with Atomic Absorption Spectrophotometer, odor, and color analysis. The maximum removal efficiency for TDS, TSS. COD, BOD, TDS, KMnO4 were 81.16%, 87.58%, 91.32%, 48.66%, 99.07%, for a flow rate of 1 mL/second, also other parameters also met have met the quality standards set by PerMenLH No. 5.

Adsorption Capacity of Activated Charcoal Made of Rice Husk on Cd(II) Metal Ions

Rice husk is one of the by-products of the rice milling process that can be used as activated charcoal to adsorb metal ions. This study aimed to determine the optimum pH and adsorption capacity of Cd(II) ions by activated charcoal made of rice husk using the Atomic Absorption Spectrophotometry (AAS) method. Determination of the optimum pH adsorption of activated charcoal was carried out by varying the pH of 2, 3, 4, 5, 6, 7, and 8. Based on the analysis results of the optimum pH for metal adsorption, pH 7 with percent absorbed metal 99.94%, while adsorption of Cd(II) ions using activated charcoal was carried out with several variations of concentration to study adsorption isotherm. The adsorption isotherm model of activated charcoal adsorption followed the Langmuir isotherm model. The results of this analysis obtained that the maximum adsorption capacity (qmax) of Cd(II) ions were 2.068 mg Cd/g.

Preparation of activated charcoal adsorbent from pitombeira seeds (Talisia esculenta) and its application for Ca2+ ions removal

Abstract Water quality that the population has access to can undergo a series of changes, contaminations and interferences. Poor water quality may be related to several contamination sources and can pose a health risk for the ecosystem and for people. The calcium ion is a determinant of water hardness, and its excess in the human body can result in a series of complications and diseases such as renal and bladder lithiasis. The seeds of the pitombeira (Talisia esculenta) were used to produce phosphoric acid activated carbon (PAC). Adsorption studies were conducted by batch technique, and isothermal and kinetic models were systematically used to evaluate the potential of PAC to remove Ca2+ ions from aqueous media. The adsorbent was characterized using BET surface area (141.6 m2/g), SEM, pHPZC (2.75), Boehm titration, and by content analysis of the moisture and ashes. The time required for the system to equilibrate was only 5 min. According to the kinetics study, the data were best fitted by the pseudo-second-order model, while the equilibrium sorption data fitted well with the Freundlich model, with a maximum adsorption capacity of 19.05 mg/g, with 90% of Ca2+ ions removal. Therefore, due to its efficiency and low cost, PAC could be employed as an alternative adsorbent for Ca2+ removal.

EFEKTIVITAS ALAT PENYARING POLUTAN DENGAN ADSORBANSI ARANG AKTIF DAUN TREMBESI (SAMANEA SAMAN)

The air existence on the surface of the earth is one of the important factors for the survival of living things on it. Indonesia’s quality of ambient air has decreased and it is categorized as not good for sensitive groups. The biggest cause of air pollution comes from motor vehicles, of which 85% is from combustion in motorized vehicle engines. Trembesi is the most effective plant in adsorbing pollutant carbon in the air. Activated charcoal is the carbon that has better absorption of cations, anions and the molecules of organic and inorganic compounds. This study aims to create a pollutant filter equipment for CO and CO2 made from Trembesi leaves activated charcoal. This research was conducted by creating an air pollutant filter with 3 different types of adsorbent, namely adsorbent made from paper pulp, trembesi leaves extract adsorbent, and trembesi leaves activated charcoal adsorbent. The data collection used 2 types of vehicles with different year of release and engines. The measurement of pollutant concentration using a Gas Analyzer instrument tester with Korean Iyasaka AET-4000Q type. The result of this study showed that the best adsorbent is activated charcoal from trembesi leaves with 100% adsorption of CO and 36,29% adsorption of CO2 using 2018 Toyota Agya car Dual VVT-I engines with eco indicator technology, and for 1988 SE 1,3 Starlet car with a carburetor type engine successfully adsorb CO by 9,65% and 7,2% for CO2.

PEMANFAATAN ARANG AKTIF KULIT JENGKOL (Pithecellobium lobatum) SEBAGAI ADSORBEN DALAM MENYISIHKAN KADAR COD DAN TSS PADA LIMBAH CAIR TAHU

Tofu liquid waste comes from the washing process, boiling, and printing on tofu production. Tofu liquid waste is usually directly discharged into rivers or sewers which can have a negative impact on the environment. Tofu wastewater treatment with activated charcoal adsorption methods can reduce the concentration of pollutants contained in the waste. This research was conducted to determine the effect of variations in stirring speed in the removal of COD and TSS levels in tofu liquid waste. The adsorbent used in this study was activated charcoal from the skin of jengkol (Pithecellobium lobatum) carbonized at 350ºC which was then activated using 1M HCL. The adsorption process in this study used a mass of 2 g of activated charcoal; 4 g, 6 g and 8 g and stirring speed 60 rpm and 120 rpm. The initial concentrations of COD and TSS were 5140 mg/L and 605 mg/L. The results of the research that have been carried out show that the stirring speed and mass of the adsorbent affect the levels of COD and TSS as well as the effectiveness and adsorption capacity. A significant decrease in COD and TSS levels occurred in the treatment using 8 g of activated charcoal and a stirring speed of 120 rpm. The COD value obtained was 1137 mg/L, TSS was 103 mg/L and the efficiency value obtained was COD of 77.88% and TSS of 82.98%.

Karakterisasi Biogas Hasil Pemurnian dengan Down-Up Purifier Termodifikasi

Biogas is a combustible gas produced from the fermentation process of organic materials by anaerobic bacteria. Biogas can be made by using a digester. A digester is a place where the process of decomposing organic matter by bacteria. The result of biogas still contains impurity gases, so that the quality of biogas is not good. Therefore, efforts to filter the gas are necessary. The purifier is a device to filter a gas. The use of purifiers in a series of digester installations aims to filter out unnecessary gases. The purpose of this research is to design a down-up purifier type biogas purification plant, to determine the changes in substrate characteristics during fermentation and conduct a gas quality test after purification. The results showed that the biogas installation type down-up purifier was designed and assembled using 150 liter drums for gas digesters and reservoirs, 1/2 inch hoses for connecting, 2 purifiers for purification and activated charcoal adsorbents. The C/N ratio is 36.37, an average substrate temperature of 28.62<sup>o</sup>C and an average pH of 5.9. Initial and final Biological Oxygen Demand (BOD) values are 960.12 mg/l and 9.312.53 mg/l. The initial and final Chemical Oxygen Demand (COD) values are 313,500.00 mg/l and 29,100.00 mg/l. Then Total Solid (TS) decreased by 1.45% and Volatile Solid (VS) increased by 0.21%. The use of activated charcoal adsorbents in the two purifiers can reduce CO<sub>2</sub> gas content by 83.79% in biogas with the most optimal purification time of 60 minutes.

Integrated Utilization of Dairy Whey in Probiotic β-Galactosidase Production and Enzymatic Synthesis of Galacto-Oligosaccharides

This work established an integrated utilization of dairy whey in β-galactosidase production from Lactobacillus bulgaricus and prebiotics synthesis by the probiotic enzyme. A cost-effective whey-based medium was newly developed for culturing Lactobacillus bulgaricus to produce β-galactosidase. The medium was optimized through response surface methodology (RSM) involving a series of statistical designs, such as the Plackett–Burman design, steepest ascent experiment, and central composite design. Under the optimized medium, the β-galactosidase activity of L. bulgaricus reached 2034 U/L, which was twice that produced from the traditional MRS medium. The cells of L. bulgaricus harvested from the whey-based medium were subsequently treated with lysozyme. The resulting crude enzyme was used as an efficient catalyst, which catalyzed the synthesis of the prebiotic galacto-oligosaccharides (GOS) in a high yield of 44.7% by using whey (200 g/L) as the substrate. The sugar mixture was further purified by activated charcoal adsorption, thereby yielding a high-purity level of 77.6% GOS.

Intestinal Chelators, Sorbants, and Gut-Derived Uremic Toxins

Chronic kidney disease (CKD) is a highly prevalent condition and is associated with a high comorbidity burden, polymedication, and a high mortality rate. A number of conventional and nonconventional risk factors for comorbidities and mortality in CKD have been identified. Among the nonconventional risk factors, uremic toxins are valuable therapeutic targets. The fact that some uremic toxins are gut-derived suggests that intestinal chelators might have a therapeutic effect. The phosphate binders used to prevent hyperphosphatemia in hemodialysis patients act by complexing inorganic phosphate in the gastrointestinal tract but might conceivably have a nonspecific action on gut-derived uremic toxins. Since phosphorous is a major nutrient for the survival and reproduction of bacteria, changes in its intestinal concentration may impact the gut microbiota’s activity and composition. Furthermore, AST-120 is an orally administered activated charcoal adsorbent that is widely used in Asian countries to specifically decrease uremic toxin levels. In this narrative review, we examine the latest data on the use of oral nonspecific and specific intestinal chelators to reduce levels of gut-derived uremic toxins.