A method for manufacturing an activated carbon, silver-coffee grounds composite

Abstract

This invention relates to the manufacturing method for an activated carbon composite, specifically a silver and coffee grounds composite consisting of the following stages: preparing the waste coffee grounds, preparing AgNO3 solution, synthesizing the silver-coffee grounds composite, activating the silver-coffee grounds composite, washing the silver-coffee grounds composite, drying the silver-coffee grounds composite, pyrolyzing the silver-coffee grounds composite, washing the silver-coffee grounds composite, and drying the silver-coffee grounds composite material, which is conducted by: a) preparing the waste coffee grounds, b) preparing a 10 mM AgNO3 solution; C) synthesizing silver-coffee grounds composite using the wave irradiation method by mixing 25 ml of 10 mM AgNO3 with 50 ml of a coffee grounds solution; d) activating the silver-coffee grounds composite physically or chemically; e) washing the silver-coffee grounds composite material using hot distilled water to reach a neutral pH; f) drying the silver-coffee grounds composite material at 110°C in the oven for 2 to 3 hours; g) pyrolyzing the silver-coffee groundss composite for 1 hour at 500°C under nitrogen gas (N2); h) washing the silver-coffee grounds composite using hot distilled water to a neutral pH; and i) drying the silver-coffee grounds composite at 110°C in the oven for 2 to 3 hours.

Description

[0001] Description

[0002] A METHOD FOR MANUFACTURING AN ACTIVATED CARBON , SILVER-COFFEE

[0003] GROUNDS COMPOSITE Technical Field of the Invention

[0004] This invention relates to a method for manufacturing an activated carbon composite material . Specifically, a method for manufacturing an act ivated carbon, silver-coffee grounds compos ite comprising impregnating AgNO3with waste coffee grounds . The resulting composite is an activated carbon material that can reduce methylene blue and methyl red dye levels from wastewater .

[0005] Background of the Invention

[0006] Rapid growth in Indonesia, accompanied by rising human populations , unplanned urbanization, and industrialization in big cities , has caused signi ficant damage to water quali ty, resulting in waste that pollutes the environment . Excessive levels of organic, inorganic, and metallic pollutants harm the environment . Exposure to high amounts of pol lutants can also cause serious illnesses and even death for living beings (Garrard et al . , 2019 Groundwater as a Source of Drinking Water in Southeast As ia and the Paci fic : A Multi-Country Review of Current Reliance and Resource Concerns ) .

[0007] Textile dye wastewater is one of the leading causes of pol lution in the aquatic environment . Wastewater from the textile industry contains chemicals with toxic effects on microbes and carcinogenic ef fects on animals (Hameed and Daud, 2008 Adsorption studies of basic dye on activated carbon derived from agricultural waste : Hevea brasiliensis seed coat. ) . More than 10 , 000 vari eties of textile dyes have been produced, with a total production of 70 million tons per year worldwide . Commercially, 5-10% of the produced dyes end up in wastewater . Wastewater contaminated with dyes exhibit high COD and BOD values (Rafatullah et al . , 2010 Adsorption of methylene blue on low-cost, adsorbents : A review) . Methylene blue (MB) and methyl red (MR) are classi fied as basic dyes used in the dyeing process in the si lk, wool , cotton, leather, and paper industries . MB is a cationic dye used in cotton and silk dyeing . It is known to cause irritation, methemoglobinemia, cyanosis , and sei zures in living creatures (Yagub, Sen, and Ang, 2014 Removal of cationic dye methylene blue (MB ) from aqueous solution by ground raw and base modi f ied pine cone powder ) . MR is an anionic azo dye used in paper printing and textile dyeing . Similarly to MB, upon contact , it can irritate the eyes , skin, and respiratory tract i f inhaled (Badr , Abd El-Waned, and Mahmoud, 2008 Photocatalytic degradation of methyl red dye by s ilica nanoparticles ) .

[0008] Activated carbon is an adsorbent widely used in waste treatment and water puri fication . Activated carbon has several advantages , such as its high surface area, microporosity, high reactivity, high mechanical strength, and high adsorption capacity ( Sai fuddin N, Nian CY, Zhan LW, 2011 Chitosan-silver nanoparticles composite as point-of-use drinking water filtration system for household to remove pesticides in water ) . However, most of the activated carbon available on the market is derived from nonrenewable materials , such as coal , lignite , and petroleum coke (Nyirenda, Kalaba, and Munyati , 2022 Synthesis and characteri zation of an activated carbon-supported silver-silica nanocomposite for adsorption of heavy metal ions from water ) . Therefore , an invention is needed to produce a metal and activated carbon composite from biomass waste .

[0009] A composite is a material consisting of various mixtures of substances . It is used because of its better adsorption performance than adsorbents made from a single material (Baig et al . , 2021 Nanomaterials : A review of synthesis methods , properties , recent progress , and challenges ) . Silver composites are an example of an adsorbent composite . A silver composite containing biomass waste has high dye-adsorption capacity because of its high selectivity . Dyes and the charge contained therein can be well adsorbed by silver composites . Methylene blue dyes contain compounds with a positive charge. Meanwhile, methyl red is a compound with a negative charge. Both dyes can be well adsorbed by silver and activated carbon composites due to chemical and physical bonds. Chemical bonds such as ionic and covalent bonds strongly influence adsorption because the opposite charges between the ions in metal atoms that release electrons and non-metal atoms that capture electrons result in adsorption.

[0010] A silver and activated carbon composite has a negative ion charge due to the oxygen atom bonded to the Ag atom. Methylene blue has positively charged sulfur and nitrogen atoms in its resonance structure. In contrast, methyl red has positively charged nitrogen atoms in acidic conditions (E. A. Khan, Shahjahan, and Khan, 2018) . Adsorption of methyl red on activated carbon derived from custard apples (Annona squamosa) fruit shell: Equilibrium isotherm and kinetic studies; I. Khan et al., 2022 Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation) . Because of the dyes' positive ion charge, methyl blue, and methyl red can be adsorbed well by silver and activated carbon composites. Physical bonds, such as Van der Waals bonds, have weaker bonds than covalent bonds. Surface mass transfer and intraparticle diffusion can also occur simultaneously between the composite material and the dye.

[0011] Furthermore, activated carbon is a supporting medium for AgNCg to improve its dye-binding affinity and process stability. The advantages of both materials (activated carbon from waste coffee grounds and AgNO3) are that they can support each other to effectively and efficiently degrade methylene blue and methyl red dyes in wastewater. Generally, two methods are combined in wastewater treatment to achieve better results (Dwivedi and Dwivedi, 2021 Chapter 22 - Sustainable biological approach for removal of cyanide from wastewater of a metal-finishing industry) . However, combining these methods is a gradual process. Thus, it is inefficient .

[0012] Several patent documents disclose technology regarding the manufacturing method of materials used for pollutant absorption. One of which is the United States Patent with the publication number US11135565B2. The patent discloses the use of MOF (Metal Organic Framework) materials, which have a broad level of hydrophobicity, to absorb pollutants such as metals and hydrocarbons. However, the disadvantage of employing the MOF method with nanocomposites is the complexity of the action mechanism used.

[0013] Other technologies concerning pollutant-absorbing materials can be found in the United States Patent publication number US11136247B2, which discloses the use of silver-zeolite nanocomposite polymer materials containing cross-links between zeolite nanoparticles and silver nanoparticles. The method used to produce silver-zeolite nanocomposites starts by dispersing silver nanoparticles into a water-oil microemulsion. It is mixed with silver nanoparticles in a solution containing surfactants, acyl amide, N, N' -methylene bisacrylamide, NaOH, and methyl methacrylate monomer (MMA) . A stable colloidal silver would then be formed by adding a co-surf actant . The application of such methods is used to control water hardness. However, the method is inefficient because it requires many resources in the manufacturing process.

[0014] Another method for manufacturing materials for handling pollutants can be found in the Chinese patent document with the publication number CN110981106B . The technology in the patent uses materials such as keramzit, volcanic rock, and coffee grounds to produce a material that can absorb heavy metal pollutants in water. The coffee grounds in the invention are carbonated at 650-800°C to produce carbon precursors. Then, the carbon precursor and potassium hydroxide solution are heated at. 400~700uC. However, the temperatures used to carbonize coffee grounds in this invention are too high to be efficient. Additionally, its use of volcanic rock is a disadvantage as its availability is limited compared to silver. Therefore, the present invention combines silver / AgNOa and coffee grounds. The studies and patents mentioned above provide the reasons for increasing production and modifying composite materials to eliminate pollutants in wastewater. Thus, a composite material’s production and modification process needs to be adjusted to the characteristics of the pollutants to be removed to obtain effective and efficient results. Manufacturing silver and activated carbon composite from coffee grounds waste as adsorbents to adsorb methylene blue and methyl red was conducted. This present invention provides a manufacturing method for a composite material that combines two types of materials to produce an activated carbon material that can adsorb methylene blue and methyl red from wastewater .

[0015] This present invention’s activated carbon, silver-coffee grounds composite contains a cross-linked mechanism between activated carbon and AgNOj . The silver diffused into the pores of the activated carbon changes the interaction of methylene blue and methyl red dyes on the surface of the activated carbon. The activated carbon activation factor also affects the dye-adsorption selectivity. There are two types of activation: physical activation (without chemical precursors) and chemical activation (uses chemical precursors) . Both activation types increase the material's surface area. The activation and carbonization processes simultaneously occurring during a chemical activation process at lower temperatures produce a better-activated carbon pore structure. Changes in material characteristics are one of the factors in improving adsorbent performance.

[0016] The concentrations of methylene blue and methyl red that will be adsorbed can also affect the adsorption process. The smaller the particle size of the adsorbate, the greater the adsorption capacity. Similarly, contact time will also affect adsorption, as a longer contact time will allow for a better adsorption process.

[0017] Summary of the Invention

[0018] The general aim of this present invention is to overcome the disadvantages of previous inventions. The specific purpose of this invention is to provide a manufacturing method for an activated carbon, silver-coffee grounds composite consisting of the following stages: preparing the waste coffee grounds, preparing an AgN03 solution, synthesizing the silver-coffee grounds composite, activating the silver-coffee grounds composite, washing the silver-coffee grounds composite drying the silver-coffee grounds composite, pyrolyzing the silver-coffee grounds composite, washing the silver-coffee grounds composite, and drying the silver-coffee grounds composite, which is conducted by: a) preparing the waste coffee grounds, b) preparing a 10 mN AgNO3 solution; C) synthesizing silver-coffee grounds composite using the wave irradiation method by mixing 25 ml of 10 mM AgNO3 with 50 ml of a coffee grounds solution; d) activating the silver-coffee grounds composite physically or chemically; e) washing the silver-coffee grounds composite material using hot distilled water to reach a neutral. pH; f) drying the silver-coffee grounds composite material at 110°C in the oven for 2 to 3 hours; g) pyrolyzing the silver- coffee groundss composite for 1 hour at 500°C under nitrogen gas (N2 ) ; h) washing the silver-coffee grounds composite using hot distilled water to reach a neutral pH; and i) drying the silver- coffee grounds composite at 110°C in the oven for 2 to 3 hours.

[0019] Brief Description of the Figures

[0020] Figure 1 shows a schematic diagram of the manufacturing method of an activated carbon, silver-coffee grounds composite composite according to this invention.

[0021] Figure 2 shows a graph of the FTIR results of the activated carbon, silver-coffee grounds composite material.

[0022] Figure 3 shows a graph of the XRD results of the activated carbon, silver-coffee grounds composite material.

[0023] Figure 4 shows the SEM results and physical differences between a non-composite material and the activated carbon, silver-coffee grounds composite material. hows a graph of the Jit ween and the coraposite material .

[0024] Figur shows a graph of the relationship between the efficiency of the activated carbor coffee grounds composite material in decreasing the concentration of methylene blue and methyl red dyes.

[0025] Figure 7 compares the differences in concentration, adsorbent dose, pH, and agitation speed to the adsorption process of methylene blue and methyl red using the activated carbon, silver-coffee grounds composite material.

[0026] Description of the Invention

[0027] This invention aims to make a composite material that adsorbs methylene blue and methyl red dyes in water. The manufacturing method of the composite material is shown in Figure 1. The material capability testing compares the composite material's reactions to chemical activation using H3PO4and physical activation (without chemical substance precursors) .

[0028] The manufacture of the activated carbon, silver-coffee grounds composite is conducted in the following stages: a) mixing 1g of coffee grounds waste with a 10 mM AgNO3solution until homogeneous at 87-100°C using a hotplate stirrer; b) synthesizing the silver-coffee grounds composite using the MARS 6 Microwave Digestion System with the following settings: 100°C, 60 minutes, and 800 Watts; c) activating the silver-coffee grounds composite physically using the pyrolysis method at 500 °C for 1 hour; d) activating the silver-coffee grounds composite chemically using H3PO4with a ratio of 1:3 for 24 hours; e) washing the silver-coffee grounds composite using hot distilled water until a neutral pH is reached; f) heating the silver-coffee grounds composite in the oven at 110°C; g) pyrolyzing the silver-coffee grounds composite at 500°C for 1 hour under nitrogen gas (N2) to become an activated carbon, s i 1 v e r - c o f f e e g r o u n d s c o mp o s i t e ; h) washing the activated carbon, silver-coffee grounds composite using hot distilled water until a neutral pH is reached; i) heating the activated carbon, silver-coffee grounds composite in the oven at 110 °C;

[0029] The silver (Ag) in the AgNOs in the silver composite material fills the pores of the activated carbon in the coffee grounds. The adsorption mechanism of the activated carbon, silver-coffee grounds composite can be physical and chemical. Therefore, this material effectively and efficiently removes methylene blue and methyl red dyes from wastewater. Physically, the silver composite material- both physically and chemically activated- is black. The characteristics of physically and chemically activated carbon, silver-coffee grounds composites are shown in Figure 4.

[0030] Physically and chemically activated carbon, silver-coffee grounds composites have significant differences in functional group characteristics, as shown by the FTIR analysis in Figure 2. Some of the peak changes (absorption bands) on the FTIR graph are caused by the release of OH" groups and their replacement by the phosphate groups absorbed by the composite. The increase in phosphate groups absorbed results in the peak area being higher and wider. Figure 3. Exhibits an XRD dif f ractogram of a physically and chemically activated sample of an activated carbon, silver-coffee grounds composite showing diffraction patterns appearing at 25° with an amorphous structure. This suggests that the sample predominant ly contains the carbon element (C) . In addition, the diffraction patterns on 38°, 44°, 64°, 77°, and 81° indicate that there are AgNPs in the sample with a crystalline structure.

[0031] In terms of the composite’s constituent elements, based on the SEM— EDX test results, physically activated carbon comprises 84.7% elemental carbon (C) , 11.9% elemental oxygen (0) , and 3% elemental Ag . After the activated carbon was chemically activated ing H3PO4, there change ir al content to a

[0032] 1 d Ag respe The invention f manuf ac ses ges in the material ’ s constituent elements in Ficfui mam d tor tivated carbor silver-coffee grounds composite consists of preparing the waste coffee ground, preparing the AgNO solutions, synthesizing the silver-coffee grounds composite, activating the silver-coffee grounds composite, washing the silver-coffee grounds composite, drying the silver-coffee grounds composite, pyrolysis the silver- coffee grounds composite, washing the silver-coffee grounds composite, and drying the silver-coffee grounds composite, which is conducted by a. preparing waste coffee grounds. This stage consists of the f o 11 o w i n g s t e p s : i. brewing coffee with hot distilled water at 87- 100 C , ii. performing the extraction process for 24 hours at room temperature, iii. drying the coffee grounds extract in the oven at 115 °C for 4 hours, iv. smoothing the coffee grounds solids using a test sieve shaker with a 325 mesh; b. preparing the 10 mN Agno3 solution; c. synthesizing the silver-coffee grounds composite using the wave irradiation method by mixing 25 mL of 10 mM AgNO3into a 50 mL coffee grounds solution; d. performing the physical or chemical activation of the silver-coffee grounds composite by; e. washing the silver-coffee grounds composite using hot distilled water until a neutral pH is reached; f. drying the silver-coffee grounds composite in the oven at 110 °C for 2 to 3 hours; g. pyrolyzing the silver-coffee grounds composite at 500 °C for 1 hour under nitrogen gas (N2) ; h. washing the silver-coffee grounds composite using hot distilled water until a neutral pH is reached; i. drying the silver-coffee grounds composite in the oven at 110 °C for 2 to 3 hours; The activated-carbon, silver-coffee grounds composite’s performance in reducing the levels of methylene blue and methyl red dyes in water is influenced by several factors, such as adsorbent dosage, phosphate concentration, pH, agitation speed, and contact time. The performance test was conducted using the following method: a) composites with varying adsorbent doses from 0.05 to 0.125 grams were added with 50 mL of methylene blue and methyl Red 50 ppm. b) 0.05 grams of the composites were added to 50 mL methylene blue and methyl red solutions with varying concentrations, from 50 ppm to 125 ppm. c) 0.05 grams of the composites were added to 50 mL methylene blue and methyl red solutions at 50 ppm with varying pH conditions of pH 3, 4, 5, 6, 7, 8, 9, and 10 by adding HC1 or NaOH. d) 0.05 grams of the composites were added to 50 mL methylene blue and methyl red solutions at 50 ppm with varying agitation speeds of 90, 120, 150, and 180 rpm. e) 0.05 grams of the composites were added to 50 mL methylene blue and methyl red solutions at 50 ppm with varying contact times of 10, 20, 30, 60, 90, and 120 minutes. f) each mixture (a) to (e) was filtered using a Whatman filter paper No. 42. The methylene blue and methyl red solutions separated from the activated carbon, silver-coffee grounds composite were measured using the UV-Vis spectrophotometer at a wavelength of 625 nm for methylene blue and 431 nm for methyl red.

[0033] In principle, the activated carbon, silver-coffee grounds composite should absorb methylene blue and methyl red dyes in water. The silver (Ag) filling the pores of the activated carbon, silver-coffee grounds composite has an effective and efficient absorption capacity to bind with methylene blue and methyl red in the water. This binding results in the decrease of methylene blue and methyl red in the water and the amount of dye particles bound will increase as the adsorption process occurs. The graph of the relationship between the efficiency and capacity of the activated carbon, silver-coffee ground composite that was physically and chemically activated can be seen in Figure 6.

[0034] Figure 7 show’s the ability of the activated carbon, silver- coffee grounds composite that was physically activated to reduce methylene blue and methyl red levels in water with an elimination efficiency range of 54.38-81.99%. The activated carbon, silver- coffee grounds composite that was chemically activated can reduce methylene blue and methyl red levels in water with an elimination efficiency range of 96.13-99.47%. The yield is higher than that of activated carbon, silver-coffee grounds composite without H3PO4precursors. Furthermore, the data significantly show’s that as an adsorbent, the activated-carbon, silver-coffee grounds composite has a high-efficiency percentage despite it being conditioned by various treatments.

Claims

Claims1 . A manufacturing method for an activated carbon, silver-coffee grounds composite comprising the following stages : preparing the waste coffee grounds , preparing the Agnossolution, synthesizing the silver-coffee grounds composite, activating the silver-coffee grounds composite, washing the silver- coffee grounds composite, drying the silver-coffee grounds composite , pyrolyzing the silver-coffee grounds composite, washing the silver-coffee grounds composite, and drying the si lver-coffee grounds composite, which is conducted by : a . Preparing waste coffee grounds . This stage consists of the following steps : i . brewing coffee with hot distilled water at 87-100 ° C, ii . performing the extraction process for 24 hours at room temperature, iii . drying the coffee grounds extract in the oven at 115°C for 4 hours, iv . smoothing the coffee grounds solids using a test sieve shaker with a 325 mesh; b . preparing the 10 mM Agno3 solution; c . synthesizing the silver-coffee grounds composite using the wave irradiation method by mixing 25 ml of 10 mM AgNC3into a 50 mL coffee grounds solution; d. performing the physical or chemical activation of the silver-coffee grounds composite by; e . washing the silver-coffee grounds composite using hot distilled water until a neutral pH is reached; f . drying the silver-coffee grounds composite in the oven at 110 °C for 2 to 3 hours ; g . pyrolyzing the silver-coffee grounds composite at 500 ° C for 1 hour under nitrogen gas (N2 ) ; h . washing the silver-coffee grounds composite using hot distilled water until a neutral pH is reached;i. drying the silver-coffee grounds composite in the oven at1103 hours;2. The manufacturing method of an activated carbon, silver- coffee grounds composite of Claim 1, where the stages of physically activating the silver-coffee grounds composite are characterized by the pyrolysis technique at a temperature of500 °C for 1 hour.

3. The manufacturing method of an activated carbon, silver- coffee grounds composite of Claim 1, states that the silver- coffee grounds composite is chemically activated by adding 30mL of 85% H3PO4into the material obtained from the synthesis in stage (c) and allowed to stand for 24 hours.

4. An activated carbon, silver-coffee grounds composite of Claim 1, where as much as 0.05 grams of the activated carbon, silver-coffee grounds composite that is physically activated can reduce methylene blue and methyl red levels at an initial concentration of 125 ppm solution with a removal efficiency of 54.38-81.99%.

5. An activated carbon, silver-coffee grounds composite of Claim1, where as much as 0.05 grams of the activated carbon, silver-coffee grounds composite that is chemically activated can reduce methylene blue and methyl red levels at an initial solution concentration of 125 ppm with a removal efficiency of 96.13-99.47%.

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