Ultrasonic Washing Research Articles

Tannic acid facilitated layer-by-layer nanoarchitectonics for hydrophobic conductive cotton fabric with improved stability for thermal management and flexible sensing.

Conductive cotton fabrics (CF) prepared using layer-by-layer (LBL) assembly are primarily driven by electrostatic interactions, facing challenges such as reliance on a single driving force and poor stability. In this study, we fabricated conductive CF through LBL assembly of tannic acid (TA) and cellulose nanofiber-dispersed carbon nanotubes (CNF-CNT) on the fabric surface. A subsequent hydrophobic treatment with stearic acid (STA) resulted in hydrophobic conductive CF (S/CCT/CF). The strong adhesion provided by the TA effectively anchor the CNF-CNT to the fabric surface, while the STA enhances the stability of the conductive CF, providing excellent resistance to tape peeling, ultrasonic washing, and water droplet impact. Furthermore, we evaluated the thermal management and sensing performance of S/CCT/CF. It exhibited exceptional electrothermal conversion capability, reaching temperatures of up to 119°C at 12V, and demonstrated stable thermal performance even after ~2330 bending cycles. Additionally, it displayed high sensitivity (GF=8.75), rapid response times (0.24s), and outstanding sensing stability, effectively monitoring human movements such as joint bending, chewing, and swallowing. The innovative use of the TA in LBL assembly offers valuable insights for designing low-cost, durable conductive fabrics, paving the way for the development of advanced smart textiles.

Utilization of Ultrasonication as a Method of Reducing Organic and Inorganic Contamination in Post‐Consumer Plastic Film Waste

AbstractPost‐consumer plastic film waste often carries organic and inorganic contaminants that challenge recycling processes and affect the quality of recycled products. An effective contaminant removal procedure through washing such single‐used plastic films (SUPFs) can address environmental and waste management concerns. This study compares the efficiency of different washing techniques in reducing SUPF contamination. To evaluate the efficacy of each washing technique, film samples collected from material recovery facilities are individually exposed to friction, ultrasonic‐assisted, and a combination of both washes. Thermal analysis indicates that the polymers' melting temperature, crystallization temperature, and crystallinity remain unaffected by the washing methods, demonstrating method aptness. Confocal laser scanning microscope images show that washing results in a cleaner sample surface. 91% ash reduction during the combined wash treatment indicates a high method efficiency compared to the individual friction and ultrasonic wash procedures. This is further validated by reducing characteristic contaminant IR bands (3600–3000, 1750–1600, and 1100–1000 cm−1). Elements of concern such as Cd, Cr, Hg, and Pb in SUPFs after each washing technique applied conform with regulations (<100 ppm) for packaging products. This research shows the novel ultrasonic washing reduces more contamination than friction with shorter wash times and no surfactants.

Ultrasonic-assisted pre-concentration of iron values in bauxite residue suitable for reduction-roasting purpose

The study aims to explore the feasibility of using low-frequency ultrasonic washing to pre-concentrate iron values in waste bauxite residue (BR) containing 32.60 wt. % iron. This novel approach involves ultrasonication followed by water-washing to pre-concentrate iron before reduction-roasting of BR. Conventional reduction-roasting of BR is more expensive compared to pre-concentrated BR, making this method potentially cost-effective. The process consists of a two-stage ultrasonic treatment procedure. In the first stage, ultrasonication at 30 °C, with 40% solid content (w/v) for 30 min, improves the iron grade to 41.2 wt. % with 82% recovery. However, a second stage of ultrasonication is necessary to further upgrade the iron. The study optimized the ultrasonication time, temperature, solid content (%, w/v), and water washing parameters. Under optimal conditions (ambient temperature, 30% solid content (w/v), 45 min of ultrasonication), the iron grade reached 49.1 wt. % (Fe2O3 70.2) with 66% recovery. Water-washing parameters were found to be less effective compared to ultrasonication parameters. The settling time after water washing significantly affects the grade and recovery of the product. The ultrasonic effect on the BR particle surface leads to the breakage of surface-alkali coating and the disintegration of locked particles to generate free iron and other particles. Particle size analysis supports the disintegration of BR particles into smaller pieces. The physicochemical characterizations of different products were carried out using ICP-OES, XRD, FTIR, and FESEM studies to support the experimental findings. The possible iron separation mechanism is discussed utilizing available literature, as well as experimental and characterization evidence.

매실 추숙에 따른 매실 및 매실청의 시안배당체 함량 변화

This study investigated the yellowing phenomenon of maesil (Prunus mume), changes in organic acid (OA), and cyanogenic glycoside (CN-Glc) contents during post-harvest ripening, and the potential use of ripened maesil as raw material for CN-Glc-reduced maesil chungs. Ripening conditions were as follows: 5℃ for Ripening I, 20–22℃ with 50–60% RH for Ripening II, 20–22℃ with 50–60% RH after ultrasonic washing of maesil for Ripening II-US, and 35℃ and 80–90% RH for Ripening III. Yellowing did not occur in maesil under Ripening I even after 7 days, but was observed after 7 days of Ripening II and Ripening II-US, and after 3 days under Ripening III. The OA content slightly decreased under all ripening conditions, while CN-Glc content significantly decreased, with ripening under all ripening conditions, with Ripening II and Ripening II-US being the most effective at reducing CN-Glc levels. In maesil chungs prepared from ripened maesil CN-Glc content was significantly lower than that of those made with untreated maesil. These results demonstrate that ripening under the conditions tested in this study significantly reduces CN-Glc content in maesil with minimal reduction in OA content, enabling the preparation of CN-Glc-reduced processed maesil products.

Photocatalytic NOx degradation and [formula omitted] adsorption by mortar modified with S-g-C3N4/MgAl-CLDH: Influence factors and stability

NOx is a harmful gas that causes respiratory diseases and acid rain. Commonly used photocatalysts for degrading NOx such as UV responsive TiO2 show weak photocatalytic degradation efficiency under visible light. Furthermore, the great concern is that the degradation product, nitrates (NO3-), from NOx could be washed away and increase the nitrogen deposition and eutrophication in the surrounding soil and aquatic environments, resulting in serious secondary pollution. To address these issues, this study proposes a novel solution by incorporating S-g-C3N4/MgAl-CLDH nanocomposites into a cementitious system which features high NOx degradation efficiency under visible light condition and the efficient capture and adsorption of NO3- in situ. The NOx degradation was comprehensively studied, encompassing the influencing factors and stability. The mechanism for NO3- adsorption process was expounded using the isothermal model. The results show that the amount of exposed S-g-C3N4/MgAl-CLDH and the contact area between S-g-C3N4/MgAl-CLDH and NOx are the essential reasons affecting the NOx degradation. The NOx degradation ability of photocatalytic mortar exhibits excellent stability with the NOx removal ratio decreasing by only 4.8 % and 14.5 % after ten consecutive tests and 120 min of ultrasonic washing, respectively. Furthermore, S-g-C3N4/MgAl-CLDH increases the NO3- adsorption capacity of photocatalytic mortar by about 1.5 times, and the adsorption process of NO3- follows the Freundlich isotherm. The study offers an alternate method for designing innovative nanocomposites in cement-based materials to control environmental pollution.

Polypropylene Blends with Durable Hydrophobicity and Enhanced Mechanical Properties Based on POSS and Alkane Modified Polypentafluorophenyl Methacrylate.

Durable functionalization on polypropylene (PP) surfaces is always a key problem to besolved. Coatings with low surface energy peel off easily especially under extreme conditions, owing to their weak adhesion. In this paper, side groups of both polyhedral oligomeric silsesquioxane (POSS) and alkane are grafted to polypentafluorophenyl methacrylate (PFP), and then PP blends with these side-group modified PFP are obtained through a melt-blending process. It is found that POSS can result in surface segregation and provide hydrophobicity in blends. Microfibers are formed because of the orientation effect during the tensile testing, which furtherly promotes mechanical strength. Significantly, alkaneside-groups can be entangled with PP segments, which brings about cross linking. Therefore, with crosslinking and synchronous orientation of POSS, the elongation at the break of blends is greatly increased up to 974%. The final blend demonstrates quite durable hydrophobicity under many extreme conditions, such as repeated tape peeling, ultrasonic washing, strong friction, and soaking in strong acid (pH = 1), strong alkali (pH = 14) and alcohol. The heat and UV resistance of the blend are also obviously improved. This study will develop anovel and facile strategy to endow PP with durable hydrophobicity as well as greatly enhanced mechanical properties.

Применение ультразвуковой кавитации при санации посуды в системе общепита

Kitchen and dining utensils can become a transmission link for infection, which can affect the development of the catering system. The degree of cleanliness of the dishes depends to a large extent on the diligence of the worker washing the dishes at the enterprise; Objective factors of tableware’s compliance with regulatory parameters also include uneven traffic flow of visitors throughout the day. Analysis of scientific literature contributed to the search for a solution to the problem of increasing the reliability of cleanliness of dishes while reducing, first of all, physical costs for auxiliary workers in school canteens and prompted the development of a patent «Method of washing tableware manually in public catering organizations,» based on the use of cheap ultrasonic washing machines during the secondary washing and rinsing stages. As a positive effect, we noted the possibility of reducing the temperature of the water used by 20–25 °C, the refusal of an additional measure – the use of a disinfectant during quarantine or a pandemic; compliance of the final result with HACCP (Hazard Analysis and Critical Control Points) requirements and a reduction in the load on the worker washing the dishes. Thus, the implementation of the proposed method, according to the authors, is economically profitable and can have a health-preserving effect on both visitors to catering establishments and the worker washing the dishes. Keywords: ultrasound, changes in the production process, HACCP, quality of work performed.

Exploring the viability of anti-microbial, superhydrophobic jute bags as an approach to sustainable food packaging system

Jute in food packaging offers several advantages, including cost-effectiveness, biodegradability, renewability, and low environmental impact. Nevertheless, its hydrophilic characteristic makes it susceptible to airborne humidity and precipitation moisture. We combated this by chemically treating jute to make it water-resistant. The coated jute (WCA = ∼162°) exhibits high mechanical endurance against exposure to air (>1 month), ultrasonic washing (6 h), brush scrubbing (>50 cycles), and mutual abrasion (>150 cycles), along with good thermal stability. During a 2-month experiment involving seed storage in an RH of 85%, wheat grains stored in the coated bag showed 8.08% less moisture content than that stored in control. Furthermore, the preserved grains in the control jute exhibited altered colour, texture, and fungal development. Additionally, compared to the control, the coated jute delivers >50% bacterial growth reduction in 48 h. The proposed jute offers a sustainable packaging solution that promotes eco-friendly practices and reduces plastic waste.

Lightweight, breathable and self-cleaning polypyrrole-modified multifunctional cotton fabric for flexible electromagnetic interference shielding

The thriving of wearable electronics and the emerging new requirements for electromagnetic interference (EMI) shielding have driven the innovation of EMI shielding materials towards lightweight, wearability and multifunctionality. Herein, the hierarchical polypyrrole nanotubes (PNTs)/PDMS structures are rationally constructed on the textile for obtaining multifunctional and flexible EMI shielding textiles by in-situ polymerization and surface coating. The modified cotton fabric possesses a conductivity of about 2715.8 S/m and an SET of 28.2 dB in the X band when the thickness is only 0.5 mm. After ultrasonic treatment, cyclic bending and washing, the conductivity and EMI shielding performance remain stable and exhibit long-term durability. Importantly, the textile's inherent lightweight, breathable and soft properties have been completely retained after modification. This work shows application potentiality in the field of EMI pollution protection and affords a novel path for the construction of multifunctionally wearable and durable EMI shielding materials.

Advanced Processing Techniques and Impurity Management for High-Purity Quartz in Diverse Industrial Applications

While numerous studies have explored the mineralogical characteristics and purification techniques of high-purity quartz (HPQ), discussions on impurity control during various purification processes and their applications in photovoltaics, electronics, and optics remain limited. This review delves into the adverse effects of impurities such as aluminum, iron, and sodium in the manufacturing processes of these industries, emphasizing their critical role as these impurities can degrade material performance. This paper focuses on analyzing the types of impurities found in quartz and evaluates existing purification technologies such as acid washing, ultrasonic acid washing, chlorination roasting, and calcination quenching. It highlights the limitations of current technologies in processing quartz ore and discusses the advantages of different impurity types under various technological treatments. Moreover, it explores the environmental and economic impacts of these high-purity processes, underlining the necessity for more environmentally friendly and cost-effective purification techniques. The purpose of this review is to provide a comprehensive technical and strategic framework for the use of high-purity quartz in high-tech applications, supporting future research and industrial applications in this critical material field.

Hemostatic Dressing Immobilized with ε-poly-L-lysine and Alginate Coated Mesoporous Bioactive Glass Prevents Blood Permeation by Pseudo-Dewetting Behavior.

The integration of hemostats with cotton fabrics is recognized as an effective approach to improve the hemostatic performance of dressings. However, concerns regarding the uncontrollable absorption of blood by hydrophilic dressings and the risk of distal thrombosis from shed hemostatic agents are increasingly scrutinized. To address these issues, this work develops an advanced dressing (AQG) with immobilized nano-scale mesoporous bioactive glass (MBG) to safely and durably augment hemostasis. The doubly immobilized MBGs, pre-coated with ε-poly-L-lysine and alginate, demonstrate less than 1% detachment after ultrasonic washing. Notably, this MBG layer significantly promotes the adhesion, aggregation, and activation of red blood cells and platelets, adhered five times more red blood cells and 29 times more platelets than raw dressing, respectively. Specially, with the rapid formation of protein corona and amplification of thrombin, dense fibrin network is built on MBG layer and then blocked blood permeation transversely and longitudinally, showing an autophobic pseudo-dewetting behavior and allowing AQG to concentrate blood in situ and culminate in faster hemostasis with lower blood loss. Furthermore, the potent antibacterial properties of AQG extend its potential for broader application in daily care and clinical setting.

BaTiO3 Catalyzed Ultrasonic-Driven Piezoelectric-Induced Reversible Addition-Fragmentation Chain-Transfer Polymerization in Aqueous Media.

Compared with normal stimulus such as light and heat, ultrasonic possesses much deeper penetration into tissues and organs and has lower scattering in heterogeneous systems as a noninvasive stimulus. Reversible addition-fragmentation chain-transfer polymerization (RAFT) in aqueous media is performed in a commercial ultrasonic wash bath with 40kHz frequency ultrasonic, in the presence of piezoelectric tetragonal BaTiO3 (BTO) nanoparticles. Owing to the electron transfer from BTO under the ultrasonic action, the water can be decomposed to produce hydroxyl radical (HO•) and initiate the RAFT polymerization (piezo-RAFT). The piezo-RAFT polymerization exhibits features of controllable and livingness, such as linear increase of molar mass and narrow molar mass distributions (Mw/Mn < 1.20). Excellent temporal control of the polymerization and the chain fidelity of polymers are illustrated by "ON and OFF" experiment and chain extension, separately. Moreover, this ultrasonic-driven piezoelectric-induced RAFT polymerization in aqueous media can be directly used for the preparation of piezoelectric hydrogel which have potential application for stress sensor.

Using ultrasonic washing combined with UV-LEDs as a novel chemical-free method to disinfect fresh ready-to-eat produce

The consumption of ready-to-eat fresh produce raises the issue of food-borne pathogen infections; thus, disinfecting ready-to-eat produce for commercial use, such as in homes and restaurants, is important to ensure food safety. Chemical sanitizers are typically used for disinfection. Ultraviolet-light emitting diodes (UV-LEDs) are a novel non-thermal disinfection technology that consumes less energy and generates less heat than traditional UV lamps, making them more appealing to consumers. In this study, we combined ultrasonic (US) washing method with UV-LEDs (US-UV-LEDs) to develop a technique for disinfecting fresh produce without using chemical sanitizers and compared its efficacy with three common household sanitizers (“84” (sodium hypochlorite) disinfectant, kettle descaler (citric acid), and vinegar (acetic acid)). In addition, we investigated the efficacy of this method in controlling pathogen numbers in the water used to wash (washing water) the produce to prevent cross-contamination between water and produce. Cherry tomatoes and lettuce were selected as produce models and Salmonella Typhimurium and Escherichia coli O157:H7 were used as the bacterial models. The results showed that US-UV-LEDs reduced the numbers of S. Typhimurium and E. coli O157:H7 on produce by 2.1–2.2 log CFU/g, consistent with the results achieved by the three household sanitizers; however, kettle descaler and vinegar had a limited effect (2.6–3.5 log CFU/mL) on residual pathogens in the washing water. Furthermore, we created washing water with low (754 mg/L) and high (1425 mg/L) chemical oxygen demand (COD) levels and determined the disinfection efficacy of “84” disinfectant and US-UV-LEDs. The results showed that US-UV-LEDs reduced the number of S. Typhimurium and E. coli O157:H7 by 2.0–2.1 and 1.8–2.1 log CFU/g under low and high COD levels, respectively, which was similar a result to that of “84” disinfectant. However, the residual pathogen numbers in the washing water were reduced to 1.4–1.9 log CFU/mL after treatment with US-UV-LED under high COD, whereas the pathogens were undetected in the washing water disinfected with “84” disinfectant. These results suggest that US-UV-LEDs have better application potential than acidic household sanitizers, but chlorine sanitizer remains the most effective disinfecting method.

Robust Optical Physical Unclonable Function Based on Total Internal Reflection for Portable Authentication.

Physical unclonable functions (PUFs) utilize uncontrollable manufacturing randomness to yield cryptographic primitives. Currently, the fabrication of the most generally employed optical PUFs mainly depends on fluorescent, Raman, or plasmonic materials, which suffer inherent robustness issues. Herein, we construct an optical PUF with high environmental stability via total internal reflection (TIR-PUF) perturbed by randomly distributed polymer microspheres. The response image is transformed into encoded keys via an iterative binning procedure. The concentration of the polymer solution is optimized to debias the bit nonuniformity and maximize encoding capacity. The constructed TIR-PUF shows significantly high encoding capacity (2370) and markedly low total authentication error probability (1.614 × 10-23). The intra-Hamming distance is as low as 0.068, indicating the excellent readout reliability of TIR-PUF. The environmental stability of TIR-PUF has demonstrated promising results under a range of challenging conditions such as ultrasonic washing, high temperature, ultraviolet irradiation, and severe chemical environments. Moreover, the challenge-response pairs of our TIR-PUFs are demonstrated on an authentication system with low-power dissipation, lightweight components, and wireless imaging capture, rendering the possibility of portable authentication for practical applications.

A facial method for constructing superhydrophobic surface by one-step surface etching combined with melt blowing process

It is a challenge to prepare fluorine-free superhydrophobic surfaces by simple methods. In this work, a simple and effective method for constructing a superhydrophobic surface was developed by combining in situ nanofibrillating melt blowing processs and one-step surface etching. Firstly, the randomly stacked meltblown microfibers as microstructure transformed the wetting performance of the surface from hydrophilic to hydrophobic. Then, by tuning the etching time, the outmost nanofibrils within the microfibers were exposed to form nanostructure thereby achieving superhydrophobic performance with a contact angle of 153°. The superhydrophobicity of the as-prepared nonwoven was maintained after various harsh treatments, such as strong acid, strong alkaline, sandpaper abrasion, and ultrasonic washing, showing stable water repellency ability. In addition, the superhydrophobic nonwoven showed promising application in self-cleaning and oil–water separation. Thus, this work not only prepares a superhydrophobic surface but also proposes a new idea for designing a micro-nano hierarchical structure on the surface.

Ultrasound Technology in Carpet Cleaning

Carpets are widely used in living spaces for beautiful appearance, heat, and sound insulation. Cleaning carpets is essential for both their lifespan and health and hygiene. Washing operations are carried out at regular intervals in carpet-washing factories. Industrial carpet washing operations must be done consciously because a significant amount of water and time is consumed during these processes. In addition, problems such as discoloration and strength losses may be encountered in delicate carpets. In this study, stained carpets were washed at mediums with and without ultrasound at room temperature at different times. Mud stain was used as an example of particle dirt. The original unwashed carpet without stain was taken as a reference and compared with the washed carpet by evaluating the color differences and changes in the yellowness index to check the amount of stain removal. The color differences (Da*, Db*, DL*, DC*, Dh*, DE*) were close to zero, and the differences in the yellowness index were low, so it was concluded that the stained carpet was cleaned and turned to the original form after washing. The washing process was evaluated as successful because the color and yellowness index of the washed carpet were close to the unwashed carpet. Effects of washing type (with and without ultrasound), washing agent (with and without detergent), and washing time (30, 60, and 90 minutes) are significant for α=0,05 in washed carpets according to the original carpet. Interactions between parameters are also significant. If the washing conditions are consciously adjusted, ultrasonic washing can be an alternative to the soaking process in carpet washing. With ultrasonic washing, it can be possible to shorten the duration of the wetting step and effectively clean sensitive carpets in softer conditions without damaging them. It would be useful to carry out studies that reduce water usage by optimizing the amount of washing baths in the future.

Freeze polymerization to modulate transverse-longitudinal polypyrrole growth on robust cellulose composite fibers for multi-scenario signal monitoring

Novel in-situ freeze polymerization assisted layer-by-layer self-assembly method was utilized to prepare robust regenerated cellulose fiber-polypyrrole (RCF-PPy) composite fibers with high-conductivity, where transverse-longitudinal polypyrrole growth on RCF was regulated by using Lewis acid FeCl3 in crystalline ice state with the template etching and oxidation effects. The RCF-PPy3 exhibited high strength (1.01 cN/dtex) and exceptional durability, withstanding mechanical deformation, friction (100 cycles), and ultrasonic washing (50 times), addressing the issues of poor interface adhesion and conductivity stability of conductive fibers. Furthermore, the composite fiber demonstrated high electrical conductivity of 87.66 mS cm−1 and outstanding sensing performances for monitoring strain, pressure, temperature (0.34 %/°C), and humidity (0.895 %/RH). Based on RCF-PPy3, a pressure sensor was constructed as a human–machine interface electronic device, achieving sedentary reminders, fingertip information transmission, indicating great potential applications in intelligent wearable fiber electronic devices.

Superhydrophobic Al2O3/MMT-PDMS Coated Fabric for Self-Cleaning and Oil-Water Separation Application.

This study introduces a novel superhydrophobic coating applied to the fabric surface through spray coating of the Al2O3/MMT nanocomposite and PDMS polymer to enhance the surface roughness and reduce the surface tension, respectively. The as-prepared coating exhibits a remarkable superhydrophobic property with a water contact angle (WCA) of ∼174.6° and a water sliding angle (WSA) < 5°. Notably, the fabric demonstrates a self-cleaning property through removing dust and dirt via adhering to water droplets. Moreover, the insignificant loss of WCA (3.2 and 1%) after exposure to alkaline and acidic media for 10 days verifies the promising chemical stability of the coated layer, whereas WCA > 160° after 24 h of immersion in various organic solvents further indicates the layer resistance. Besides, the layer sustains WCA of 174.5, 172.5, and 168.45° after 1 month of air exposure, ultrasonic washing, and 50 cycles of home laundry. The mechanical resistance of the fabric was verified by maintaining a WCA of 158.73° after 200 abrasion cycles. Also, the layer exhibits thermal resistance with <4.1% of WCA loss in the temperature range of -10 to 180 °C. Additionally, the superhydrophobic coating excels in oil-water separation, achieving >99% separation efficiency for various oils. These exceptional properties position the fabric for diverse applications, including protective clothing, outdoor gear, medical textiles, and sportswear, emphasizing its versatility and novelty in the realm of superhydrophobic materials.

One-step fabrication of strengthened breathable composite nanofiber membranes by electrospinning/electrospraying for highly waterproof application

Waterproof breathable membranes (WBMs) have attracted intense research interest due to their wide applications, however, there are still great challenges in effectively preparing WBMs with desirable waterproofness, breathability and elasticity. Here, a facile and scalable fabricating strategy combining electrospinning and electrospraying is proposed to manufacture nanofiber WBMs, which are comprised of both hydrophobic thermoplastic polyurethane (TPU) nanofibers and inter-fiber polyvinyl butyral (PVB) bonding containing a short perfluoroalkyl hydrophobic agent. The obtained composite nanofiber membranes showed durable water/oil repellent properties against ultrasonic washing and abrasion. The interconnected fibrous structure together with liquid repellent surface have endowed the WBMs with comprehensive properties with hydrostatic pressure of 73.7 kPa, water vapor transmission rate of 6.88 kg m−2 d−1, outstanding tensile strength of 25.72 MPa and large elongation at break of 217%, which have exceeded the majority of their nanofiber counterparts. This work could provide a novel approach for the preparation of waterproof and breathable membranes with balanced structural stability, waterproofness and wearing comfort, especially suitable for the personal protective material application.

Experimental study on modified fruit shell carbon for methane adsorption and decarbonization

Modification of activated carbon has the potential to improve its adsorption and separation capacity. Different concentrations of ammonia (6%, 9%, 12%, 15%) and treatment times (4 h, 6 h, 8 h, 10 h) were used to modify jujube shell carbon and coconut shell carbon in ultrasonic washing equipment. Biogas adsorption experiments were carried out with modified activated carbon to study the effect of adsorption and decarbonization on activated carbon surface functional groups. After modification, the surface alkaline functional groups of activated carbon increased, the acidic functional groups decreased, and the adsorption performance of CO2 was enhanced. In addition, the specific surface area and total pore volume of activated carbon decreased, the average pore size increased, and the degree of graphitization increased. In the experimental research range, under ultrasonic conditions, jujube shell carbon impregnated with 12% ammonia water for 4 h and coconut shell carbon impregnated with 9% ammonia water for 10 h had the best modification effect. The adsorption capacity for CO2 was 1.83 and 1.745 mmol/g, respectively, which increased by 0.8 mmol/g and 0.599 mmol/g, respectively, compared with the unmodified sample.