Germicidal Properties Research Articles

Disinfection effect of ozonated water on SARS-CoV-2 in the presence of salivary proteins.

Ozonated water is expected to be an effective disinfectant for SARS-CoV-2 present on environmental fomites; however, ozone is consumed by organic substances, resulting in attenuation of its effect. SARS-CoV-2 present in saliva can contaminate environmental surfaces; therefore, it is essential to understand the effect of organic substances in saliva on the disinfectant properties of ozonated water. To assess organic factors in saliva and the extent to which they diminish the effect of ozonated water on SARS-CoV-2. Ozonated water was exposed to salivary organic factors and residual ozone concentrations were measured. SARS-CoV-2 was exposed to a salivary factor and virus inactivation by ozonated water was measured. Amylase and mucin consumed ozone in a concentration-dependent manner. Urea did not. Ozonated water appeared to inactivate SARS-CoV-2 within 30 sec. The amount of inactivated SARS-CoV-2 decreased as the protein concentration increased. Virus inactivation was stronger by 1.5 mg/L ozonated water than by 0.5 mg/L ozonated water. This study suggests that the salivary amylase and mucin decay ozone in a concentration-dependent manner, thereby attenuating the disinfection properties of ozonated water for SARS-CoV-2. An increase of the initial amount of ozone can ameliorate the disinfection effect of ozonated water on SARS-CoV-2. Ozone consumption should be taken into consideration for virus infection control. These results provide fundamental information about the effect of ozonated water when used to decontaminate surfaces harbouring SARS-CoV-2 in saliva.

TUDY OF CHRONIC TOXICITY OF AN IMPROVED A-SILICONE IMPRESSION MATERIAL PRODUCED IN UKRAINE

The objective of this study is to evaluate the potential toxic effects of an improved A-silicone impression material with decorative properties on the organs and mucous membranes of laboratory animals. Materials and Methods The experiment was conducted on white laboratory rats aged 9 months and weighing 230–285 g. Findings indicate that prolonged contact (30 days) with the material does not result in significant changes in the function of major organ systems in these laboratory rats. Results. A single exposure of laboratory rats to A-silicone impression material with disinfectant properties did not cause significant changes in the physiological state of the animals. Weights of internal organs, including the liver, spleen, heart, and adrenal glands, remained within normal limits, indicating that the material had no toxic effects. The analysis of the peripheral blood composition did not reveal any abnormalities in the number of red blood cells, leukocytes, hemoglobin and other cellular components. The functional state of the liver and kidneys, including the activity of the enzymes AlаT and AсаT, levels of total protein, albumin, creatinine and urea, remained stable and did not change under the influence of the material. There was also no effect on carbohydrate metabolism. No abnormalities in protein synthesis and nitrogen excretion functions were detected, which confirms the safety of the material during the 30-day observation. Conclusion. It was established that this material in the tested dose does not affect the enzyme-synthetic function of the liver and does not exhibit cytolytic effects. The material was found to have no toxic impact on liver function with prolonged use, nor does it cause statistically significant deviations in the measured indicators between the control and experimental groups. The absence of sugar, ketones, and protein in the urine indicates no adverse effect on the renal nitrogen-excreting and saluretic functions, as well as on the vital organs of the rats.

Investigation of Microbiological Effects of Atmospheric Pressure Cold Plasma on Hand Disinfection

<b>Aim:</b> Atmospheric pressure cold plasma is the fourth state of matter obtained at low temperature with atmospheric pressure, which has antimicrobial, anti-inflammatory, sterilization, disinfection and surface modification enhancing properties. The aim of this study is to investigate the effectiveness of plasma activated medium (PAM) obtained from atmospheric pressure cold plasma on hand disinfection.<br /> <b>Methods and Materials</b>: The study was carried out on 15 individuals aged between 18 and 65 with healthy hand structures (no wounds, no pathology). Of the 15 individuals, 5 were selected as cleaning staff, 5 as office stuff, and 5 as academics. Samples were first taken from individuals using swap for bacterial identification. Afterwards, they were asked to wash their hands for 5 minutes in 250 ml PAM. At the end of the period, samples were taken from the individuals in the same way for bacterial identification using swap. The effectiveness of PAM in terms of hand disinfection was determined by comparing these two samples.<br /> <b>Results:</b> As a result of our study, it was found that bacterial colonies decreased in 3 of the samples taken from the hands of 5 cleaning personnel, remained stable in 2, a decrease in bacterial colonies in 4 of 5 office stuff, remained constant in 1, a decrease in bacterial colonies in 3 of 5 academicians, and remained stable in 2 of them. <i>Staphylococcus aureus, Staphylococcus epidermidis, Bacillus megaterium, Staphylococcus capitis, Streptococcus mitis, Staphylococcus warneri</i> bacteria were identified on the hands of individuals.<br /> <b>Conclusion:</b> As a result of our study, it was found that PAM, which has no side effects in the literature, can be an effective tool for hand disinfection.

Electrolyzed Water Treatment for the Control of the Zoonotic Pathogen Vibrio vulnificus in Aquaculture: A One Health Perspective.

Vibrio vulnificus (Vv) is a bacterial pathogen native to warm and brackish water ecosystems that can cause fatal septicemia (Vv-vibriosis) in humans and various farmed fish species. From a One Health perspective, controlling Vv-vibriosis outbreaks on farms is essential not only for animal but also for human health, as it reduces the risk of Vv transmission to humans. Electrolyzed water (EW) is a sustainable control method, exhibiting transient disinfectant properties due to the formation of hypochlorous acid (HOCl). We hypothesized that EW could effectively reduce Vv populations in aquaculture facilities, preventing outbreak emergence. To test this hypothesis, survival assays in EW were conducted under varying conditions of salinity, pH, and free available chlorine (FAC). The results indicated that an intermediate concentration of FAC had a significant bactericidal effect on Vv populations regardless of the condition and tested strain. Consequently, the strategic use of EW could serve as an eco-friendly preventive and control measure against Vv-vibriosis by significantly decreasing the bacterial load in farm water.

Bacteria and RNA virus inactivation with a high-irradiance UV-A source

Disinfection with LED lamps is a promising ecological and economical substitute for mercury lamps. However, the optimal time/dose relationship needs to be established. Pathogen inactivation by UV-A primarily relies on induced reactive oxygen species (ROS) formation and subsequent oxidative damage. While effective against bacteria and enveloped viruses, non-enveloped viruses are less sensitive. In this study, we explored the disinfection properties of 10 W UV-A LED, emitting in the 365–375 nm range. UV-A at high values of irradiance (~ 0.46 W/cm2) can potentially induce ROS formation and direct photochemical damage of the pathogen nucleic acids, thus improving the disinfection. The UV-A inactivation was evaluated for the bacterium Escherichia coli (E. coli), non-enveloped RNA bacteriophage MS2, and enveloped mammalian RNA virus—Semliki Forest virus (SFV). The 4 log10 reduction doses for E. coli and SFV were 268 and 241 J/cm2, respectively. Furthermore, in irradiated E. coli, ROS production positively correlated with the inactivation rate. In the case of MS2 bacteriophage, the 2.5 log10 inactivation was achieved by 679 J/cm2 within 30 min of irradiation. The results demonstrate significant disinfection efficiency of non-enveloped virus MS2 using high-irradiance UV-A. This suggests a potential strategy for improving the inactivation of UV-A-unsusceptible pathogens, particularly non-enveloped viruses. Additionally, the direct UV-A irradiation of self-replicating viral RNA from SFV led to a significant loss of viral gene expression in cells transfected with the irradiated RNA. Therefore, the virus inactivation mechanism of high-irradiance UV-A LED can be partially determined by the direct damage of viral RNA.Graphical abstract

Assessing the effectiveness of performic acid disinfection on effluents: focusing on bacterial abundance and diversity.

Poorly-treated wastewater harbors harmful microorganisms, posing risks to both the environment and public health. To mitigate this, it is essential to implement robust disinfection techniques in wastewater treatment plants. The use of performic acid (PFA) oxidation has emerged as a promising alternative, due to its powerful disinfection properties and minimal environmental footprint. While PFA has been used to inactivate certain microbial indicators, its potential to tackle the entire microbial community in effluents, particularly resistant bacterial strains, remains largely unexplored. The present study evaluates the efficacy of PFA disinfection on the microbial communities of a WWTP effluent, through microbial resistance mechanisms due to their membrane structure. The effluent microbiome was quantified and identified. The results showed that the number of damaged cells increases with CT, reaching a maximum for CT = 240mg/L•min and plateauing around 60mg/L•min, highlighting the optimal conditions for PFA-disinfection against microbial viability. A low PFA level with a 10-min contact time significantly affected the microbial composition. It is worth noting the sensitivity of several bacterial genera such as Flavobacterium, Pedobacter, Massilia, Exiguobacterium, and Sphingorhabdus to PFA, while others, Acinetobacter, Leucobacter, Thiothrix, Paracoccus, and Cloacibacterium, showed resistance. The results detail the resistance and sensitivity of bacterial groups to PFA, correlated with their Gram-positive or Gram-negative membrane structure. These results underline PFA effectiveness in reducing microbial levels and remodeling bacterial composition, even with minimal concentrations and short contact times, demonstrating its suitability for widespread application in WWTPs.

An exploration of AFLC-14-doped ceric phosphate, a novel liquid crystal hybrid ion exchanger: synthesis, ion exchange studies and analytical insights

ABSTRACT In this paper, we present the synthesis and characterisation of an anthraquinone-based discotic liquid crystal (DLC), AFLC-14-doped ceric phosphate, a novel composite ion exchanger which exhibits superior ion exchange properties. The incorporation of AFLC-14 betwixt the layers of ceric phosphate aims to strengthen the material’s thermal property, adsorption capacity, and disinfectant properties along with ion-exchange capabilities. The reported material underwent extensive physico-chemical characterisation using various analytical techniques, including FTIR, UV-vis spectrophotometry, XRD analysis, SEM imaging, TGA/DTA studies and elemental investigation. Additionally, ion-exchange characteristics were investigated, encompassing ion-exchange capacity, concentration dependency, thermal property, adsorption studies for alkaline earth and heavy/transition metal ions, and binary separation experiments. Our findings reveal that the incorporation of a DLC betwixt ceric phosphate matrix significantly improves the exchanger’s overall performance. Notably, the hybrid ion exchanger exhibits remarkable selectivity for mercury (II) ions, indicating its potential for selective ion removal applications in environmental remediation and water purification processes.

Preliminary study of triclosan analysis: A GC/ECD optimization

Abstract Triclosan is one of emerging contaminants with antimicrobial and disinfection properties. It is commonly used in soaps, toothpastes, detergents, hand sanitizers, disinfectants, and other personal care products. Triclosan is ubiquitous in environmental samples and its concentration in natural waters is drastically increase owing to the use of hand-sanitizer during COVID-19 pandemic. Triclosan cancer classification has not been determined yet, but recent studies and government assessments had shown its adverse effect, including as endocrine disruptor compound (EDC) to living things even at relatively low concentration. Triclosan analysis in environmental samples are mostly performed on LC/MS or GC/MS instruments. However, these instruments are relatively expensive. This study was aimed to optimize GC/ECD for triclosan quantification as an alternative to MS based instruments. Triclosan standard solutions at several concentrations were injected into the GC/ECD and the result is evaluated. The result showed that GC/ECD was able to detect triclosan at 0.1 ppb with good repeatability showed by %RSD of 0.48 %. The calibration curve at range of 0.1 to 1000 ppb showed a good linearity (r=0.99999).

Multifunctional FFP2 Face Mask for White Light Disinfection and Pathogens Detection using Hybrid Nanostructures and Optical Metasurfaces.

A new generation of an FFP2 (Filtering Face Piece of type 2) smart face mask is achieved by integrating broadband hybrid nanomaterials and a self-assembled optical metasurface. The multifunctional FFP2 face mask shows simultaneously white light-assisted on-demand disinfection properties and versatile biosensing capabilities. These properties are achieved by a powerful combination of white light thermoplasmonic responsive hybrid nanomaterials, which provide excellent photo-thermal disinfection properties, and optical metasurface-based colorimetric biosensors, with a very low limit of pathogens detection. The realized system is studied in optical, morphological, spectroscopic, and cell viability assay experiments and environmental monitoring of harmful pathogens, thus highlighting the extraordinary properties in reusability and pathogens detection of the innovative face mask.

Аспекты безопасного использования современных дезинфицирующих средств на молочных предприятиях

The article analyzes the main aspects of safe application of chemical disinfectants widely used at dairy enterprises. Effective disinfection at dairy enterprises is directly related to the production of high-quality, safe and competitive food products. When selecting a disinfectant for use at a dairy enterprise, a comprehensive evaluation is necessary not only for effectiveness, but also a multilateral consideration of its safe use. Increasing requirements to ecologization of milk processing enterprises dictate the search for new combinations of functional components in the formulations of chemical sanitizers. The article shows the necessity of consideration of adhesion properties of disinfectants, their corrosive activity and indifference to various materials used at food processing enterprises. It is suggested to control working chloroactive disinfectant solutions, first of all, obtained by electrolysis method, not only by the content of active chlorine, but also by the value of redox potential. The relevance of research aimed at studying the inhibitory properties of active substances and residual quantities of disinfectants on starter microflora and the importance of a systematic approach to the integrated assessment of all elements of safe use of disinfectants at dairy enterprises is formulated. Keywords: disinfectants, toxicity and hazard, effect on human body, environmental safety, redox potential, corrosivity, chemical contamination, inhibition.

Unraveling the Magnetic Properties of NiO Nanoparticles: From Synthesis to Nanostructure

NiO nanoparticles have garnered significant interest due to their diverse applications and unique properties, which differ markedly from their bulk counterparts. NiO nanoparticles are p-type semiconductors with a wide bandgap, high discharge capacity, and high carrier density, making them ideal for use in batteries, sensors, and catalysts. Their ability to generate reactive oxygen species also imparts disinfectant and antibiotic properties. Additionally, the higher Néel temperature of NiO compared with other antiferromagnetic materials makes it suitable for high-temperature applications in spintronic devices and industrial settings. This review focuses on the critical role of structure and composition in determining the magnetic properties of NiO nanoparticles. It examines how finite-size surface effects, morphology, crystallinity, and nickel distribution influence these properties. Fundamental physical properties and characterization techniques are discussed first. Various synthesis methods and their impact on NiO nanoparticle properties are then explored. Their magnetic phenomenology is examined in detail, highlighting the effects of finite size, particle composition and surface, and crystal quality. The review concludes with a summary of key insights and future research directions for optimizing NiO nanoparticles in technological applications.

Destructive effect of UV-C light radiation on lettuce growth: risk assessment of long time exposure

Ultraviolet C (UV-C) light technology employs a particular wavelength within the ultraviolet spectrum to deactivate microorganisms, utilizing radiation as its method. UV-C light possesses germicidal properties, effectively disrupting the DNA of microorganisms such as bacteria, viruses and various pathogens, thereby impeding their ability to replicate and induce illness. Additionally, UV-C could enhance the production of phytochemicals and prevent contamination in agricultural applications. However, overexposure to UV-C can cause safety issues, especially for operators handling its utilization in germicidal or sterilization applications. This study investigated the destructive effects of UV-C light on the morphology and chlorophyll content of lettuces exposed to various durations, aiming to assess the risks associated with prolonged exposure. The results showed that prolonged UV-C exposure affects morphological and chlorophyll content changes. The most damaging effect on lettuce morphology and chlorophyll content was found in the 2 h of UV-C exposure treatment. In the 2 h of UV-C exposure treatment, lettuce length was reduced from 6.01 ± 0.80 cm on day 2 to 5.55 ± 0.78 cm on day 3. The lowest fresh weight of lettuce was also found at 2 h of UV-C exposure treatment (4.32 ± 0.94 gr). In addition, the lowest total lettuce stomata aperture was found in 2 h of UV-C treatment (41 units). Furthermore, on day 4, after 2 h of UV-C exposure treatments, the chlorophyll a, chlorophyll b and total chlorophyll content in lettuces were found to be 1.59 ± 0.02 mg g−1 FW, 0.93 ± 0.02 mg g−1 FW and 2.52 ± 0.04 mg g−1 FW, respectively. Therefore, the most destructive effect of UV-C was found during 2 h of UV-C exposure treatment. These findings indicate the dangers of long-term UV-C exposure to lettuce. Practically, this could also have a negative impact on humans. The knowledge gleaned from these findings is useful for safety issues in the industrial application of UV-C.

Chemical and disinfectant properties of a chlorine-containing chemical from underground mineralized water

Chemical and disinfectant properties of a chlorine-containing chemical from underground mineralized water

Modulation of Electronic Availability in g-C3N4 Using Nickel (II), Manganese (II), and Copper (II) to Enhance the Disinfection and Photocatalytic Properties.

Carbon nitrides can form coordination compounds or metallic oxides in the presence of transition metals, depending on the reaction conditions. By adjusting the pH to basic levels for mild synthesis with metals, composites like g-C3N4-M(OH)x (where M represents metals) were obtained for nickel (II) and manganese (II), while copper (II) yielded coordination compounds such as Cu-g-C3N4. These materials underwent spectroscopic and electrochemical characterization, revealing their photocatalytic potential to generate superoxide anion radicals-a feature consistent across all metals. Notably, the copper coordination compound also produced significant hydroxyl radicals. Leveraging this catalytic advantage, with band gap energy in the visible region, all compounds were activated to disinfect E. coli bacteria, achieving total disinfection with Cu-g-C3N4. The textural properties influence the catalytic performance, with copper's stabilization as a coordination compound enabling more efficient activity compared to the other metals. Additionally, the determination of radicals generated under light in the presence of dicloxacillin supported the proposed mechanism and highlighted the potential for degrading organic molecules with this new material, alongside its disinfectant properties.

Investigation of the properties of electrical sources of ozonators through mathematical models

Abstract The study of the properties of electrical power sources of ozonators through mathematical models is crucial for satisfying sanitary-hygienic and industrial needs. Ozone is a strong oxidant with disinfectant properties, making its application widespread. However, the efficiency of its production largely depends on the quality of the ozonators’ electrical power sources. In this research, we developed and utilized mathematical models aimed at determining the main electrical parameters of various types of ozonators used in ozone production. The results of the study show possibilities for enhancing the energy efficiency of ozonators and optimizing their operational parameters. Mathematical modeling serves as a significant tool for predicting the operating modes and necessary electrical power parameters of ozonators, helping to increase their overall productivity and reduce the cost of ozone production. During the analysis, we considered the stability of the electrical power sources of ozonators, their high-frequency power transmission, and the level of electrical energy consumption. Our research aimed to determine how these parameters affect the ozone production process and, considering these effects, to design and improve the electrical power sources of ozonators.

Coconut husk waste products valorization for fabrication of luminescent titanium dioxide NPs as powerful tool for photodecomposition and food born infection: A sustainable strategy.

Fabricating metal oxide nanoparticles has garnered much attention lately because creating safe chemicals, sustainable materials, economic processes, and renewable resources is becoming increasingly important. This research shows how TiO2 nanoparticles (NPs) could be generated in an ecologically responsible way using waste coconut husk with the help of tender coconut. This extract functions as both a reducing agent and a sealing agent. The investigation of TiO2 NPs exploited ultraviolet (UV), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray (EDX) methods. The germicidal properties of TiO2 NPs against food-borne pathogenic strains were studied using the agar well method. Employing Congo red pigment, the photodecomposition behavior was investigated. The TiO2 NPs produced had a crystallite size measuring 16.2nm. The average grain size of the sample, as measured by FE-SEM inspection, falls within the range of 15 to 25 nm. Impressive anti-germ effects against food-borne germs like Gram-positive (Staphylococcus aureus and Listeria monocytogenes), Gram-negative (Salmonella typhimurium and Escherichia coli) bacteria, and fungi (Candida albicans and Aspergillus niger) have been proved by the sustainable fabrication of TiO2 NPs. The catalytic effectiveness of Congo red decreased by 88% after 90 min. The findings suggest that sustainable synthesis of TiO2 NPs is an effective tool for food-borne germicides and photodecomposition behaviors.

Black Phosphorus and E7-Functionalized Sulfonated Polyetheretherketone with Effective Osteogenicity and Antibacterial Activity

Given its excellent biological properties and the matching of its elastic modulus with that of human bone tissue, medical polyetheretherketone (PEEK) is considered a desirable candidate for bone-implant materials. However, its poor osseointegrative and antibacterial properties greatly limit its clinical application. To address these concerns, a functional PEEK implant is needed. Herein, a novel photo-responsive multifunctional PEEK-based implant material (sPEEK/BP/E7) with both effective osteogenesis and good disinfection properties was constructed via the self-assembly of black phosphorus (BP) nanosheets, mussel-inspired polydopamine (PDA), and bioactive short peptide E7 on sulfonated PEEK (sPEEK). The versatile micro-/nano-structured PEEK surface provides superior hydrophilicity, a favorable osteogenic microenvironment, and excellent photothermal effects under near-infrared (NIR) irradiation. The in vitro results showed that sPEEK/BP/E7 displays enhanced cytocompatibility and osteogenicity in terms of cell adhesion, proliferation, alkaline phosphatase (ALP) activity, matrix mineralization, and osteogenesis-related gene expression, superior to those of the sPEEK and sPEEK/BP samples. In addition to osteogenesis, the multifunctional coating exhibited strong antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, it was confirmed in a rat femoral infection model that sPEEK/BP/E7 effectively resisted infection caused by S. aureus under NIR light irradiation and promoted osseointegration in vivo. Thus, this work presents a facile strategy to realize improvement of the “functional integration” of new polymer bone-implant materials and provide new ideas for their clinical application.

Phytochemical and Pharmacological Study of Thymus Vulgaris : A Review

The thymus vulgaris is a kind of flowering plant native to southern Europe, ranging from the western part of the Mediterranean to southern Italy. It is additionally referred to as gardening thyme, German thyme, ordinary thyme, or simply thyme. The Lamiaceae family of mints includes it. Because it can be used in so many different products—including additives for food, medicines, and cosmetics—thyme is incredibly significant. Thyme leaves are used as aromatic spices, either dried or fresh, in various cooking applications, including stews, soups, sauces, and fish and meat dinners, as well as for flavouring liqueurs and herbal beverage preparations. This is because of the leaves' strong aroma. Bitter, diuretic, antioxidant, antirheumatic, disinfectant, antispasmodic, antimicrobial, heart, and expectorant properties are a few of thymus's therapeutic advantages, a noteworthy medicinal herb that comes strongly suggested. In addition, the plant helps with digestive problems, diabetes, chest infections, coughs, and colds. Flavonoids have promising properties as both antioxidants and antifungal agents. The current review article provides in-depth details on the thymus plant's pharmacological properties and variety of phytochemical.

Design of eco‐synthesized nanocomposites (PVA/TiO2) for promising agents in germicidal and photodecomposition behaviors

AbstractIn recent decades, there has been a significant surge in enthusiasm surrounding the topic of nanotechnology due to the rapid progress of innovation. The enhanced benefits exhibited by nanoparticles (NPs) in comparison to micro‐materials provide a diverse array of applications. Sustainable synthesis is a very efficient technique for producing nanomaterials using a simple, rapid, and eco‐friendly approach. In this investigation, titanium dioxide (TiO2) NPs were produced by combining the residue of coffee extract with PVA/TiO2 as an anchor material. The use of PVA/TiO2 substrates was employed to enhance the surface area of TiO2 NPs to enhance their characteristics. The TiO2 NPs/PVA nanocomposites (NCs) were characterized using procedures. The TiO2/PVA NCs exhibited an absorbance peak at 319 nm in the ultraviolet–visible spectrum, and the particle size was calculated to be 19.2 nm based on the data obtained from FE‐SEM and x‐ray diffraction analysis. Furthermore, an investigation was conducted to examine the photodecomposition and germicidal properties of the TiO2/PVA NCs. The TiO2/PVA NCs showed remarkable germicidal efficacy against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The investigation focused on examining the photodecomposition performance of the TiO2/PVA NCs in the presence of methylene blue (MB). The MB dye exhibited the greatest photocatalytic activity, reaching 89% within 70 min. Hence, the findings of this study indicate that the TiO2/PVA NCs have promising characteristics for use as both germicidal and photodecomposition properties.

Steam gasification of lime dried sewage sludge: Effects of temperature and addition of lime

Gasification shows great potential as an alternative method for energy utilization from sewage sludge. Lime (CaO) is a cheap and commonly used dewatering conditioner for sewage sludge. The calcium hydroxide (Ca(OH)2) generated during the drying process with lime can enhance the pH level of the sludge, thereby providing disinfection properties. This paper investigated enhancement mechanism of Ca(OH)2 on hydrogen gas generation and the effect on gas product yield during the steam gasification process of lime-dried sludge. The experiments were conducted in an electrically heated reactor at 500–800 °C. The forms of calcium present in the gasified sludge char samples were analyzed using X-ray diffraction (XRD) analysis to investigate their transformation process. Fourier transform infrared spectroscopy (FTIR) was utilized to obtain information regarding the chemical structure in the gasified sludge char samples, with the aim of exploring the mechanism behind hydrogen production from lime-dried sludge. The results indicate that the CaO generated from Ca(OH)2 dehydration acts both CO2 adsorbent and catalyst during the gasification process. The addition of Ca(OH)2 during the sewage sludge gasification process leads to a reduction in the aromatic CH content in the organic matter, while significantly increasing the content of reactive CH3-chains. It also promotes the ring-opening and rearrangement reactions of aromatic hydrocarbons and nitrogen-containing heterocycles and steam reforming reaction of tar. The combined effects of these factors contribute to an overall increase in hydrogen gas yield.