Lime Water Research Articles

[formula omitted] Affects the crystalline calcium silicate hydrate minerals synthesized by fly ash-based silicon extraction solution and lime milk

When extracting amorphous silicon from fly ash using a strong alkaline solution, other elements such as Al also enter the silicon extraction solution in the form of AlOH4−. To systematically investigate the impact of AlOH4− on the synthesis of typical calcium silicate hydrate crystals in a silicon extraction solution, a specific amount of AlOH4− was added to the silicon extraction solution, and calcium silicate was hydrothermally synthesized at 90℃ and 230℃. Scanning electron microscopy (SEM) and Brunner−Emmet−Teller (BET) analysis revealed that with the increasing in AlOH4− content, microporous calcium silicate gradually loses its microporous morphology. While the specific surface area shows no significant change, the median pore diameter first increases from 1.47 nm to 1.58 nm and then decreases to 1.55 nm. The xonotlite fibers underwent a gradual refinement, diminishing from 0.28 to 0.15 µm. Simultaneously, the specific surface area increases from 28.87 to 56.8 m2/g. At an AlOH4− concentration of 3 mol/L, the microscopic morphology transforms into a sheet-like structure. X-ray diffraction (XRD) analysis reveals that AlOH4− promotes the formation of tobermorite while inhibiting the further development of calcium silicate. Additionally, Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance indicate that Al can replace Si in the calcium silicate hydrate system, primarily substituting positions the Q2 and Q3 sites. Qualitatively, it is suggested that with the increasing incorporation of Al, the polymerization degree of the silicon-oxygen tetrahedra decreases. According to experimental results, the concentration of AlOH4− should be below 0.05 mol/L when synthesizing microporous calcium silicate hydrate and less than 0.2 mol/L when synthesizing fibrous xonotlite-type calcium silicate hydrate.

Crystal growth of hydrated calcium silicate synthesized from fly ash and lime milk at 100 °C

To maximize the high-value application of fly ash, this study investigates the incorporation of amorphous silica derived from fly ash as a silicon source and lime milk as a calcium source into microporous calcium silicate powders through dynamic hydrothermal synthesis at 100 °C for a duration of 2 h or less. The products were collected at various synthesis intervals and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric differential scanning calorimetry (TG-DSC). Results indicate that microporous calcium silicate forms through a dynamic reaction that disrupts Si-O bonds, enhancing the mobility of silica-oxygen tetrahedra and generating H2SiO42−groups. Ca2+ ions also interact with these bonds, resulting in Q1 and Q2 forms of silica-oxygen tetrahedra. Phase transformation of calcium silicate at various intervals was noted, beginning with 3CaO·2SiO2·3H2O, shifting to 2CaO·3SiO2·2.5H2O, and finally to CaO·2SiO2·2H2O at 90 min. Thus, microporous calcium silicate evolves from an amorphous C-S-H gel into a crystalline form, featuring diverse calcium silicate minerals with calcium-silicon ratios and particle sizes between 10 and 20 μm, with sizes increasing until the 80-min.

The analysis of suspension process in conical agitator in terms of lime milk preparation reactor

The analysis of suspension process in conical agitator in terms of lime milk preparation reactor

Enhancing epoxy composite materials through lime‐treated sugarcane bagasse and glass fiber reinforcement: Morphological, mechanical, and flame‐retardant insights

AbstractThis study investigates the utilization of sugarcane bagasse and glass fiber to reinforce epoxy composites, enhancing both mechanical and fire resistance properties. Initially, bagasse is collected, sun‐dried, and finely ground before being treated with lime water at concentrations of 3%, 5%, and 7% by weight. The treated bagasse is then mixed with epoxy resin and a hardening agent, followed by a curing process. For samples incorporating glass fibers, the fibers are manually integrated and cured similarly. The methodology involved detailed preparation of the bagasse, its treatment, and subsequent integration with epoxy resin. The mixture was processed under controlled conditions to ensure uniformity and quality. Mechanical properties such as tensile strength, flexural strength, compressive strength, and impact resistance were measured. Thermogravimetric analysis (TGA) was employed to assess thermal stability, while fire resistance was evaluated using the limiting oxygen index (LOI) and the 94‐V test method. Results demonstrated significant improvements in both mechanical and thermal properties with the addition of bagasse and glass fibers. The optimal treatment was identified at a 5% lime water concentration, yielding a tensile strength of 295.08 MPa, flexural strength of 371.24 MPa, compressive strength of 255.39 MPa, and Izod impact strength of 157.04 kJ/m2. TGA results showed the highest thermal stability at 5% concentration, with decomposition temperatures peaking at 402.52 °C. Fire resistance was markedly enhanced, achieving an LOI of 29.8% and meeting V2 level standards according to the 94‐V test method. In conclusion, treating sugarcane bagasse with a 5% lime water solution significantly enhances the mechanical and fire‐resistant properties of epoxy composites. The combination of sugarcane bagasse and glass fiber creates a robust material with high thermal stability and fire resistance, making it a viable option for applications requiring these enhanced properties.

Enhancing remineralization in seawater desalination: Optimizing reagent injection for improved water quality at AL HOCEIMA plant

The water quality produced by reverse osmosis is aggressive and highly demineralized, making it unsuitable for direct use and consumption as a source of drinking water. For this reason, the remineralization stage plays a crucial role in the treatment of desalinated water, and its improvement will be necessary to solve the problem of the aggressiveness of the water treated at the AL HOCEIMA seawater desalination plant. This improvement involves injecting three reagents into the limewater saturator, to obtain lime water that ensures the turbidity of the treated water is less than or equal to 1NTU, TAC, equal to 8°F. These reagents are polyelectrolyte, ferric chloride, and sodium silicate. The results show that adding polyelectrolyte and ferric chloride reduces turbidity to an acceptable level for the plant. However, it should be noted that ferric chloride has significant effects on other treated water parameters. These findings underscore the importance of optimizing remineralization processes to meet water quality standards effectively.

Strength Values of a Soil Stabilized with Fly Ash, Lime, and Sea Water

In this study, the strength values of a soil to which fly ash (FA) and lime additives treated were examined experimentally. In addition to the additives, the effect of using sea water as kneading water was also examined. In experimental studies, Sieve analysis, Consistency limits, Proctor Test, Unconfined compression (UCS) and California bearing ratio (CBR) tests were carried out on the samples. In addition, X-ray fluorescence (XRF), Fourier transform infrared (FT-IR) and Scanning Electron Microscopy (SEM) analyses were carried out to describe the structural properties of FA. Test results showed that the UCS and CBR values of the soil were 134 kPa and 3.1% respectively. After 28 days of curing, these values increased to 846 kPa and 16.3%, respectively, in the mixture which all additives were used together.

Processing the Fluorocarbon-containing Waste from Electrolytic Aluminum Production

The characteristics of fine fluorocarbon-containing waste from aluminum production are given and the influence of changes in aluminum production technology that have occurred in recent years on the formation structure, composition and properties is analyzed. The currently proposed methods for processing these wastes are reviewed. An assessment of the method for processing fine fluorocarbon-containing waste from aluminum production was carried out on the example of coal foam flotation tailings using the method of causticization with lime milk to produce a product containing synthetic fluorite, used as a mineralizer for the preparation of straight cement. The influence of operating parameters (temperature, process time, dilution) on the completeness of causticization of raw materials has been determined. The greatest influence on the extraction of fluorine into fluorite and sodium into solution is exerted by the liquid to solid ratio (L:S), at that, the yield of fluorite reaching 220 kg per ton of supplied raw material. It has been found that the high alkalinity of the solution allows sodium hydroxide to be extracted from it and used after causticization as a gas cleaning solution.

Exploring the potential of nitrophosphogypsum and calcined water-treatment plant sludges in mortar mixtures: A study on workability and strength

Mortar mixtures that consider alternative mineral admixtures are of constant research interest to reduce ordinary Portland cement (OPC) content thereby lowering final cost and carbon footprint. An additional concern is the proper management of industrial process residues that could be used in mortar mixes to avoid their disposal in landfills or water bodies. This work investigated the potential of using calcined water treatment plant sludge (CWTPS) and nitrophosphogypsum (NPG) - a byproduct of the fertilizer industry - as partial replacements of OPC in mortar mixtures. For this purpose, this research evaluates the crystallographic, chemical, and physical properties of NPG and CWTPS through X-ray diffraction (XRD), X-ray fluorescence (XRF), and Scanning Electron Microscope (SEM). XRF and XRD findings strongly suggests that CWTPS qualifies as supplementary cementitious materials, due to its high content of silicon and aluminum oxides in a non-crystalline state. On the other hand, NPG could be used as a mineral admixture. The design of mixtures was based on the workability of 85% flow. The evaluation of properties encompasses the measurement of density, compressive strength, durability (pH and sulfate environments), and water absorption. The results demonstrate that incorporating of NPG and CWTPS to mortar mixes, each at a 5% inclusion rate (with a total replacement of 10% of OPC), increase compressive strength by up to 6.65% at 90 days compared to the control group in mortar mixes. However, the inclusion of NPG and CWTPS significantly decreases the workability of mortar mixes by up to 51.49%. The utilization of NPG as a partial replacement for OPC increases the water-to-cement ratio proportionally compared to the control sample, which can be explained by the anhydrite content of this byproduct. For its part, replacing 10% of OPC with NPG and CWTPS results in a 1.99% decrease in resistance after 28 days in sulfated environments compared to specimens cured in lime water. This protection of NPG against sulfate attack on mortars is based on the fact that SO3 saturation hinders the phase change from AFt to AFm during curing, as demonstrated by the XRD results. Additionally, the inclusion of NPG in mortar mixes increases capillary water absorption by up to 19.8%, while CWTPS, due to its pozzolanic nature, reduces it by up to 5.75%. Finally, this study explores the potential combined use of NPG and CWTPS in mortar mixes as a partial replacement for cement, presenting a viable and sustainable alternative for these cementitious-based construction materials.

Effect of soaking mangrove fruit (Sonneratia alba) with lime water on crude protein, crude fiber, and nitrogen free extract content as a ruminant feed

The mangrove plant is among the strees found growing in the seaside zone, one part by the mangrove plant that Could be utilized as livestock feed for ruminants is mangrove fruit. Mangrove fruit is usually rarely used so it only rots and pollutes the coast. The aim in thus study is to see effects by mangrove fruit tannin reduction with lime water on crude protein, crude fiber, and NFE content. This study used 4x3 Faktorial pattern group randominsation plan using 2 seplicates. The first factor is the concentration by lime water with 4 levels, that is T1 (1% lime water), T2 (3% lime water), T3 (5% lime water), T4 (7% lime water). The second factor is different soaking times with 3 times, namely 10 minutes, 20 minutes, and 30 minutes. The conclusion of the research on soaking mangrove fruit with lime water gives a very significantly different effect on crude protein, crude fibre, and NFE content. The highest crude protein content is in the A1B1 treatment with a grade of 8.1%, the best crude fibre was in the A3B3 treatment with a value of 24.91%, and NFE was in the A1B1 treatment with a value of 58.07%.

Effectiveness and Safety of Using Warm Lime Water in Pregnant Women

Effectiveness and Safety of Using Warm Lime Water in Pregnant Women

ТЕХНОЛОГИЯ ЗАМКНУТОГО ЦИКЛА ПОЛУЧЕНИЯ СТРОИТЕЛЬНОГО ГИПСА ИЗ ОТХОДА ЭНЕРГЕТИКИ И ДЫМОВЫХ ГАЗОВ ТЕПЛОВОЙ ЭЛЕКТРОСТАНЦИИ

A closed-cycle technology for building gypsum producing using energy waste and flue gases of thermal power plants has been developed. The technology is based on an absorption method for purifying gas emissions from industrial enterprises from sulfur dioxide SO2 using a suspension of carbonate sludge and obtaining a finished product – gypsum dihydrate. The commercial gypsum is obtained by using a suspension of carbonate sludge as a reagent. The suspension is formed at the stage of preliminary purification of natural water during coagulation and liming. Coagulation is carried out with ferrous sulfate heptate FeSO4×7H2O, liming – with a saturated solution of lime milk Ca(OH)2. As a result of combining the two processes, a suspension of a certain chemical composition is formed. The chemical composition of the sludge and its technological characteristics are presented. The main substance in the chemical composition is calcium carbonate CaCO3, which allows using a sludge suspension in the chemical reaction of the interaction of flue gases from thermal power plants with the formation of building gypsum. An absorber with a fluidized nozzle has been selected and designed to purify gas emissions from wet suspensions and produce commercial dihydrate gypsum. Hollow or solid hydrophobic polyethylene balls were selected as nozzles to reduce the adhesion of sludge suspension particles to their surface. A technological scheme is presented for purifying flue gases from sulfur dioxide to obtain the finished product – building gypsum. The scheme includes the proposed adsorber, sludge suspension tank, hydrocyclone and filter press. The cost of the resulting commercial building gypsum was calculated, which amounted to 15 rub./year, the payback period was 3,5 years. The prevented environmental harm from soil and land degradation from the introduction of this technology at thermal power plants was calculated by reducing the emission of sulfur dioxide into the air, which amounted to about 1 mil. rub./year.

Impact of pre-soaked lime water carbonized recycled fine aggregate on mechanical properties and pore structure of 3D printed mortar

Compared to natural fine aggregate, recycled fine aggregate has disadvantages such as high water absorption and poor strength. Accelerated carbonization is considered a method to enhance recycled aggregate performance. However, the lack of substances available for carbonation reaction in old cement mortar restricts the enhancement of RFA performance. In this study, a pre-soaked lime-water carbonization method was employed to enhance carbonization efficiency and improve cement mortar performance by introducing additional sources of calcium. Therefore, the focus was on investigating the effects of pre-soaked lime-water carbonization-treated recycled fine aggregate with different replacement ratios (0%, 30%, 50%, 70%, 100%) on the mechanical properties of 3D printed mortar. In addition, combining XRD、SEM-EDS, and X-CT microscale testing methods, the study analyzed the influence of carbonized recycled fine aggregate on the pore structure of 3D printed recycled mortar. The purpose was to reveal the reinforcement mechanism of pre-soaked lime water composite carbonization. Experimental results showed that the pre-soaked lime water carbonization method improved the physical properties of recycled fine aggregate, with the most significant decrease in the water absorption ratio, which decreased by 53.89%. Incorporating appropriate carbonized recycled fine aggregate can enhance the mechanical properties of 3D printed mortar, increase interlayer bonding strength, reduce mechanical anisotropy and overall porosity, and improve pore defects. Defects on the aggregate surface are filled with CaCO3 carbonization products, improving the pore structure and strengthening the interfacial transition zone, thus enhancing the resistance of 3D printed recycled mortar to external forces. The findings of the present work not only improve the utilization of recycled sand but also provide methods and ideas for improving the properties of 3D printed recycled mortar.

Evaluation of Eco-Friendly Consolidating Treatments in Pugliese Tuff (Gravina Calcarenite) Used in Italian Heritage Buildings

This work evaluates the effectiveness of various consolidating treatments applied to Pugliese tuff (Gravina Calcarenite). This type of stone has been used in numerous historic buildings in the Puglia area (southeast of Italy), which presents durability problems due to high porosity, low cohesion between clasts, and low mechanical resistance. Eco-friendly treatments that generate CaCO3 have been selected, specifically bioconsolidant KBYO biological and lime water, which a priori are capable of consolidating without occluding the pores or reducing them excessively, thereby creating compounds similar to those contained in the stone and being respectful of the environment. Nano-sized treatments have also been tested, including nanosilica and nanolime, to compare results with eco-friendly treatments. The bioconsolidating treatment has been applied in two different ways, the usual way consisting of two applications a day for 7 days, as well as a double treatment that is applied in two batches of 7 days with a rest of 7 days between applications. Double treatment has shown a great improvement in consolidation compared to the usual 7-day application; this treatment has obtained the best results in both mechanical and petrophysical properties. This study not only demonstrates the effectiveness of the bioconsolidant but also expands eco-friendly conservation strategies to improve the preservation of historical structures built in calcarenite.

Study on Carbonation of Porcine Blood Hydrogel in the Composite Mortar of Ancient Chinese Architectural Painting.

In the ancient Chinese recipe for composite mortar used in the construction of ground layers for architectural painting, the mixture of porcine blood and lime water is one of the constituent materials. Herein, according to the traditional recipe, the interaction between porcine blood and lime water was systematically and deeply investigated. The experimental investigation demonstrated that porcine blood mixed with lime water at the ratio found in the recipe can form a hydrogel with a hydrophobic surface. During air-drying, the lime water in porcine blood hydrogel can react with CO2 to form calcium carbonate. The crystal morphology of the formed calcium carbonate depends on the surrounding micro-environment of calcium ions in the porcine blood hydrogel. The formed morphology of calcium carbonate includes small calcite crystallites, small graininess calcite crystals with round features, calcite aggregates with layered ladder-like structures, and amorphous calcium carbonate (ACC). Interestingly, the calcium carbonate formed in the inner part of the porcine blood hydrogel exhibits lamellar distribution due to a Liesegang pattern formation. Based on the findings that the porcine blood hydrogel has surface hydrophobicity and brittleness, it can be predicted that in the preparation process of composite mortar for ancient building color painting base course, porcine blood used in the form of a hydrogel is not only easier to be dispersed in hydrophobic tung oil than in liquid porcine blood but also the affinity between porcine blood gel and tung oil is enhanced. As constituent material dispersed in the composite mortar, the layered distribution of calcium carbonate in the porcine blood hydrogel may presumably be beneficial to reduce the internal stress of the composite mortar material.

Mechanism for formation of porcine blood hydrogels used as additives in the mortar of traditional Chinese architectural painting

Ancient Chinese architecture drawing is a unique form of ancient Chinese art. Porcine blood hydrogels are distinctive ingredients used to prepare the composite material of the substrate layer for architecture drawing. This investigation was focused on the mechanism for porcine blood hydrogel formation. Based on the traditional Chinese recipe for the preparation of porcine blood-lime mortar, samples with different ratios of porcine blood and lime water were prepared, and the molecular-scale interactions between the lime water and proteins in the porcine blood were examined with FTIR spectroscopy, Raman spectroscopy, XRD, XPS, fluorescence spectroscopy, contact angle and rheology studies. The mechanical properties and morphological features of the samples were detected with a rheometer, universal material testing machine and SEM. The results indicated that an appropriate amount of lime water was required for gelation of the porcine blood. With the appropriate alkalinity, sufficient carboxyl groups on the fibrin chains were deprotonated, and coordination with Ca2+ ions formed enough cross-links for support networks within the structure of the porcine blood hydrogel. Complexation of deprotonated carboxyl groups on the fibrin chains with Ca2+ ions led to the formation of a hydrophobic surface due alterations of the fibrin conformation and increased the adhesive properties of the hydrogel. With the hydrogel used as an ingredient in the preparation of a substrate layer composite, it is suggested that the hydrophobic surface of the hydrogel facilitated mixing with hydrophobic tung oil during preparation of the composite material, and strong adhesion of the hydrogel increased the mechanical strength and crack resistance of the substrate layer.

The Influence of Alkaline Pretreatment of Waste Nutshell for Use in Particulate Biocomposites

The aim of this work was to determine how different types of alkaline pretreatment influence the properties of waste almond and hazelnut nutshell, as well as their compatibility with model inorganic geopolymer matrixes for the formation of biocomposites with potential use in civil engineering. For alkaline pretreatment, 3, 6 and 9% NaOH water solutions and milk of lime were used under different temperature and time conditions. The rise in the crystallinity index was confirmed by X-ray powder diffraction analysis, while the corroboration of the removal of amorphous and undesirable components was demonstrated through Fourier-transform infrared spectroscopy. Furthermore, the effectiveness of the pretreatments was confirmed via simultaneous differential thermal and thermogravimetric analysis, and the positive change in the morphology of the surface of the waste nutshell (WN) and the deposition of the desired phases was established using scanning electron microscopy. Surface free energy and adhesion parameters were calculated using the Owens, Wendt, Rabel and Kaelble method for WN as fillers and geopolymers as model novel inorganic binders. This research indicates that the 6% NaOH treatment is the optimal pretreatment process for preparing WN as the filler in combination with potassium and metakaolin geopolymer that has been cured at room temperature.

Red Dyes from West to East in Medieval Europe: From Portuguese Manuscript Illuminations to Romanian Textiles

Red is the color par excellence, its symbolism being linked with protection and magic through its primary attributes, fire and blood. It was the predominant color from the earliest times, certainly during the Greek and Roman periods and into Medieval Europe, until blue became a competitor around the 13th century. Mineral pigments, like iron oxides, were the first red sources, used to draw lines, dots, or spots on cave walls or stones. Later, other mineral red pigments were also exploited: Cinnabar, natural mercury sulfide, since the Neolithic, and realgar, arsenic trisulfide, in Ancient Egypt. Scientific investigation revealed that, although inorganic pigments were mainly used in painting, iron oxides and cinnabar were also the first available sources for coloring textiles. Plant dyes have been known since the Neolithic, exploited by people living in climatically mild areas rich in vegetation. Their use is strongly connected with two other fundamental textile processes: Spinning and weaving. Scholarly literature indicates Egyptian privet (henna, Lawsonia inermis) as the oldest red vegetal source used. Although widely known as a source of brown, the dried leaves, when powdered and treated with lime water, yield an intense orange red, which is efficient for dyeing the body — skin and hair — and textiles of animal origin. Madder (Rubia tinctorum or relatives) was the first dye to be reported from archaeological European Bronze and Iron Ages textiles preserved in the Hallstatt salt mines, Scandinavian bog sites, and other European burials. Apart from madder, the most widely appreciated red dye sources in the European Classical period were kermes (Kermes vermilio and K. ilicis), purple (species of sea snails from the Muricidae family), and extracts of red tree resins, as dragon’s blood (e.g. Dracaena draco, Dracaena cinnabari, and Daemonorops draco). These sources were used for textile dyeing and as organic pigments in paintings.

Properties of soils on fluvio-marin landform and their land management strategy for paddy field in Bataguh swampy area, Kapuas Regency, Central Kalimantan Province, Indonesia

Tidal swamp land has strategic and prospective value in sustaining national food resiliency and reserves. This land has the potential for the development of commodity paddy fields. However, this type of tidal swamp has a unique character and influences land management. This research aims to determine soil properties on landform fluvio-marine and its potential for developing lowland rice in Bataguh District, Kapuas Regency, Central Kalimantan. A total of 4 representative soil profiles were identified and characterized in the field and laboratory. Research results show that the lands under study have fine texture. Soils in the surface layer are classified as very acidic to acidic (soil pH 3.3-4.7), has very high organic C levels (5.46-9.37%), potential P moderate (21-40 mg.100g-1), K potential low until moderate (16-21 mg.100g-1), exchangeable Ca low (2.24-3.17 cmolckg-1), exchangeable Mg medium (5.11-8.30 cmolckg-1), soil CEC medium until high (19.63-38.09 cmolckg-1), and base saturation low until high (37-63%). The depth of sulfidic materials or pyrite layer is shallow until deep within 50-85 cm. The sand mineral fraction is dominated by quartz, while the mineral fraction of clay is dominated by kaolinite, followed by vermiculite and illite. The land studied is classified as marginally suitable (S3) for the development of tidal rice fields with a limiting factor for acid to very acid soil reactions (soil pH <5). Balanced fertilization, liming, and micro water management can be done to increase the productivity of this land.

Antibacterial Potential of African Black Soap Decoctions against Selected Clinical Isolates

Africa black soap is widely use in Africa. This study aimed at examining antibacterial potential of African black soap and its different decoction preparations against selected bacterial agents. Soap sample was collected and prepared into three different decoctions (i.e. black soap only, black soap with aloe vera and black soap, cam wood and lime water). Afterwards, different concentrations of 200 mg/ml, 100 mg/ml, 50 mg/ml, and 25mg/ml of each decoction preparation were prepared. Antibacterial activities of each decoction concentration against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Bacillus subtilis was carried out using agar well diffusion method. The result revealed that black soap with cam wood and lime water at 200mg/ml tested against Streptococcus pneumoniae had the highest (26.5 mm) zones of inhibition while at similar concentration black soap with aloe vera showed zone of inhibition of 24.5 mm, 23 mm, and 21.5 mm against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis, respectively. Black soap only showed lowest inhibitory activities compared to other mixtures because at 200mg/ml, zone of inhibition of 18.5 mm, 17.5 mm and 12.5 mm against Pseudomonas aeruginosa, Streptococcus pneumonia and E. coli, respectively were observed. This study has shown that African black soap mixed with the tested mixtures could have a better synergetic effect in inhibiting different types of pathogenic bacteria compared to using the soap only, therefore, could have potential ability to increasing the antimicrobial properties of the soap during usage. Hence, addition could improve Africa black soap quality by indigenous companies.

Pengaruh Lama Penyimpanan Nira Kental Sulfitasi Terhadap Karakteristik Nira Pada Proses Produksi Gula

Sulfated Condensed Nira is sugarcane juice that has undergone several production processes ranging from milling and purification to evaporation and has been mixed with other substances such as lime/sulfur. One of the problems encountered in Indonesian sugar factories is the waiting time for the thick sulfate juice in the crate of thick sap before the cooking process is carried out. This is caused by several things, such as damage to the production machine, overcapacity cooking process, and mill wash. This study aimed to determine the effect of extended storage of sulfate viscous sap on the characteristics of the sap produced in the production process of white crystalline sugar. It uses a sample of thick sulfate sap taken in a crate of thick sap with five treatments, namely storage time of 0 hours, 2 hours, 4 hours, 6 hours, and 8 hours. Parameters tested include total dissolved solids (% Brix), sugar content, pH, color, and turbidity. The results showed that the storage of concentrated sulfate juice significantly affected %Brix. At 0 hours to 4 hours of storage, it increased and decreased after 6 hours. The sugar content in the thick sulfated sap increased at 0 to 4 hours of storage and decreased after 6 hours. Increasing the sugar content in sap is caused by the decomposition of polysaccharides into sugars (sucrose, glucose, and fructose), and the decrease in sugar content is caused by fermentation by Saccharomyces. The storage time of 0 hours was significantly different from the storage time of 2 hours, 4 hours, 6 hours, and 8 hours on the pH of the sulfitation thick juice due to the addition of lime milk to keep the pH of the juice high and prevent hydrolysis either by microbes or acids. The longer the storage, the darker and more cloudy the resulting color.