Papers by Keyword: pH

Abstract: The aim of this study was to create a practical water filter to improve the quality of Muara Angke well water. There are three main steps in this research, namely initial testing of Muara Angke residents' well water, making water filters, and testing filtered well water. There are three types of tests carried out, namely resistivity, pH, and turbidity. The water filter uses sedimentation techniques using natural materials. The composition of the materials from top to bottom is gravel (30 cm), silica sand (40 cm), manganese zeolite (40 cm), and activated carbon (40 cm). Well water, whether filtered or not, still contains more dissolved ions which causes its resistivity to be lower than bottled water. The filtration process using silica sand, manganese sand, and activated carbon does not directly cause a significant decrease in pH. However, if the source water has certain chemical characteristics or there are reactions that result in increased acidity (such as from CO₂ or oxidation reactions), the pH of the water may decrease slightly. The filtration media used helps reduce water turbidity, but has not reached the desired standard.

Abstract: Many factors influence the effectiveness of traditional binders used for soil stabilization, including anions present in the soil and carbonates. Natural pozzolana-lime stabilization is a relatively new technique that has shown promising results. However, no study has specifically evaluated its success in the presence of phosphate for high-carbonate soils. This paper investigates this question using marly soil from Medea, which was pre-contaminated with the common fertilizer monoammonium phosphate at 0, 2, 4, and 6% by dry weight, then stabilized with lime and/or natural pozzolana at 0, 8%, and 20%, respectively, by dry weight. To assess the effect of phosphate, mineralogical and macrostructural changes in these mixtures were analyzed through X-ray diffraction tests and scanning electron microscopy, respectively. Additionally, pH levels were monitored over 90 days, and changes in Atterberg limits between 1 and 30 days of curing were compared. Variations in immediate bearing indexes and compaction parameters were also examined. The study found that lime alone was ineffective in stabilizing the soil due to high carbonate content, with improvements in geotechnical properties only observed when natural pozzolana was added with lime. Phosphate was found to impact the lime-natural pozzolana stabilization technique significantly.

Abstract: Silver nanoparticles (AgNPs) are very useful in biomedical applications, especially for the development of anti-infection implants. For biomedical applications, AgNPs that were fabricated by green synthesis approach are more favorable than conventional approach using toxic reducing agent such as NaBH₄ or N₂H₄. In this study, AgNPs were prepared through green synthesis approach using extract of Seminyak leaves and pH were varied (5; 8 and 11) to know the influence of pH on formation of AgNPs. Visual observations reveal that increasing pH led to faster color change of samples (yellow to black) suggesting that pH is directly proportional to reaction kinetics. UV-Vis spectroscopy results unveil that strong peak at 422 nm was observed in sample with pH 11, while low and broad peak were observed in sample with pH 5 and 8, implying the presence of nano-sized particles in sample with pH 11 and larger particles in sample with pH 5 and 8. Transmission electron microscopy (TEM) characterization results shows that dispersion of nano-sized particles with particle size 15.4 ± 4.1 nm were observed in sample with pH 11, while aggregation of nano-sized particles with particle size 29.2 ± 7.2 nm and 20.8 ± 7.0 nm were observed in sample with pH 5 and 8 respectively. X-ray diffraction (XRD) results show that the intensity of Ag’s peak in sample with pH 11 is at least two times higher than other samples, indicating formation of AgNPs in sample with pH 11 is more favorable than other samples. The results suggest that formation of dispersed and uniform AgNPs in the presence of extract of seminyak leaf as capping and reducing agent were favorable at high pH conditions.

Abstract: In this study, zinc dross (ZD) was used as precursor to prepare hematite/zinc oxide (Fe₂O₃/ZnO) nanocomposites with bacterial cellulose (BC) as catalyst support to prevent agglomeration of the obtained Fe₂O₃/ZnO. pH during the dissolution process of ZD was varied at 4.2 and 5.5 (namely ZD4 and ZD5, respectively) to know the effect of pH on the formation of Fe₂O₃/ZnO/BC. As comparison, Fe₂O₃/ZnO from its pure precursor was also prepared with the same pH and Zn concentration of ZD4 and ZD5 (namely ZF4 and ZF5, respectively). Atomic absorption spectroscopy (AAS) results showed that Zn and Fe content in ZD4 sample (42,059 and 8,615 ppm, respectively) are higher than Zn and Fe content in ZD5 sample (25,554 and 2,204 ppm, respectively). X-ray diffraction (XRD) and Fourier transform infra-red (FTIR) results of all samples confirmed the successful synthesis and deposition of Fe₂O₃/ZnO on BC. Scanning electron microscope (SEM) results revealed that the average particle size of Fe₂O₃/ZnO/BC samples at pH 5.5 (341 nm for ZD5 and 385 nm for ZF5 samples respectively) are slightly smaller than samples at pH 4.2 (418 nm for ZD4 and 426 nm for ZF4 samples respectively). Photocatalytic activities results showed that Fe₂O₃/ZnO/BC samples at pH 5.5 (45.7% for ZD5 and 57.9% for ZF5 samples respectively) have slightly higher activity than samples at pH 4.2 (38.1% for ZD4 and 41.9% for ZF4 samples respectively). These findings demonstrate the potential use of ZD and suggest that dissolution of ZD at pH 5.5 led to smaller particles size and higher photocatalytic activity than pH 4.2.

Abstract: The quality of water stands particularly in the context of green globalization. Ensuring the safety of drinking water necessitates of water quality monitoring in real-time. The present study introduces a cost-effective solution for water quality monitoring in real-time through the advance developing of a cost less system. The system integrates multiple sensors capable of measuring both physical and chemical parameters of water, including temperature, pH, turbidity, and total dissolved solids. The data collected from these sensors are processed by a core controller, with the Arduino model identified as a suitable candidate. This system offers an affordable and efficient means of continuous water quality monitoring, thereby contributing to the provision of clean and safest drinking water resources in era of green globalization.

Abstract: The increasing demand for electric vehicles affects the high demand for nickel-based batteries, including Nickel Manganese Cobalt (NMC) batteries. Generally, NMC is processed from high-quality ore (sulfide ore) to produce nickel (II) sulfate hexahydrate or NiSO₄.6H₂O. But sulfide ore face scarcity due to a long history of mining and exploitation. Thus, laterite-type nickel ore can be an alternative to nickel resources. This study aims to produce mixed sulfate precipitates from a ferronickel leaching solution that can be utilized further to produce NiSO₄.6H₂O. Also, this research will study the pH effect of the precipitation process on the product's elemental composition, recovery, and compounds formed. The precipitation process was conducted using 5% MgO (weight basis) with a pH range of 2.5 to 6.5 with one increment. The mixed sulfate precipitates were characterized using AAS, EDX, and XRD. When using a pH of 3.5, a nickel concentration of 1473.00 ppm, nickel recovery of 23.02%, and Nickel grade of 3.18% could be obtained. As a result, the phase of NiSO₄.6H₂O was formed. Also, the other phases were formed after precipitation, such as CoSO₄, FeSO₄, and MgSO₄.

Abstract: Anthocyanins exhibit exciting colours in plants. Java plum fruit (Syzygium cumini) is considered a non-conventional and rarely consumed fruit with high levels of anthocyanins. This study was conducted to extract, purify, and characterise anthocyanins from dried Java plum fruits. The stability of anthocyanins was also studied. Anthocyanins in this study were extracted from dried Java plum fruits using acidified water (0.01% HCl, v/v) as a sustainable solvent. The crude extracts were loaded into a solid phase extraction (SPE) column packed with Amberlite-XAD-7HP with sequential elution. The ethanol solution was then analysed and characterised using UV-Vis spectrophotometry and Liquid Chromatography-Mass Spectrometry (LC-MS) to confirm the anthocyanins profiles present in the extracts; Anthocyanins extracted from Java plum fruits were identified as cyanidin-3-O-glucoside ([M+] m/z of 449.3), delphinidin-3-O-glucoside ([M+] m/z of 465.3), and petunidin-3-O-glucoside ([M+] m/z of 479.3). Total monomeric anthocyanin content (TMAC) was 0.13 mg/mL (cyanidin-3-O-glucoside eq.). Anthocyanins show various colours depending on the pH of the solution. Anthocyanins are stable at acidic pH and start degrading at neutral to alkaline pH. The suggested application of highly coloured anthocyanins extracted from dried Java plum is as natural colorants in foods, beverages, textiles, cosmetics etc.

Abstract: Wastewater is a by-product of industrial and commercial facilities. If not treated, it could cause environmental and health problems. The proposed IoT-Based Real-Time pH Monitoring of wastewater can regulate the disposed waste through web browsers. The device has undergone several trials with wastewater from the chemical laboratory at different pH levels. It gave the signal to the solenoid motor to position either close when the pH level is more significant than pH 7.5 and less than pH 6.5 or open when the pH level is pH 6.5 to pH 7.5. The output's accuracy was measured using buffer solutions at different temperatures. It showed that the value of the pH level varied in temperature with significantly small changes. The system monitoring in the web browser captured the data every minute and saved it in a database for data comparison purposes. The device conformed to the Department of Environmental Natural Resources - Environmental Management Bureau (DENR-EMB) in the Philippines' standard permissible pH level (pH 6.0 to pH 9.0). Using an Arduino NANO microcontroller that served as a central processing unit and a Node MCU to connect the system to the internet, the equivalent output of an industrial pH meter was obtained, allowing the user to monitor the system at any time using a web browser.

Abstract: Modification of activated carbon using chemical surfactant is not eco sustainable because the chemical will have the potential to desorb into aqueous medium. Due to the environmental concerns, this research aims to investigate the usage of plant-based surfactant as a modifying agent onto the surface of activated carbon (AC) to be used in the removal of lead from aqueous solution. AC was impregnated with sodium lauryl sulfoacetate (SLSA), a plant based anionic surfactant at different concentrations. Atomic absorption spectroscopy (AAS) was used to examine the percentage removal of lead and to identify the effect of pH on the adsorptive properties of SIAC. The results exhibited the enhancement in the adsorption of lead using modified AC with SLSA. It was found that SIAC at 25 mg/L has the highest lead removal which was 99%. The optimum concentration anionic surfactant obtained was used in parametric study effect of pH. The optimum pH was obtained at pH 6 as it indicated the highest removal of lead (84.92%). Excel software was used to fit the data using polynomial regression. R² and adjusted R derived from the analysis were 0.9043 and 0.9522, respectively. As a result of the ANOVA study, it was shown that the mathematical formula can be utilised to forecast the removal of lead from aqueous solution.

Abstract: Alkaline-surfactant-polymer (ASP) flooding has been identified as the most effective enhanced oil recovery (EOR) technique to boost up the production of crude oil and improve the recoverable reserves. However, surfactant loss into the formation due to adsorption has been one of the issues, which could degrade the efficiency of the process. This study highlights the static adsorption of anionic sodium dodecyl sulphate (SDS) surfactant on the quartz sand with presences of alkaline and polymer at different pH and surfactant concentration. The critical micellar concentration (CMC) of SDS was determined using surface tension method and found at 0.22wt%. Three different systems were formulated namely A, B and C referring to the Surfactant formulation, Alkaline-Surfactant (AS) formulation and Alkaline-Surfactant-Polymer (ASP) formulation, respectively. For static adsorption tests, ASP system was formulated by adding 10,000 ppm sodium carbonate (Na₂CO₃) and 500 ppm of anionic Hydrolyzed Polyacrylamide (HPAM) polymer into the surfactant solution. The formulation was then mixed with the quartz sand at a fixed mass to volume ratio of 1:5. The adsorption tests involved shaking the mixtures, centrifuging, and analysing the supernatant solutions using UV-Visible spectrophotometer for adsorption measurement. The adsorption tests resulted in low adsorption at higher pH and low surfactant concentration. It was discovered that the lowest surfactant adsorption exhibited by ASP system with approximate reductions of 65% and 63% as compared to surfactant formulation at ~pH 12 and 2000 ppm surfactant concentration, respectively. Thus, anionic surfactant has a great performance in ASP system compared to its individual formulation, resulting in lower surfactant adsorption.