PSRU Journal of Science and Technology

บทบรรณาธิการ

2026-03-30T16:45:26+07:00

บทบรรณาธิการ

สารบัญ

2026-03-30T16:46:20+07:00

สารบัญ

KINETIC AND THERMODYNAMIC STUDIES ON THE ADSORPTION OF CRYSTAL VIOLET USING MODIFIED ACTIVATED CARBON FROM DIALIUM COCHINCHINENSIS SHELLS

2025-03-30T10:16:15+07:00

This research studies the kinetics and thermodynamics of crystal violet adsorption on the activated carbon of Dialium cochinchinensis shells; DS, a biomass waste material from the Yarang in Pattani province. The DS was carbonized and activated with potassium hydroxide (KOH) and phosphoric acid (H₃PO₄) to enhance its adsorption properties. The study also examined
the adsorption of crystal violet on modified activated carbon (DSAC-KOH and DSAC-H₃PO₄), revealing that the adsorption behavior follows the Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum adsorption capacities (q_m) for crystal violet were 294.12 and 416.67 mg g^-1 on DSAC-KOH and DSAC-H₃PO₄ at 30°C and pH 5, respectively. From thermodynamic studies, the adsorption process was endothermic and spontaneous. This research demonstrates the potential of utilizing local agricultural waste as a low-cost and effective adsorbent for dye-contaminated wastewater treatment, contributing to environmental pollution reduction and promoting sustainable circular economy practices at the community level.

EFFECT OF PLANT GROWTH REGULATORS ON IN VITRO CULTURE OF CHINESE GINGER (BOESENBERGIA ROTUNDA (L.) MANSF.)

2025-03-13T17:25:01+07:00

The objective was to study the effect of plant growth regulators on shoot multiplication and root induction of Chinese ginger at the Phichit Agricultural Research and Development Center. Sterilizing the young shoots of Chinese ginger and culturing them on MS medium without plant growth regulators for 4 weeks to initiate new shoots. After that, cultured shoot explants on MS medium supplemented with plant growth regulators. The experiment design was CRD with four treatments and four replications: 6-benzyladenine (BA), 6-furfurylaminopurine (Kinetin), 6-(γ,γ-dimethylallylamino) purine (2iP) or N-phenyl-N’-1,2,3-thidiazol-5-yl urea (TDZ) concentrations of 2 mg/L for 12 weeks. The result indicated that shoot explants cultured on MS medium supplemented with 2 mg/L TDZ for 4 weeks had shoot multiplication of 80.90%, a shoot number of 3.51 shoots, root induction of 26.30%, and a root number of 6.54 roots. After being cultured for 12 weeks on MS medium containing 2 mg/L TDZ, it has the highest shoot and root number at 7.48 shoots and 12.70 roots, respectively. Therefore, MS medium containing 2 mg/L TDZ is suitable for in vitro Chinese ginger to produce disease-free plants.

CHARACTERIZATION OF YEAST PROBIOTICS FOR MARINE SHRIMP CULTURE

2025-05-02T09:08:51+07:00

Marine shrimp culture confronts significant challenges due to disease outbreaks and the increasing antibiotic resistance of pathogenic bacteria. Therefore, alternative methods are needed to enhance shrimp production and confer disease resistance. Yeast probiotics have been shown to provide nutritional benefits and protective effects against infectious agents. The objective of this study was to evaluate some probiotic features of five yeast isolates: BUU 01 BUU 02 BUU 03 BUU 04 and BUU 05. The isolates were assessed for their ability to lyze red blood cells, inhibit marine shrimp pathogens, tolerate various salinity levels, temperatures and pH values, produce catalase and digestive enzymes and their growth kinetics were monitored. Additionally, the isolates were identified their species. All five yeast isolates were considered safe and non-pathogenic to the host due to no hemolytic activity observed. These isolates also exhibited inhibitory effects against pathogenic Vibrio species, including V. harveyi, V. vulnificus, V. parahaemolyticus and V. alginolyticus. The three stains also showed other some in vitro promising probiotic properties, including rapid growth, tolerance to a wide range of temperatures (25-37°C), pH (4-8), and salt concentrations (0-6% (w/v)), as well as the ability to effectively produce digestive enzymes: lipase (81.43±0.11–106.95±0.14 U/mL) and protease (19.12±0.20–43.70±0.15 U/mL). These isolates were identified as Debaryomyces sp. BUU 01, Rhodotorula sp. BUU 02, and Saccharomyces sp. BUU 05. This study suggests that the three yeast strains have promising probiotic potential for marine shrimp culture. Further study focused on administration of the yeast probiotic in shrimp farming should be performed to confirm their efficacy in promoting shrimp growth and health.

DEVELOPMENT OF A SEMI-INDUSTRIAL SCALE PROTOTYPE SYSTEM FOR THE PRODUCTION AND PURIFICATION OF ETHANOL FROM LOW-GRADE RAMBUTAN (NEPHELIUM LAPPACEUM) FOR GASOHOL APPLICATIONS

2025-04-04T11:08:10+07:00

This research explores ethanol production from low-quality rambutan as an alternative energy source. It aims to determine optimal fermentation conditions and study the distillation process for ethanol extraction during scale-up. The findings indicate that the ideal fermentation conditions involve preparing low-quality rambutan with 20 %w/v fruit pulp (weight per volume of rambutan juice), adding 0.96 g/L of Di-ammonium Phosphate; DAP as a nitrogen source, and sterilizing with 0.18 g/L Potassium Metabisulfite; KMS. Fermentation with selected S. cerevisiae TISTR 5339 yeast yielded a maximum ethanol concentration of 5.83 %v/v. Scaling up the fermentation to 18 liters in a 20-liter fermenter for 21 days increased ethanol production to 8.83 %v/v. Distillation using a fractional distillation system at 90 °C resulted in 50 %v/v ethanol concentration, which increased to 95 %v/v after four rounds of distillation. Further purification using zeolite molecular sieves (100 g) produced ethanol at 99.20 %v/v, suitable for blending with gasoline to create gasohol. The study demonstrates the feasibility of developing a semi-industrial ethanol production model, contributing to future renewable energy sources.

FABRICATION OF MERCURY SENSOR USING DITHIZONE-MODIFIED GRAPHENE QUANTUM DOTS

2025-04-26T17:07:12+07:00

This study presents the fabrication and evaluation of a mercury sensor based on dithizone-modified graphene quantum dots; GQDs. The sensor was fabricated using a filter paper coated with GQDs and functionalized with dithizone, then assembled with gold electrodes for electrochemical measurement. The sensor was tested with various concentrations of mercury (II) chloride to evaluate its sensing performance. The results revealed a noticeable shift in color. The color changed from blue to orange, indicating the formation of a complex between mercury ions (Hg²⁺) and dithizone-modified GQDs. Electrical measurements revealed a non-ohmic current-voltage response with a consistent threshold voltage of approximately 2.50 V across all conditions. The sensor exhibited a clear correlation between mercury concentration and sensor response, where increased resistance and decreased conductivity corresponded to higher Hg²⁺ levels. Linear regression analysis showed a strong correlation, indicating high sensitivity and potential for quantitative detection. These results suggest that the proposed sensor was a promising low-cost, portable, and reliable tool for monitoring mercury contamination in environmental settings.

ANTIBACTERIAL ACTIVITY AGAINST STAPHYLOCOCCUS AUREUS OF 7 THAI MEDICINAL PLANT EXTRACTS

2025-05-10T16:01:21+07:00

Staphylococcus aureus is a major human pathogen causing infections in multiple organs and is now becoming antibiotic-resistant which is a global crisis. The aim of this study was to investigate the antibacterial effect of medicinal plant extracts for S. aureus inhibition. Crude extracts of plants, including Psidium guajava L. leaf, Oroxylum indicum (L.) Kurz. leaf, Garcinia cowa Roxb. ex Choisy leaf, Curcuma longa L. rhizomes, Alpinia galanga (L.) Willd. rhizomes, Cinnamomum verum, and Syzygium aromaticum L., were obtained by ethanol extraction. Their antibacterial activities were investigated by disk diffusion method. The minimum inhibitory concentration; MIC was performed by the broth microdilution method and the minimum bactericidal concentration; MBC values of these extracts was tested. The results found that 4 herb extracts namely P. guajava leaf, G. cowa leaf, A. galanga rhizomes and S. aromaticum rhizomes showed an inhibitory activity which the inhibition zone as 9.54-22.93 millimeters. The MIC and MBC values of these extracts were in the range of 0.25-8 mg/ml and 2-128 mg/ml, respectively. The G. cowa leaves extract was the best antibacterial activity which MIC and MBC values of 0.2 and 2 mg/ml, respectively. In addition, all extracts showed the MBC to MIC ratio value greater than 4. Therefore, these extracts presented the bacteriostatic activity. These results show that many Thai herbs are effective in inhibiting pathogens. It can be developed into an antimicrobial product used in food, which can help to reduce the incidence of food-borne diseases.

DEVELOPMENT OF BODY MASK PELLETS FROM MELALEUCA QUINQUENERVIA LEAVES EXTRACT CONTAINING ANTIBACTERIAL EFFECT

2025-05-02T09:53:10+07:00

Melaleuca quinquenervia (Cav.) S.T. Blake, commonly known as Cajuput, is a prominent species typically found in the southern region of Thailand. It has been found that Cajuput oil possesses antibacterial properties. Therefore, researchers were interested in developing a body mask pellet product from M.quinquenervia leaf extract. The study aimed to investigate the physical and chemical properties, short-term and long-term stability, antioxidant activity using the DPPH assay method, total phenolic compound content using the Folin-Ciocalteu method, antibacterial and antifungal using Broth dilution method, and cytotoxicity using the MTT assay. The body mask pellet formula consists of cassava starch, corn starch, polyvinylpyrrolidone-K30, croscarmellose sodium, preservatives, and M. quinquenervia leaf extract. The evaluation of short-term stability over 4 cycles revealed that the weight, pH, and odor changed slightly, while the color and texture remained unchanged. After 3 months, the pH value was 5.64±0.01, and the color and odor showed no alterations. The antioxidant activity of the body mask pellet product from M. quinquenervia leaf extract, compared with the standard ascorbic acid, showed an IC₅₀ values of 2.44 mg/mL and 2.36 µg/mL, respectively. The total phenolic compound content was 6.02±0.46 mg GAE/1 g Sample. The product exhibited inhibitory effects against bacteria and fungi (Staphylococcus epidermidis, Propionibacterium acnes, and Malassezia furfur) with the minimum inhibitory concentration (MIC) values of 32, 8, and 8 mg/mL, respectively. The minimum bactericidal concentration (MBC) values of 32, 32, and 32 mg/mL, respectively. When tested for cytotoxicity against Human Skin Fibroblast-hTERT cells, the test substance concentration was found to be nontoxic to cells <0.10 mg/mL. It can be further developed at the industrial level and lead to the creation of products that can add value to Thai herbs that can be found locally.

EFFECTS OF DRYING METHODS ON ANTIOXIDANT ACTIVITIES OF GERMINATED GRAINS UNDER SALINITY STRESS

2025-05-01T10:12:50+07:00

The purpose of this research was to study the effects of drying methods on the antioxidant activities of germinated cereal grains under salinity stress. Ten cereal grains, mung beans, red beans, black beans, soybeans, black sesame, RD43 rice, jasmine rice, black rice, riceberry and Leum Pua black sticky rice were germinated under both salinity stress (0.50% NaCl) and normal conditions. Following germination, the samples were subjected to two drying methods: whole grain drying and powder drying. Antioxidant content was determined by measuring total phenolic compounds, proline and ascorbic acid. Antioxidant activities were evaluated using 2,2’-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid); ABTS and 1,1-Diphenyl-2-picrylhydrazyl; DPPH radical scavenging assays, as well as ferric reducing antioxidant power; FRAP assay. The results indicated that drying process had differential effects on the antioxidant activity of cereal grains, depending on the drying method and type of grain. Powder drying was found to increase the total phenolic compounds and ascorbic acid content in mung beans, increase the proline content in black beans, soybeans, black rice and riceberry, and enhance the ABTS radical scavenging activity in red beans. While, whole grain drying was found to increase the total phenolic compounds content in soybean and black sesame, increase the proline content in mung bean, black sesame and RD43 rice, and increase the ascorbic acid content in red bean, RD43 rice and black rice, and also increase the FRAP in black sesame, RD43 rice and black rice. The finding of this research can serve as foundational data for extending the shelf life of germinated cereal grains through whole grain drying and powder drying processes. These methods help retain nutritional value and antioxidant compounds beneficial to health and also enhancing the convenience in consumption and storage.

FLUXES OF MICROPLASTICS 1-5,000 MICROMETER IN URBAN WASTEWATER FLOWING INTO BIVALVE MARICULTURE ALONG THE CHONBURI COAST

2025-04-04T12:24:17+07:00

The coastal areas of Chonburi Province, particularly in Mueang and Si Racha districts, are key aquaculture zones for mussels, blood cockles, and oysters. These areas also receive municipal wastewater, which increasingly contains microplastic contamination. This study aimed to analyze the quantity and transport of microplastics in community wastewater discharged into the sea and assess their relationship with bivalve aquaculture zones. Wastewater samples were collected from four sites: Khlong Sangkhep, Khlong Bang Phong, Wonapha Beach drainage, and Ko Loi Bridge drainage. Microplastics were isolated through filtration and analyzed using optical microscopy and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that microplastic transport ranged from 3.30×10¹¹ to 2.90×10¹³ particles per day, with particles sized 1–60 micrometers accounting for over 99% of the total. The most common shapes were fragments and fibers, with polymer types including polyethylene (PE), polypropylene (PP), and polyester. These microplastics originated mainly from human activities, such as plastic bags, synthetic fabrics, and packaging. The findings highlight that municipal wastewater is a significant source of microplastic transport into the marine environment and suggest that bivalves cultivated in these areas may accumulate high levels of microplastics. This research provides essential data for developing strategies to mitigate microplastic pollution at its source and promote sustainable coastal aquaculture management.

SOIL QUALITY ASSESSMENT AND NUTRIENT MANAGEMENT GUIDELINES FOR DURIAN LONG RAK THAI (DURIO ZIBETHINUS MURR.) ORCHARDS IN PHITSANULOK PROVINCE

2025-05-22T14:42:28+07:00

This study aimed to assess soil quality and propose nutrient management strategies for 'Long Rak Thai' durian orchards in Chomphu Subdistrict, Noen Maprang District, Phitsanulok Province. Soil samples were collected from 11 farmers during two crop periods: the fruit development stage and the harvesting stage. Key soil properties analyzed included pH, organic matter, nitrogen, available phosphorus, and available potassium. The results showed that the average soil pH significantly decreased from 6.22 to 5.72 (P<0.05). In contrast, organic matter, nitrogen, available phosphorus, and available potassium levels showed no statistically significant differences between the two periods. Organic matter averaged 5.01±1.22% and 5.74±0.40%, while nitrogen remained low level at 0.26±0.06% and 0.27±0.15%. Available phosphorus averaged 34.19±20.88 and 27.45±12.94 mg/kg, with only 18.18% of plots falling within the optimal range for durian cultivation. Available potassium levels were markedly higher than recommended levels, averaging 370.91±149.77 and 314.09±171.94 mg/kg. Overall soil fertility was at a moderate level during both periods, with no significant difference (P>0.05). Based on soil nutrient data, a site-specific nutrient management; SSNM approach was proposed. Most plots were recommended to apply nitrogen fertilizer at 720 g/tree, phosphorus (P₂O₅) at 400 g/tree, and potassium (K₂O) at 400 g/tree during both periods. This tailored strategy aims to enhance fertilizer efficiency, reduce costs, and improve durian fruit quality in the long term.