Kowit Suwannahong

Preparation of TiO2/Bio-Composite Film by Sol-Gel Method in VOCs Photocatalytic Degradation Process

Biodegradable of polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT) and polybutylene succinate (PBS), which were biodegradable aliphatic polyesters, composite films were contained with titanium dioxide (TiO2) as a photocatalyst to evaluate the photocatalytic activity of bidegradable composite films for toluene removal. The synthesized TiO2 was prepared by sol-gel method between titanium isopropoxide with acetic acid. To form the anatase structure, it was calcined at 500°C. TiO2 were added to PLA/PBAT/PBS as a biopolymer blend at 0, 5 and 10 wt% .The TiO2/Bio-composite films were fabricated via blown film technique to produce 40 μm films. Photocatalytic activity efficiency of TiO2/Bio-composite films was performed in an annular closed system under UV light. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the biopolymer matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the biopolymer matrix. The X-ray diffraction (XRD) ensures the deposition of TiO2 as crystalline anatase phase. In addition, the photocatalytic results shown that the toluene removal efficiencies increased with an increasing TiO2 dosages at 0 wt%, 5 wt%, and 10 wt% , respectively. As aspects, the photocatalytic degradation results showed the highest tolune photocatalytic degradation efficiency of 52.0% at 10 wt% TiO2 .

Characteristics of Bacterial Cellulose Production from Agricultural Wastes

There are increasing demands to substitute the plastic from the petrochemical industry with bacterial cellulose which were produced from microorganisms as Acetobactor xylinum strain. The aim of this study was to produce bacterial cellulose from banana peels which are agricultural waste around Walailak University area. The banana peels were used as a carbon source together with nutrient medium for the growth of bacteria. The ratio between Hestrin and Schramm nutrient medium (HS) with banana peel to DI water was 1:0.5, 1:1, and 1:1.5 (%V/V). Sugar content in banana peel (control) was 4.0% Degree Brix. The initial pH was 6.0 and sugar contents varied in this study were 5.5%, and 11% Degree Brix. A.xylinum dosages used in the cultivation were 5, 6.67, and 8.33 (%V/V) respectively. The cultivation times were 15 days at the temperature of 30 °C. As a result, the highest yield of produced bacterial cellulose was 19.46 gram and the best condition which maximum yield of bacterial cellulose 1.95% can be obtained was 11% (Brix) of sugar content, 6.67 (%V/V) of A.xylinum added, and 1:1.5 of banana peel to DI water. The physical properties of bacterial cellulose were studied with ATR-FTIR spectroscopy which shown adsorption spectrum at 3279, 2915, 1627 and 1013 cm-1 corresponding to the-OH,-CH,-CH2 and carboxyl function groups, respectively. Glass transition Temperature (Tg) was 116.85°C. Tensile strength was measured with UTM and had average value of 41.13±5.43 Mpa. The bacterial cellulose had moisture content of 90.00±0.02%. The synthesized bacterial cellulose can be used as adsorption media and also has its chemical properties like petroleum polymer. Result suggested that the similar property can be observed when compared with petroleum plastic, however with the exception of methyl group (CH3). Methyl group which can be found in plastic synthesized from petrochemical is responsible for the strength of plastic. Thus, bacterial cellulose, synthesized in this study, is not as strong as petrochemical plastic. But it can be used to produce bio-plastics because of the-CH and-CH2 functional group attached. With the similar physical and chemical properties to those of petrochemical plastic, bacterial cellulose can be used as biopolymer.

Fabrication and photocatalytic activity of TiO2 composite membranes via simultaneous electrospinning and electrospraying process

In present study, a simultaneous electrospinning and electrospraying (SEE) process was employed to produce microclusters of TiO2 nanoparticles and interlock them in nanofibrous network. The photocatalytic composite membranes (PCMs) were fabricated by electrospraying TiO2 nanoparticle suspension into microcluster form that dispersed and entrapped within nylon-6 electrospun fiber membrane. Three PCMs membrane with TiO2 content of 52.0, 83.6, and 91.7wt.% were successfully fabricated. The membrane consisted of TiO2 microclusters, ranging in sizes from around 0.3 to 10μm, distributed uniformly within the nylon-6 nanofibrous network. PCMs photocatalytic activity against Methylene Blue (MB) in aqueous solution showed more than 98% MB removal efficiency after 120min of photocatalytic oxidation (PCO) for all PCMs. For PCM with the highest TiO2 content tested for 5 PCO cycles, it was found that most of their TiO2 content remained incorporated within the nanofibrous structure. The concept of nanoparticles clusters entrapment with SEE fabrication employed here provide a simple and effective method for reducing detachment of nanostructure phase from nanocomposite membrane.

Characteristics of mineral water from nature hot springs in Ranong Province, Thailand

Background: There is interest in characteristics of mineral waters from two famous hot springs in Ranong province, Thailand, including Raksawarin and Porn-Rang hot springs. Aims: To objective is to determine characteristics of thermal mineral waters of Ranong region and describe its classification and therapeutic indications. Material and Methods: Mineral waters were collected from Rahsawarin and Porn-Rang hot springs. All analyses were conducted according to American Public Health Association. Temperature was measured in the field at the time of sample collection. Analyses of fecal coliforms and total bacterial count were performed. Physical-chemical analyses were used to evaluate pH, total dissolved solids (TDS), and conductivity. Total hardness was measured in the laboratory by titration. Metals (Al, Si, Fe, Mn, Pb, Cd, Ni, Cu) were measured by graphite furnace atomic absorption spectroscopy (GFAAS); major ions (Ca, Mg, Na, K, Cl, F, HCO3-, SO4, S2-) and nutrients (NH4, PO4-, NO3) were measured by ion chromatography technique. Results and Discussion: The mean of pH, TDS, and conductivity values observed for hot springs were met to reference value of Thai tap water standard by WHO guideline. Neither hot spring contained fecal coliform bacteria. Chemical parameters were also within standard excepted aluminum concentration. Potassium levels from mineral waters were also high. Ranong mineral spring water can be thermal waters and define to hot waters. Ranong mineral spring water can be define to fresh and low sodium water. Conclusions: Our suggestions regarding this mineral water indication were properly for external use and may concern in case of drinking.

Biomarker related lead exposure of industrial battery's workers

Background: The risk of occupational lead exposure exists in lead smelting plants and battery industries, which may give rise to the issues related to lead poisoning among battery workers and low-exposed workers. Aims: To investigate the relationship between biochemical and hematological markers of lead effects and occupational exposure in battery workers and determine the role of work-related lead poisoning with emphasis on hemopetic system in exposed workers. Materials and Methods: Present study was carried out from July to October 2015, which collected demographic data, nonwork, and work-related symptoms from lead exposure nonexposed workers (N = 33) and battery wokers (N = 30), Nakhon Pathom, Thailand. Each blood sample was collected and analyzed for lead biomarkers, blood lead level (BLL)and δ-aminolevolinic dehydratase (ALAD) and hematological markers, such as complete blood count and recticulocyte count. Results and Discussion: Major non-work-related symptoms were droopiness and muscle pain among nonexposed groups. Major work-related symptoms in battery workers were occurred in lungs and nose. There was a significant increase in BLL, and a significant decrease activity of ALAD was observed in battery workers. Strong positive correlation between years of exposure and employment with BLL was observed and respiratorytract symptoms were also presented.Inverse correlation between the activity of ALAD and hemoglobin and a strong positive correlation between hemoglobin and BLL were found. Conclusion: The lead level and ALAD were good markers for screening lead exposures by significant related to hematological values, duration of work, and exposure and hypertension.

Removal of Natural Dyes from Tie Dye Effluent by Coagulation Process

The aim of this research was to find the efficiency ways to treat wastewater from dye tie dye technique by using an effective wastewater treatment system and find out how to implant the technology of the waste water treatment system to help the problems of the community activities which the tie-dye fabric were the major product of their area. The wastewater from the tie-dye industry were collected and were treated with physical, chemistry and biological treatment by using local materials such as sea shell, alum and clay in a laboratory scale. The data from the treatment were used in the designing the small scale water treatment and apply to the study area. Moreover, the treatment technique knowledge will transfer to the community and establish guidelines for community Wastewater treatment. The COD of wastewater from the dying materials of Bark of Xylocarpus granatum, Bark of Sea almond and Bark of Ebony tree seed were 479.2, 428.5, and 564.2 mg/l, respectively. The water quality were improved better up to 83.61% after were treated with the treatment technique. The satisfaction of the community that participate in the training, technology transfer and adoption of guidelines for therapists to use in the community were found that 86 percent had gained the knowledge in wastewater treatment, 95 percent were satisfied and 85 percent of knowledge were benefit to the community, respectively.

Modification of Titanium Dioxide Embedded in the Bio-Composite Film for Photocatalytic Oxidation of Chlorinated Volatile Organic Compound

This research aimed to apply the Blown Film Extrusion technique to synthesize the titanium dioxide (TiO2) bio-composite films incorporated on a thin film as a photocatalyst. The biopolymer materials have great recognition via their renewable and biodegradable characteristic and the green composite has been a new challenge path to replace traditional polymer composite. In this work, TiO2/Polybutylene succinate (PBS) bio-composite film was developed to be used as a supporter for determining the photocatalytic oxidation activity of the TiO2 on the chlorinated volatile organic compounds degradation. PBS is a synthetic biopolymer which has a reasonable mechanical strength. The modified-TiO2/PBS bio-composite films were studied to evaluate the degradation of dichloromethane. In order to improve the distribution of the developed photocatalyst, the TiO2 powders were modified by 0.05% mole of ethyl triethoxysilane (ETES) and stearic acid (SA), respectively. The 10% wt. TiO2/PBS bio-composite films with thickness of 30 μm were prepared by blown film technique. To evaluate the dispersion efficacy, the modified-TiO2/PBS bio-composite films were characterized by Scanning Electron microscopy (SEM). Photocatalytic degradation of dichloromethane in gas phase was determined using an annular closed system photoreactor. The obtained result which was corresponding to the absorption of TiO2/PBS bio composites film was investigated in a range of 300-400 nm via UV/VIS spectrophotometry. The energy band gap of TiO2, ethyl triethoxysilane-TiO2 and stearic acid-TiO2 bio-composite film was found to be 3.18, 3.21, and 3.26 eV, respectively. The SEM shows that the modified-TiO2 with both ETES and SA exhibit uniform dispersion, while the only TiO2 shows an evidence of agglomeration in the PBS matrix. For photocatalyst efficiency, the photocatalytic activity of modified-TiO2/PBS bio-composite film increased comparing to the TiO2/PBS bio-composite film. Moreover, the photocatalytic degradation of dichloromethane by ETES-TiO2/PBS bio-composite film yielded degradation efficiency of 47.0%, whereas SA-TiO2/PBS bio-composite film yielded the removal efficiency of 41.0% for detention time at 350 min.