The purpose of a cross-sectional study was to investigate factors influencing the quality of life among Thai workers in textile dyeing factories. Samples included 205 Thai workers from five textile dyeing factories located in the suburban area of Bangkok in Thailand. Data were collected with a self-administered questionnaire. Scales of the questionnaire had reliability coefficients ranging from 0.70–0.91. The results revealed that the overall quality of life among workers was most likely between good and moderate levels, and the percentage-mean score was 74.77. The seven factors associated with the overall quality of life were co-worker relationships, safety at work in the dimension of accident prevention, job characteristics, supervisory relationships, welfares, marital status, and physical environment. Furthermore, co-worker relationships, accident prevention, and marital status were three considerable predictors accounted for 23% of the variance in the overall quality of life among workers in textile dyeing factories.

Arsenic (As) removal in pilot-scale subsurface-flow constructed wetlands (CWs) was investigated by comparing between CW units with vetiver grasses (CWplanted) and CW units without vetiver grasses (CWunplanted) in order to determine the roles of vetiver grasses affecting As removal. Based on the data obtained from 147 days of experiment, it is apparent that CWplanted units could remove As significantly higher than those of CWunplanted units with approximately 7-14%. Although analysis of As mass balance in CW units revealed that only 0.5-1.0% of total As was found in vetiver grasses, the As retained within bed of the CWplanted units (23.6-29.7 g) was higher than those in the CWunplanted units (21.3-26.8 g) at the end of the experiment, illustrating the effect of vetiver grasses on As accumulation in the CW units. Determination of As in different fractions in the CW bed suggested that the main mechanism of As retention was due mainly to As entrapment into the porous of bed materials (50-57% of total fraction), this mechanism is likely not affected by the presence of vetiver grasses. However, fraction of As-bound in organic matters that could be released from plant roots decomposition indicated the increase adsorption capacity of CW bed. In addition, organic sulfides produced from their root decomposition could help remove As through the precipitation/co-precipitation process. Under reducing condition in those CWplanted units, As could be leached out in the form of iron and manganese-bound complexes.

Bio-succinic acid is a commodity chemical with potent application in bioplastic and food industries which can be produced from renewable resources. In this study, bioprocess for production of bio-succinic from glycerol by Actinobacillus succinogenes was studied. The maximum succinic acid concentration in small-scale serum bottle experiments was 6.8 and 6.5 g/L using pure and crude glycerol, respectively, with supplemented MgCO3. The ratio of acetic acid to succinic acid (AA/SA) implied the increased carbon flux to the C4 pathway using crude glycerol supplemented with MgCO3 compared to that with CaCO3.The carbonate salts tended to induce C3 metabolic pathway in fermentation using pure glycerol which was in accordance with the ratio of acetic acid to glycerol (AA/GL). The highest succinic acid concentration of 17.9 g/L from crude glycerol was achieved from batch fermentation in a lab-scale fermenter with the maximum glycerol utilization of 99.9% which were higher than those obtained from fed- batch and semi-continuous processes. Acetic acid tended to increase throughout the fermentation process in fed-batch and semi-continuous operations, which resulted in the lower product yield and substrate utilization efficiency. The time for initial purging of CO2 showed effects on succinic acid production and internal metabolic pathways. This work provided a basis for process development on bio-succinic acid production from crude glycerol in industry.

Arsenic (As) removal in subsurface-flow constructed wetlands (CW) planting with vetiver grasses was experimented by comparing between two different configurations; (i) deep-bed units (dpCW) with length to depth (L:D) ratio ¼ 2 and (ii) shallow-bed units (shCW) with L:D ratio ¼ 8;operating at hydraulic retention time (HRT) of 6, 9, and 12 days. The tracer study of CW units revealed that no effect of L:D ratio on dispersion number could be determined, but affecting to the effective volume ratio. Based on the data obtained from the pilot-scale experiments of CW units for 117 days, it is apparent that the dpCW could achieve relatively high As removals (52.9%, 59.2%, and 72.1% at HRT of 6, 9, and 12 days, respectively). Analysis of As mass balance showed that only 0.2-0.4% of As input was uptaken by vetiver grasses whereas the major portion was retained in the CW media (38.9-77.6%). Forms of the retained As was determined by sequential fractionation which could indicate As complexation with iron and manganese on the media surface of 31-38% and As trapping into the media of 42-52% of the total. No obvious difference of As fractions in bed of between dpCW and shCW units was observable.

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This cross-sectional study investigated the indoor air quality (IAQ) of public health centers (PHCs) and primary health care units in Bangkok to determine the impact of the different locations and ventilation systems concerning IAQ. Three indoor air pollutants: PM2.5, CO2, and CO were measured in three areas (medical record departments, outpatient departments and examination rooms) of six PHCs located in two different locations (main and secondary roadsides). The results showed that the average levels of PM2.5, CO2, and CO in the PHCs located on main roadsides were higher than those located on secondary roadsides. Among these parameters, only CO was found to significantly differ between those two locations indicating the result of vehicles and traffic sources regarding indoor CO level. Furthermore, all parameters were compared among the sampling areas with different ventilation systems; natural ventilation and air conditioner with and without ventilation fan. The amounts of all three pollutants significantly differed in each area with different ventilation systems. The average levels of PM2.5 and CO2 were the highest in areas with air conditioner without ventilation fan, while the level of CO was the highest in areas with natural ventilation. The ventilation was proved to be a key measure to improve IAQ. PHCs should consider ventilation efficacy to improve the IAQ by using ventilation fans in rooms using air conditioners. Finally, the average levels of all parameters were found below the recommended values in related standards, indicating safe IAQ for people working and receiving services in PHCs.