Investigation and disinfection of bacteria and fungi in sports fitness center.

This study investigated the air quality improvement in terms of bacterial and fungal contamination in an exercise room of a fitness center under normal operating conditions. Environmental conditions including air conditioning, ventilation, moisture, CO2, particulate matters, and total number of users were also recorded. In addition, fungal and bacterial load were assessed and disinfection on sports equipment surface was also examined. Background bacteria and fungi densities in bioaerosols were in the range of 249 ± 65 to 812 ± 111 CFU/m3 and 226 ± 39 to 837 ± 838 CFU/m3 in the exercise room of the fitness center and 370 ± 86 to 953 ± 136 CFU/m3 and 465 ± 108 to 1734 ± 580 CFU/m3 in the outdoor air, respectively. Chlorine dioxide and weak acid hypochlorous water aerosols could remove both bacteria and fungi much better than water scrubbing. Contact time of 15 min was sufficient to control both bacteria and fungi to comply with the official air quality standards. User density and carbon dioxide deteriorated both bacteria and fungi disinfection performance whereas temperature was only statistically significant on fungi disinfection. Other factors including relative humidity, airflow velocity, and particulate matters did not have any statistically significant effect on microbial inactivation. Apart from bioaerosol disinfection, inactivation of microorganisms on surfaces of sports equipment was also conducted using chlorine dioxide, zinc oxide, weak acid hypochlorous water, and commercial disinfectant. The surfaces of bicycle handle, dumbbell, and sit-up bench were found to be contaminated with bacteria. Overall bacterial load was 390 to 3720 CFU/cm2 with Escherichia coli specifically 550 to 1080 CFU/cm2. Chlorine dioxide and zinc oxide were noticeably better than weak acid hypochlorous water and commercial disinfectant in terms of bacteria inactivation whereas all tested disinfectants had comparable effectiveness on E. coli disinfection. Targeted microorganisms on the sports equipment surface were sufficiently inactivated within 2 min after the application of disinfectant.

Purification of landscape water by using an innovative application of subsurface flow constructed wetland.

This study attempted to purify eutrophic landscape water under a low pollutant concentration and high hydraulic volume loading using an embedded subsurface flow (SSF) constructed wetland (CW). Three species of aquatic plants (i.e., Cyperus alternifolius subsp. flabelliformis, Canna indica, and Hydrocotyle verticillata) were found to be conducive to the requirements of purifying the low-polluted water. Field results of nearly 2 years of experiments showed that SSF CW purified the eutrophic water and maintained the landscape water in a visibly clear condition. In an environment approaching the SSF CW background concentration, pollutant removal processes were divided into modulation and optimum performance periods. Average concentrations of biochemical oxygen demand (BOD), ammonium-nitrogen (NH4 (+)-N), and total phosphorous (TP) in the optimum performance period were 0.69-1.00, 0.35-1.42, and 0.19-0.23 mg/L, respectively. Almost 500 days of BOD and NH4 (+)-N removals were necessary to perform optimally. A shorter period, 350 days, was required for TP optimum removal. This feature of two stage removals was not found in chlorophyll-a (Chl-a) and suspended solids (SS), whose averages were 11.86-17.98 and 13.30 µg/L, respectively. Filter cleaning and water replacement were unnecessary, while only water recharging was needed to compensate for the water lost by evapotranspiration. The field SSF CW has maintained its performance level for over 7 years.

Seasonal variations of heavy metals content in muscle and viscera of green-lipped mussel Perna viridis from Da-Peng Bay Lagoon in Taiwan.

As a natural lagoon, rich in biological resources including fish, crabs, and bivalves, Da-Peng Bay Lagoon receives the discharges from the neighboring rivers, Kao-ping, Dong-gang, and Lin-Bian, which have harmed the ecology and reduced the water quality of the lagoon. This study analyzes seasonal variation of heavy metals concentration (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in the muscle and viscera of the green-lipped mussel Perna viridis from Da-Peng Bay Lagoon. Data from this study may provide information on the use of Perna viridis as a bioindicator for heavy metals pollution in the lagoon. The heavy metals concentrations were greater in viscera than in muscles of the green-lipped mussel Perna viridis. Results showed that the mussel is capable of accumulating high contents of Cu and Zn. Generally, the order of concentrations in the muscle by season was Zn > Cu > Cr or As. In viscera, the general order of concentrations was Zn > Cu > Pb or Cr or As. Mercury was not detected in winter and spring in muscle and viscera. Cadmium displayed significant variation with season. There was also significant correlation between tissue concentration and heavy metals, including Cu, Pb, Zn, Ni, Cd, and As.

Factors affecting degradation of dimethyl sulfoxide (DMSO) by fluidized-bed Fenton process.

In this study, the target compound is dimethyl sulfoxide (DMSO), which is used as a photoresist stripping solvent in the semiconductor and thin-film transistor liquid crystal display (TFT-LCD) manufacturing processes. The effects of the operating parameters (pH, Fe(2+) and H2O2 concentrations) on the degradation of DMSO in the fluidized-bed Fenton process were examined. This study used the Box-Behnken design (BBD) to investigate the optimum conditions of DMSO degradation. The highest DMSO removal was 98 % for pH 3, when the H2O2 to Fe(2+) molar ratio was 12. At pH 2 and 4, the highest DMSO removal was 82 %, when the H2O2 to Fe(2+) molar ratio was 6.5. The correlation of DMSO removal showed that the effect of the parameters on DMSO removal followed the order Fe(2+) > H2O2 > pH. From the BBD prediction, the optimum conditions were pH 3, 5 mM of Fe(2+), and 60 mM of H2O2. The difference between the experimental value (98 %) and the predicted value (96 %) was not significant. The removal efficiencies of DMSO, chemical oxygen demand (COD), total organic carbon (TOC), and iron in the fluidized-bed Fenton process were higher than those in the traditional Fenton process.

Tributyltin distribution and producing androgenic activity in water, sediment, and fish muscle.

This study investigated the concentrations of Tributyltin (TBT) in water, sediment, and fish muscle samples taken from Kaohsiung Harbor and Kaoping River estuary, Taiwan. TBT concentrations in water and sediment samples ranged from less than 18.5 to 34.1 ng Sn L(-1) and from 2.44 to 29.7 ng Sn g(-1) weight per weight (w/w), respectively. Concentrations in the TBT-contaminated fish muscle samples ranged from 10.8 to 79.6 ng Sn g(-1) w/w. The TBT concentrations in fish muscle were higher than those in water and sediment samples. The fish muscle/water TBT bioconcentration factor (BCF) ranged from 590 to 3363 L kg(-1). Additionally, the water samples were assessed for androgenic activity with an MCF7-AR1 human breast cancer cell line. The androgenic activity ranged from 0.94 to 3.1 ng-dihydrotestosterone per litre water (ng-DHT L(-1)). Higher concentrations of TBT in water and sediment samples occurred in the dry season, but the androgenic activity had higher values in the rainy season.

Treatment of TFT-LCD wastewater containing ethanolamine by fluidized-bed Fenton technology.

The objectives of this study are: (1) to determine the effect of pH, initial concentration of Fe(2+) and H(2)O(2) dosage on the removal efficiency of MEA by fluidized-bed Fenton process and Fenton process, (2) to determine the optimal conditions for the degradation of ethanolamine from TFT-LCD wastewater by fluidized-bed Fenton process. In the design of experiment, the Box-Behnken design was used to optimize the operating conditions. A removal efficiency of 98.9% for 5mM MEA was achieved after 2h under optimal conditions of pH3, [Fe(2+)]=5mM and [H(2)O(2)]=60mM.