No abstract

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.

We report a survey on the occurrence and distribution of nonylphenol (NP) and 17beta-estradiol equivalent quotient (EEQ) concentrations in Donggang River, Taiwan. Concentrations of NP were measured with a high-performance liquid chromatography/fluorescent system and EEQs were carried with an MVLN cell line. Concentrations of NP ranged from less than 93 to 511 ng/L; EEQs ranged from less than 0.16 to 8.64 ng-E2/L. Concentrations of NP were higher in the dry season than in the wet season, which was affected by a high flow rate. In the main water course, higher EEQ occurred in the wet season than in the dry season; rainfall may have flushed substances containing estrogenic activity. NP and EEQ concentrations occurred in seawater only in the dry season, especially high EEQ values, and were not detected in the wet season. The reasons are not clear at this moment. Furthermore, NP concentrations provided low contribution to the total estrogenic activity.

No abstract

This study investigates the effects of alkali catalyst quantity, reaction temperature, reaction time, and acid catalyst quantity on biodiesel production via the transesterification of microalgae using two-level fourfactor full factorial design. Under the experimental range considered, the most important factor for FAME yield is the base catalyst quantity. The FAME yield increases with increasing base catalyst quantity. The reaction time and acid catalyst quantity also have positive influences. There is an appreciable interaction between alkali catalyst quantity and the acid catalyst quantity, and thus the effects of these variables must be considered jointly. The best results for laboratory-scale biodiesel production via transesterification were obtained at a 1:65 weight ratio of dry microalgal biomass to alkali catalytic methanol (NaOH/MeOH, 2.5 wt.%), with the acid catalysis process (HCl/MeOH, 5.8 vol.%), a 60 °C reaction temperature, and a 30-min reaction time.