| 英文摘要 |
The objectives of this project include (1) to understand the presence of toxic cyanobacteria and cyanotoxins in the source water and finished water in Taiwan, (2) to evaluate the management strategy of international organization and other countries for the control of cyanotoxins in drinking water, and (3) to help the establishment of national standards and management strategies for cyanotoxins in drinking water of Taiwan.
In this year, 155 water samples were collected and analyzed in 6 major drinking water reservoirs and associated treatment plants. A solid-phase extraction (SPE) concentration technique followed by liquid chromatograph-mass spectrometer (LC-MS) was used for the quantification of six microcystin congeners (LR, RR, YR, LA, LW, and LF), anatoxin-a, nodularin, and cylindrospermopsin. The concentrations of microcystins were between N.D. -0.9 g/L in surface water samples, were between N.D. -0.5 g/L in raw water samples, and were all < 0.1g/L for finished water samples.
A correlation between major cyanobacteria and their metabolites was conducted for the samples collected from T Reservoir. Among the parameters analyzed, chlorophyll-a concentration is proportional to microcystins concentration, microcystis cell concentration, and β-cyclocitral concentration, indicating that chlorophyll-a may be a good indicator for the estimation of the algal metabolites in the reservoir.
For the treatment efficiency in the waterworks, 40-92% of microcystins removal efficiency were observed for the waterworks with conventional treatment processes, 61-92% were for the conventional waterworks with floatation and slow sand filtration units, and around 53 to 96% were for the advanced waterworks.
Cylindrospermopsin and potential producers, cylindrospermopsis, were detected in two reservoirs, T and J. The concentrations of cylindrospermopsin in the surface water were as much as several g/L, and however, those in the finished water were much lower at < 0.5 g/L. New strains of cylindrospermopsis were detected using Real Time PCR and other biotechnical methods. The linkage between toxin production and cylindrospermopsis strains in the two reservoirs needs to be further explored.
For the management of cyanobacteria and cyanotoxins in the drinking water systems, three cyanobacteria bloom episodes, including one domestic reservoir and two Australian reservoirs, were reported and analyzed. In addition, a workshop for the identification of toxic cyanobacteria in drinking water was held at National Cheng Kung University. Finally, a framework and time table of implementation was suggested for the management of cyanobacteria and cyanotoxins in drinking water systems for different responsible agencies.
|