Field observations and management strategy for hot spring wastewater in Wulai area, Taiwan

摘要

Hot springs are important centers for recreation and tourism. However, the pollutionnthat may potentially be caused by hot spring wastewater has rarely been discussed.nMore than half of Taiwan’s hot springs are located in areas where the water quality ofnwater bodies is to be protected, and untreated wastewater could pollute the receivingnwater bodies. In this study, we investigate hot spring wastewater in the Wulai area,none of Taiwan’s famous hot spring resorts. Used water from five hot spring hotelsnwas sampled and ten sampling events were carried out to evaluate the changesnin the quality of used water in different seasons, at different periods of the week,nand from different types of hotels. The concentrations of different pollutantsnin hot spring wastewater were found to exhibit wide variations, as follows: COD,n10–250 mg/L; SS, N.D. 293 mg/L; NH3-N, 0.01–1.93 mg/L; TP, 0.01–0.45 mg/L; and E. coli,n10–27,500 CFU/100 mL. The quality of hot spring wastewater depends on the operationnof public pools, because this affects the frequency of supplementary fresh water andnthe outflow volume. Two management strategies, namely, onsite treatment systemsnand individually packaged treatment equipment, are considered, and a multi-objectivenoptimization model is used to determine the optimal strategy.