Hau-Ying Lee
3*
, Chun-Lan Huang
2
, Chitsan Lin
1
, Huei-Ya Huang
4
1. Professor of the Department of Marin Environmental Engineering, National Kaohsiung Marine
University, Kaohsiung 81157, Taiwan
2. Professor of the Department of Aquaculture, National Kaohsiung Marine University, Kaohsiung
81157, Taiwan
3. Graduate student of the Department of Marin Environmental Engineering, National Kaohsiung
Marine University, Kaohsiung 81157, Taiwan
4. Master of science of the Department of Marine Environmental Engineering, National Kaohsiung
Marine University, Kaohsiung 81157, Taiwan
* e-mail:dodo780724@hotmail.com
With the industrial growth, cause the river has become a variety of pollutants directly or indirectly acceptor, resulting in a variety of pollutants. Among them, the heavy metal pollution is very serious, such as Hou-Jing River in northern Kaohsiung. The Hou-Jing River is mainly abide by the pollution of five industrial parks, include Dashe Industrial Park, Renwu Industrial Park, Nanzi Export Processing
Zone, Formosa Plastic Group in Renwu and Chinese Petroleum Corporation Kaohsiung Oil Refinery.
There are high potential of waste water and sewage discharges from those factories cause tremendous pollution to water environment.
Three sampling points (upstream Bakong Bridge, midstream Dehuei Bridge and downstream
Xingzhong Bridge) are set at Hou-Jing River area from March to November 2010, in order to perform the sampling of water, sediment and Tilapia. Inductively coupled plasma atomic emission spectroscopy
(ICP-OES) is used to perform heavy metal concentration analysis of Environmental Protection Bureau standard, including arsenic, lead, cadmium, chromium, copper, zinc and nickel, and a mercury analyzer is used to perform mercury concentration analysis.
The investigation result demonstrates: In Hou-Jing River water, the average concentration of five elements, including chromium, copper, nickel, lead and zinc, is highest at Dehuei Bridge. As for heavy metals in the sediment of Hou-Jing River, arsenic is not detected, but the average concentrations of the other metals are highest at midstream Dehuei Bridge. It might be related to the factory in the midstream area and semi-conductor production in the Nanzih Export Processing Zone, which causes the pollution to be injected into the water immediately. And heavy metal accumulates and deposits in the sediment of this river area, resulting in higher concentration.
The concentrations of heavy metal arsenic, chromium and lead in the water samples do not exceed the river water quality classification standard in Taiwan. The concentrations of cadmium, copper and mercury in part of the water body do exceed the standard, and the exceeding rates are:

cadmium 44.4%, copper 72.2%, mercury 27.7%, and zinc 16.7%.
The concentration of heavy metal in sediment is mostly lower than the limit of the soil pollution and the food crop agricultural standard. However, the maximum values of cadmium (21.4 mg/kg dry wt.), copper (557 mg/kg dry wt.) and zinc (2718 mg/kg dry wt.) in part of the sediments are higher than the standard value. The exceeding rates of cadmium and copper are 5.56%, and the exceeding rate of zinc is 22.2%.
The enrichment distribution of Hou-Jing River sediment heavy metal demonstrates that there is an enrichment phenomenon in total cadmium (EF=0~30.9), total copper(EF=1.69~6.08), total mercury
(EF=0.673~1.71), total lead, (EF=4.15~5.95) and total zinc (EF=3.36~22.5) in the river area.
Especially in the case of zinc, anthropogenic pollution is obvious.
As for the spatial distribution of heavy metal concentration in Hou-Jing River Tilapia , there is no obvious variation rule in heavy metal of each river area’s fish. This possibly results from the mobile nature of fish, so the feeding and growing environments are not stable, which causes this concentration distribution result.
The highest concentrations of cadmium and lead in Tilapia exceed the aquatic animal heath standard for about 2.2 times and 6.2 times, and the exceeding rates are 34.8% and 33.7%. There is no regulation for the other heavy metals. As for the Bioconcentration Factor (BCF) of heavy metal in
Tilapia in Hou-Jing River, the maximum values of copper, nickel and zinc exceed regulation standards.
Zinc levels especially exceed standards, at a maximum value is 8190 with the exceeding rate 25.7%.
There is obvious positive correlation between sediment and mercury and lead of Tilapia . The correlation between water and sediment achieves r > 0.96. There is also obvious positive correlation between water and Tilapia , r > 0.73.
Based on the above results, there is certainly serious man-made pollution in Hou-Jing River.
Government units should perform more active and serious action toward the pollution prevention and control of Hou-Jing River.
Keywords: Hou-Jing River, heavy metals, water, sediment, Tilapia, bioaccumulation