Source and Ecological Risk Characteristics of PAHs in Sediments from Qinhuai River and Xuanwu Lake, Nanjing, China

Table 1

Sampling sites and the corresponding regional characteristics.

Reach	Code	Position	Sedimentation rate a year	Regional characteristics
Northern section of IQR	1#	Zhenzhu Bridge	30–40 cm	Near the main road and downtown of city, there are floating contaminations.
Eastern section of IQR	2#	Yixian Bridge
Middle of IQR	3#	Wenjin Bridge	50–60 cm	Locates at Chaotian Temple, receiving sewage discharge, with slow water flow due to gate controlling.
	4#	Wenzheng Bridge		Receives incoming water from eastern section of Internal Qinhuai River, representing water quality of Qinhuai scenic zone.
Southern section of IQR	5#	Xiafu Bridge	40–50 cm	Receives sewage discharges and commercial contaminations
Nanhu Lake Area	6#	Saihong Bridge	50–60 cm	A typical black and odorous river near urban arterial road.
Yunliang River Area	7#	Yunliang River	10–30 cm	Receiving the tail water of sewage treatment plant, it is the local Sewage River.
	8#	Wetland Park	10–20 cm	Locates between the downstream of Yunliang River and External Qinhuai River, belonging to the main body water of Qiqiaoweng Wetland Park
Upstream of Qinhuai River	9#	External Qinhuai River	20–30 cm	The upstream incoming water of urban water body.
External Qinhuai River	10#	Fengtai Bridge	20–40 cm	Subject to the disturbance of traffic and commercial activities with stable flow volume and concrete revetment.
	11#	Hanzhongmen Bridge
	12#	Yuhua Bridge
	13#	Inside of the Sancha estuary		The estuary of External Qinhuai River into the Yangtze River.
	14#	Outside of the Sancha estuary
Xuanwu Lake	15#	Xuanwu Lake	20–30 cm	Receiving the water diversion from drink water treatment plant (1.8 × 10^5 t/d).

Note. IQR: Internal Qinhuai River.