The following table gives an overview of the rivers’ contamination. For comparison, the last row reads the requirements according to the lowest of the five Chinese water quality categories (GB 3838-2002). Category V determines the minimum requirements for agricultural water use.
(Presentation by Dr. Hungjie Gao (CRAES), 21.01.2013 in Shenyang)
As the table shows, in spite of tremendous efforts in the field of waste water treatment, the effect of waste water discharge on water quality remains severe.
The graph below identifies municipal waste water as the dominant source for water contamination in terms of COD and ammonium nitrogen. It should be noted, however, that, although sometimes pre-treated, a major share of the waste water originates from the pharmaceutical industry. CRAES believes the industrial waste water to be the primary reason for the river’s high COD due to their refractory constituents.
(Vortrag Dr. Hungjie Gao (CRAES) am 21.01.2013 in Shenyang)
Location Shenyang (Liaohe)
The Liao River is a result of the confluence of Dongliau and Xiliao and has a total length of 1,390 km. 43.5 mn. people live in the river’s 220,000 km² catchment area displayed in the picture below.
The annual precipitation ranges from 300 to 1000 mm. As 85 % of the rain occurs between July and September, the discharge in the rivers is very low during most months. Especially in the densely populated region of Shenyang with its 7.2 mn. inhabitants (2010) and multiple industrial companies the waste water discharge into the rivers leads to high pollution concentrations. Liao’s tributary, the Hun river, and its branches, Xi, Pu, Baitapu, and Mantung are particularly affected.