A Study On The Removal Of Odor Of Tap Water In Winters From A Water Company With Yellow River As Its Water Source In Baotou City

The odor problem in water body has been existing as a difficulty hard to solve both nationally and internationally. In this paper the tap water supplied in winter by a water company in Baotou City was studied. With the detection of the odor problem as a focus, a long term monitoring of water quality had been carried out. The materials that potentially resulted in odor problems were studied. Simultaneously, a lot of experimental work had been done on the removal of algae and other suspected odor causing substances.Based on the analysis of long-term monitoring data of yellow river and reservoir, we concluded that a great deal of propagation of algae result in odor problem of leave-factory-water. In order to resolve this problem, long-term algae total count and authentication wim classification had been carried out, and total amount of algae and their category in winter reservoir confirmed. These algae were mainly classified to Chlorophyta, Bacillariophyta and Cryptophyta. And Chlorella, Cosmarium Cord of Chlorophyta, C. ovata, C. erosa of Cryptophyta, Genus Thalassiosira, Asterionellais of Bacillariophyta were most common. The quantity of algae in reservoir had been kept beyond 10⁷/L. In March time, as the season changing and temperature rising, algae grew rapidly to beyond 1.2×10⁸ /L. As time went on, because of ice melting and the use of Grit Clarifier in water treatment, water quality got better and the amount of algae declined gradually and had been at a lower level until May because of the relatively low temperature. Since June, as temperature rose to high, the algae concentration rose too.In the meantime, through GC methods, the secretions of algae were also measured. The secretions included Geosmin, MIB, TCA and IPMP. The MIB amount was between 29ng/L and 102ng/L, being 3¹0 times beyond TON of MB. The density of TCA was 13ng/L⁵9ng/L, 2-9 times exceeding its TON. Geosmin was 20ng/L^the 65ng/L, 2⁶times over its TON. The IPMP content was between 9ng/L and 38ng/L, 4¹9times beyond its TON.As the experiment carried on, we used CuSO₄, KMnO₄, and H₂O₂ and so on, to get ridof algae. And the results showed that all the three kinds of chemical agents were effective in the treatment of algae. The removal efficiency was beyond 90% with a dosage of 0.9mg/L CUSO4. The efficiency kept beyond 85% when 1.3mg/L KMnQ*. was used. And an efficiency of 90% reached using 4mg/L H2O2. The study was furthered to get rid of the odor problems using KMnO4 and H2O2, and both of the two kinds of oxidants could remove the odor by a great deal, but with a remaining not negligible.