Purification・・・Rivers 　★ There are two ways available, depending on the states of rivers. 　● Flow from the upper reach to the lower reach of a river 　　The point of WK dropping is located at the upper reach of a river, but the purification of water begins at the estuary of the lower reach. This is because the flow of river comes into collision with the salt water at the estuary and the residence time of WK becomes long enough to be able to activate microorganisms. Even if WK is added at the upper reach, the effect of WK appears at the lower reach first and the effect is transferred toward the upper reach. 　　● Rivers subject to tidal action 　　In this case, the tidal action is utilized. Accordingly, WK is added at the middle reach of river to be purified. Due to the rise and fall of the tide every six hours, the effect of WK spreads over the entire of river. 　1) Water purification by the addition of WK to polluted rivers 　Comparison of river before and after the addition of WK 　 　 　July 10, 1999 Just after WK addition, dirty color of water BOD 5.6,　 but level of odor 5 in the atmosphere Degree　 of transparency less than 10 cm 　February 17, 2000 Around 8 months after WK addition Color of fresh water recovered BOD decreases to 2.6. Level of odor decreases to 0. Degree of transparency is recovered to more than 1 m. 　Phenomena observed by eyes in the course of purification 　① Methane generation 　 　In case of deep sedimentary sludge: 　Continuous and vigorous evolution of methaneDentrification (generation of nitrogen) begins. 　Odor eliminated In case of shallow sedimentary sludge: Methane bubbles disappear every after generating Denitrification begins. Odor eliminated 　② Floatation of disintegrated sedimentary　sludge by decomposition 　③ Increase of degree of transparency and　recovery of algae after decomposition　of sedimentary sludge 　 　Harmful materials in sedimentary sludge are decomposed and the disintegrated sludge floats. Planktons are acticated much for fish to eat such a sludge. After the complete decomposition of sludge has been accomplished, the degree　of water transparency is recovered and　aquatic plants grow at either side of river. 　Please watch the time variation of microorganisms there after the addition of WK to polluted river in PDF attached. 　　 Time variation of microorganisms 　Please watch self-cleaning functions by activated microorganisms there after the addition of WK to polluted river on PDFs attached. 　in the lower reach of river 　　in the middle reach of river 　　in the upper reach of river 　 2) Recently, execution of river purification has been decided in a public enterprise. It's starting shortly. (to be exhibited) 　 3) Water purification accompanied by sludge decomposition in Longtan River in Guangzhou City, Quandong Province, China 　　　About 2 months passed after WK addition. Please watch on attached video; the circumstances in which methane bubbles are vigorously generated by methane formers activated by WK from deep sedimentary sludge there. 　 left photograph:　before WK addition, January 5, 2001 　 Surface waters are very turbid and of bad odor because of serious pollution. Degree of water transparency amounts to 10 cm. The color of water changes day by day; black, brown, grey, etc. River water seems to be viscous because of the input of municipal wastes. The depth of sedimentary sludge has been about 3 m for these 8 years. 　The addition of WK starts on the 1st of June, 2001. right photographs:　One year and 4 months passed after the addition of WK (October 20, 2002) About one year later, 2 meters of sedimentary　sludge were decomposed and eliminated. River water was felt transparent as a whole,and was recovered to the essential color. Naturally no bad odor was felt. 　* Water quality:　 Before WK addition　　　　　　 One year after WK addition 　　　　　　　　　　　COD above 1,000 mg/L 　　　　　　　42 mg/L 　　　　　　　　　　　BOD above 1,000 mg/L 　　　　　　　15 mg/L 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　to top ｜home｜technology｜rivers｜sewage｜effluents｜energy saving ｜　 　Minaki Advance Inc. (Postal Code 731-5124) 12-301, 1-ban, 4-chome, Minaga, Saeki-ku, Hiroshima-city, Japan 　Note: Any transfer of all contents in the present home page is forbidden.　　　　　　 　Copyright(c) 2001-2005 Minaki Advance Inc. All Rights Reserved