11882
The COD and color removals were both more than 90 % when FeCl3 was used as the coagulation ( dosages of two - step coagulation were 0 . 031 and 0 . 012 mol / L respectively ) after a ferrous hydrogen peroxide oxidation pretreatment at a H2O2 dosage of 0 . 06 mol / L .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
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