Research On The Treatment Of Printing And Dyeing Wastewater

Printing and dyeing wastewater including dye, slurry, dyeing auxiliary, oil solution,heterocycle etc lead to its higher COD, dark chroma,difficult degradation and lower biodegradability. Ultrasound degradates printing and dyeing wastewater for elevation of biodegradability, which has been one hotspot of research in domestic and foreign.This paper summarizes technology of treatment on printing and dyeing wastewater and degradation organic contamination by ultrasound. Printing and dyeing wastewater derived from a textile mill in Anhui is studied in this paper. The impect of ultrasound on biodegradability of printing and dyeing wastewater and the effet of coagulation sedimentation-ultrasound-SBR-coagulation sediment- tation technics on printing and dyeing wastewater are carried out. In addition, We design renewedly one sonachemical reactor, because actual sonachemical reactor have some disadvantage. The valuable results which were obtained by we as follows:(1) The conclusions of the experiment about impact of ultrasound on biodegradability of printing and dyeing wastewater can be expressed these: the COD_B/COD of original printing and dyeing wastewater which's COD_B/COD was 0.52～0.53 achieves 0.71, when printing and dyeing wastewater is diluted one times and ultrasounded one hour.(2) The removal rate of COD_cr in printing and dyeing wastewater of which COD_cr before treatment up to 1000～1500mg/l increase to 96% under the processes coagulation sedimentation(with swinging in with FeSO₄ of 1.0g/l)—ultrasound(with half concentration and an hour ultrasound)—SBR(with MLSS is 5000 mg/l , DO is 3.0 mg/l and aerate time last 5h)—coagulation sedimentation(with swinging in with Al₂(SO₄)₃ of 1.0g/l). The result of this experiment provides base of theory for combined technology.(3) This paper finds that the treatment efficiency of ultrasound wave at combined frequencies of low and high excels other fashion ultrasound wave. The combined frequencies ultrasound wave with 28 kHz and 840 kHz can compensate other's trough each other and eliminate stationary wave and can make furthest effect of cavitate in liquid anywhere. We abecedarian design the Parallel-plate near-field acoustical processor which's length,breadth and highness is 25cm,20cm and 10.56 cm respectively base on research from above paragraphs.