Pilot Plant Study On Printing And Dyeing Wastewater Treatment By Hybrid Anaerobic Baffled Reactor And Project Engineering Design

Printing and dyeing wastewater is characterized by complex properties such as highchroma, high pollutant concentration, high pH, poor biodegradability, which pose great threatto the environment. HABR is an effective method for water pollution treatment and controlwith the advantages of simple design,wide range for use,strong shock resistance,low cost.In the present study, pilot-scale hybrid anaerobic baffled reactor （HABR）for printing anddyeing wastewater has been investigated in different operating conditions. Pilot study showsthat HABR showed sufficient contaminants removal capacity for printing and dyeingwastewater. The COD_Crremoval was63.0%and chromaticity removal was55.6%when thereflux rate was4at12h of HRTThe removal of COD_Crand chroma declined gradually as the hydraulic retention time（HRT） decreased. Variety of COD_Crand chroma removal was occurred in differentcompartment at different HRT. The maximum26.6%⁴4.3%COD_Crremoval and maximum34.5%⁴5.0%chroma removal was observed in the first compartment. At higher HRTcondition, the front compartments showed a higher COD_Crremoval while the major COD_Crremoval was achieved in back compartments as HRT was decreased.The pH of wastewater saw a sharp decreased while the B/C increased obviously afterHABR treatment. Significant decrease of pH and increase of the B/C was found at16h and12h of HRT. The decrease of pH occurred in the first compartment and then pH increased inthe following compartments while the B/C showed the opposite trend. The lowest pH and thehighest B/C was found in Compartment1at24h and20h of HRT, and in Compartment2at16h,12h and8h of HRT. When HRT was lowered, pH, relative removal ratio of COD_Crandchroma of each compartments tended to be identical while B/C increased gradually alongcompartment.The height of the sludge bed increased gradually with the increase of the reflux rat（eR）.As the reflux rate increasd, the relative removal ratio of COD_Crand chroma firstly increasedand then decreased. As the reflux rate increased further, sludge washed away seriously andCOD_Crremoval ratio and chroma removal ratio declined rapidly.Compartment1had the besteffect on COD_Crand chroma removal in different reflux rate, and the COD_Crremoval ratioaccounted for around21.3%³0.7%while chroma removal ratio around for27.9%⁴2.8%.Asreflux rate increased, phase separation function of HABR was weaken, and the difference ofpH, relative removal ratio of COD_Crand chroma of each compartment became insignificant.Besides，pilot study also shows that the filler in the upper part of HABR was able to improve the operation efficiency of the reactor at longer HRT and played an important role inretaining sludge at higher up-flow velocity（Vap）. In this regard, efficiency and stable operationof reactor was achieved.Since corresponding data was collected and then relative operating parameters wereoptimized, this field study has act as an important reference for the design of HABR projectof Centralized Wastewater Treatment for Dongguan Shatian Printing and Dyeing ProfessionalBase.