The Treatment Of Printing And Dyeing Wastewatwer By Hydrolysis Acidification-biological Contact Oxidation Process

The textile industry is one of the most chemical intensive industries onthe earth and the major polluter of water. It generates huge quantities ofcomplex chemical substances as a part of unused materials including dyes inthe form of wastewater during various stages of textile processing. Pollutantremoval from printing and dyeing wastewater by means of cheaper andenvironmental friendly technologies is a major challenge. Hence, developingmore efficient and economical technology to treat printing and dyeingwastewater is an important issue.In this manuscript, an ecological carbon fiber composite material wasused as the bio media in the hydrolysis acidification biology contactoxidation activated carbon bioreactor, to treat printing and dyeing wastewater.The influences of hydraulic retention time (HRT), volume load and aerationrate on the removal of COD were studied. The effect of activated carbonadsorption on the contact oxidation reactor effluent was also studied. Basic on this, each unit performance of the hybrid process on removal of COD,ammonia, color was analyzed.Hydrolytic acidification treatment performance is affected by thehydraulic retention time. The optimal HRT is10h, reaching16.9%on CODremoval efficiency. The maximum COD removal rate of hydrolyticacidification reactor is0.285kg·m3·d1, when the volume load is1.942kg·m3·d1. The hydraulic retention time and aeration rate significant impactthe contact oxidation reactor performance. The optimal HRT and gas waterratio is12h,28:1, respectively, while the COD removal reached74.3%. CODremoval rate increased with the increase of volume load, reached1.429kg·m^-3·d^-1 when the volume load is2.499kg·m^-3·d^-1. COD removal rate ofcontact oxidation reactor is3to5times of hydrolysis acidification. Monodequation can describe the organic degradation kinetics of the biologicalcontact oxidation well, the correlation coefficient is0.934.The optimum adsorbent dosage, adsorption time, pH is4g,24h and9,respectively. In this condition, the removal efficiency of COD and color was46.2%and56.3%, respectively. The Langmuir equation can be a betterresponse to activated carbon adsorption characteristics.Hydrolysis acidification biological contact oxidation activated carbonbioreactor has a well performance in treat printing and dyeing wastewater.Hydrolysis acidification reactor has a strong ability to adapt to changes inwater quality and quantity. The ammonia value of effluent was average14.0 mg·L1higher than influent and its color average removal rate is19.8%. Theremoval of contact oxidation reactor on COD, ammonia and color is73.7%,86.3%and51.6%, respectively. Activated carbon adsorption tank removed49.9%color. The effluent average COD, ammonia and color is110.7mg·L^-1,4.10mg·L^-1and0.067, whose removal efficiency is85.8%,86.1%and80.6%.The effluent can achieved Ⅱgrade of GB42871992textile dyeing andfinishing industrial water pollutant discharge standards. The microscopicexamination showed that the ecological carbon fiber composite bio media hasa preferable biocompatibility with high biocompatibility.