Study And Application On The Process Of Cigarette Industry Wastewater Treatment

Cigarette wastewater is comprised of industrial wastewater and sewage of cigarettefactory. It is showed that, cigarette wastewater is a kind of high concentration organicpollutant wastewater with COD of600to1000mg/L, and BOD₅of200to800mg/L. Themain part organic of wastewater are polysaccharides hydrolyzed by cellulose andhemicelluloses, including low carbon acid and higher fatty acid. The suspend solid ofwastewater was300to600mg/L and turbidity of100to200NTU. Because of unsaturatedconjugate double bond of molecular structure of nicotine, phenols, benzene rings, it madewastewater with high chroma, coloritiy of128to256times. The pH of wastewater was6.0to7.5.In this paper, combined process of air flotation-hydrolytic acidification-biologicalcontact oxidation-ozone biological aerated filter was applied. It was concluded that thiscombined process was stable, reliable, simple operation and impact resistant strongly. Theeffluent can reach the greening standard of code for design of wastewater reclamation andreuse （GB50335-2002）, and operation cost is2.73yuan/m³.PAC was selected as floatation agent, while PAM as flocculant. The surface load ofair-flotation tank was1.5m³/（m2·h）. The optimal dosage of PAC was800mg/L, while optimalpH value was7. Under this condition, the COD removal rate was15.2%, and decoloriationrate was55.7%.Seeding sludge methods was chosen for rapid starting up the biological process. Theorganic load of hydrolytic acidification was2.4kg COD/（m³·d）. And the organic load ofbiological contact oxidation was1.8kg COD/（m³·d）, while gas water ratio was8:1. The CODaverage concentration of influent was744.02mg/L. After processing by hydrolyticacidification units, the COD average concentration of effluent was450.45mg/L. And then theCOD average concentration of effluent processing by biological contact oxidation was133.90mg/L. And the ammonia average concentration of influent was36.07mg/L. Afterprocessing by hydrolytic acidification units, the ammonia average concentration of effluent was37.94mg/L. And then the ammonia average concentration of effluent processing bybiological contact oxidation was9.40mg/L. The COD average removal rate of biological unitswas79.62%, while ammonia average removal rate was73.64%.Ozone dosage of ozone biological aerated filter was37.65mg/L, while organic load as0.6kg COD/（m³·d）, gas water ratio was4:1, media layer height as4.3m, effective volume as200m³. The COD average concentration of ultimate effluent was60.72mg/L, and theammonia average concentration was3.44mg/L. The COD average removal rate was91.84%,while ammonia average removal rate was90.27%.