General cleaning wastewater ( low concentration of cleaning wastewater ):
Cleaning wastewater daily emissions of 6,400 tons ( a period of 3,200 tons / day ), collected in the regulating pool, while the other pre-treated wastewater and waste liquids discharged into the regulating pool together with the mixing. The concentration of pollutants is low, PH value is 2.5-5, and the total content of heavy metal ions is below 30mg/l; the CODcr of mixed wastewater is generally below 150mg/l. It is lifted by lifting pump to PH adjustment tank Ⅰ for treatment.
Ink wastewater:
The main feature of ink wastewater is that the CODcr concentration is very high, up to 15,000mg/L, an average of 8,000
mg/L or so. The organic matter in the developing and stripping wastewater has a greater impact on the coagulation and precipitation and ion exchange of the comprehensive wastewater behind. Ink wastewater is characterized by easy precipitation under acidic conditions, so it is impossible to mix with other wastewater in the treatment. Ink wastewater is collected separately, pumped by the pump to the acidification tank, add acid, in acidic conditions (PH3-5) ink in the photographic film will precipitate, forming a thick gelatinous cohesion into a mass to become slag removal, and then adjust the pH value of 7 to 8, while adding coagulants, and then after precipitation separation, precipitation supernatant COD generally 400-800mg / L, supernatant self-flowing into the regulator tank mixed and then processed.
Complex wastewater:
Because copper complex (EDTA copper complex ion or copper ammonia complex ion) structure is quite stable, dissolved in water, not precipitation, although only 1~3% of the total amount of water, but because of its complex is extremely stable, if the complex is not broken, the effluent copper ions will be difficult to meet the standard (0.5mg/L or less). Complexed copper wastewater if mixed with other wastewater treatment, in order to break the complex is a very large amount of dosage, the operating costs increase, so complexed copper wastewater must be collected separately and pre-treatment. Complexed wastewater pumped by the pump into the broken complex tank, add oxidizing agents such as sodium hypochlorite oxidation to break the complex (EDTA and NH3 can be oxidized by NaOCl under neutral conditions). Then add coagulant and coagulant aid, after precipitation, the supernatant flows into the regulation tank.