Silicone ink wastewater is non-toxic and harmless, but it has the properties of complex composition, stable chemical properties, insoluble in water and other solvents, and large chromaticity. Different types of silica gel have different wastewater quality due to different manufacturing methods, so the treatment methods are also different.
Direct discharge will cause serious pollution to the water body, high suspended solids content, easy to be swallowed by fish, harm human body through the food chain, turbidity, affect the photosynthesis of plants in the water, destroy the ecological balance.
Because silicone ink wastewater contains a large number of suspended solids, and it is not easy to dissolve in water, and its biodegradability is poor, it is generally necessary to use flocculation and other pretreatment methods to remove certain suspended solids, so as to improve the biodegradability of wastewater and reduce the subsequent process load.
The following methods can be used in the future:
Physical methods include adsorption, flotation, microfiltration, ultrafiltration, millimeter microwave and reverse osmosis. Among them, air flotation is widely used in China.
Chemical method includes iron carbon micro electrolysis, oxidation-reduction, coagulation precipitation, photocatalytic oxidation and acid precipitation. Among them, iron carbon micro electrolysis, coagulation precipitation and acid precipitation are the main processes of silicone ink wastewater treatment in China.
Biological methods includes hydrolysis acidification, activated sludge process and so on. Most of silicone ink molecules are refractory organic compounds, which are difficult to be decomposed by aerobic treatment alone, and the decolorization effect is poor.