An embodiment of the invention discloses a
sewage pretreatment process used during
organic product preparation. The process includes: (a), adding a nonpolar
solvent,
sodium alcoholate and main and auxiliary raw materials into a synthesis kettle for reaction; (b), adding a saturated
sodium salt solution into a water-washing
neutralization kettle, cooling, adding reaction liquid in the synthesis kettle into the water-washing
neutralization kettle, and titrating till being slightly acidic; (c), standing a solution in the water-washing
neutralization kettle to obtain a lower-layer
solid-liquid mixture and an upper-layer
organic layer; (d), performing suction filtering on the lower-layer
solid-liquid mixture to obtain
sodium salt and a
mixed solution; (e), taking the
mixed solution in the step(d) as the solution added into the water-washing neutralization kettle in the step (b) for reutilization; (f), using water to wash the
organic layer, and distilling or rectifying to obtain an organicproduct. The process can promote recycling of
sodium salt and reutilizing of
sewage, reduce salt in the
sewage and substantially lower sewage yield, thereby reducing COD in the sewage and
sewage treatment energy consumption and treatment cost.