Abstract: Disclosed is an external acceleration system for a biological denitrification process during wastewater treatment, including a biological denitrification mechanism, a denitrification acceleration mechanism, and a water circulation mechanism, where the biological denitrification mechanism includes a biological denitrification tank, a three-way valve, a wastewater assembly, and a water inlet pipe; the denitrification acceleration mechanism includes a denitrification accelerator and an assembly for enhancing the sulfur disproportionation reaction; the water circulation mechanism includes a first water delivery pump, a first water delivery pipe, a second water delivery pipe, and a second water delivery pump.

Abstract: An electrolytic solution includes a lithium salt, an organic solvent, and an additive. The additive is a salt with a formula of M1M2xOy. The M1 is selected from one or more of alkali metal element and NH4+. The M2 is selected from one or more of VB-VIII group elements in a fourth cycle of a periodic table of elements. x is in a range of 0.01-4, and y is in a range of 0.1-9.