What kind of company is Feida Environmental Protection? State-owned enterprises or private enterprises?

It is a state-owned enterprise.

The controlling shareholder of Feida Environmental Protection is Zhejiang Feida Electromechanical Group Co., Ltd., which is state-owned, so Feida Environmental Protection is also a state-owned enterprise with a state-owned holding background.

If you want to elaborate, it belongs to state-owned joint-stock enterprises.