1. Qingdao Xianghe Weiye Environmental Protection Science and Technology Co.
2. Chongqing Hengxinda Environmental Protection Science and Technology Co.
3. Qingdao Qingrun Environmental Protection Science and Technology Co.
4. Qingdao Original Activated Carbon Science and Technology Co.
5. Changsha Qiaobo Environmental Protection Science and Technology Co.
These are considered to be in the industry reputation is relatively good, you can compare a few more look.