Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Changes in physical and chemical indicators in wastewater: (PE) E. crassipes; (PL) L. adscendens; (BC) black control; (PT) T. natans (the same in the following figures). (A): the value of pH; (B): the concentration of DO; (C): the value of ORP; (D): the value of EC.
