My waste water included NaCl, KH2PO4, CaCl2, MgSO4. If I was using electrocoagulation with pH>8, after finishing to test the pH decreased. However, when I tested with pH =7.12 and especially with pH = 4 after experiment the pH increased followed experiment time. For instance, with pH=4 after 2hr the pH =7.6.
Please explain for me!