How to address the poor sedimentation property of aerobic sludge and MBR sludge? Seeking guidance

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The raw water is phosphating wastewater generated from metal surface spraying. The first-stage physicochemical treatment process involves calcium chloride, sulfuric acid for demulsification, hydrogen peroxide, sodium hydroxide, along with PAC and PAM. The second-stage physicochemical treatment process adds more sodium hydroxide, calcium chloride, PA, and PAM. The biological treatment process includes hydrolysis and acidification, contact oxidation, and MBR. The current problem is that the sludge has poor sedimentation properties: the SV30 value is 30%, and the SV60 value is 15%. After 10 or 20 minutes, almost no sedimentation occurs; even after one hour, the supernatant remaining after sedimentation is not clear. I seek advice from experts regarding this issue. The designed capacity for the physicochemical treatment is 200 units per day, while that for the biological treatment is 320 units per day. Currently, some domestic wastewater is entering the biological treatment system. The system has been in operation since November 2015, yet no sludge has been discharged yet. The industrial wastewater entering the biological treatment system has an OOD value of 100–200, while the domestic wastewater has a COD value of 300. There are no tools available to measure other parameters, including DO. During the New Year period, aeration was kept running continuously – could this be why the sludge has broken down into smaller particles?