DELTA STPN Series (STPN-250 through STPN-8400)

Verify air blower functionality, check for abnormal noise or vibration, measure dissolved oxygen levels in aeration tanks (should maintain 2-4 mg/L), inspect air hoses for blockages or leaks

Visual inspection of membrane module for fouling or damage, measure membrane pressure drop, verify permeate quality (suspended solids < 50 mg/L, BOD5 < 50 mg/L), test system backflushing effectiveness

Verify chlorine/bisulphite dosing system calibration, check chemical storage levels and expiry dates, measure residual disinfectant in effluent, ensure coliform bacteria count < 200/100 ml per IMO standards

Monitor aerobic process conditions to prevent anaerobic degradation, check for methane or hydrogen sulfide odor, verify settling tank sludge level and solids accumulation, test for absence of anaerobic gas production

Verify discharge pump operation and pressure, test effluent quality parameters (suspended solids, BOD5, coliform bacteria), confirm compliance with MARPOL 73/78 Annex IV discharge standards, check overboard discharge valve positioning