metal finishing pretreatment in connecticut sneatp tech talk presentation mariana miller february...
TRANSCRIPT
Metal Finishing Pretreatment in
Connecticut
SNEATP Tech Talk Presentation
Mariana MillerFebruary 10, 2015
What is Metal Finishing?
• ‘Finish’ a metal off by:– Depositing coatings of one metal on to another– Coating metals, based on specific requests from
customers– Producing specific designs or appearances on part
surfaces• Metal finishers – 47% of regulated CT industry
Pollutants generated
• Metals• Hexavalent chromium• Cyanides• Oils• Toxic organic compounds• Solids
Pretreatment
• Treatment plants are not designed to handle pollutants in raw wastewater
• Wastewater must be treated prior to discharge to sewer
• Prevents: – Interference with processes at the treatment plant– Pass through of pollutants
Common types of Pretreatment
• Metals precipitation prior to discharge– Neutralization– Flocculation/coagulation– Sludge dewatering
• Hexavalent chromium reduction• Cyanide destruction• Filtration• Oil/water separation• Haul wastewater
Without Pretreatment…
• EPA NPDES Permit Writers’ Course Workbook– Bottom left: Hexane explosion– Top right: Manhole cover blown off after gas
explosion– Bottom right: Buildup of hydrogen sulfide/buildup
of solidified oil• Other effects…
How is this regulated?
• Local, state, federal regulations• CT DEEP permits• Effluent limitations• Treatment plant’s review/approval• Inspections• Monthly reporting• Enforcement actions
Questions?