case study - treatment solutions for difficult to treat electroplating waste
TRANSCRIPT
Industrial Water Management Technologies, Services and Solutions:
Case Study: Treatment Solutions for Difficult to Treat Electro/Electroless Plating Shop Wastewater
www.chemalliance.us864.201.5418
Plating shop baths and rinses can be some of the most difficult wastewater to treat and be able to meet discharge limits. The wastewater can include a variety of metals from both electroless and electroplating processes as well as chelators, stabilizers, reducing agents, surfactants and other chemicals from operations such as activation, neutralization, rinsing, stripping, etc. It is often necessary to separate wastewater from electroless operations, stripping and electroplating to effectively treat it to meet discharge permit limits.
A well known plater of aircraft components was facing this situation. Their present chemical treatment program for wastewater included separating EN baths and rinses and slowly bleeding them off into their batch system EQ to treat and sometimes this wastewater required being treated multiple times to meet discharge limits. They also used nitric acid to strip copper and this too required special treatment. This was slowing up their WWT operations.
They partnered with ChemAlliance to develop a chemical treatment program. Their requirement was a chemical program to successfully treat all EN and copper strip wastewater in one pass without having to dilute. ChemAlliance spent 2 days on site collecting data and working with their chemist in their laboratory . The cycle that ChemAlliance and the customer developed appeared promising but it had a narrow process window. A 20 liter sample of their “worst case” wastewater was sent to ProChem Inc for further cycle development.
Industrial Water Management Technologies, Services and Solutions:
Case Study: Water Treatment of Waste from EN (Electroless Nickel) Plating (Contin’d)
www.chemalliance.us864.201.5418
They reported on eight tests that were run. There were with six successful results . Two of these are summed up in the table below.
Result – Customer ordered materials and is successfully treating their wastewater without having to dilute or treat the same batch multiple times and meeting their discharge permit requirements.
I II Permit Limits (month avg)Pre Treat
ConcentrationCoagulant X X pH adjust 8.0 -11 8.0- 11
Metal Precipitant X X Polymer X X Cu (ppm) 0.514 0.724 1 1192Cr (ppm) 0.985 0.476 1.7 20.2Ni (ppm) 0.481 0.488 1 767Zn (ppm) 0.093 0.03 0.54 3.2P (ppm) < 1 < 1 6 120
Chemists at ProChem’s labs in Elliston, VA received the sample and got right to work . They ran extensive jar testing taking detailed notes on observations and reactions, along with photographs. All of this data was shared with the customer in a detailed eight page report .