Columbia Manufacturing Company of Westfield, Massachusetts began producing bicycles in 1877. The company, while still producing bicycles, transitioned its core product line to institutional furniture with chrome plated bases made from tubular steel. Large amounts of potable water were required for the old plating system. The company was using 180,000 gallons of potable water a day, which required extensive wastewater treatment. The excessive potable water usage, high wastewater treatment costs and the loss of valuable plating chemistry greatly affected the company’s profitability.
The waste contained chromic acid, sulfuric acid, fluoride salts and sulfates from the chromium bath. Dissolved nickel salts from the nickel plating bath were also present, as well as combined ion exchange regeneration wastes and backwash waters from the GAC filters. Suspended and dissolved oils and greases are used to prevent oxidation of the steel tubing.
The client was using standard hydroxide precipitation treatment to precipitate metal salts from their existing chrome over nickel plating operation. The existing wastewater system was clarifier based and utilized sodium hydroxide, coagulants and flocculants to treat the stream prior to discharge to the local POTW.
Waste Disposal Goals
The client’s goal was to recover and recycle expensive chromium and nickel plating chemistries, recover and reduce the demand for potable water used in parts rinsing, eliminate wastewater permits as they relate to the plating line and minimize and or eliminate fees paid to the local POTW.
Wastewater Treatment Challenge
The wastewater treated by the conventional hydroxide precipitation system was permit discharged to the local POTW. The company had historic challenges with hexavalent chrome removal from the final treated effluent. The flocculated metal solids were dewatered using a plate and frame filter press and hauled as F-006 solid waste at a considerable expense.
Metal finishing - Columbia manufacturing company - case study