INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY # 163

1.   Headline:  Water Reduction and Wastewater Treatment in an
     Electroplating Plant of Printed Circuit Boards

2.   Background:  See Below

3.   Cleaner Production Principle:  process modification

4.   Description of Cleaner Production Application:

     Technology Principle:  This technology involves using
     electrolysis and ion exchange to remove copper, spray
     rinsing        to reduce water usage, and treatment of
     wastewater by        neutralization and ultrafiltration.

     Process and Waste Information:  The process consists of
     four lines, two of which contain an acidic copper bath, a
     lead/tin bath, and spray or cascade rinse baths.  The
     third line is a stain bath with NH4OH and the rinse water
     is returned to the bath.  The fourth line is a mechanical
     brush line, releasing heavy metal particles.  Before 1980,
     wastewater was sewered without treatment.  It contained
     5-8 mg/l of heavy metals, totally 160 kg/yr.  Concentrates
     were disposed as chemical waste by specialized companies.

     In the new process, water reduction is achieved by
     changing the rinse baths to cascade rinse baths, using
     water from the cascade rinses for spray rinsing.  The
     spray water is transported to a wastewater treatment
     installation.

     The treatment begins by electrolytically recovering
     copper.  Copper particles from a mechanical brush line are
     first dissolved by acids.  Concentrations are decreased
     from 300-400 ppm to approximately 10 ppm.  A further
     decrease in copper concentration is achieved by an ion
     exchanger, reducing the copper content to less than 1 ppm.
     Water containing heavy metals (only copper) in low
     concentrations undergoes neutralization and
     ultrafiltration.  The sludge and concentrates are chemical
     waste and disposed of by specialized companies.  Water not
     containing heavy metals is released without treatment.

     Water use decreased by 15,000 m3/yr and 100-200 kg/yr of
     sludge is produced.  No new feedstocks were introduced and
     no effects on product quality were reported.

     Scale of Operation:  The facility produces 100 m2/day of
     printed circuitry and employees 5 people in the
     electroplating department.

     Stage of Development:  The technology is fully
     implemented.

     Level of Commercialization:  All equipment is widely
     available.

     Material/Energy Balances and Substitutions:

Material Category           Quantity Before
Quantity After     Waste Generation
       (kg/yr):

                              Copper                160
                              1
                              Heavy metals           unknown
                              negligible
     Sludge                     0                    100-200
     Feedstock Use:             N/A                         N/A
     Water Use (m3/yr):         25,000                  10,000
     Energy Use:                N/A                  negligible
5.   Economics

     Investment Costs:  Investment costs were Dfl 350,000 for
     1980.  Capital costs were 35,000 Dfl/yr.

     Operational & Maintenance Costs:  Costs were 9,000 Dfl/yr
     for chemicals and 3,000 Dfl/yr for manpower.

     Payback Time:  The investment will not be paid back since
     annual costs (Dfl 47,000) outweigh savings (Dfl 6,000 on
     copper).

6.   Advantages:  Demands by water regulation authorities
     prompted use of the measures.  The facility now meets the
     regulatory standards. Water usage has decreased by 15,000
     m3/yr and copper levels in the wastewater have decreased
     from 160 kg/yr to 1 kg/yr. Savings on copper were Dfl
     6,000.

7.   Constraints:  It took 7-8 months (1.5 man-years) to
     properly regulate the ultrafiltration system.  No other
     problems were encountered.

8.   Contacts

     Citation:  Wastewater problems in the metal industry:
     results of interviews in 48 companies).  Dr. Ir W.H.
     Rulkens, TNO, Maatschappelijke Technologie, postbus 342,
     7300 AH Apeldoorn, Netherlands.  TEL:(055)773344.

     Industry/Program Contact and Address:

              H.W. du Mortier
              VOM
              Jan van Eycklaan 2
              Postbus 120
              3720 AC Bilthoven
              Netherlands
              TEL: 31-30-287111
              FAX: 31-30-287674

9.   Keywords:  the Netherlands, printed circuit board,
     electroplating, ISIC 2113, electrolysis, ion exchange,
     copper, ultrafiltration, heavy metal, rinsing, sludge.

10.  Reviewer's Comments:  This case study was originally
     compiled by the UNEP IE Working Group on Metal Finishing.
     It underwent a UNEP IE funded technical review in 1994 for
     quality and completeness.  It was edited for the ICPIC
     diskette in July 1995.

DOCNO: DOCUMENT NOT AVAILABLE *****10-05