A Hazardous Waste Reduction Audit of Pioneer Metal Finishing, Inc.

Transcription

1 . A Hazardous Waste Reduction Audit of Pioneer Metal Finishing, nc. Presented by Harry DeSoi Pioneer Metal Finishing, nc. Franklin, New Jersey

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3 Hazardous Waste Reduction Audit of Pioneer Metal Finishing nc. As with solving any problem the problem must be clearly identified and the--final goal must be clearly defined. Pioneer Metal. Finishing nc. provide2 a service to manufactures. This service is to electroplate copper, nickel and chrome onto substrate metals consisting of steel, cast steel, zinc diecasting and brass. The buffing room had potential air problems but they w i l l not be discussed at this time. The problems were identified and divided into the following areas:!/l Dragout from Hex-Chrome tanks 112 Dragout from Cyanide-Copper tanks 83 Dragout from Nickel tanks 1/4 Dragout from Cleaner ranks!/5 Dragout from Acid tanks The most serious problems were yet to be identified.!/6 Periodic dump of Diecast soak 87 Periodic cump of O i l containing Steel soak 118 Periodic dump of Diecast electro-cleaner containing large quantities of Zn and Cu and Cr.!/9 Periodic dump of steel electro-cleaner containing C r metal and very high content of caustic. 1/10 Periodic dump of 2% sulfuric with up to 2000 ppm zinc #11 Periodic dump of 75% hydrochloric with up to 1000 ppm copper plus up to 600 lb of ferric-chloride!#12 Periodic dump of saturated rack strip with very high content of copper, nickel and chrome!/13 Periodic dump of saturated strip used to strip rejects. This contains high volumes of copper and nickel. C14 Mate; from vibratory finishing containing large volume of zinc metal, media (ceramic and plastic) and vibratory compounds that do not want to let go of the metal. Upon close examination we discovered that we had problems within problems that were not to be solved by simple treatment steps. Most treatment "experts" selling treatment systems had very little experience in solving problems when small quantities of metals were left in the water that had to be discharged. They were good at getting 300 and 400 ppm of metal out but were confused when you get down to 6 to 10 ppm and the remaining metal w i l l not drop out. Some of these chemical companies have admited that their proprietory chemicals w i l l not release all of the metal by using conventional treatment methods. Some act as if it is not a problem while others 212

4 _.;:..,.:,.. id-.- ~ are concerned. Through trial and error we found these additional problems: 1/15 One soak tank contained a chemical that at a ph of 9.5 to 10 retained metals. 1/16 One elecrocleaner was heavy formulate with chemicals used very widely in the cleaning industry which are very difficult to treat. #17 One plating bath contained enough amnonia to retain enough metals to place our discharge violation even after treatment. 1/18 Concentrated strip would not treat by conventional methods The most serious compliance problem of all came last. f we could install a system that would produce acceptable water on a reliable basis what would me do to stay in compliance. as equipment ages and normal unexpected problems present themselves? On a normal day there are many variables in the plating that create some rejects. n waste treatment there could be many variables that could produce water in violation of State and Federal laws. Now that we found most of our problems we had to look at the expense of correcting these problems. The cost of equipment is significant but the week to week expenses can even be more detriment.al. We had to look at the most expensive treatment problems and see if we could change some of the products we were using. f1 We changed one of our soak solutions to one that is more treatable. 1/2 We changed products in one of our electrocleaners to a product that treats quite easily. #3 We changed from hexovalent chrome to tri-valent chrome in our chrome plating line. We then went to a tri-valent chrome co-ntaining no ammonia. Trivalent chrome is treated by simply raising the ph to 9.5. Hexovalent chrome solutions are 20 times more concentrated with metal and very costly to treat. 84 We installed spray rinsing, educated employees, redesigned plating racks and increased drip time to conserve on chemicals drug out of plating baths. #5 Replaced batch dump strips with electro strips that can be filtered. Batch strips are very expensive to treat. Most must be greatly diluted to be treated properly if they are cyanide strips. 86 The greatest area to reduce expenses was in the type" of treatment. From 2975 to 1981 we used a segregated-continuous discharge system. From 1981 to present (1987) we have used a close looped batch treatment system. - Continuous discharge system was heavy on chemical use, heavy on maintainance, heavy on sludge production and heavy on 213

5 L ' 4 labor. Approximate expenses were 10% of gross sales. Batch treatment-close Loop system has low chemical use, low on maintainance, low in sludge production and very low on labor. Approximate expenses are 3% of gross sales Reduce.Liability The most threatening liability is the potential of discharging in violat_ion of Federal, State or local laws. The way we reduced this liability to the lowest possibility was to repiace our continuous discharge system with a close-loop system that captures all rinses water and dumps, treats water, desalts the water through modified boilers and reuses the water, While there was water leaving the plant the liability factor was greatly increased. With no process water leaving the plant the liability factor is greatly reduced. Other steps to reduce liability is to reuse as much as possible in the plant, substitute less toxic chemicals for more toxic ones and throughly investigate the companies to be used to haul any waste from the plant. 214

6 .. *. -. ' WATER FROM PbANT 8 ' l * ' '. :. -..,.. LEATMEN' TANK B A, (,.,-.,, *. ;,. - A. TREATEP WATEP ~ TO BE REUSED N PCANT. t. '. -..,..,,.,.,. -.,, ' ' Pioneer. Metal Finishing nc Close-Loop treatment' system. < '(Zerpol)' fitartup.aug: 1981 '. ',.,,,.,.!. 1 :. -.,.... *, BE USED N PRME RNSES '.! '! L ' 1 '...

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