PHYSIOCHEMICAL TREATMENT OF LITHOGRAPH WASTEWATER
John A. Olofsson, Jr., Assistant Professor
Paul L. Bishop, Associate Professor
Department of Civil Engineering
University of New Hampshire
Durham, New Hampshire 03824
Richard A. Dickson, Engineer
Dickson and Holden Associates
Concord, New Hampshire 03301
INTRODUCTION
The industrial wastewater treatment literature contains virtually no mention of lithograph process wastewater characteristics or treatment alternatives.   This report presents
a description of lithograph wastewater produced by a small New Hampshire printing firm
and discusses preliminary experimental results with regard  to a feasible treatment scheme.
The firm in question has recently been forced to deal with the specific problem of
waste treatment.   Presently, virtually no attempts have been made to modify processes
and operations in such a way as to minimize concentration or volume of wastes generated.   Although almost no mention of specific lithograph process descriptions from an
industrial waste standpoint have been uncovered, there is no apparent reason to believe
that the present operation is atypical with regard to other similar operations in New
England.
The lithograph operation examined can best be described as being composed of a
series of discrete processes, several of which produce various liquid waste materials.   It
appears from a brief survey of the overall operation that it may be a prime candidate
for internal process modification as a means of waste concentration, reduction and ultimate segregation of various specific waste components.   It also appears feasible to
perform some recovery of materials such as solvents, dyes and other process chemicals
if it can be shown that such recovery will be economically attractive.    At present
virtually no recovery is practiced and wastes from all sources, both process as well as
sanitary wastes, are combined within the plant prior to discharge.
In many cases the various processes and operations are carried out on a surprisingly
small scale.   In several cases, printing materials are processed by hand and the application of process chemicals is accomplished by using very small amounts of reagents.   The
various etching processes, for example, are carried out in tanks and on stainless steel
tables which collect excess etching materials in perimeter troughs leading to a waste
drain.   For several operations it appears that the materials are used and discarded before their usefulness has been completely exhausted.   The implication is that reuse of
certain materials may be a very attractive process modification which will result in reduction of wastes   generated.   Reuse of process reagents may necessitate some reconditioning, however, and exploration of possible materials reuse should be considered as a
part of an overall plan for waste treatment.   To date this has apparently not been considered although the scale of the operation and degree of process control seem to make
this a logical step.
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