Organic Residue In A Closed-Loop Hypochlorite System
V. DEAN ADAMS, Research Chemist
Utah Water Research Laboratory
E. JOE MJDDLEBROOKS, Professor and Head
Division of Environmental Engineering
Utah State University
Logan, Utah 84322
PAUL D. NANCE, Manager
Marketing and New Products
Wasatch Division
Thiokol Chemical Corporation
Brigham City, Utah 84302
INTRODUCTION
With the advent of more stringent water quality standards it has become necessary for
recreational vehicles, particularly boats, and homes located in isolated areas to provide
effective wastewater treatment. Because of the inconveniences associated with obtaining
adequate culinary water at many isolated recreational areas, recycling of the used water has
been proposed and has been incorporated into many prototype wastewater disposal
systems.
The use of filtration, incineration, and heavy application of chlorine with hypochlorite generating cells had been very successful for shipboard wastewater treatment (1).
An obvious variation in this shipboard process for application in isolated areas and aboard
recreational boats was the reuse of the effluent for flushing operations. The following study
was performed using effluent from such a wastewater treatment system.
The most significant problem occurring in a recycled effluent process utilizing physical
treatment in conjunction with a catalyzed hypochlorite generating wastewater treatment
process is the accumulation of organic compounds in the recycled effluent. Although these
effluents are discharged to the environment infrequently, care must be exercised to ensure
that unexpected consequences are not produced. The greatest concern for these
accumulated compounds results in the reuse of the effluent for flushing operations. If the
chlorine residual were to be exhausted before the effluent were returned to the treatment
plant, biological activity and discoloration could occur. The discoloration is of aesthetic
concern and most users of the process would insist upon an odorless and clear flush water.
To prevent the recurrence of this type of difficulty in the process, it was first necessary
to identify these compounds. The results presented herein describe a study utilizing
advanced chemical detection techniques to identify the compounds that accumulated in the
recycled effluent.
DESCRIPTION OF PROCESS
Figure 1 shows a flow diagram with component sizes of a full scale physical-chemical
process developed for use at an isolated recreation area. The flow diagram is identical to the
system developed for use aboard pleasure boats and the pilot scale unit which produced the
effluent studied. The process equipment was designed for use aboard recreational vehicles
or in isolated areas where water is in short supply or the effluent cannot be discharged.
Figure 2 shows an arrangement of the system aboard a small pleasure boat that was
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