Page 57 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

12 Fundamentals of Water Treatment Unit Processes: Physical, Chemical, and Biological

Platte River about 16 km (10 mi) downstream. The first plant . Fifth, the management philosophy is the most import-
was built in 1954, i.e., 18 years prior to being required by ant facet of how an industry deals with its environ-
federal=state regulations. In 1981 a new plant, dedicated to mental issues. Coors (now Miller-Coors) has had a
the Coors Brewery industrial wastes (i.e., malting, brewing, history of identifying potential issues ahead of the
and packaging) was put on line. (The 1954 plant then served public perception, political movements, and legal
only the City of Golden, along with sanitary wastes from other mandates, and dealing with them as matters of good
industrial operations and industrial wastes from the can manu- business and good citizenship (some call this being
facturing and ceramics facilities.) The new wastewater treat- ‘‘proactive’’), which has been the position of many
ment system (i.e., the 1981 plant) included a coarse screen and industries, as opposed a perception by some that they
grit removal (the latter to remove barley and other grain par- all are ‘‘foot-dragging.’’
ticles), an equalization basin to mitigate the effects of batch . Sixth, as a rule, industries want to know the rules and
discharges, primary settling, activated sludge treatment using to know that the rules are enforced fairly upon their
pure oxygen, and secondary settling. The plant was designed competitors as well, and to have confidence that there
with the filtration of secondary settling effluent, using Parkson will not be vacillation (i.e., that the rules do not vary
Dynasand filters with discharge to Clear Creek. In the years from year-to-year as political administrations
since 1981, the plant has been modified to more effectively and change).
more economically achieve its objectives.
In 2001, an anaerobic pretreatment plant was built at site of 1.4.2.1.2 Anheuser-Busch Brewery
the 1981 WWTP; the anaerobic plant receives about 60% of The Anheuser-Busch Brewery in Fort Collins, Colorado, was
the organic loading from the brewery and removes about put on line about 1986. The brewery is located about 16 km
65%–85% of the soluble organics, depending upon the (10 mi) northeast of the City, adjacent to Interstate 25 and in
hydraulic detention time. (The anaerobic process is sometimes an area that is largely irrigated agriculture. Prior to coming to
used for high-strength industrial wastes as a means to reduce the Fort Collins, an agreement was developed with the City of
loading to an aerobic biological treatment system. In the case of Fort Collins to utilize its south WWTP, constructed in 1968
Coors, the BOD varies but about 1800 mg=L may be considered and largely mothballed in 1976 after construction of a new
representative.) The Parkson Dynasand filters were taken out plant on the same site, i.e., the North Plant (further modified
of operation in 1999 due to maintenance difficulties caused by in 1993). The South Plant was renovated in 1986 to accom-
adhesion of a cationic polymer to the filter media. The polymer modate the brewery wastes and was comprised of primary
was used in secondary settling, and in the evaluation of the settling, activated sludge, and secondary settling. A bar screen
trade-offs was selected in preference to the tertiary filtration. was located at the plant site. As an alternative to the Fort
The effluents from the two plants are co-mingled and a single Collins South Plant, the brewery can discharge to a land
discharge permit then serves both plants. treatment site. The site is located about 8 km (5 mi) east of
Some notes on the Coors operation—technical, manage- the plant. The site has storage and is set up to spray irrigate the
ment, and political—may help to understand better the field of wastewater on the land. The spray irrigation rate does not
industrial wastewaters: exceed the infiltration rate of the soil. The system is utilized
irrespective of crop growth cycles but is suspended during cold
. First, equalization basins are common to industries months when freezing may be a problem.
subject to batch discharges. The basins are aerated to
maintain aerobic conditions and to minimize the
1.4.3 INDUSTRIAL PROCESS WATER TREATMENT
deposition of solids. Equalization basins have been
advocated for municipal treatment but they have not Industrial water treatment for process water is another signifi-
become assimilated into practice. cant area. The variation may include industries that can use
. Second, the pure oxygen provides a higher reaction potable water directly without further treatment, such as for
rate and thus smaller aeration basins (i.e., a smaller food products, with perhaps dechlorination. The electric
‘‘footprint,’’ important in the Coors case). energy industry requires mineral-free water for boiler feed,
. Third, the filtration process was used originally at while the electronics industry requires essentially molecular
Coors to provide a buffer to ensure compliance with water. The unit processes in each case may require many of
the 30=30 permit. those listed in Table 1.1 (and in Tables 1.2a and b).
. Fourth, the Miller-Coors Brewery is highly visible
because of its size and because of its historical prom-
1.4.4 HAZARDOUS WASTES
inence in Colorado. Any noncompliance with envir-
onmental standards, particularly on Clear Creek that Contaminated groundwater is a common context for hazard-
receives the discharge from Coors, is noted quickly ous wastes. In some instances, the remedial action is to
by the news media. The selection of processes and pump the aquifer and pass the flow through a treatment
technologies for the treatment train reflects these plant, which is called a ‘‘pump-and-treat’’ situation. Organic
political factors, i.e., to ensure compliance at a high chemicals are common contaminants and there are thousands
probability level. of possibilities. Adsorption by GAC is a common unit