70    START-UP AND OPERATION OF AN ANAEROBIC FACILITY
FOR PRETREATMENT OF CORN-ETHANOL WASTEWATER
Jelte Lanting, Environmental Engineer
BIOTHANE Corporation
Camden, New Jersey 08104
Robert L. Gross, Environmental Engineer
Ashland Petroleum Corporation
Ashland, Kentucky 41114
INTRODUCTION
In 1985, a paper was presented at this conference describing the results of a five month pilot study
on anaerobic pretreatment of wastewater from South Point Ethanol, a 60 million gallon per year
corn-ethanol producer.'
The continuous-flow study was carried out with a skid mounted six cubic meter BIOTHANE
upflow anaerobic sludge blanket (UASB) reactor.
A summary of operating performance during the pilot study is shown in Table 1.
The study was considered very successful by South Point Ethanol and a contract for construction of
an industrial scale anaerobic pretreatment facility was awarded in May of 1985. Construction began in
the Autumn of 1985 and the project essentially was completed by the Summer of 1986.
This paper will describe the modifications made to the existing wastewater treatment plant
(WWTP) during the nine months construction project. The focus of the paper will be the start-up,
performance test, and subsequent operation of the anaerobic facility. In the final section of the paper,
the economics of the treatment system and the aerobic polishing of the anaerobic effluent will both be
addressed.
CONFIGURATION OF THE WWTP BEFORE CONSTRUCTION
Figure 1 shows a diagram of the wastewater treatment plant as it existed before major system
modifications were made.
Wastewater generated in the production facility was cooled by means of a heat exchanger to about
45 C and collected in a 7,500 cubic meter surge tank. In this tank coarse pH adjustment was made.
From there the wastewater was pumped to the wastewater treatment site and cooled by means of a
second heat exchanger to a temperature of about 32 C. Just prior to entering the first bio tower, a 280
m2 cross section by 19.5 m high trickling filter, macro-nutrients and caustic were added to the waste
stream. Following the first bio tower, the wastewater was passed through a second bio tower, a 65 m2
Table I.    Pilot Plant Performance Characteristics
Influent Effluent Removal
76%
86%
88%
90%
20%
TCOD (mg/L)
3627
874
SCOD (mg/L)
2889
416
TBOD (mg/L)
2441
288
SBOD (mg/L)
1910
181
TSS  (mg/L)
414
330
Volumetric Loading
9.3 kg TCOD/m3/d
Hydraulic Retention Time
9.4 hours
Methane Content Biogas
83 %
Methane Yield
0.33 m3/kg TCOD rem.
707