UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Food and Wood Products Branch Corvallis Field Station 200 SW 35th Street Corvallis, OR 97330 January 2, 1976 SUBJECT: Transmission of Waste Treatment Technology for Meat and Poultry Processing Plants t As requested, a copy of our most recent publication is being sent to you. The enclosed paper describes the second phase of a three phase project. A documentary movie on all three phases will be shown at the Food Processing Waste Symposium being held April 9-11, 1976 at the Atlanta American Hotel in Atlanta, Georgia. The Symposium is held annually at locations in which food processing is concentrated. The Symposium is co-sponsored this year by the American Meat Institute, the Southeastern Poultry and Egg Association, and EPA's Food and Wood Products Branch located here in Corvallis. Very truly yours, Jack L. Witherow Food Wastes Research Enclosure ------- SMALL MEAT-PACKERS WASTES TREATMENT SYSTEMS - II by f Jack L. Witherow Food and Wood Products Branch Corvallis, Oregon Field Site Industrial Environmental Research Laboratory-Cincinnati INTRODUCTION The second phase of a research project to demonstrate treatment technology for meat packing wastewater is reported herein. The first phase is in the proceedings of this conference in 1973 (1). Since the project was designed in 1970, National Discharge Guidelines have more precisely defined the technologies needed by the meat packing industry. In the second phase the scope of the project was enlarged to meet these needs. Because the use of full time waste treatment personnel is not practical for small meat-packers, minimum operational requirements are more important than minimum capital cost. To meet this constraint, the treatment processes were designed to minimize and automate the mechanical equipment. Full scale processes combined with pilot scale processes were evaluated in this study (Figure 1). The full scale processes were a novel extended aeration unit and two aerobic lagoons. The pilot processes were spray runoff irrigation and intermittent sand filtration. The facilities are located at the W. E. Reeves Packinghouse two miles west of Ada, Oklahoma, on 64 acres of rolling land. The plant slaughters 500 to 700 cattle per month and 600 to 800 hogs per month, or about 10 million pounds of live weight annually and produces some 30 ------- F U L L EXTENDED AERA TION Ist AEROBIC LAGOON 2nd AEROBIC LAGOON Manhole A L E P I L 0 T S c A L E Aerator Manhole Automated- Valves Manhole INTERMITTENT SAND FILTERS Alum Addition-^ IRRIGATION PLOT Man- hole Storage Tank Pump Figure I. Schematic of Waste Treatment Systems ------- items including cut and uncut beef and pork and its own brand of fresh sausage, bacon, weiners, cold cuts, chili and other meat items. OBJECTIVES The objectives were: (1) to demonstrate the technical and economic feasibility of aerated and aerobic lagoon processes where hydrogen sulfide odors would be a problem or where ammonia limits are imposed; (2) to develop the spray runoff irrigation process in conjunction with the aerated lagoon for 80% removal of nitrogen and phosphorus, and (3) to demonstrate the capabilities of these processes and sand filtration to meet National Discharge Guidelines. EXPERIMENTAL DESIGN A treatment system, consisting of an extended aeration unit followed by two aerobic lagoons in series, was evaluated over a 12 month period. This system was put into operation on July 10, 1973, and operated 6 months before the evaluation began on January 9, 1974. Since liquid retention in the three units was four months, this period was necessary to obtain typical effluents. The experiments using the pilot scale units were designed after a year of operation of the full scale treatment system. The first five months of evaluation of the extended aeration unit alone or in combination with the first aerobic lagoon indicated that effluents from both systems would meet National Discharge Limitations if additional suspended solids could be removed. The needed decrease in oxygen demand would be accomplished by the suspended solids reduction. No additional removal of ammonia was needed. ------- The spray runoff irrigation process was put into operation in series with the extended aeration unit on July 2, 1974, and evaluated for 6 mcnths. Previous studies on this process using anaerobic lagoon effluent. (1) and raw wastewater (2) indicated that 80% removal of nitroger would be obtained but that the hydraulic loading would be severely limited to obtain 80% removal of phosphorus. The experiment was designed to emphasize suspended solids removal. Phosphate removal was increased by adding alum to the effluent from the extended aeration process. The removal of phosphate in the extended aeration process reduced the needed chemical dosage. With the low organic concentration in the extended aeration effluent and the chemical addition the decision was to increase the hydraulic loading using only one of three irrigation plots ar,d the entire capacity of the delivery system. The intermittent sand filters were put in operation on September 10, 197E>, and evaluated for three months. The suspended solids from the extended aeration unit were a biological floe; the suspended solids from the aerobic pond were mainly algae. The experiment was designed to use intermittent sand filtration on each of these effluents to determine if these solids characteristics would affect removal. Intermittent sand filtration offered a solids removal process requiring simple and infre- quent maintenance which is critical to small packers. Over a dozen small meat packing plants in Ohio are using sand filters behind various primary treatment processes. At two plants visited, the filters appeared to be operating satisfactorily with minimum maintenance. The Ohio EPA furnished analytical data on one effluent sample from each of these two filters, The analyses indicated the suspended solids limits in the Nationa" Discharge Guidelines could be met. Middlebrooks and Marshall (3), Reynolds et. al., (4) and Walter and Bugbee (5) have recently reported on the successful operation of intermittent sand filters to upgrade municipal lagoon effluent to meet National Discharge Guidelines. ------- Automatic composite samples were taken of the raw wastewater, extended aeration effluent, and the effluents from the two aerobic ponds. Grab samples were taken of the effluents from the two sand filters and the irrigation plot. Grab samples were considered sufficient because of the short duration and small volume of discharge from the sand filters and because of previous experience (6) in sampling the runoff from the irrigation process. The automatic samplers collected four samples per hour which were composited in iced containers. Samples of the raw wastewater were composited on Tuesday over the normal operating hours at the packinghouse. The three pond effluent samples were composited between 2 a.m. and 6 a.m., on Wednesday when the effluent was being discharged. The grab samples were obtained before 11 a.m. on Wednesday when all samples were taken to the laboratory. Collected samples were stored at 4°C in the laboratory. The weekly samples were analyzed for five-day biochemical oxygen demand (BODg), chemical oxygen demand (COD), pH, total solids (TS), total volatile solids (TVS), total suspended solids (TSS), ammonia (NH~- N), nitrate plus nitrite (NCy-NCyN), total Kjeldahl nitrogen (TKN), and total phosphate (T-P). In situ measurements were made for temperature and dissolved oxygen (DO) during sample collection. Once a month, specially collected samples were analyzed for oil and grease (FOG), settleable solids, and fecal coliforms. Weekly analyses of mixed liquor suspended solids (MLSS), and mixed liquor volatile suspended solids (MLVSS), and sludge volume index (SVI) were made on the mixed liquor from the aerated pond. All analyses were made in accord with EPA Methods for Chemical Analysisof Water and Wastes, .1971. The chemical analyses were subjected to standard EPA quality control procedures. ------- Weekly flow measurements were made of the raw wastewater, the final discharge and the influent and effluent to the pilot scale units. The amount of power and chemical used and the live weight killed (LWK) were recorded, Air temperatures and precipitation measurements were obtained from tha local weather station. FACILITIES DESIGN The design and construction of the three full scale lagoons and the pilot scale irrigation plots were described in the previous article (1). In the socond study the first lagoon was changed from an anaerobic digestion process to an extended aeration process, a storage tank and a chemical addition unit were added to the flow delivery system for the irrigation plots, and two intermittent sand filters were constructed and installed. Packing plants usually have one operating shift and one cleanup shift wi ;h little or no flow in the middle of the night. This intermittent flow is ii disadvantage in most process designs. In this design, the period of no flow was used advantageously. The anaerobic lagoon was converted to extended aeration by the addition of a floating aerator and an automated valve on the outlet. Both the aerator and valve were controlled by timers. The valve remained closed except from 2 a.m. to 6 a.m. The aerator was operated from 6 a.m. to midnight. This batch operatici enabled both aeration and settling to occur in one vessel without ii mechanical sludge collection and handling system. The extended aeration pond is shaped as an inverted truncated pyramid, with a volume of 18,500 cu. ft. at 9 ft. water depth. Based on previous information (1), the average daily flow is 17,800 gallons and the maximum daily flow is 22,100 gallons. The BOD5 of the raw wastewater averages 1247 mg/1 and has a standard deviation of 802 mg/1. Using this ------- data and a MLSS ranging from 2500 to 4000 mg/1, a series of oxygen requirements were calculated using alphas of 0.35 and 0.48 and betas of 0.03 and 0.09. With 18 hours of operation per day and 2 Ibs. of oxygen per Hp-hr., aerator horsepower requirements were calculated. The average day requirements ranged from 5 to 10 Hp and the maximum day ranged from 7.5 to 11 HP. A 10 Hp Peabody Welles floating aerator with a variable oxygen transfer valve was selected. This valve when open, reduces power consumption along with oxygen transfer. The pond outlet was a submerged 6 inch pipeline. An automated 6 inch valve was placed in the line at a manhole where maintenance could be performed. An accumulation of one day's flow in the first lagoon would raise the water level 6 to 9 inches. This small head allowed use of a rubber stead butterfly valve. An air actuated valve was selected because of an available air supply and savings in costs over a motor actuated valve. The surface areas of the first and second aerobic lagoons were 0.32 and 0.74 acre, respectively. The corresponding volumes were 0.4 and 1.1 million gallons. The minimum and maximum water depths were 3 and 7 feet, respectively. Since the extended aeration unit discharges only four hours per day a storage facility was necessary to operate the spray irrigation system for longer periods. A 3 inch pipeline was connected between the outlet line of the aerated lagoon and the storage tank. An automated valve was placed on the 3 inch line near the lagoon and a float switch was located in the tank. After several minutes of lagoon discharge, the automated valve was opened by a signal from a timer, and when the tank was full the float would actuate the valve to close. A small amount of air was introduced at the bottom of the storage tank to keep the liquid aerobic and mixed. The 2100 gallon storage facility had sufficient volume to operate one irrigation plot 8 to 10 hours per day. 7 ------- A constant speed positive displacement pump was used to apply and measure the flow to the irrigation plot. This pump was operated up to 60 hours per week during the regular hours of plant operation. The application to the plot was determined by measuring the flow per minute and the length of time the pump was operated. The 0.1 acre plot was 33 ft. by 115 ft. The surface was graded to a 6% slope and planted with Burmuda grass. A berm was placed on the upper end to divert rainfall and aluminum stripping was placed along the sides and bottom to direct the discharge through an outlet structure. The discharge was measured by a calibrated tipping bucket and counter. Alum addition was made just prior to the spray pump. The addition system consisted of a 50 gallon tank and a chemical feed pump. The pump was started by a timer after the spray pump was operating and stopped prior to the spray pump to prevent plugging of the pipeline by the chemical precipitant. The chemical addition system used was one developed by Thomas, et. al., (7) for this process when treating raw domestic wastewater. The two intermittent sand filters were constructed by packinghouse personnel from 55 gallon metal drums and local gravel and sand. Two drums were welded together to form a cylinder 5.75 ft. in height with a surface area of 2.73 sq. ft. A 3 in. drain pipe was welded into the filter. The filter media consisted of three graded layers of gravel with a total depth of 14 inches and 28 inches of sand. The bottom gravel was 8 inches in depth with size ranging from 1/2 to 1-1/2 inches. Next was a 3 inch layer with size ranging from 1/4 to 1-1/4. The top layer was 3 inches deep with size ranging from 1/8 to 1/2 inch. Five local sands were analyzed for particle size. The sand selected had an effective diameter of 0.2 mm and a uniformity coefficient of 4. Measured volumes of wastewater were applied manually. ------- EVALUATION OF TREATMENT SYSTEM As shown in the schematic drawing, Figure 1, four different processes were combined to evaluate six treatment systems. The evaluation is divided into full scale pond systems, the pilot scale intermittent sand filter systems, and the pilot scale spray runoff irrigation system. The discharge from these systems are compared with the National Discharge Limitations. Systems which meet these limitations were considered technically feasible and emphasized with more detailed evaluation. Full Scale Pond Systems In Table 1, the discharges from three full scale systems can be compared with the Best Practicable Technology (BPT) limitations for the category Low Packinghouse which are to be met by July 1, 1977. The limitations shown as Means are defined as an average of data collected during 30 consecutive days. The maximum values (Max) are from a one day composite sample. Table 1. Treatment Systems Discharges vs. Effluent Limitations (lb/1000 Ibs LWK) Items BOD5 Mean BOD5 Max. TSS Mean TSS Max. Either extended aeration or extended aeration plus the 1st aerobic lagoon meets the limits for BODj-. However, only the latter system meets the limits for TSS. The maximum day TSS discharge for extended aeration Extended Aeration .07 .27 .22 2.46 1st Aerobic Lagoon .11 .29 .21 .47 2nd Aerogic Lagoon .11 .79 .25 .85 Low Pack. BPT .17 .34 .24 .48 ------- process greatly exceeded that limitation. The addition of the 2nd aerobic lagoon increased the quantities of BOD5 and TSS discharged. Other discharge limitations are placed on FOG, fecal coliforms and pH. Limitations on NH~-N are placed on New Sources of pollutants. The NH,-N *j 0 and FOG limitations were met by all the systems. The maximum pH limit of 9.0 was exceeded by both aerobic ponds. The discharge from the 1st aerobic pond exceeded the pH limitation three out of 45 measurements. These three samples were all taken in April. The discharge from the 2nd aerobic pond exceeded the pH limitation 15 out of 46 measurements. All 15 samples were taken during the warm months, July through October. There were no discharges with a pH of less than 6.0, the lower guideline limitation. None of the fecal coliform measurements on the discharges from the tnree ponds met the maximum guideline limitations of 400 mpn/100 ml. Extended Aeration Unit The number of analyses (n), mean concentrations of pollutants in the influent and effluent, and removals in the extended aeration unit are given In Table 2. The removal efficiencies based on mean concentrations of BOD5, COD, FOG, NH3-N, and TKN exceeded 90 percent. Removal of TSS was 96 percent when based on median concentrations. After the j:irst two months of the study period the TSS in the effluent dropped from around 200 mg/1 to about the median value of 23 mg/1. Removal of T-P was lowest at 71 percent; however, no T-P was removed when this unit v/as operated as an anaerobic lagoon. The maximum discharge of NH3-N was 7.0 mg/1, except for 4 days when the aerator was off due to vandalism. Both NHL-N and TKN concentrations decreased in the unit with only 2% of the decrease accounted for by the increase in N02+N03> Apparently denitrification occurred during the 6 hours each day when the aerator was turned off. Within the pH range of 7 to 8 the maximum ammonia in the form of strippable gas was about 20 percent (8). The 10 ------- .odors of ammonia or other objectionable compounds i.e., hydrogen sulfide or mercaptans, were not detected on the banks of the pond. Table 2. Concentrations and Removals - Extended Aeration Items BOD5 COD TSS FOG NH3-N N02+N03-N TKN T-P Influent Effluent Removal 42 46 45 10 44 44 46 46 (mg/1) 714.8 1630.2 535.8 138.6 12.5 0.4 7.9.0 11.0 (mg/1) 17.0 121.6 65.4 11.9 1.9 2.6 7.8 3.3 (%) 98 93 88 91 95 — 90 71 The extended aeration unit was organically and hydraulically loaded lower than usual in this country. The loadings are common for oxidation ditches used in the Netherlands. The ratio of food to microorganism (F/M) averaged 0.06 Ib BOD5/lb MLVSS. The mean hydraulic detection was 9.8 days and sludge retention time (SRT) averaged 64 days. Sludge was wasted five times during the study period. Mixed Liquor Suspended Solids (MLSS) averaged 3350 mg/1 and the SVI averaged 217. A previous study (9) evaluated the oxidation ditch (extended aeration) process at the John Morrell packinghouse in Ottumwa, Iowa. In that study the F/M averaged 0.26 Ib BOD5/lb MLSS and the detention averaged 3.6 days. The effluent concentration for BODr, TSS, FOG, and NH--N averaged 70, 142, 21 and 18 mg/1, respectively. Both the loadings and the effluent concentrations were several times greater than in this study. With those higher loadings the extended aeration processes exceeded the 30 day BPT limitations for BOD,- and TSS five and seven fold, respectively. 11 ------- To determine the effects of several operating parameters on effluent quality, a number of regression analyses were made. The dependent variables were effluent concentrations of BOD,-, TSS and NH--N. The independent variables were: hydraulic detention time, organic loading (Ib BOD/day/1000 ft3), F/M, SRT, SVI, and MLSS. Over the 12 months study period there were 43 sets of data which included most of these variables end 35 sets which include all these variables. The statistical analysis failed to show high enough regression coefficients to predict effluent ccncentrations from any one operating parameter. Because of the low effluent concentrations, the measurement techniques account for a large part of the variation in effluent quality. Aerobic Pords The organic loadings on the first and second aerobic ponds were 8 and 5 Ibs EOD5/acre/day, respectively. The detention times based on influent volume averaged 30 and 84 days, respectively. Based on average concentrations, the first aerobic pond removed 24% of the suspended solids and 48% of the oil and grease. The reduction in suspended solids resulted from a dampening of the high concentrations in the influert during the first two months. Based on median values, the suspended solids concentrations almost doubled in the first aerobic pond. The combined effects of the first and second aerobic ponds were most significant in reduction of concentrations of nitrogen. Mean concentrations of ammonia and total nitrogen in the discharge were 0.4 mg/1 and 4.5 mg/1, respectively. The change in mean concentrations of BOD, COD, TVS or TSS was not meaningful, but the quantities of these pollutants were increased in the two ponds, apparently due to algae production. 12 ------- The average discharge flow from the second aerobic pond was larger than the average wastewater flow from the plant. The raw wastewater was measured 45 times and averaged 18,546 gallons per day. The discharge was measured on the following day when the flow was released from the first pond and averaged 26,040 gallons per day over 45 measurements. The change in flow ranged from a loss of 7000 gallons to an increase of 73,000 gallons. The flow increased when rain occurred and decreased during periods of high air temperature. Rainfall data from the local weather station was compared with the change in flow. The rainfall data was divided into five groups. Grouping was based on change in flow. Four 10,000 gallon groups were from -10,000 gallons to +30,000 gallons. The fifth grouping was for increases in flow over 30,000 gallons. The mean rainfall was found to increase proportionally with the change in flow. When the increase in flow exceeded 20,000 gallons, a rainstorm of an inch or more had occurred either on the day of measurement or during the previous two days. The surface area of the ponds was slightly larger than one acre and an inch of rainfall was equivalent to 27,000 gallons. The increase in flow, due to rainfall, was expected to cause a short term increase in the quantity of BOD,- and TSS discharged. To test this, events of rainfalls and flow increases were grouped by mass discharge values. These events exceeding the maximum day BPT limits were in one group. Those events less than the maximum day but exceeding the 30 day average BPT limits were in a second group. 13 ------- BOD5 2/2 2/2 TSS 7/10 10/10 BOD, 0 4/8 8/8 TSS 6/11 10/11 Table 3. Rainfall and Flow vs Violations of BPT Limits Number of Events Events Discharge > Max. Day > Discharge > 30 Day Avg. Rainfalls/Total Increased Flow/Total The data in Table 3 show that both events in which the maximum day limit for EODr- was exceeded were also rainstorm events. The BPT limits D were exceeded when the discharge flow was greater than the wastewater input in all but one case. In most cases, the BPT limits were exceeded when a rainstorm occurred on the day of sampling or during the previous two days. These rainstorms averaged .65 inches and ranged from .13 to 1.5 inches. Rainfall and the resulting increase in flow did cause increases in mass discharges which resulted in maximum daily limitations on BODc and TSS being exceeded. The owner of the facilities, W. E. Reeves, placed several hundred fish, mainly black bass, catfish and carp in the aerobic ponds. The fish survivad and grew. Black bass fingerlings grew from 3 to 8 inches in one warm season. The fish also acted as an effluent monitor. During a weekend ii October vandals cut the mooring ropes to the floating aerator and it moved to the bank and shut off. The aerator was returned to service on Tuesday. On Monday, about a hundred dead fish were floating on the surface of the aerobic ponds. Measurement on Wednesday showed NHo-N concentrations had significantly increased in the first aerobic and remained above 6.5 mg/1 for two weeks. The second aerobic pond with v:s large volume discharged a maximum NHL-N of 1.5 mg/1 three weeks after the occurrence. Dissolved oxygen in the two aerobic ponds remained near saturation. The detention and dilution in the aerobic ponds reduced the ammonia concentration and prevented a fish kill in the 14 ------- receiving stream. However, overall the disadvantages of the aerobic ponds outnumbered their advantages in meeting National Discharge Limi- tations for the meat industry. The importance in including in the design more than one aerator, steel cable morrings, an alarm system or a means of temporary storage was dramatically demonstrated by the rapid increase of ammonia concen- tration and the resulting fish kill when the aerator was shutdown. The use of captive fish population in the aerobic ponds or in the discharge has obvious merit as a monitoring tool. Pilot Scale Intermittent Sand Filter Systems The utilization of intermittent sand filters was to upgrade the effluents from both the extended aeration pond and the first aerobic pond to meet the BPT limitations and the Best Available Technology (BAT) limitations which will be required by July 1, 1983. A comparison of the discharges from these two systems with BPT and BAT limits is shown in Table 4 for BODr and TSS. Both systems meet these limitations for BPT but neither meet the BAT limits. The amount the discharge of BOD5 exceeded the BAT limits was within the accuracy of measurements. An additional 50% reduction of TSS was needed to meet those BAT limits. The BAT limits for NHj-N, FOG, and pH were met. All fecal coliform measurements exceeded the limit. 15 ------- Extended Aeration Effluent .05 .11 .11 .22 Aerobic Lagoon Effluent .05 .09 .11 .22 Low Packinghouse BPT BAT .17 .34 .24 .48 .04 .08 .06 .12 Table 4. Sand Filters Discharges Vs. Effluent Limitations (lb/1000 Ibs LWK) Items BOD5 Mean BOD5 Max. TSS Mean TSS Max. Each filter was dosed around 10 a.m. with 30 gallons (0.5 mgad) five days per week. Cleaning of the filters was not required during three months of operation. An additional analysis, total volatile suspended solids (TVSS) was determined on the influents and effluents. An initial washout of fines in the filter media was expected to increase the suspended solids but not the volatile suspended solids in the effluent. The rrean concentrations and resulting removal efficiencies for the two sand filters are given in Table 5. Both filters had significant removals of BODgS COD, NH3-NS T-N, and T-P. The extended aeration effluent and the first aerobic lagoon effluent were applied to sand filters No. 1 and sand filter No. 29 respectively. Filter No. 2, usually had higher removal efficiencies, especially in regard to the critical parameter, TSS. However, this was caused by the higher TSS concentrations in the influent. The difference in effluent concentrations was not significant. Because of the wash out of filter media, the 44 to 66% removal of TVSS is considered more representative of filter performance than the values shown for TSS. Oil and grease measurements on the effluents from each filter give concentrations less than 5 mg/1, the accuracy o" the analysis. Influent concenterations varied from less than 5 mg/1 to 26 mg/1. During the study period the pH of the influent 16 ------- and effluent of both filters ranged between 7 and 9. At pH 9, the maximum NH3-N in the form of strippable gas was about 50 percent. The NOp+NOo-N was usually increased about 1 mg/1 in both filters. Removals were mainly due to solid-liquid separation, but oxidation, air stripping and perhaps denitrification also played a part. Table 5. Intermittent Sand Filters (Mean values) Items BOD5 COD TSS TVSS NH3-N T-N T-P Influents (mg/1) Effluents (mg/1) Removals (%) No. 1 26.0 71.2 35.5 25.4 4.3 10.3 2.9 No. 2 28.7 99.7 46.8 32.3 2.7 6.5 4.3 No. 1 10.4 40.4 23.8 14.4 0.3 3.3 0.8 No. 2 8.1 48.1 22.2 11.1 0.1 3.3 2.1 No. 1 60 44 33 44 93 68 73 No. 2 72 52 53 66 96 50 52 The water temperature dropped from a high of 25°C in September to a low of 5°C in December. The change between influent and effluent temperatures was small. Temperature and dissolved oxygen (DO) concen- tration were not inversely related. The DO consistently increased in Filter No. 1. In Filter No. 2, DO concentrations increased half of the time. Effluent concentrations of DO ranged from 5 mg/1 to 9.8 mg/1. Three measurements for fecal coliforms were made on the influent and on the effluent of both filters. A reduction in number of fecal coliforms occurred in 5 of 6 sets of measurements. Maximum and minimum counts in the effluent were 14,000 mpn/100 ml and 1000 mpn/100 ml, respectively. 17 ------- Pilot Scale Spray Runoff Irrigation System A con pan'son of the quantity of BODr and TSS in the raw wastewater, extended aeration effluent, and spray irrigation discharge are compared with the BAT limitations for the category Low Packinghouse in Table 6. The effluent from the extended aeration unit was sprayed on the irrigation plot. The discharge from the spray irrigation process met the BODr and TSS limitations for BPT and except for maximum day TSS met these limita- tions for BAT. The BAT limits for FOG, NH3-N, and pH were met, but the fecal coliform limitation was exceeded by an order of magnitude. Table 6. Spray Irrigation Discharge Vs. Effluent Limitations [lb/1000 Ibs LWK) Raw Extended Runoff Low Pack. Items Wastewater + Aeration + Irrigation BAT BOD5 Mean 3.03 .07 .01 .04 BOD,- Max. 7.25 .27 .03 .08 b TSS Mean 2.24 .22 .01 .06 TSS Max. 5.55 2.46 .21 .12 The raw wastewater values in Table 6 are less than normal for packinghouses because of in-plant control. The lower wastes loads aid in obtaining the low quantities of pollutants in the discharge from the two processes. The extended aeration values are repeated here to compare the two treatment processes. Both processes have high removal efficiencies and both have a maximum day discharge of TSS an order of magnitude greater than average conditions. These high maximum day discharges prevented the extended aeration unit and that unit plus the spray runoff irrigation from meeting the limitations for BPT and BAT, respectively. However, thtire was a difference in frequency and cause of these violations. 18 ------- The extended aeration unit due to high concentrations of TSS exceeding the maximum day limit in four of the first five weekly measurements. The spray irrigation discharge exceeded the maximum day limit once when it discharged both its highest flow and highest concentration of TSS due to 5.6 inches of rainfall during the seven days prior to sampling. On this occasion, the concentrations of COD, TVS, TSS, TVSS were greater in the effluent than in the influent. A study (2) in which the raw packinghouse wastewater was applied to these same irrigation plots also demonstrated the importance of rainfalls. A conclusion from that study was, "During periods when wastewaters are applied, rainfalls of greater than 0.7 inch/day can increase the quantity of BODf- and TSS discharged to as much as ten times average conditions, exceeding the maximum daily BAT limitations." Control of the discharge in respect to volume and/or suspended solids concentration is necessary during intense rainfall to meet BAT limitations. Temporary storage with a controlled discharge and facilties for partial recycle to the irrigation area could offer this control at minimum cost. Evaluation of the spray irrigation dicharge data indicated two modes of operation. The difference was most noticeable in terms of TSS. The effluent concentrations were 10 mg/1 or less from July through September; however, in October concentration in the effluent significantly increased. The data collected was grouped by these two time periods and the means (x) and differences are shown in Table 7. A statistical test was made and the levels of probability at which the means are different are given in Table 7. 19 ------- Table 7. Spray Irrigation Effluent Items July thru Sept. Oct. thru Dec. Difference Probability (x-|) (x2) (x-r*2^ p(x-|^x2) Flow on (gpd) 1887 1826 61 0.900 Flow off (gpd) 207 452 245 0.995 Temp. (°C) 25.3 15.2 10 0.995 BOD5 (mg/1) 3.5 10.2 6.7 0.975 COD (mg/1) 78.1 63.5 14.6 0.950 TSS (mg/1) 8.1 59.3 51.2 0.975 The difference in Flow off (the discharge), BOD,- and TSS and the decrease in temperature in the fall were most meaningful. To retain the low discharge volume and concentrations obtained in the summer, a lower rate of application would be needed in the fall. The similar study (2) utilizing raw packinghouse wastewater supports this observation, that the waste load discharge can be controlled by matching hydraulic loading with seasonal conditions. In that study, loadings of 16,600 gallons per acre per clay (gpad) in the summer and 6500 gpad in the winter resulted in identical waste load discharges which met the BAT limits for BOD,- and TSS. The loadings on the irrigation plot in terms of flow and nutrients are given in Table 8. The hydraulic loading is equivalent to 20,500 gpad. All loading values are based on means established during the six months of operation. The nitrogen loading is important because a few states put limitations on this nutrient to protect ground water supplies. 20 ------- Table 8. Spray Runoff Irrigation Loadings Parameter Units Daily Annual Flow BOD5 TSS NH3-N T-N T-P inches Ibs/acre Ibs/acre Ibs/acre Ibs/acre Ibs/acre .75 3.6 4.6 0.8 2.2 0.5 195 936 1196 200 572 130 The total phosphate concentration averaged 11.1 mg/1 in the raw wastewater, which is the same as the 11.4 mg/1 average obtained in the first study (1). The extended aeration unit reduced this concentration by 71% to 3.3 mg/1. Alum was added to the spray irrigation influent to reduce T-P below 1.0 mg/1. A series of jar tests were run in which the alum dosage was varied and the residual of T-P in the supernatant determined. The residuals ranged from 1.9 to < 0.01 mg/1. The minimum dosage of alum which reduced the residual below 1.0 mg/1 was selected. This dosage of 120 mg/1 gave an A1:P ratio of 3:1 and required 1.7 Ibs of alum per day. Alum was applied during the study period except for a three weeks which the chemical feed system was being repaired. During the study period, the influent, sampled prior to the point of alum addition, had a mean concentration of 3.76 mg/1. The effluent from the plot sampled when alum was added had a mean concentration of 2.85 mg/1. The decrease in T-P concentration was only 25%. A statistical test showed no signi- ficant difference in mean concentrations of T-P in the effluent with or without alum addition to the influent. Alum addition was of little benefit in reduction of the T-P concentration of the effluent. However, greater than 80% of the water applied to the plots was lost to evaporation 21 ------- and seepage, and 88% of the quantity of phosphorus applied to the plots was removed from the effluent. The water seeping below ground, the plant and tie soil were all vehicles for T-P removal from the effluent. Since a material balance on T-P was not attempted, the total effect of the alum addition is unknown. Costs Costs have been determined for four treatment systems. Costs on the full scc.le systems were based on actual expenditures. Costs for the pilot seals processes were estimated from design and operational infor- mation obtained in these studies. The cost of the full scale treatment system is given in Table 9. The capital cost for the three lagoons and appurtenances was obtained by competitive bidding in 1971. The equipment cost was the sum of prices for the floating aerator, control panel, automated valve, air compressor, pneumatic and electrical supplies, and for their installation. To obtain the annual capital cost, the lagoon and structures were amortized at 7% over 23 years and the equipment was amortized at 7% over 10 years. Annual equipment repair was estimated at 3% of capital cost. Annual operating and maintenance were based on 8 to 10 man hours per week needed durinij a year when the evaluation was inactive. This manpower covered mowings, daily inspection, and occasional repairs. Electrical power costs v/ere determined from separate billings for the waste treatment system. Power usage was 4600 KWH per month. Monitoring costs were based on the NPDES permit requirements, sampling by plant personnel and analyses by a commercial laboratory. 22 ------- Table 9. Treatment Costs for Full Scale System CAPITAL COSTS Three Lagoons and Appurtenances $20,000 Installed Equipment 6,000 Capital Cost $26,000 ANNUAL COSTS Amortized Structure (7% - 20 years) 1,890 Amortized Equipment (7% - 10 years) 850 Equipment Repair (3%) 180 Operating and Maintenance 1,200 Electrical Power 1,100 Monitoring and Reporting 980 Total Annual Costs $6,200 Installation Cost: $1.40/gpd Capacity Treatment Cost: $0.21/lb BOD5 Applied The capital costs of the extended aeration unit and the first aerobic pond was determined at $16,000. The cost of the two lagoons and appurtenances was $10,000. This reduction in captial cost would reduce the total annual cost to $5,250. A full scale intermittent sand filter is to be constructed at the plant this summer. A design was prepared for a 0.5 mgad sand filter. After determining cost of local materials and services, cost of construc- tion was estimated at $13,300. The cost of the first deep pond and appurtenance was 1/3 of the total pond system or $6,700. Capital cost of the extended aeration unit and intermittent sand filter would be 23 ------- $26,000. Annual costs would be identical to those in Table 9 with a total of $6,200. Cost of a spray irrigation system was estimated from a layout sketch made to match conditions at the packing plant. The system included an 18,000 gallon wet well, two - 2 Hp pumps, automated valves, timers, 900 ft. of pressure pipe, 100 ft. of gravity pipeline, sprinkler nozzles and risers, a diversion dike, a collection and storage dike, and 2.5 acre;, of land. Prices were based on those developed in a previous study (2]. Total capital cost for the irrigation system was $9,300. The land, structure, and pipelines were $7500 and the installed equipment was $1800. Capital costs for the extended aeration unit were $6,700 for structures and $6000 for equipment. Total capital cost of the extended aeratin unit and the spray irrigation system was estimated at $22,000. Annual costs were computed the same as in Table 9. Equipment repair and electric power costs were increased. Annual costs for both treatment processes were estimated at $6100. In sjmmary, capital and annual costs would be nearly the same for the extended aeration unit followed by (1) the two aerobic lagoons, (2) the iitermittent sand filter or (3) a spray runoff irrigation system. Annual co:;ts for the extended aeration unit and one aerobic lagoon were about 15% less than the above. To all of these systems an additional $200 per year will be needed to cover chlorine and amortization of the chlorinat'on equipment. Additional cost for maintaining the pH below 9.0 would be incurred in a treatment system utilizing aerobic lagoons. CONCLUSIONS Four processes (extended aeration, aerobic lagoons, spray-runoff irrigation and intermittent sand filtration) were combined into six treatment systems and evaluated at a small meatpacking plant. 24 ------- The extended aeration process in conjunction with (1) an intermittent sand filter, (2) spray runoff irrigation, or (3) one aerobic lagoon and an intermittent sand filter meet the BPT limitations, except for fecal coliforms. None of the six treatment systems meet the limitation for fecal coliforms of 400 mpn/100 ml. Disinfection will be a necessary addition to these systems. Treatment of meatpacking wastewater by extended aeration was demonstrated as an advantageous substitute when anaerobic treatment causes a problem due to hydrogen sulfide or ammonia production. The extended aeration unit, except for maximum day limits on suspended solids and fecal coliforms, meet the BPT limitations. Removal of BOD5, COD, TSS, FOG, NH3~N and TKN ranged from 88 to 98 percent at a F/M of 0.06. The batch operation used in the extended aeration unit was apparently able to nitrify and denitrify the wastewater reducing the mean concen- trations of total nitrogen from 92 to 12 mg/1. Due to the batch operation, both aeration and solid-liquid separation were accomplished in the same basin without sludge return equipment. The two aerobic lagoons reduced the concentrations of ammonia and total nitrogen and dampened high incoming concentrations of suspended solids and ammonia during periods of upset in extended aeration unit. The aerobic lagoons increased the quantities of BODj- and suspended solids, apparently because of algae production. Both aerobic lagoons had pH values greater than 9.0, the National Effluent Limitation. Rainfall increased the discharge volume and was the usual cause for the quantities of BODg and suspended solids discharged exceeding the maximum daily value in the BPT limitations. The disadvantages of the aerobic lagoons outnumbered their advantages in meeting National Discharge Limitations for the meat industry. 25 ------- For small packers aerated systems should include alarms and dual i pieces of equipment or alternate schemes of operation in case of equipment failure to prevent fish kills due to ammonia. The use of captive fish populations in the discharge has merits as a monitoring tool. Intermittent sand filtration following extended aeration offers potential for meeting the 1983 National Discharge Limitations but a 50 percent increase in removal of suspended solids will be necessary. Spray runoff irrigation following extended aeration will meet the 1983 National Discharge Limitations if provisions are made for control of the discharge volume with partial recycle to the irrigation area during intense rainfalls. The quantity of pollutants discharged from a spray irrigation system is also controlled by matching hydraulic loading with seasonal conditions. Spray runoff irrigation in conjunction with extended aeration removed in excess of 80% of the nitrogen and phosphorus in the packing- house wastewater. Alum addition to the influent of the irrigation system was of little benefit in reducing the total phosphate concentration in the effluent. Capitil and annual costs would be nearly the same for the extended aeration unit followed by either two aerobic lagoons, intermittent sand filters, or spray runoff irrigation. For small packers installation cost for these three systems would be $1.40/gpd capacity and treatment cost would be $0.21/lb BOD5 applied. Additional costs would be incurred for disinfection on all systems and for pH control where aerobic lagoons are used. 26 ------- ACKNOWLEDGEMENTS This research project was a cooperative study by W. E. Reeves Packinghouse, East Central Oklahoma State University, Robert S. Kerr Environmental Research Laboratory, and the Industrial Environmental Research Laboratory. The project was supported in part by the U. S. Environmental Protection Agency under Grant No. 120560 GPP and Contract No. 68-03-0361. 0 Special recognition is given to Dr. Mickey L. Rowe, Director, School of Environmental Science, East Central Oklahoma State University; to Jimmie L. Kingery, Mathematical Statistician, Robert S. Kerr Environ- mental Research Laboratory; and to W. E. Reeves, President, W. E. Reeves Packinghouse; without these individuals, the project could not have succeeded. Messers, Michael Cook and Kenneth Jackson, chemistry technicians at the Kerr Laboratory, gave outstanding performance in aiding packinghouse and university personnel in operating, sampling and analytical quality control procedures. Dr. Ralph Ramsey and Mr. James Arnold, University pesonnel, most satisfactorily managed plant operation, sample collection and weekly report preparation. 27 ------- REFERENCES 1. Withei-ow, Jack L. Small Meat-Packers Waste Treatment Systems. Proceedings of the 28th Industrial Waste Conference, Purdue University, Lafayotte, IN. May 1973. 2. Witherow, Jack L., Mickey L. Rowe and Jimmie L. Kingery, Meat Packing Wastewater Treatment by Spray Runoff Irrigation. Proceedings Sixth National Symposium on Food Processing Wastes. EPA-660/2-75- 045, L.S. Government Printing Office. April 1975. 3. Middlebrooks, E. J., and G. R. Marshall. Stabilization Pond Upgracing with Intermittent Sand Filters. Upgrading Wastewater Stabilization Ponds to Meet New Discharge Standards. Utah State University, Logan, Utah, November, 1974. 4. Reynolds, J. H., S. E. Harris, D. Hill, D. S. Filip and E. J. Middlebrooks. Intermittent Sand Filtration to Upgrade Lagoon Effluents - Preliminary Report. Upgrading Wastewater Stabilization Ponds to meet New Discharge Standards. Utah State University, Logan, Utah. November 1974. 5. Walter, C. M., and S. L. Bugbee. Progress Report. Blue Springs Lagoon Study, Blue Springs, Missouri. Upgrading Wastewater Stabili- zation Ponds to Meet New Discharge Standards. Utah State University, Logan, Utah, November 1974. 6. Law, Je.mes R., R. E. Thomas and Leon H. Myers. Nutrient Removal from Cc.nnery Wastes by Spray Irrigation of Grassland. Robert S. Kerr Weter Research Center, Ada, OK. November 1969. 28 ------- 7. Thomas, P. E., K. Jackson and L. Penrod. Feasibility of Overland Flow for Treatment of Raw Domestic Wastewater. EPA-660/2-74-087, U.S. Government Printing Office. December 1974. 8. Adams, Carl E. and W. W. Eckenfelder. Process Design Techniques for Industrial Waste Treatment. Enviro. Press. Austin, Texas. 1974. 9. Paulson, W. L., L. D. Lively and J. L. Witherow. Analysis of Wastewater Treatment Systems for a Meat Processing Plant. Proceedings of the 27th Industrial Waste Conference. Purdue University, Lafayette., Indiana. May, 1972. 29 ------- |