Swine Waste Treatment Research Articles

An on-farm swine waste management system in Hawaii

A prototype of a swine waste treatment system for a 20–25 sows operation was investigated for its potential of odor control, byproduct utilization and treated wastewater reuse. The high solid portion of the swine waste ranging from 4% to 8% TS was treated and stabilized by the anaerobic process with an HRT (hydraulic retention time) of 32 days. The diluted liquid portion from raw and anaerobically digested swine wastewater was effectively treated by the aeration and sedimentation units with the HRT of 3 and 4 days, respectively. The overall removal efficiency of 89–95·4% for TCOD, 82·3–88·5% for TKN and 81·2% for T-P was achieved. The treated effluent was reused for irrigation of pasture without any negative impact of odor problems. Also, it meets the requirements of the wastewater reuse criteria, R-3, issued by the State of Hawaii, Department of Health. The economic analysis was conducted by calculating the NPW (net present worth). It was found that the capital cost is the major cost for the proposed treatment system. The reuse of biogas as energy and sludge as fertilizer are the key factors as to whether or not it will turn the treatment system into a profit. More than 830 pigs (or approximately 80 sows) are required to achieve the break-even point for the application of the swine waste treatment system. Thus, a profit could be made with the application of this treatment system to more than 830 pigs if the comprehensive utilization of methane gas and stabilized sludge could be realized.

Assessment of Biologically Converted Swine Waste as a Fertilizer Source in Container Production

Swine waste (SW), the by-product of North Carolina's booming hog industry, is one of the state's most underutilized resources. Currently, SW is used to grow coastal bermuda hay, a “disposal” crop with little to no economic value. Use of SW by commercial growers as fertilizer would reduce the need to dispose of SW and could reduce the overall input of nutrients into the environment. Our objectives were to determine: plant growth characteristics of SW, the effects of SW on leachable forms of nitrogen, and the physical effects of SW in a pine bark media. To avoid pathogens, we used SW (BionSoil™) that had been biologically digested as part of a proprietary SW treatment process (Bion Technologies, Inc.). Liners of `Rose Madness' petunia, `Skogholm' cotoneaster, `Girard's Red' azalea, and `Wilson's Yellow' daylily were planted in 3.8-L plastic pots that contained one of the following (by volume): 10% SW:90% pine bark, 20% SW:80% pine bark, 30% SW:70% pine bark, or pine bark (control) amended with 3.6 kg of 23-4-8 controlled release fertilizer (CLF), 3.6 kg dolomitic limestone, and 330 g micronutrient fertilizer per m3. Shoot dry weights were determined for all species at harvest. Root dry weights were obtained for cotoneaster and daylily. Leachate nitrogen and pH was determined periodically throughout the 22-week study. By the 14th week, nitrogen and potassium deficiencies were identified on plants growing in SW-amended media. Those treatments were subsequently topdressed with a corrective application of 9 g of 23N–4P–8K CRF. Generally, SW can produce plants similar to short-term CRF without the need for supplemental micronutrients or lime Root biomass was greater in SW media than in the control. A mid-season application of a N–P–K fertilizer may be necessary.

Biological treatment of swine waste using anaerobic baffled reactors

Four laboratory-scale anaerobic baffled reactors (with two, three, four, and five chambers, respectively) were used to successfully treat whole swine waste. The baffled reactors did an excellent job of trapping the small diameter, methane-containing particles of proteins, cellulose, hemicellulose, and lipids. Solids retention times of 25, 30, 36, and 42 days were achieved with a corresponding hydraulic retention time of 14 days for two-, three-, four- and five-chamber anaerobic baffled reactors, respectively. COD reductions ranged from 70 to 78% among all the reactors studied. Maximum methane production was observed in the reactors with four and five chambers with a value of 0.59 and 0.62 l/g of volatile solids added at a loading of 4 g VS/l/day, respectively.

A prototype small swine waste treatment system for land limited and tropical application

A prototype of a 300-pig waste treatment system was constructed at the animal research farm of the University of Hawaii. The system includes a solid/liquid separation (12 m3), two anaerobic reactors (10 m3 each), one aeration unit (20 m3) and one combined rock bed filter with the aquatic plant reactor (20 m3). Based on the current results of a 240-pig operation, the methane gas production and TS reduction are 0.75 m3/m3/day and 72.7%, respectively, at the loading rate of 3.09 kg TS/m3/day. The aeration unit provides a TCOD and NH3-N reduction of 94% and 91%, respectively. The rock filter achieves a TCOD, NH3-N and NO3-N reduction of 32.8%, 26.8% and 68.4%, respectively. The annual cost for each of the treatment component is presented. It is very useful for the application of each treatment unit for the various needs of each pig farm.

A prototype small swine waste treatment system for land limited and tropical application

A prototype of a 300-pig waste treatment system was constructed at the animal research fart of the University of Hawaii. The system includes a solid/liquid separation (12 m3), two anaerobic reactors (10 m3 each), one aeration unit (20 m3) and one combined rock bed filter with the aquatic plant reactor (20 m3). Based on the current results of a 240-pig operation, the methane gas production and TS reduction are 0.75 m3/m3/day and 72.7%, respectively, at the loading rate of 3.09 kg TS/m3/day. The aeration unit provides a TCOD and NH3-N reduction of 94% and 91%, respectively. The rock filter achieves a TCOD, NH3-N and N03-N reduction of 32.8%, 26.8% and 68.4%, respectively. The annual cost for each of the treatment component is presented. It is very useful for the application of each treatment unit for the various needs of each pig farm.

Treatment of swine wastes by a high-rate-modified-anaerobic-process (HRAMP)

In order to solve an actual problem existing in Cuba in swine waste treatment plants, a system called ‘high-rate-modified-anaerobic-process’ (HRAMP) was developed. It consisted mainly of the incorporation of a liquid anaerobic reactor (LAR) into the existing plants to treat the supernatant liquid coming from the sedimentation unit. In this work, the main results were obtained over a 3-year period. A laboratory-scale comparison with conventional processes was made which showed that HRAMP was 16–50% more efficient than conventional plants. This better operation was due to the inoculum, that would be added daily to LAR from the anaerobic sludge-digester that already exists in piggery waste treatment plants.

Free and immobilized cultures of Spirulina maxima for swine waste treatment

We have analyzed the behavior of spirulina maxima at increasing concentration of ammonium nitrogen present in swine waste when it is either growing in suspension or immobilized in polymeric supports. We compared the response of spirulina maxima growth to different concentrations of aeration stabilized swine waste (total phosphorus, ammonium nitrogen) as a way to determine the treatment efficiency of both systems. At a dilution of 50 % of swine waste, the suspended system reached the best results for biomass concentration and nutrient removal. In the immobilized system, at dilutions of 25 and 50 % of swine waste, more than 90 % ammonium nitrogen removal was obtained, and the optimal cell concentration for immobilization was 2 g/l (wet basis).

Microbiological aspects of aerobic thermophilic treatment of swine waste

A thermophilic strain (D2) identified as a Bacillus sp. was isolated from an aerobic digestor of swine waste after several months of operation at 55 degrees C. Aerobic thermophilic batch treatment of swine waste inoculated with strain D2 was studied in a 4-liter fixed-bed reactor. Stabilization of the waste was achieved in less than 30 h when the original chemical oxygen demand (COD) was between 15 and 20 g/liter or in less than 48 h when the COD was around 35 g/liter. When the COD was higher than 30 g/liter, the pH of the waste reached 9.2 to 9.5 during the treatment, and periodic adjustment of the pH to 8.5 was necessary to maintain the activity of the biofilm. In this reactor, ammoniacal nitrogen was completely eliminated by desorption in less than 72 h of incubation. The different packing materials used resulted in similar rates of degradation of organic matter. The thermophilic treatment was also efficient in the 75-liter digestor, and stabilization was achieved in approximately 50 h. A bank of 22 thermophilic bacterial strains originating from different environments and adapted to the thermophilic treatment of swine waste was established. This thermophilic treatment allows, in one step, rapid stabilization of the waste, elimination of the bad smell, and complete elimination of ammonia nitrogen by stripping.

Studies on the Treatment of Animal Excreta. II. Mechanism of High-Concentration Swine Waste Treatment by Aerobic Digestion

To investigate purification mechanism of the aerobic treatment of high-concentration swine waste, behavior of several components in swine waste on aeration was examined by the batch process and following results were obtained. (1) When COD value is conspicuously reduced, total solid, ignition loss, protein, and saccharides are markedly removed from the waste. (2) Lower fatty acids are removed completely by 24-hr aeration. This removal caused early high reduction of BOD. (3) Hexosamine, one of the components of protein-polysaccharide complex, was removed slowly four days. (4) As the purification progressed, substances not precipitated by standing but precipitated by centrifugation at 10000 rpm for 15 min were removed. (5) Substances responsible for COD remaining in the supernatant of the treated waste might be soluble components mainly composed of saccharides, pigments, and NO-2

Enhanced treatment of livestock wastewater: III. Enhanced aerobic treatment of swine waste by anaerobic pre-conditioning

A slurry of screened hog waste, diluted fivefold (1 : 5), was pre-treated anaerobically for periods of several days prior to the beginning of aerobic treatment. The rates of COD and TS reduction in the aerobic stage were enhanced by the anaerobic pretreatment. Thus, in systems designed for remote oxidative treatment, possible savings in aeration power requirements can be realized.

Studies on the Treatment of Animal Excreta. I. Treatment of High-Concentration Swine Waste by Aerobic Digestion

Fresh excreta of a swine (40-60 kg in body weight, which was bred with arranged feed) was analysed for physical and chemical nature. Analytical data were as follows : in the fresh feces, BOD value, 61800 ppm ; COD value, 63200 ppm ; albumin-N, 6320 ppm ; kjeldahl-N, 11400 ppm. In the freshurine, BOD value, 4790 ppm ; COD value, 3640 ppm ; albuminoid-N, 775 ppm ; Kjeldahl-N, 4510 ppm. By the activated sludge treatment of high-concentration swine waste, stable treated effluent was obtained after 3 days. Aeration of high-concentration swine waste gave activated sludge after 6 days, and it had good purification ability. The more activated sludge was added, the quicker the waste was purified. By aeration, BOD substances were almost removed, but about 30-40% of COD remained in the supernatant. When BOD load was 5 kg/m3·d, the treatment results were not good. With low aeration (325 m3 air/m3·d), effluent water was not good, while with high aeration (650 m3 air/m3·d), SV value was not good. When BOD load was 2.5 kg/m3·d and aeration volume was 650 m3 air/m3·d, the treatment result was good. The quality of effluent water showed the following mean value : BOD value, 66 ppm ; SS value, 12 ppm. Their removal rate was both over 99%. Air temperature of injecter was higher than that around the plants, and this might be one cause for the rise of liquor temperature.

豚ふん尿の生物処理 (活性汚泥法) において生ずる余剰汚泥に関する研究

豚ふん尿の生物処理 (活性汚泥法) において生ずる余剰汚泥に関する研究