Swine Manure Treatment Systems Research Articles

Exploring bacterial diversity and antimicrobial resistance gene on a southern Brazilian swine farm

The bacterial composition of and the circulation of antimicrobial resistance genes (ARGs) in waste from Brazilian swine farms are still poorly understood. Considering that antimicrobial resistance (AMR) is one of the main threats to human, animal, and environmental health, the need to accurately assess the load of ARGs released into the environment is urgent. Therefore, this study aimed to characterize the microbiota in a swine farm in southern Brazil and the resistome in swine farm wastewater treated in a series of waste stabilization ponds (WSPs). Samples were collected from farm facilities and the surrounding environment, representing all levels of swine manure within the treatment system. Total metagenomic sequencing was performed on samples from WSPs, and 16S-rDNA sequencing was performed on all the collected samples. The results showed increased bacterial diversity in WSPs, characterized by the presence of Caldatribacteriota, Cloacimonadota, Desulfobacterota, Spirochaetota, Synergistota, and Verrucomicrobiota. Furthermore, resistance genes to tetracyclines, lincosamides, macrolides, rifamycin, phenicol, and genes conferring multidrug resistance were detected in WSPs samples. Interestingly, the most abundant ARG was linG, which confers resistance to the lincosamides. Notably, genes conferring macrolide (mphG and mefC) and rifamycin (rpoB_RIF) resistance appeared in greater numbers in the late WSPs. These drugs are among the high-priority antibiotic classes for human health. Moreover, certain mobile genetic elements (MGEs) were identified in the samples, notably tnpA, which was found in high abundance. These elements are of particular concern due to their potential to facilitate the dissemination of ARGs among bacteria. In summary, the results indicate that, in the studied farm, the swine manure treatment system could not eliminate ARGs and MGEs. Our results validate concerns about Brazil's swine production system. The misuse and overuse of antimicrobials during animal production must be avoided to mitigate AMR.

Estimation of material flow and greenhouse gas emissions from different piggery sewage treatment methods at the swine manure treatment system

Estimation of material flow and greenhouse gas emissions from different piggery sewage treatment methods at the swine manure treatment system

Lemna minor Cultivation for Treating Swine Manure and Providing Micronutrients for Animal Feed.

The potential of Lemna minor to valorise agricultural wastewater into a protein-rich feed component to meet the growing demand for animal feed protein and reduce the excess of nutrients in certain European regions was investigated. Three pilot-scale systems were monitored for nine weeks under outdoor conditions in Flanders. The systems were fed with a mixture of the liquid fraction and the biological effluent of a swine manure treatment system diluted with rainwater in order that the weekly N and P addition was equal to the N and P removal by the system. The design tested the accumulation of elements in a continuous recirculation system. Potassium, Cl, S, Ca, and Mg were abundantly available in the swine manure wastewaters and tended to accumulate, being a possible cause of concern for long-operating recirculation systems. The harvested duckweed was characterised for its mineral composition and protein content. In animal husbandry, trace elements are specifically added to animal feed as micronutrients and, thus, feedstuffs biofortified with essential trace elements can provide added value. Duckweed grown on the tested mixture of swine manure waste streams could be considered as a source of Mn, Zn, and Fe for swine feed, while it is not a source of Cu for swine feed. Moreover, it was observed that As, Cd, and Pb content were below the limits of the feed Directive 2002/32/EC in the duckweed grown on the tested medium. Overall, these results demonstrate that duckweed can effectively remove nutrients from agriculture wastewaters in a recirculated system while producing a feed source with a protein content of 35% DM.

Fate and transport of estrogenic compounds in an integrated swine manure treatment systems combining algal-bacterial bioreactor and hydrothermal processes for improved water quality.

An integrated manure treatment system, including a mixed algal-bacterial bioreactor (MABB) and hydrothermal processing of biomass solids, was found to remove 76.4-97.0% of the total estrogenic hormones (estrone (E1), 17β-estradiol (E2), and estriol (E3)) from the liquid portion of animal manure (LPAM). The mixed biomass was converted into either biocrude oil with a yield up to 40% via hydrothermal liquefaction (HTL) or syngas with a yield up to 54% yield via catalytic hydrothermal gasification (CHG). Adding granular activated carbon (GAC) in the MABB enhanced the removal of estrogenic hormones (+ 7.2%), cytotoxicity (+ 58%), and heavy metals (+ 10.5%). After the integrated system with the MABB, HTL, and CHG processes, the overall percent removal of heavy metals from the LPAM ranged from 27.1 to 40.3%. The concentrations of potentially toxic heavy metals (lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), nickel (Ni), chromium (Cr)) in the aqueous phase after HTL and CHG tests ranged from 0.01 to 25.3 mg/L.

Chemical Removal of Phosphorus from Swine Effluent: the Impact of Previous Effluent Treatment Technologies on Process Efficiency

Chemical phosphorus removal with hydrated lime was evaluated on effluents from different biological treatment processes applied to swine manure. The objective of this study was to establish the most suitable process for this kind of wastewater treatment. Effluents a UASB reactor, a nitrification reactor (NR), a modified Lutzak–Ettinger (MLE) reactor and a deammonification (DMX) reactor were evaluated. A comprehensive study was developed at laboratory scale to evaluate the effect of possible interferences, including alkalinity, total organic carbon, and ammonia, on phosphorus precipitation. The highest soluble phosphorus (Psol) removal efficiency and the lowest Ca:P molar ratio were obtained for the NR effluent (92% and 2.0, respectively). The good performance of the NR effluent could be attributed to the low level of ammoniacal nitrogen and alkalinity and to the presence of a relatively high concentration of calcium. Highly promising results were also obtained in field experiments, where a phosphorus removal unit was installed as the last step in a swine manure treatment system, and precipitation was applied to effluent from the NR. In this case, efficiencies of Psol removal higher than 90% were obtained. The produced sludge was rich in phosphorus and could be used as, for example, fertilizer. The results obtained in this work showed the importance of applying an efficient treatment system to swine manure for reduction of ammoniacal nitrogen, alkalinity, and carbon before chemical removal of phosphorus by precipitation with hydrated lime.

High-Rate Solid-Liquid Separation Coupled With Nitrogen and Phosphorus Treatment of Swine Manure: Effect on Water Quality

This study determined the water quality improvements in swine lagoons by an innovative swine manure treatment system operating at full-scale during five pig production cycles. The system performed high-rate solid-liquid separation, biological ammonia treatment and phosphorus treatment. Based on performance results obtained, it was determined that the treatment system met the technical environmental performance criteria for swine waste management systems in new or expanding operations in North Carolina. The system substantially reduced odor by 99.9%; pathogens by 99.99%, nutrients (phosphorus and nitrogen) by > 90%, and heavy metals by 99%. As the treated effluent and/or rainwater renovated the liquid in the anaerobic lagoons, they became aerobic (Eh > 300 millivolts). By the end of the second year, the NH4-N concentration in the lagoons liquid was reduced from the initial 370-485 mg L-1 to lower than 15. After conversion, the sludge accumulation in the former lagoons was halted. This was a significant outcome because one converted lagoon served twice the number of animals than before implementation of the innovative manure treatment system, which is similar to a situation of herd expansion. These findings overall showed that cleaner alternative technologies can have significant positive impacts on water quality in intensive swine production.

Economic feasibility of biogas production in swine farms using time series analysis

ABSTRACT: This study aimed to measure the economic feasibility and the time needed to return capital invested for the installation of a swine manure treatment system, these values originated the sale of carbon credits and/or of compensation of electric energy in swine farms, using the Box-Jenkins forecast models. It was found that the use of biogas is a viable option in a large scale with machines that operate daily for 10h or more, being the return period between 70 to 80 months. Time series analysis models are important to anticipate the series under study behavior, providing the swine breeder/investor means to reduce the financial investment risk as well as helping to decrease the production costs. Moreover, this process can be seen as another source of income and enable the breeder to be self-sufficient in the continuous supply of electric energy, which is very valuable nowadays considering that breeders are now increasingly using various technologies.

생물반응기를 도입한 돈분뇨의 생물학적 처리공정에서 악취발생 특성 및 미생물동정에 관한 연구

A bioreactor filling with pellets and stones was equipped to the swine manure treatment system, which is expected to emit high concentration of odor in the process of the organic wastewater treatment system, and in comparison with the activated sludge process as the control process, the reactor operation state, treatment water quality and odor emission concentration were measured. The reactor using the bioreactor proved to be much more stable in the bubble condition, treatment water transparency, etc, and BOD removal efficiency was also much better. The removal efficiency of T-N and T-P, however, showed little difference in the two reactors. Odor, as a result of examining NH3-N, NH3 concentratio, and complex odor, was 4 times to 24 times less emitted in the system using bioreactor than in the activated sludge system. H2S, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide were not found or were found in only 5 ppbs in each reactor and showed little difference between the two reactors. In the bioreactor process, Bacillus sp./ Pseudomonas sp. species were mainly found and in the activated sludge process, acterium sp. Chryseobacterium sp. species were mainly found.

Utility of specific biomarkers to assess safety of swine manure for biofertilizing purposes

Swine production is an important economic activity in Brazil, and there is interest in the development of clean production mechanisms to support sustainable agro-industrial activities. The biomass derived from swine manure has good potential to be used as a biofertilizer due to its high nutrient concentration. However, the land application of manure should be based on safety parameters such as the presence of pathogens that can potentially infect animals and people. This study was designed to assess the presence of porcine circovirus-2 (PCV2), porcine adenovirus (PAdV), rotavirus-A (RV-A) and Salmonella spp. in liquid manure, as well the infectivity of two genotypes of circovirus-2 (PCV2a and PCV2b) present in liquid manure. Three swine farms were evaluated: 1) a nursery production farm (manure analyzed before and after anaerobic biodigestion), 2) a grow–finish production farm (analyzed before and after anaerobic biodigestion), and 3) a second grow–finish production farm (raw manure–affluent). PCV2, PAdV and RV-A were present before and after anaerobic biodigestion (either affluent or effluent) at all farms. Salmonella spp. were detected at farm 1 (affluent and effluent) and farm 3 (raw manure–affluent) but not farm 2 (affluent and effluent). When the ability of the anaerobic biodigestion process to reduce viral concentration was evaluated, no significant reduction was observed (P>0.05). Both the PCV2a and PCV2b genotypes were detected, suggesting viral co-infection in swine production. The results revealed infectious PCV2 even after anaerobic biodigestion treatment. The presence of Salmonella spp. and enteric viruses, especially infectious PCV2, in the final effluent from the anaerobic biodigester system suggests that the process is inefficient for pathogen inactivation. Due to the prevalence and infectivity of PCV2 and considering the successful use of molecular methods coupled to cell culture for detecting infectious PCV2, we suggest that this virus can be used as a bioindicator in swine manure treatment systems to check the efficiency of pathogen inactivation and ensure the production of safe biofertilizers from swine manure.

Performance of two swine manure treatment systems on chemical composition and on the reduction of pathogens

Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid–liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen – TKN – and NH3), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required.

Culturing and molecular methods to assess the infectivity of porcine circovirus from treated effluent of swine manure

Samples were collected at the effluent of two swine manure treatment systems and were analyzed by qPCR to determine the presence and amounts of porcine circovirus (PCV2) genetic material. ST cells were inoculated with the positive samples to evaluate virus viability and for viral genotyping. Twenty-five water samples were collected monthly from treated effluent (March 2009 to December 2010). The PCV2 genome was identified by qPCR in 60% of the samples, and all of the positive samples were able to infect ST cells in vitro. Positive samples were genotyped and 60% of them were positive for both PCV2a and PCV2b, 20% were positive for genotype 2a, and 20% were positive for genotype 2b. Our results suggest that these viruses were able to resist the regular wastewater treatment, and this finding demonstrates the necessity of adding a virus inactivation step to the treatment system to guarantee the safety of water reuse.

Detection of circoviruses and porcine adenoviruses in water samples collected from swine manure treatment systems

Samples collected from two swine manure treatment systems including: swine manure treatment system and demonstrative unit (SMTS and DU), were analyzed by qPCR to quantify the amount of porcine adenovirus (PAdV) and porcine circovirus (PCV2) present. Positive samples were tested for virus integrity using DNase assay. Fifty-six water samples were collected monthly from March 2009 to May 2010. PAdV genome was found 66% of the samples in the SMTS and in 78% of the samples in the DU system. PCV2 was detected in 96% of samples collected from the SMTS system and in 86% of samples from DU. DNase assay revealed that there were undamaged virus particles of both PAdV and PCV2 in all sampling sites in the SMTS. However, undamaged particles of both viruses were detected in samples from the DU system in the affluent and middle sites, though undamaged PCV2 was absent in the effluent samples.

Advanced swine manure treatment and utilization in Brazil

Animal production has changed from subsistence to an industrial model, lowering production costs but giving rise to higher potential environmental impact. When the effluents are not correctly managed, serious pollution events can occur. In Brazil liquid manure is commonly stored in reception pits or covered lagoons (biodigestors), followed by land application as a biofertilizer. In some regions there is an excess of manure due to low soil support capacities, and in these cases new technologies have to be adopted to export or treat the excess effluent. Manure storage time in pits/covered lagoons and new polymers to separate the solid fraction have been studied in Brazil. Treatment technologies, like swine manure treatment systems (SMTS), have been developed from a technical and economical point of view to optimize the processes and give a technological alternative to pork producers increasing production while reducing environmental impact.

Technologies to address air quality issues impacting animal agriculture

The continued productivity, profitability and sustainability of animal production agriculture in most parts of the world will be dependent upon implementation of effective technologies and management practices to mitigate perceived and documented environmental impacts resulting from confined animal operation emissions. North Carolina State University Animal and Poultry Waste Management Center (APWMC) program efforts to identify such technologies through support of research, development and demonstration projects involve collaborative efforts with approximately 20 other universities (nationally and internationally). Many of these projects are well beyond the laboratory developmental stage and some are yielding encouraging results. Performance data, to date, has shown that swine manure treatment systems including a covered in-ground anaerobic digester, a sequencing batch reactor, and an upflow biological aerated filter system significantly improved odor emission variables.

Swine Wastewater Treatment by a Batch-Mode 4-Stage Process: Loading Rate Control Using Orp

A bench-scale, four-stage process operated in a batch-mode (FBM) was studied for the treatment of swine manure. The objectives of the study were two-fold: first, to evaluate the effectiveness of the FBM process in the treatment of swine manure; and second, to study the potential of using ORP for the control of organic and nitrogen loading. Two SRT periods were assessed with all other operational conditions kept constant. Phase I of the study (FBMa) had a system SRT of about 17 days, including a 3.5 day SRT in the aerobic reactor. Phase II (FBMb) had a 47 day system SRT, with a 22.7 day SRT in the aerobic reactor. The average concentrations of COD, NH4-N and TKN of the swine waste influent used for this research were 5,085, 1,254 and 2,018 mg L−1 in the FBMa operation, and 3,878, 1,142 and 1,896 mg L−1 in the FBMb operation, respectively. Under FBMa operating conditions, removal efficiencies for BOD5, COD, ammonia-N and TKN were 92 %, 83.1%, 85.3% and 82.1%, respectively, while 85 %, 58.3%, 86.0% and 76.5%, respectively, were also obtained under FBMb conditions. A high rate of denitrification was achieved in Phase II, with the nitrate concentrations dropping from 508 mg L−1 in the aerobic reactor to less than 2 mg L−1 in the final effluent. ORP tracking identified a significant correlation between the ammonia-N loading and the ORP value. In particular, the trend of ORP values in the aerobic reactor appeared to be directly related to the ammonia-N concentration after loading. This suggests that ORP may be successfully utilized to control this swine manure treatment system.