A. Kunz

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.

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 NH(3)), 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.

Chemical phosphorus removal: a clean strategy for piggery wastewater management in Brazil

The intensive production of animal protein is known to be an environmental polluting activity, especially if the wastewater produced is not managed properly. Swine production in Brazil is growing, and technologies to manage all pollutants present in the wastewater effluent are needed. This work presents a case of study of phosphorus (P) removal from piggery wastewater using Ca(OH)2, and demonstrates the feasibility of this strategy for P management. The effluent of a swine manure treatment plant was treated with Ca(OH)2. According to the addition of Ca(OH)2 the pH of the effluent ranged from 8.0 to 10.0. Different conditions of sludge dewatering were evaluated, and the chemical composition of sludge was investigated. Ion chromatography analysis of effluent samples showed that 92% of total P (TP) was present as soluble P (SP) whereas 75% of SP species were present as phosphate. The efficiency of P removal was typically 90% at pH 8.5 and higher than 98% at pH 10.5. The sludge was separated by sedimentation, centrifugation or filtration and dried. The TP content of dried sludge was 9.3% (w/w). X-ray diffraction analysis of the dry sludge showed the presence of amorphous compounds of Ca and P, which is an indication that the sludge obtained from the swine manure treatment has a potential for application as biofertilizer.

Effect of storage time on swine manure solid separation efficiency by screening

Confined animal feeding operations (CAFOs) have suffered considerable transformations since the last decade in Brazil, because of increasing of their production scale. Swine production is following this same trend, and the volume of manure produced and the form that is managed has a direct impact on houses air quality and efficiency of treatment systems. The objective of this work was to study the manure solid-liquid separation efficiency by screening, subject to different screen opening sizes and pit disposal time under tropical climate conditions. An ammoniacal nitrogen producing rate of 24 mg/L per storage day was observed and a decrease in screen separation efficiency in the first eight days of storage, obtained by solid group analysis. The storage time influenced directly the degradation of organic fraction indicated by the chemical oxygen demand increase overtime. The results suggest that the efficiency of solid-liquid separation is increased when carried out with the shortest storage time.

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.

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.

Bacterial biodiversity from an anaerobic up flow bioreactor with ANAMMOX activity inoculated with swine sludge

The present study aimed to describe the bacterial community present at an anaerobic up flow bioreactor with ANAMMOX activity, inoculated with the sludge from the anaerobic pond of a swine slurry treatment system. The description was based on the molecular DNA techniques using primers for amplification of complete 16S rRNA gene and also new primers to amplify smaller fragments from 16S rRNA. During the bioreactor operation time, the bacterial community changed significantly, increasing the nitrogen removal efficiency, reaching after 500 days a removal rate of 94%. The complete PCR amplification of 16S rRNA gene generated 17 clones, where three presented similarity with Candidatus Jettenia asiatica (97%), twelve with Janthinobacterium (99%) and two with uncultured clones. The PCR amplification of 436 base pairs had generated 12 clones, of which eight presented 96-100% similarity with Candidatus Anammoxoglobus propionicus, Planctomycete KSU-1 and one with Pseudomonas sp. (99%) and three with uncultured clones.

Surveillance of human and swine adenovirus, human norovirus and swine circovirus in water samples in Santa Catarina, Brazil

Animal and human wastewater can potentially contaminate water sources and the treatment of drinking water may not effectively remove all contaminants, especially viruses. The purpose of the present study was to evaluate the viral contamination of water used for human and animal consumption in the city of Concórdia, located in southern Brazil. Porcine circovirus type 2 (PCV2), porcine adenovirus (PAdV), human adenovirus (HAdV) and human norovirus (NoV) were searched for using quantitative polymerase chain reaction (qPCR). HAdV-positive samples were tested for viral infectivity by plaque assay. The qPCR results showed that PAdV, PCV2 and HAdV genetic material were present in all sampling sites. NoV was absent in all samples. The presence of genetic material from PAdV and PCV2 was detected in 30% and 45% of the 36 analyzed samples, respectively, with an average of 10(2) gc mL(-1) for PAdV and 10(4) gc mL(-1) for PCV2. HAdV was present in 100% of the samples, with an average of 10(4) gc mL(-1). However, in plaque assay, only 36% of the samples were positive. As viable particles of HAdV were found in drinking water, these results confirm that swine manure and human sewage impact surface water and groundwater, endangering water quality and indicating a potential risk to public health.

Enrichment and acclimation of an anaerobic mesophilic microorganism's inoculum for standardization of BMP assays.

Appropriate enrichment of anaerobic microorganisms consortium is crucial for accurate biochemical methane potential (BMP) assays. An alternative method to produce and maintain a mesophilic methanogenic inoculum was demonstrated. Three sources of inoculum were mixed and acclimated for 857days in order to reach steady conditions (pH=7.90±0.46; VS/TS>50%; VFA/alkalinity=0.16±0.04gAcetic Acid/ [Formula: see text] ). Biogas yield >80% was obtained after 70days of inoculum acclimation in comparison to standard cellulose (>600mLN/gVS). Methanogen community analysis based on 16S rDNA of the inoculum revealed Archaea concentration of 3×10(12) gene copies/g (Methanobacteriales 8×10(10); Methanomicrobiales 8×10(10); and Methanosarcinales 4×10(11) gene copies/g). The proposed method for development and maintenance of microorganism enrichment inoculum demonstrates consistent BMP data which is a requirement for dependable prediction of biogas production at field scale operations.

Kinetic models for nitrogen inhibition in ANAMMOX and nitrification process on deammonification system at room temperature

In this study were fitted the best kinetic model for nitrogen removal inhibition by ammonium and/or nitrite in three different nitrogen removal systems operated at 25 °C: a nitrifying system (NF) containing only ammonia oxidizing bacteria (AOB), an ANAMMOX system (AMX) containing only ANAMMOX bacteria, and a deammonification system (DMX) containing both AOB and ANAMMOX bacteria. NF system showed inhibition by ammonium and was best described by Andrews model. The AMX system showed a strong inhibition by nitrite and Edwards model presented a best system representation. For DMX system, the increased substrate concentration (until 1060 mg NH3-N/L) tested was not limiting for the ammonia consumption rate and the Monod model was the best model to describe this process. The AOB and ANAMMOX sludges combined in the DMX system displayed a better activity, substrate affinity and excellent substrate tolerance than in nitrifying and ANAMMOX process.