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BACKGROUND This study investigated the use of a novel start-up strategy to obtain nitrogen removal via nitrite using real-time aeration control, in a sequencing batch reactor (SBR1), for the treatment of slaughterhouse wastewater. In addition, another SBR (SBR2) was operated with the same objective, but with a start-up from seed sludge. Furthermore, analysis of the nitrous oxide (N2O) production and emission was conducted for different nitritation levels. RESULTS Through the absence of an inoculum in SBR1, the nitrifying population could be regulated from the beginning. Beceause of this, nitrite oxidising bacteria could be prevented. This was proved by the nitritation degree (ND) which was already above 80% from day 28, although it took 59 days to achieve sufficient nitrogen removal efficiency (> 80%). In contrast for SBR2, it took 90-110 days to achieve full nitritation, however the nitrogen removal efficiency was above 90% at all times. The maximum N2O emission resulted to be 0.12% of the nitrogen load. CONCLUSION This study suggested the importance of seeding sludge for the achievement of full nitritation. Moreover, a strong positive relationship between the ND and N2O emission was observed. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Dairy manure is regularly applied to crop fields as a solid or liquid to improve the soil nutrient status. However, pathogens may survive during manure storage and enter the environment during application. In this study, three storage practices were evaluated to understand the survival patterns of Eschericia coli O157:H7 and Listeria spp. in dairy manure using a culture-based approach. To replicate common farm manure storage techniques, solid manure was stacked as piles with periodic turning or as static piles without turning, whereas liquid manure (feces, urine, and water) was stored as a slurry in small tanks to simulate lagoon conditions. The E. coli and Listeria levels in the manure samples were determined for 29 wk. Results showed that there was an initial reduction in bacteria levels in the first month; however, both E. coli and Listeria managed to survive in the solid manure piles for the full study period. In slurry samples, E. coli was not detected after 14 wk, but Listeria survived until the end of the experiment at relatively lower levels than in the solid manure piles. Ambient weather and pile size were identified as the main reasons for bacteria survival during the course of the experiment. The outcome of this study is important in terms of understanding pathogen survival in manure piles and slurries prior to their application to crop fields. [ABSTRACT FROM AUTHOR]

RATIONALE: Bilin tetrapyrroles including stercobilin are unique to mammalian waste; they have been used as markers of source water contamination and may have important diagnostic value in human health conditions. Unfortunately, commercial isotopomers for bilins are not available. Thus, there is a need for isotopomer standards of stercobilin and other bilins for quantification in environmental and clinical diagnostic applications. METHODS: A procedure is described here using H2 18O to label the carboxylic acid groups of bilin tetrapyrroles. Reaction conditions as a function of temperature and reagent volume were found to produce a mixture of isotopomers, as assessed by electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). Stability as a function of storage time and temperature and in conjunction with solid-phase extraction (SPE) was assessed. RESULTS: The highest labeling efficiency was achieved at 70 °C for 8 h, while a stable ratio of the isotopmers could be produced at 60 °Cfor 4 h. The stability of the isotopic distribution was maintained under storage (room temperature or frozen) for 20 days. It was also stable throughout SPE. The high mass accuracy and resolving power of FTICRMS enables clear distinction between 18O-labeled bilins from other unlabeled bilins present, avoiding a potential interference in quantitation. CONCLUSIONS: A procedure was developed to label bilins with 18O. The final ratio of the 18O-labeled bilin isotopomers was reproducible and highly stable for at least 20 days under storage. This ratio was not changed in any statistically significant way even after SPE. Thus a reliable method for producing stable isotopomer ratios for bilins has been achieved. [ABSTRACT FROM AUTHOR]

Livestock manure management accounts for almost 10% of greenhouse gas emissions from agriculture globally, and contributes an equal proportion to the US methane emission inventory. Current emissions inventories use emissions factors determined from small-scale laboratory experiments that have not been compared to field-scale measurements. We compiled published data on field-scale measurements of greenhouse gas emissions from working and research dairies and compared these to rates predicted by the IPCC Tier 2 modeling approach. Anaerobic lagoons were the largest source of methane (368 ± 193 kg CH4 hd−1 yr−1), more than three times that from enteric fermentation (~120 kg CH4 hd−1 yr−1). Corrals and solid manure piles were large sources of nitrous oxide (1.5 ± 0.8 and 1.1 ± 0.7 kg N2O hd−1 yr−1, respectively). Nitrous oxide emissions from anaerobic lagoons (0.9 ± 0.5 kg N2O hd−1 yr−1) and barns (10 ± 6 kg N2O hd−1 yr−1) were unexpectedly large. Modeled methane emissions underestimated field measurement means for most manure management practices. Modeled nitrous oxide emissions underestimated field measurement means for anaerobic lagoons and manure piles, but overestimated emissions from slurry storage. Revised emissions factors nearly doubled slurry CH4 emissions for Europe and increased N2O emissions from solid piles and lagoons in the United States by an order of magnitude. Our results suggest that current greenhouse gas emission factors generally underestimate emissions from dairy manure and highlight liquid manure systems as promising target areas for greenhouse gas mitigation. [ABSTRACT FROM AUTHOR]

Manure composting has become commonplace in the beef cattle (Bos taurus L.) feedlot industry in Alberta. However, the nitrogen (N) and phosphorus (P) characteristics of runoff from windrows subjected to heavy rainfall at different compost maturities are unknown. On Days 18, 26,40, 54, 81, 109, and 224 of composting, a rainfall simulator generated runoff, which was collected in timed 5-L increments, creating the variable "time during runoff event" (TDRE). The volumetric runoff coefficient of windrows increased from 24% of incident rainfall on Day 0 to 69% by Day 90. Ammonium-nitrogen showed a significant maturity X TDRE interaction on Day 18, increasing from 46 mg L-1 for the 0- to 5-L increment to 172 mg L-1 for the 25- to 30-L increment, as did total dissolved phosphorus (TDP), increasing from 36 to 61 mg L-1. Nitrate-nitrogen had a runoff export coefficient of 19.5 mg m² min-1 on Day 224, which was significantly higher than 1.8 to 6.3 mg m² min-1 on Days 18 to 54. Across the 224-d composting period, compost NO3-N concentration explained 87% of runoff NO3-N, whereas compost water-soluble P explained 68% of runoff TDP. The occurrence and duration of rainfall events relative to the compost maturity spectrum has implications for the magnitude of N and P mobility and overall nutrient losses. [ABSTRACT FROM AUTHOR]

The article discusses research investigating the potential use of an experimentally designed, pilot anaerobic membrane bioreactor (AnMBR) to treat agricultural wastes. The AnMBR system, which was modeled after a complete mix anaerobic digester (CMAD), achieved high removals of both biological and chemical agents. The microorganisms which were effectively removed included Escherichia coli (E. coli), enterococci, and coliphages. A comparative analysis of the removal efficiencies of AnMBR and CMAD was performed. The team used a nested polymerase chain reaction (PCR) method to monitor bovine adenoviruses and bovine polymaviruses (BPyV). Statistics related to the removal of phosphate, nitrogen (N), and chemical oxygen demand (COD) are also presented.

The article discusses how land application of animal waste may result in the environmental entry of antibiotics and antibiotic resistance of gastrointestinal bacteria. While antibiotics are used in animal livestock production for treating diseases, promoting growth, and improving feed efficiency, approximately 75% of the agents are excreted in livestock waste. Researchers have begun examining the fate and transport of drug residues and break-down metabolites due to concerns about bacterial resistance gene selection and the dissemination of resistance genes. Genetic elements can survive regardless of cell viability, and phylogenetic studies show that resistance genes may have evolved.

The article presents the experiments conducted to elucidate the transport behavior of cysts of Giardia and manure suspensions through several aquifer sands. Simulations of the transport of the Giardia and manure particles using a simple and flexible power law model for the solid-water mass exchange term provided a satisfactory description of the effluent and spatial distribution data. The cumulative size distribution (CSD) of manure particles in the suspension initially and after passage through the packed columns was used to identify the mechanisms that were controlling the deposition of manure particles and Giardia.

This article develops a spatial model of regional livestock production and three attendant environmental effects: spills from animal waste stores; nutrient runoff due to the application of manure to croplands; and direct ambient pollution, including odors, pests, and gases. Assuming that neither environmental outcomes nor operators' manure-spreading practices can be monitored and regulated, constrained efficient production arrangements and waste-handling practices are described. The efficiency effects of several regulatory policies are then explored, including (a) scale regulations that limit animal inventories, (b) chemical fertilizer taxes, and (c) waste storage and handling standards that affect storm protections and manure transport. [ABSTRACT FROM AUTHOR]