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Abstract Livestock farms are a propagating source of antibiotic resistance genes (ARGs) via the discharge of animal waste carrying resistant bacteria. Groundwater is widely used in traditional livestock farming. However, there is little available information on ARGs in pumped well water. To investigate the dissemination of ARGs in well water and to assess the impact of rainfall on ARGs, the abundance and diversity of ARGs on a long-term co-livestock feedlot farm where both pig and fish farming is conducted were analysed during the dry and wet seasons in this study, and twenty ARGs were detected. The total concentrations of the target ARGs (∑ARGs) in piggery wastewater and fishponds were approximately 109 copies/mL and 106 copies/mL, respectively. The wastewater treatment plant at this farm failed to avoid ARG contamination, and the biogas digester and lagoon treatment showed low abilities to eliminate ∑ARGs. The open operation mode of the lagoon and fishpond facilitated the dissemination of ARGs, which was assisted by the nearby stream, especially in the wet season. Additionally, the tetracycline resistance gene tet B showed the highest levels among the target ARGs in well water, which were higher in the wet season than the dry season. Affected by rainfall, the concentrations of ARGs in the samples rose, and the correlation between surface water and groundwater increased. These results suggested that both the surface water and the well water in the livestock farming area harboured serious ARGs contamination, which could pose ecological risks and cause food safety problems. Graphical abstract Image 1 Highlights • Wastewater treatment facilities on the farm were not effective in elimination of ARGs. • Rainfall drove the spread of ARGs to groundwater with the assistance of a stream. • Tet B was suggested to be an ARGs pollution indicator in groundwater of a poultry farm. • High levels of ARGs in well water pose a threat to ecological and human health safety. [ABSTRACT FROM AUTHOR]

Highlights • Urea (UR), buffalo manure (BRM) and liquid digestate (BLD) were applied on bare soil. • Open field trials were carried out during summer season under Mediterranean climate. • Two measuring methods were tested: Integrated Horizontal Flux and Wind Tunnels. • WT measurements differ from IHF results by 32% (UR), 43% (BRM) and 46% (BLD). • Prolonging sampling time exposure increases correlation between WT and IHF methods. Abstract Agriculture is still the main source of NH 3 emissions. Consequently, ammonia reduction and monitoring are included in the strict EU targets. Unfortunately, the main issue with the quantification of NH 3 emissions is that some uncertainties are still related to NH 3 volatilization measurements, mainly because of the absence of a standard measurement technique. This study compares two different methods for measuring NH 3 fluxes: the Integrated Horizontal Flux (IHF) method used with glass tubes and the wind tunnels (WT) with acid traps, in order to provide further insights into quantification of NH 3 emissions. Specifically, three field trials were carried out, using different fertilizers on bare soil: urea, raw manure and liquid separated digestate from Mediterranean buffalo cows (Bubalus bubalis L.). Results show that the same diurnal flux variations for both methods was observed, except for those in urea trials, mainly because of the dynamics of urea volatilization. Generally, WT underestimated ammonia emissions, especially during the first six hours of experimentation, since the fixed air speed inside the tunnel is lower than the outside wind speed at the same height. Cumulative ammonia volatilization measured with WT differs from those measured with IHF by 32% (urea), 43% (raw manure) and 46% (liquid separated digestate), respectively. Moreover, WT estimations seemed to be affected by a short exposition time of the acid traps, demonstrating a poor correlation of IHF and WT method within 2–3 h. Indeed, linear correlation between two methods was improved to R2 = 0.92, by increasing the minimum samplers exposition time up to 3 h. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3 ) emission from animal manure contributes to air pollution and ecosystem degradation, and the loss of reactive nitrogen (N) from agricultural systems. Estimates of NH 3 emission are necessary for national inventories and nutrient management, and NH 3 emission from field-applied manure has been measured in many studies over the past few decades. In this work, we facilitate the use of these data by collecting and organizing them in the ALFAM2 database. In this paper we describe the development of the database and summarise its contents, quantify effects of application methods and other variables on emission using a data subset, and discuss challenges for data analysis and model development. The database contains measurements of emission, manure and soil properties, weather, application technique, and other variables for 1895 plots from 22 research institutes in 12 countries. Data on five manure types (cattle, pig, mink, poultry, mixed, as well as sludge and “other”) applied to three types of crops (grass, small grains, maize, as well as stubble and bare soil) are included. Application methods represented in the database include broadcast, trailing hose, trailing shoe (narrow band application), and open slot injection. Cattle manure application to grassland was the most common combination, and analysis of this subset (with dry matter (DM) limited to <15%) was carried out using mixed- and fixed-effects models in order to quantify effects of management and environment on ammonia emission, and to highlight challenges for use of the database. Measured emission in this subset ranged from <1% to 130% of applied ammonia after 48 h. Results showed clear, albeit variable, reductions in NH 3 emission due to trailing hose, trailing shoe, and open slot injection of slurry compared to broadcast application. There was evidence of positive effects of air temperature and wind speed on NH 3 emission, and limited evidence of effects of slurry DM. However, random-effects coefficients for differences among research institutes were among the largest model coefficients, and showed a deviation from the mean response by more than 100% in some cases. The source of these institute differences could not be determined with certainty, but there is some evidence that they are related to differences in soils, or differences in application or measurement methods. The ALFAM2 database should be useful for development and evaluation of both emission factors and emission models, but users need to recognize the limitations caused by confounding variables, imbalance in the dataset, and dependence among observations from the same institute. Variation among measurements and in reported variables highlights the importance of international agreement on how NH 3 emission should be measured, along with necessary types of supporting data and standard protocols for their measurement. Both are needed in order to produce more accurate and useful ammonia emission measurements. Expansion of the ALFAM2 database will continue, and readers are invited to contact the corresponding author for information on data submission. The latest version of the database is available at http://www.alfam.dk . [ABSTRACT FROM AUTHOR]

Introduction: Household drinking water can be contaminated by diarrheagenic enteropathogens at numerous points between the source and actual consumption. Interventions to prevent this contamination have focused on preventing exposure to human waste through interventions to improve drinking water, sanitation and hygiene (WASH). In many cases though, the infectious agent may be of zoonotic rather than human origin suggesting that unsafely managed animal waste may contribute to the contamination of household drinking water and the associated diarrheal disease burden. Methods: A cross-sectional household survey of 800 households was conducted across three informal peri-urban neighborhoods of Kisumu, Kenya, collecting stored drinking water samples, administering a household survey including water, sanitation and hygiene infrastructure and behaviors, and recording domestic animal presence and ownership. We used multivariate logistic regression to assess the association of traditional WASH factors and domestic animal presence and ownership on microbial contamination of household drinking water. Results: The majority of households sampled had fecally contaminated drinking water (67%), defined by the presence of any colony forming units of the fecal indicator bacteria enterococci. After adjustment for potential confounders, including socio-economic status and water and sanitation access, both household animal ownership (aOR 1.31; CI 1.00–1.73, p = 0.05) and the presence of animal waste in the household compound (aOR 1.38; CI 1.01, 1.89, p = 0.04) were found to be significantly associated with household drinking water contamination. None of the conventional WASH variables were found to be significantly associated with household drinking water contamination in the study population. Conclusions: Water, sanitation, and hygiene strategies to reduce diarrheal disease should consider the promotion of safe animal contact alongside more traditional interventions focusing on the management of human waste. Future research on fecal contamination of unsafe household drinking water should utilize host-specific markers to determine whether the source is human or animal to prepare targeted public health messages. [ABSTRACT FROM AUTHOR]

In this study, biochar, a carbonaceous solid material produced from three different waste sources (poultry litter, rice husk and pulp and paper mill sludge) was utilized to replace cement content up to 1% of total volume and the effect of individual biochar mixed with cement on the mechanical properties of concrete was investigated through different characterization techniques. A total of 168 samples were prepared for mechanical testing of biochar added concrete composites. The results showed that pulp and paper mill sludge biochar at 0.1% replacement of total volume resulted in compressive strength close to the control specimen than the rest of the biochar added composites. However, rice husk biochar at 0.1% slightly improved the splitting tensile strength with pulp and papermill sludge biochar produced comparable values. Biochar significantly improved the flexural strength of concrete in which poultry litter and rice husk biochar at 0.1% produced optimum results with 20% increment than control specimens. Based on the findings, we conclude that biochar has the potential to improve the concrete properties while replacing the cement in minor fractions in conventional concrete applications. [ABSTRACT FROM AUTHOR]

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]

This narrative review paper begins with a brief history of biogas digesters in South Africa followed by a listing of the biogas digesters that have been installed in the country then the critical analyses of the different types of small scale biogas digesters since the introduction of the biogas technology into the country in the year 1957. The analysis is done on a basis of conducted studies and observations of the strengths and limitations of each small scale digester design installed. It is the aim of the review to help stakeholders in the selection of the most appropriate digester type well suited to their environmental conditions and to fill the knowledge gap existing in the biogas technology and hence making it easier to map of a way forward into the design of improved anaerobic digesters. In this review, the in-situ cast concrete digester has been analyzed to be the most suitable design for installation in the South African context though stakeholders can still do their own selection based on the analyses of the other designs. Some recommendations of aspects to consider in the introduction of a new design are also given. [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]

This study aims to investigate the effects of the organic loading rate (OLR) and the aeration rate on denitrifying phosphate removal (DPR) from slaughterhouse wastewater treated at a temperature of 11 °C. Three laboratory-scale intermittently aerated sequencing batch reactors (IASBRs) were set up and three OLRs and five aeration rates were employed in the study. The results indicated that efficient removals of nitrogen (N) and phosphorus (P) from DPR were achieved. Furthermore, the intermittent aeration pattern benefitted both the phosphorus-accumulating organisms (PAOs) and the denitrifying phosphorus-accumulating organisms (DPAOs) that accumulated at 11 °C. The ratio of P uptake in the aeration periods/P release in the non-aeration periods was in the range of 0.94-1.10 in the three stages. The relationship between the specific poly-β-hydroxybutyrate (PHB) degradation rate (z), the specific P removal rate (x), and the specific total oxidized nitrogen (TON) reduction rate (y) can be fitted approximately as a plane (z = 1.3626x+0.2882y-0.6722, R² = 0.83). [ABSTRACT FROM AUTHOR]

Herein, pyrolysis of chicken manure is investigated to establish a sustainable platform for the disposal of chicken manure while efficiently recovering energy as a form of syngas. To this end, this study lays great emphasis on the exploitation of CO 2 in pyrolysis of chicken manure. As an initial assay for the role CO 2 in the pyrolysis process, thermal degradation of chicken manure in N 2 and CO 2 is characterized thermo-gravimetrically. Except the temperature regime (≥720 °C) governed by the Boudouard reaction, the TGA results with chicken manure do not reveal any differences associated with physical aspects such as onset and end temperatures. For in-depth study, pyrogenic products generated from pyrolysis of chicken manure in N 2 and CO 2 are characterized. Particularly, an enhanced generation of CO is substantial at temperatures higher than 500 °C. This enhanced generation of CO is likely due to an enhanced thermal cracking behavior of volatile organic carbons (VOCs) evolved from pyrolysis of chicken manure. The enhancement of CO generation is catalytically expedited by biogenic salt such as calcite (CaCO 3 ) in chicken manure. The introduced approach for utilizing CO 2 in pyrolysis could be a sustainable option to treat biowaste such as chicken manure along with developing an effective waste-to-energy strategy. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of pig slurry (PS) and chemical fertilizer (NPK 02–20–20) applications on soil water infiltration; sediment, water and nutrient losses by runoff; and soybean yield during a soybean ( Glycine max L.) cropping cycle. A field study was carried out in Rio Verde, Goiás, Brazil on a Cerrado Oxisol managed with no tillage. The experiment was arranged as a randomized block design with three replications and treatments. The treatments consisted of two doses of PS, 25 and 100 m 3 ha − 1 , and chemical fertilization at 370 kg ha − 1 (NPK 02–20–20) applied to the soil surface in a single application. After the occurrence of rainfall events, the volume of percolated water in lysimeters and the sediment and water losses in plots was measured. To determine the macro and- (Ca, Mg, K, P) micronutrients (Fe, Mn, Cu, Zn), runoff water was collected. We also assessed the dry biomass and productivity of soybean production at the end of the experiment. Treatment with 25 m 3 ha − 1 of PS resulted in higher amounts of (106 mm) percolated water in the soil ( p > 0.05). Neither losses of water, sediment and nutrients or biomass production and soybean productivity were significantly affected by the PS treatments compared with chemical (NPK) fertilization ( p > 0.05). A trend of higher sediment and water losses was observed in the 25 m 3 ha − 1 PS treatment (249.86 kg ha − 1 and 20.58 mm, respectively) compared with the 100 m 3 ha − 1 PS and chemical (NPK) treatments; the 25 m 3 ha − 1 PS treatment showed ~ 10% and ~ 43% higher values of sediment losses, respectively, and ~ 43% and ~ 23% higher values of water losses, respectively. Regarding soybean productivity, the 25 m 3 ha − 1 PS treatment showed a tendency of low productivity (3405 kg ha − 1 ) that was ~ 15% and ~ 20% lower than that of the 100 m 3 ha − 1 PS and chemical (NPK) treatments, respectively. The low values of sediment and water required per kilogram of soybean produced in the chemical fertilization and 100 m 3 ha − 1 PS treatments indicate that these management regimes are more sustainable. [ABSTRACT FROM AUTHOR]

Agricultural use of treated wastewater, biosolids, and animal wastes introduces a multitude of contaminants of emerging concerns (CECs) into the soil-plant system. The potential for food crops to accumulate CECs depends largely on their metabolism in plants, which at present is poorly understood. Here, we evaluated the metabolism of naproxen and ibuprofen, two of the most-used human drugs from the Profen family, in Arabidopsis thaliana cells and the Arabidopsis plant. The complementary use of high-resolution mass spectrometry and 14C labeling allowed the characterization of both free and conjugated metabolites, as well as nonextractable residues. Naproxen and ibuprofen, in their parent form, were conjugated quickly and directly with glutamic acid and glutamine, and further with peptides, in A. thaliana cells. For example, after 120 h, the metabolites of naproxen accounted for >90% of the extractable chemical mass, while the intact parent itself was negligible. The structures of glutamate and glutamine conjugates were confirmed using synthesized standards and further verified in whole plants. Amino acid conjugates may easily deconjugate, releasing the parent molecule. This finding highlights the possibility that the bioactivity of such CECs may be effectively preserved through direct conjugation, a previously overlooked risk. Many other CECs are also carboxylic acids, such as the profens. Therefore, direct conjugation may be a common route for plant metabolism of these CECs, making it imperative to consider conjugates when assessing their risks. [ABSTRACT FROM AUTHOR]

Animal manure contributes considerably to ammonia (NH3) and greenhouse gas (GHG) emissions in Europe. Various treatment technologies have been implemented to reduce emissions and to facilitate its use as fertilizer, but a systematic analysis of these technologies has not yet been carried out. This study presents an integrated assessment of manure treatment effects on NH3, nitrous oxide (N2O) and methane (CH4) emissions from manure management chains in all countries of EU-27 in 2010 using the MITERRA-Europe model. Effects of implementing 12 treatment technologies on emissions and nutrient recovery were further explored through scenario analyses; the level of implementation corresponded to levels currently achieved by forerunner countries. Manure treatment decreased GHG emissions from manures in EU countries by 0-17% in 2010, with the largest contribution from anaerobic digestion; the effects on NH3 emissions were small. Scenario analyses indicate that increased use of slurry acidification, thermal drying, incineration and pyrolysis may decrease NH3 (9-11%) and GHG (11-18%) emissions; nitrification-denitrification treatment decreased NH3 emissions, but increased GHG emissions. The nitrogen recovery (% of nitrogen excreted in housings that is applied to land) would increase from a mean of 57% (in 2010) to 61% by acidification, but would decrease to 48% by incineration. Promoting optimized manure treatment technologies can greatly contribute to achieving NH3 and GHG emission targets set in EU environmental policies. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Department of Agronomy, PAU, Ludhiana. The twelve treatments were rice sole (without herbicide, pendimethalin 750 g ha-1 as PRE, bispyribac 25 g ha-1 as POST and pendimethalin 750 g ha-1 fb bispyribac 25 g ha-1), rice+Sesbania (Brown manuring (BM) of Sesbania at 4 WAS, pendimethalin 750 g ha-1 and BM of Sesbania at 4 WAS, BM of Sesbania at 4 WAS and bispyribac 25 g ha-1 and pendimethalin 750 g ha-1 and BM of Sesbania at 4 WAS and bispyribac 25 g ha-1) and rice+Sesbania (BM of Sesbania at 5 WAS, pendimethalin 750 g ha-1 and BM of Sesbania at 5 WAS, BM of Sesbania at 5 WAS and bispyribac 25 g ha-1 and pendimethalin 750 g ha-1 and BM of Sesbania at 5 WAS and bispyribac 25 g ha-1). Rice with Sesbania, knockdown at 4 and 5 WAS recorded less weed density as compared to sole rice. Integrated use of rice+Sesbania (BM of Sesbania at 4 WAS) with pendimethalin 750 g ha-1 fb post-emergence bispyribac 25 g ha-1 recorded significantly higher biological yield than all other combinations of BM and herbicides. The nitrogen content in paddy grains and straw was not influenced significantly by different brown manuring treatments. N content and uptake in weeds was significantly higher in sole rice under unsprayed check as compared to all other treatment combinations which were at par with each other. Nitrogen uptake in paddy grains was influenced significantly by different brown manuring treatments which varied from 40.12 to 56.22 kg ha-1. N uptake in straw was significantly higher with rice+BM (4 WAS) in pendimethalin fb bispyribac. [ABSTRACT FROM AUTHOR]

Experimental researches performed in manufacturing cowsheds have demonstrated a variation of ammonia concentration and the factors influencing this most during different periods of the year. The process of ammonia evaporation from manure is influenced by many varying and interrelated factors with temperature and the intensity of air ventilation being the most critical ones. The influence of these factors on the process of ammonia evaporation was established by laboratory researches. An increase in temperature results in an exponential increase in ammonia emission, whereas the dependence of the emission on the air velocity is best expressed by a second degree polynomial. The results obtained may be used as a forecast of the ammonia emissions from cowsheds during different periods of the year. Intensive ventilation is required for the removal of excess moisture from the housing, and this limits the possibilities to reduce ammonia emissions by controlling the intensity of ventilation. A reduction in the amount of ventilation is only recommended if the air quality indices meet the requirements applied to the housing. Better opportunities to reduce ammonia emissions are provided through management of the thermal processes in a cowshed. If the average annual air temperature (11.3 °C) is reduced by one degree in a cubicle housing cowshed, the ammonia emissions will decrease by 10%. [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]

Sulfamethazine (SMT) as an ionic compound can enter the soil environment via the application of livestock wastes in agricultural fields and via the abuse of pharmaceuticals. Goethite as one of the most important iron oxides in soil might interact with SMT and influence its environmental behavior and bioavailability in soil. In this study, the sorption properties of SMT on goethite under different solution conditions were investigated. The sorption isotherm exhibited a significant nonlinear shape and desorption hysteresis, while the data could be fitted well by the Freundlich model with the correlation coefficient R = 0.991. Sorption capacity initially increased and then decreased as pH values increased from 3 to 13, while the strongest uptake occurred in neutral conditions. The sorption increased slightly and then kept relatively constant as the ionic strength of the solution increased. The results indicated that the sorption mechanism would be altered in different solution conditions. In acidic and neutral conditions, the π-π electron donor-acceptor interactions and outer- and inner-sphere complexions might be the dominating sorption mechanisms. The sorption in alkali conditions might be dominated by electrostatic interactions between SMT and goethite. It should be noted that the heterogeneous sorption affinity of SMT on goethite under various solution conditions will influence its environmental fate. [ABSTRACT FROM AUTHOR]

Gaseous emissions during thermal animal waste treatment in a meat production plant have been determined. A dry flue gas system with a multisectional bag filter was installed at a meat production plant. Animal waste was incinerated in a rotary kiln, the capacity of the plant was 700 kg/h. The average thirty-minute (1352 samples) emission values of volatile dust, total organic carbon (TOC), hydrogen chloride (HCl), hydrogen fluoride (HF), sulfur dioxide (SO2), nitrogen oxide (NO), nitrogen dioxide (NO2) and carbon oxide (CO) were obtained during a study period of 1 month. Specific samples were collected to determine dioxin, furane, heavy metal, mercury, cadmium and thallium concentrations. Histograms of the obtained results were prepared, and the results were compared with the permissible emission levels defined by the European Union. Additionally, justification was provided when the observed values exceeded the levels defined by the European Union. [ABSTRACT FROM AUTHOR]

In many developing countries where pathogenic diseases of animal waste origin, such as giardiasis and cryptosporidiosis, are often prevalent, facilities are limited to treat livestock waste. However, household-scale anaerobic digesters are currently being promoted for bioenergy production from livestock manure. Since the effluent is often used as a fertilizer for food crops, it is critical to understand the effect of environmental conditions within household-scale digesters on the viability of Cryptosporidium parvum oocysts and Giardia lamblia cysts. In this study, key environmental parameters affecting (oo)cyst inactivation were measured in four tubular anaerobic digesters, which are a type of household-scale digester promoted for treatment of swine waste in rural Costa Rica. Interviews and participant observations were used to understand digester operation and maintenance procedures. Ambient temperatures (21–24 °C), near-neutral pH, total ammonia nitrogen (TAN) concentrations < 250 mg/L and hydraulic retention times (HRTs) between 23 and 180 days were observed. Laboratory (oo)cysts inactivation studies were performed in bench-scale digesters, which were maintained under conditions similar to those observed in the field. Apparent first-order inactivation rate coefficients for Giardia lamblia and Cryptosporidium parvum were 0.155 ± 0.041 and 0.054 ± 0.006 day − 1 , respectively. Temperature and volatile fatty acids were the main factors contributing to Cryptosporidium parvum and Giardia lamblia inactivation. A mathematical model was developed that predicts the concentration of (oo)cysts in the liquid effluent of tubular digesters like those observed in Costa Rica. A mathematical model was developed that predicts the concentration of (oo)cysts in the liquid effluent of tubular digesters like those observed in Costa Rica. Two dimensionless groups can be used to predict the performance of the digesters for inactivating pathogens; both dimensionless groups depend upon the average HRT in the digester. This is the first study to combine mathematical modeling with qualitative analysis, field and laboratory studies to predict the concentrations of (oo)cysts in tubular digester effluents. [ABSTRACT FROM AUTHOR]

Coupling microalgae cultivation with wastewater treatment may provide an economically and environmental friendly way for the production of algae-based biofuel or other value-added products. The nutrient supplement to poultry waste anaerobic-digested effluent (PWADE) as the substrates forChlorella pyrenoidosaY3 (isolated from Tai Lake) cultivation was investigated and optimized using a response surface methodology (RSM). Based on the Plackett–Burman design, NaHCO3and MgSO4·7H2O were selected as the most crucial supplemental nutrients for enhancing the biomass yield and chlorophyll-a content ofC. pyrenoidosaY3. A central composite design was employed to determine the optimal concentration of the two selected supplemental nutrients. With the canonical and ridge max analysis method, the maximum biomass yield of 0.819 g/L was obtained from algae cultivated in the 2% (v/v) PWADE substrate with addition of 4.81 g/L NaHCO3and 92.9 mg/L MgSO4·7H2O after 20 d of the cultivation, which was 1.5 times higher than that of algae cultured in the non-optimized PWADE medium (0.559 g/L). The chlorophyll-a content of algae reached to 27.51 mg/L, and about 100.0% NH4-N and 59.5% total phosphorus were removed from the PWADE with the optimized medium condition. Results indicate that RSM is a reliable method in proposing models for optimizing the algae growth in PWADE. [ABSTRACT FROM PUBLISHER]

Water pollution from animal waste, and its influence on grazing animals, is a current concern regarding Mongolian grazing lands. We allocated 32 free-grazing lambs to four groups and provided each with water from a different source (upper stream, lower stream, well, and pond) for 49 days. We recorded the amount of water consumed by the lambs, as well as their body weight, white blood cell count, acute phase (haptoglobin) protein level, and fecal condition. We measured the chemical and biological qualities of the four types of water, and we detected enteropathogenic and enterohemorrhagic Escherichia coli in fecal samples by using a genetic approach. Pond water contained high levels of nitrogen and minerals, and well water contained high levels of bacteria. On day 15 of the experiment, the following parameters were the highest in lambs drinking water from the following sources: water intake (pond or lower stream), body weight gain (pond), WBC count (lower stream), haptoglobin concentration (well), and enteropathogenic E . coli infection rate (lower stream). Lambs given upper or lower stream water exhibited more severe diarrhea on day 15 of the experiment than before the experiment. Mongolian sheep seemed to adapt to chemically contaminated water: their productivity benefited the most from pond water, likely owing to its rich mineral content. Lambs that drank lower stream water showed increases in enteropathogenic E . coli infection, clinical diarrhea, and WBC count. Water intake was lowest in the lambs given well water, suggesting that they avoided drinking the water because of potential E. coli infection; they were thus at increased risk of negative health and production effects. Our study revealed the profound nature of the effects of water quality on livestock health and performance. [ABSTRACT FROM AUTHOR]

Food of animal origin derived from livestock farming establishments is necessary to meet the needs of human beings. The wastes generated during the production stages of cattle breeding (manure, ground covers, etc.) create a danger to the environment and water resources when they are released to the environment randomly. Therefore, the waste generated by livestock farming establishments should be stored in a controlled manner and should not cause environmental pollution. The research was carried out in the Euphrates basin and covered four provinces (Adiyaman, Sanliurfa, Gaziantep, and Kilis) and 35 districts. In the context of this study, the number of the cattle bred in the establishments in 328 villages which are at least 150 m and at the most 5 km distance to the flow path of the Euphrates was taken into consideration. In the study, Erdas Imagine 9.3 and ArcMAP 10.0 software were used; the number of the cattle and the distance to the rivers were evaluated as a layer. The subject of the study was the investigation of the potential pollution effects of the cattle breeding on the Euphrates River and its tributaries, and it was carried out to determine risky, non-risky and partially risky areas and attract attention to this issue. As a result, it was concluded that 4 districts and villages of Sanliurfa Region would be classified as risky areas, 3 districts and villages of Gaziantep Region would be classified as partially-risky areas, and 3 districts and villages of Adiyaman Region and all districts and villages of Kilis Region would be classified as non-risky areas. [ABSTRACT FROM AUTHOR]

The contamination of agricultural ground with estrogen compounds through application of animal wastes is a present concern. At the same time, current uses for waste fly ash having high carbon content are limited. To help mitigate these problems, we examine using waste fly ash as a useful adsorbent for Estradiol in pig waste digests. In this study, Estradiol was added to vials containing water and fly ash from several different power plants. After an extraction process, the amount of Estradiol in the water was measured. Commercial activated carbon was also used for comparison purposes. Vials containing varying concentrations of Estradiol and no trapping material were used as a control. The results from this study indicate that fly ash can be used as a trapping material for Estradiol in water, but that commercially available activated carbon can trap about an order of magnitude more Estradiol than the fly ash and that the effects of the fly ash matrix can both inhibit and promote the solvation of Estradiol into water depending possibly upon pH and cation concentration effects. In addition, preliminary extraction studies using pig waste digest indicate that fly ash can be used as adsorbent for Estradiol present in pig waste. [ABSTRACT FROM AUTHOR]

Nutrient loading and air emissions from swine operations raise environmental concerns. The objective of the study was to describe and evaluate a mathematical model (Davis Swine Model) of nutrient partitioning and predict manure excretion and composition on a daily basis. State variables of the model were AA, fatty acids, and a central pool of metabolites that supplied substrate for lipid synthesis and oxidation. The model traced the fate of ingested nutrients and water through digestion and intermediary metabolism into body protein, fat, water, and ash, where body protein and fat represented the body constituent pools. It was assumed that fluxes of metabolites follow saturation kinetics, depending on metabolite concentrations. The main inputs to the model were diet nutrient composition, feed intake, water-to-feed ratio, and initial BW. First, the model was challenged with nutrient partitioning data and then with excretion data. The data had 48 different feeding regimes with contrasting energy and lysine intakes at 2 different stages of growth. The overall observed and predicted mean were 109 and 112 g/d for protein deposition and 132 and 136 g/d for lipid deposition respectively, suggesting minor mean bias. Root mean square prediction error (RMSPE) was used in evaluation of the model for its predictive power. The overall RMSPE was 2.2 and 4.1 g/d for protein and lipid deposition, respectively. The excretion database used for evaluation of the model was constructed from 150 digestibility trials using growing-finishing pig diets that had a wide range of nutrient chemical composition. Nutrient and water excretion were quantified using the principle of mass conservation. The average daily observed and predicted manure production was 3.79 and 3.99 kg/d, respectively, with a RMSPE of 0.49 kg/d. There was a good agreement between observed and predicted mean fecal N output (9.9 and 9.8 g/d, respectively). Similarly, the overall observed and predicted mean urine N output was 21.7 and 21.3 g/d, respectively, suggesting minor mean bias. The RMSPE was 1.9 and 4.1 g/d for fecal and urinary N, respectively. Evaluation of the model showed that the model predicts manure excretion and N content well and can be used to assess environmental mitigation options from swine operations. [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]

The objective of the study consisted of testing the effect of residual water resulted from swine breeding complexes on earthworms Eisenia fetida (Savigny, 1826) (Phyllum Annelida, Class Oligochaeta, Family Lumbricidae) under the following aspects: mortality, body weight, prolificacy. The experiment has been carried out in laboratory (microcosm experiment, according to the adjusted OECD methodology (Guideline for testing of chemicals--Earthworm, acute toxicity tests, no. 207/1984), using the test of artificial soil. The test lasted 14 days. All earthworms involved in the experiment were adults, with weight over 4000 mg. In each recipient were introduced 10 earthworms. Data recording was made in the 14th day: weight, mortality, prolificacy (number of cocoons). After 14 days of experiment, there was observed a decrease of earthworm number per recipients only for concentrations 12.5 and 25 ml swine wastewater per kg artificial soil, by 10% and 20%, respectively, related to control. Regarding the prolificacy, the cocoon number was the highest (17) at the concentration of 6.25 ml swine wastewater per kg artificial soil, followed by the concentration of 3.12 (15), which means with 30.76% and respectively with 15.38% higher than in the control recipient. These two concentrations were the most favourable. The highest concentrations of swine wastewater determined a decrease of cocoon number, with 15.39% as compared to the control recipient. In all concentrations of swine wastewater the earthworm biomass was higher than in the control recipient, the increase ranging between 0.17- 6.73%. There were no notable changes at clitellum or locomotion levels after 14 days of exposure on swine wastewater. [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]

Abstract: Thin-layer models are commonly used to estimate NH3 emissions from liquid waste. However, such models differ in their ability to accurately reproduce observed emissions, which may be partly due to an incomplete mechanistic understanding of NH3 volatilization. In this study, NH3 release from pure solutions of (NH4)2SO4 (AS), swine pit liquid (PL), swine lagoon liquid (LL), dairy lagoon liquid (DLL), and dairy manure liquid (DML) were evaluated under controlled conditions (pH 7.6 and temperature 20 °C). Relationships between the NH3 release and pH, temperature, and total ammoniacal nitrogen (TAN) were established. Under similar TAN conditions, the NH3 release was higher for PL, LL, DLL, and DML than for AS. Pure solutions of AS that were spiked with NaHCO3 showed NH3 emissions rates that were comparable to DML, DLL, LL and PL. The enhanced NH3 emissions of PL, LL, DLL and DML were therefore explained by linkages between TAN and HCO3 −. [Copyright &y& Elsevier]

In this paper we estimate the external cost caused by odor from an animal waste processing facilio, in Flanders, using new odor measures based on field measurements. We compare four ways of incorporating odor nuisance: distance to the source, distance zones, continuous odor measures, and odor zones. The odor zones approach seems best suited to estimate the external costs. We test these specifications for some 1,400 observations of house sales transaction between 2004 and 2008. Results show that houses subject to moderate and severe odor nuisance sell at a discount of 5% and 12%, respectively, compared to houses without nuisance. [ABSTRACT FROM AUTHOR]

Contamination of environmental matrixes by human and animal wastes containing antibiotics is a growing health concern. Because tetracycline is one of the most widely-used antibiotics in the world, it is important to understand the factors that influence its mobility in soils. This study investigated the effects of pH, background electrolyte cations (Li, Na, K, Ca and Mg), heavy metal Cu and humic acid (HA) on tetracycline adsorption onto kaolinite. Results showed that tetracycline was greatly adsorbed by kaolinite over pH 3-6, then decreased with the increase of pH, indicating that tetracycline adsorption mainly through ion exchange of cations species and complexation of zwitterions species. In the presence of five types of cations (Li, Na, K, Ca and Mg), tetracycline adsorption decreased in accordance with the increasing of atomic radius and valence of metal cations, which suggested that outer-sphere complexes formed between tetracycline and kaolinite, and the existence of competitor ions lead to the decreasing adsorption. The presence of Cu greatly enhanced the adsorption probably by acting as a bridge ion between tetracycline species and the edge sites of kaolinite. HA also showed a major effect on the adsorption: at pH < 6, the presence of HA increased the adsorption, while the addition of HA showed little effect on tetracycline adsorption at higher pH. The soil environmental conditions, like pH, metal cations and soil organic matter, strongly influence the adsorption behavior of tetracycline onto kaolinite and need to be considered when assessing the environmental toxicity of tetracycline. [ABSTRACT FROM AUTHOR]

Strategies are sought to reduce the impact of nonpoint sources of pollution, including fecal bacteria, and meet TMDL criteria. Vegetative filter strips (VFSs) are one such strategy, though the data of VFS function under field conditions, particularly for fecal bacteria, are limited. The objective of this study was to evaluate the efficiencies in removing fecal bacteria, N, and P from VFSs installed to treat contaminated runoff from a working feedlot. VFSs were found to be effective in removing a broad range of constituents from beef feedlot runoff pretreated by a settling basin. The first 30 m provided most or all of the reductions found within the 150 m VFSs studied: reductions average 85% of inflow water, 85% of sediment, 77% of N, and 84% of P. Fecal bacteria removal by the VFSs was about one order of magnitude: reductions at 30 m ranged from 83.5% for FC and FS to 91% for E. coli. On the site being studied, this provided an important level of protection and reduced surface-flow concentrations of fecal coliforms to below the 200 CFU/100 mL (coliform-forming units, CFU) water-quality standard for Kansas. [ABSTRACT FROM AUTHOR]

Long-term applications of animal manures to agricultural fields have caused serious environmental concerns over release of excessive nutrients, heavy metals, and fecal coliforms into waterbodies. An alternative is to control nutrient bioavailability of animal manures before their land application. In this study, two types of bauxite residues (red mud and brown mud) were evaluated for their potential use in reducing leachability of phosphorus (P), copper (Cu), and zinc (Zn) as well as fecal coliform and NH release from animal manures. Poultry litter and cattle manures collected from production farms were mixed with bauxite residues at mixing rates of 11%, 22%, and 50%. Bauxite residues were effective in suppressing the leaching of water-soluble P, As, Cu, and Zn from animal manures. At 22% mixing rate, brown mud reduced water-extractable P by 40% and 70% from chicken litter and cattle manure, whereas red mud reduced water-extractable P by 27% and 55%, respectively, in five successive extractions. Amending manures with bauxite residues also decreased populations of fecal coliform. Bauxite residues did not increase NH release despite its relatively high pH. The results suggest that bauxite residues could be used as a potential amendment for reducing P and other contaminant leaching in animal manures and improve the application of both wastes for beneficial use. [ABSTRACT FROM AUTHOR]

Quantification of malodorous substances at trace concentration levels in piggery wastewater remains a great challenge for environmental studies. The objective of this study was to determine the 4-methylphenol, 4-ethylphenol, indole and skatole (3-methylindole) of piggery wastewaters in anaerobic facilities by headspace solid-phase microextraction (HS-SPME) and solid-phase extraction (SPE) pre-concentration. The validation results of both pre-concentrations revealed high selectivity and sensitivity. The detection of malodorous substances can provide clues to track the source of these contaminants. The results of real sample detection showed that all of these malodor substances appeared in both influent and effluent wastewaters. [ABSTRACT FROM AUTHOR]

In this work, the dynamic responses of different phosphorous factions in swine manure to aeration treatment were investigated and profiled to provide insight on potential ways to improve the biological phosphorus removal process. Batch reactors fabricated from clear acrylic columns were filled with fresh swine manure containing a 4.6 % solids content, which was aerated continuously for 15 days at an airflow rate of 2 L/min. The results indicate that the treatment can reduce soluble phosphorus (P) by about 78 % after only one-day aeration due largely to chemical precipitations. At the end of the experiment, the average soluble inorganic P level was reduced by 12 % (from 91 down to 79 %), while the average soluble organic P was increased by 13 % (from 9 to 22 %). The biomass P (DNA/RNA/poly-P) was increased by 24 % in the first three days, but only by 14 % in the rest 12 days of aeration. Also increased by aeration was the lipid P (47 %) but not the protein P. The data reveal that the current aeration rate cannot maintain a stable oxygen level [represented by the oxidation-reduction potential (ORP)] in the treated manure, evidenced by the decrease in ORP from 250 mV at the beginning to almost zero at the conclusion of the experiment, which is considered the major factor hindering the growth of aerobes, including the phosphorus-accumulating organisms (PAOs). Therefore, it may be concluded that continuous aeration of swine manure at a constant rate will not guarantee the supply of sufficient oxygen to the growth of PAOs. On another front, it was observed that too much aeration might negatively impact the overall P removal by increasing the release of soluble organic P from dead cells. [ABSTRACT FROM AUTHOR]

Abstract: Major releases of airborne ammonia and hydrogen sulfide from the decomposition of animal waste have the American public concerned about the health of persons near farms. Emissions of these hazardous substances are regulated by the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPCRA). Moreover, federal regulatory provisions delineate thresholds for reporting hazardous pollutants being released into the air. In 2008, the US Environmental Protection Agency (EPA) adopted a reporting exemption under which all farms were exempted from reporting air emissions under CERCLA and small farms were exempted under EPCRA. The US EPA''s exemption poses questions about whether the rule is contrary to congressional mandates. Environmental and industry groups have challenged this exemption in federal circuit court, and the judiciary will need to decide whether the agency had authority to adopt the rule. To accord protection to humans from hazardous airborne emissions from farms producing livestock, state agencies may want to adopt scientifically-justified ambient air quality standards. [Copyright &y& Elsevier]

The impact of a confinement dairy operation (>2000 head) using best management practices for land application of animal wastes, on estrogenic activity (E-Screen), estrogens, and nutrients of associated surface waters and tile drain runoff were evaluated. Farm tile drain and creek samples were collected from the drainage region: above and below a municipal wastewater treatment plant located upstream from the dairy; and downstream from animal housing, parlor, and fields receiving applied wastes. Fifty-four thousand tons of waste (from ∼1000 milking head) were applied to ∼809 ha from April to July. Maximum estradiol equivalents (E2Eqs) present in tile drain samples (≤0.257 ng/L) were 2-fold maximum creek E2Eqs, but only 25% of the proposed no observable effect concentration for E2 (1 ng/L). Relative manure slurry estrogen concentrations were estrone >17α-E2 > 17β-E2. Creek nutrient concentrations were similar above and below the dairy, with higher concentrations found in tile drain samples: tile ammonia ranged from <0.05 to 0.70 mg/L, nitrate/ite from 1.2 to 14 mg/L, and total phosphorus from 0.04 to 0.34 mg/L. No differences in estrogenic activity or nitrate/ite, ammonia, and phosphorus concentrations were detected in surface waters downstream of a large confinement dairy facility and measured nutrients were within regional norms. [ABSTRACT FROM AUTHOR]

Land application of manure constitutes an effective means of recycling manure nutrients to the soil. However, odours from manure application activities can hinder the expansion of the livestock industry because of the potential nuisance to neighbours. The objective of this study was to assess the efficiency of subsurface application at reducing odours from both solid and liquid manure applications. Flux chambers and dynamic dilution olfactometry were used to assess odours from two manure types (solid and liquid) applied at four application rates using surface and subsurface application methods. The results of the study indicated that odour concentrations from subsurface application plots were up to 66% (37% on average) lower than concentrations from plots where the manure was surface applied. Subsurface application seemed to have a larger impact on reducing odours from solid manure than liquid manure, mainly due to better manure coverage after subsurface application of solid manure. Odours from solid manure applications measured immediately after application were also 37% lower than from liquid manure applications. In general, odours from liquid and solid manure increased with higher application rates, but there was little difference among the low, mid, and high application rates. Based on the results of this study, subsurface application of manure is an effective way to reduce the overall odour emissions from manure spreading, particularly for solid manure. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) are emerging contaminants found in the water and sediments surrounding animal feedlots. In this study, the fate of five tetracycline-resistance and 16S-rRNA genes released in swine waste were monitored for 21 days in the water column and biofilms in 12 mesocosms mimicking different natural receiving water bodies. Four treatments were employed in triplicate: two light exposures (light/dark) and two loading scenarios (single/periodic). As seen previously, light exposure had a significant effect on disappearance rates of tet genes in both the water column and biofilms, although absolute rates were significantly lower in the biofilms. Further, periodic versus single loading events resulted in >2 orders of magnitude higher tet gene levels in associated tanks. Regardless of treatment, ARGs migrated quickly to biofilms, with 3% and >85% of detected tet determinants found in biofilms on days 1 and 4, respectively. Overall, these are the first quantitative data on specific ARG disappearance rates in biofilms, and also the first evidence of progressively accumulating ARG levels in biofilms under loading conditions typical of natural receiving waters. In summary, ARGs migrate rapidly to biofilms where they persist longer than adjacent waters, which suggests biofilms likely act as reservoirs for ARGs in nature. [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.

A dramatic gain in efficiency is an absolute necessity if we are to overcome the agricultural challenges of the third millennium. One of the ways that could lead to such a gain in efficiency is a renewed and augmented use of by-products. In an agricultural context the food industry is a major source of potentially valuable byproducts. For other Western European countries VALORBIN (2003a) mentions 5 million tons in Denmark, 11 million in The Netherlands, and 14 million tons in Germany. 70 to 80 % of food industry by-products are reused in feed manufacturing. In all applications, two important ethical aspects seem to overarch all others, being (the care for) public health, and the need for recycling. Both aspects will be important with all by-products and all applications, but their relative importance will differ. This does not mean that zero-risk or maximum recycling need to be the goal. In both aspects environmental considerations are included. It is important to keep an eye out for direct and indirect impacts on other products. A hierarchy seems to exists, in which reuse as food has priority over use as feed or biomass (energy or green chemistry), and with a sustained faith as waste as the least preferable option. The by-products that one wants to use in feed production, will have to be selected based on type (e.g. category 3 animal by-products should be safe), traceability (single sourced products are preferred) and goal (e.g. is the target animal omnivorous). [ABSTRACT FROM AUTHOR]

A Lo Constructed Wetland system was used to treat Wu-Lo Creek water that has been polluted by wastes discharged from animal farms. The polluted water contains 16.2–35.6 mg/L biochemical oxygen demand (BOD), and 64–188 mg/L suspended solids (SS) during the wet season (May through September) as well as 8.0 –104 mg/L BOD and 33.2–297 mg/L SS during the dry season (October through March next year). The constructed wetland was operated for two years. Results of water quality monitoring indicated 80.4–84.4% BOD and 93.2–95.3% SS removal during the wet season as well as 66.3–75.3% BOD and 69.3–97.1% SS removal during the dry season. Additionally, the wetland provides a living space for various plants and animals. In this study, the wetland effluent quality was monitored and the results were used to investigate the efficiency of constructed wetland for treating organic wastewater. [ABSTRACT FROM AUTHOR]

Abstract: A pilot plant bioenergy recovery system from swine waste and garbage was constructed. A series of experiments was performed using swine feces (SF); a mixture of swine feces and urine (MSFU); a mixture of swine feces, urine and garbage (MSFUG); garbage and a mixture of urine and garbage (AUG). The system performed well for treating the source materials at a high organic loading rate (OLR) and short hydraulic retention time (HRT). In particular, the biogas production for the MSFUG was the highest, accounting for approximately 865–930Lkg−1-VS added at the OLR of 5.0–5.3kg-VSm−3 day−1 and the HRT of 9 days. The removal of VS was 67–75%, and that of COD was 73–74%. Therefore, co-digestion is a promising method for the recovery of bioenergy from swine waste and garbage. Furthermore, the results obtained from this study provide fundamental information for scaling up a high-performance anaerobic system in the future. [Copyright &y& Elsevier]

Dairies are a major source of volatile organic compounds (VOCs) in California''s San Joaquin Valley; a region that experiences high ozone levels during summer. Short-chain carboxylic acids, or volatile fatty acids (VFAs), are believed to make up a large fraction of VOC emissions from these facilities, although there are few studies to substantiate this. In this work, a method using a flux chamber coupled to solid phase micro-extraction (SPME) fibers followed by analysis using gas chromatography/mass spectrometry was developed to quantify emissions of six VFAs (acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid and 3-methyl butanoic acid) from non-enteric sources. The technique was then used to quantify VFA fluxes from a small dairy located on the campus of California State University Fresno. Both animal feed and animal waste are found to be major sources of VFAs, with acetic acid contributing 70–90% of emissions from the sources tested. Measured total acid fluxes during spring (with an average temperature of 20°C) were 1.84±0.01, 1.06±0.08, (1.3±0.5)×10−2, (1.7±0.2)×10−2 and (1.2±0.5)×10−2 gm−2 h−1 from silage, total mixed rations, flushing lane, open lot and lagoon sources, respectively. VFA emissions from the sources tested total 390±80gh−1. The data indicate high fluxes of VFAs from dairy facilities, but differences in the design and operation of dairies in the San Joaquin Valley as well as seasonal variations mean that additional measurements must be made to accurately determine emissions inventories for the region. [Copyright &y& Elsevier]