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PubMed2001

Odour emission rates from manure treatment/storage systems.

The effects of agitation, liquid-only manure, depth and time on odour emission rates were investigated. Manure storage tanks were filled to incremental depths every two weeks. At each depth odour samples were collected twice. The second sample was collected seven days after the first. Odour concentration was measured with an olfactometer. Three different pig-manure treatments were investigated. In one treatment, slurry manure in a storage tank was agitated before and during odour sampling. In a second treatment, the settlable solids in manure were removed gravimetrically over 24 hours and liquid manure was pumped to a storage tank. In the third treatment (control), odour samples were collected from unseparated and undisturbed slurry manure. Overall, the odour emission rates in the agitated manure treatment ranged between 0.39 and 1.02 ou s(-1) m(-2), increased with depth and decreased with time, i.e. after seven days at each depth. In the liquid-only manure treatment, the emission rates ranged between 0.09 and 0.69 ou s(-1) m(-2), increased with depth but the effect of time was not evident. In the control treatment, the emission rates ranged between 0.20 and 0.66 ou s(-1) m(-2) and increased with depth on the first odour sampling day but decreased with depth on the second sampling day.

Agriculture↗
PubMed2005

Microbial quality of runoff following land application of cattle manure and swine slurry.

Concentrations of human health-related microorganisms in runoff from agricultural plots (0.75 m x 2 m) treated with fresh and aged cattle manure, swine slurry and no manure (control) were determined. Three consecutive simulated rainfall events, producing 35 mm rainfall and separated by 24 h, were carried out for each plot. Fecal indicator (Escherichia coli, enterococci, Clostridium perfringens and coliphage) loads released in rainfall runoff from plots treated with fresh cattle manure, aged cattle manure and swine slurry treatments ranged from 5.52 x 10(5) to 4.36 x 10(9), 3.92 x 10(4) to 4.86 x 10(8), and 9.63 x 10(5) to 3.05 x 10(8), respectively. Plot runoff concentrations of protozoa (Cryptosporidium oocysts and Giardia cysts) ranged from 1.65 x 10(5) to 1.04 x 10(6), 2.93 x 10(3) to 2.75 x 10(5), and 9.12 x 10(4) to 3.58 x 10(6) for fresh cattle manure, aged cattle manure and swine slurry plot treatments, respectively. These results suggest that large microbial loads could be released via heavy precipitation events that produce runoff from livestock manure-applied agricultural fields, of even modest size, and could have a significant impact on water bodies within the watershed. Because of the lack of multiplication in the environment, highly elevated concentrations in manured land runoff, and correlation to protozoan parasite presence, Clostridium may be an alternative indicator for livestock manure contamination.

Agriculture↗
PubMed1997

Manure Enhances Plasmid Mobilization and Survival of Pseudomonas putida Introduced into Field Soil.

We report a field study on plasmid mobilization in an agricultural soil. The influence of pig manure on the mobilization of the IncQ plasmid pIE723 by indigenous plasmids or by the IncP(alpha) plasmid pGP527 into the recipient Pseudomonas putida UWC1 (Rif(supr) Nal(supr)) was studied in field soil. Six plots were prepared in duplicate, three of which were treated with manure prior to inoculation of the donor and recipient strains. As a donor strain, either Escherichia coli J53(pIE723) or E. coli 600(pIE723, pGP527) was used. Putative transconjugants obtained on a selective medium were confirmed by DNA hybridization and PCR. Plasmid mobilization by indigenous mobilizing plasmids was observed on two occasions in manured soil. Manuring of soil significantly enhanced the frequency of pIE723 mobilization by pGP527, since mobilization frequencies into P. putida UWC1 were at least 10-fold higher in manured soil than in nonmanured soil. Enhanced numbers of P. putida UWC1 transconjugant and recipient colonies could be observed in manured soil throughout the 79-day field test. Transfer of pIE723 or pG527 into indigenous soil or rhizosphere bacteria could not be detected when indigenous bacteria isolated by selective cultivation were screened for the presence of these plasmids by DNA hybridization. Furthermore, the presence of IncN-, IncP-, or IncQ-specific sequences was confirmed in total community DNA extracted directly from the manured or nonmanured soil by PCR. IncW plasmids were detectable only in manured soil, indicating entry of these plasmids into soil via manure.

Journal Article↗
PubMed2005

An enzymatic hydrolysis approach for characterizing labile phosphorus forms in dairy manure under mild assay conditions.

Characterizing labile P forms in animal manure is a challenge due to their susceptibility to hydrolysis. In this study, we enzymatically characterized P forms in dairy manure (no bedding), collected from a representative dairy farm in New York, by separating into soluble and residual components under mild assay conditions using water and sodium acetate buffer (pH 5.0). About 75% of total manure P in the fresh manure was characterized, with the remainder (25%) regarded as recalcitrant or biochemically unidentified P. The hydrolyzable organic P in soluble and residual fractions was then characterized by using phosphatase enzymes to simple monoester P, polynucleotide P, phytate-like P, and non-hydrolyzable P. Of the total P in water extracts, 77% was inorganic P, 11% hydrolyzable organic P and 12% non-hydrolyzable P. In the residual resuspension, the distribution of characterized P was 25% spontaneous labile P, 32% simple monoester P, 7% polynucleotide P, 9% phytate-like P, and 26% non-hydrolyzable P. Ultrasonication increased the P(i) release from the manure residues, but the deviation in Pi concentrations due to the sampling variance was greater that the increase in P(i) due to sonication. Autoclaving sped up the release of both spontaneously labile P and enzymatically hydrolyzable P trapped in the manure residual matrix. Quantifying labile P forms by this approach may advance our ability to predict amount of manure P that will be hydrolyzed and eventually become bioavailable. The information obtained by our modified method would be complementary to that obtained by other methods (such as P-31 NMR and sequential fractionation) for a full spectrum of P species in animal manure.

6-Phytase↗
PubMed2006

Characterization of manures from fish cage farming in Chile.

This study aims to characterize salmonid manures and to determine their potential use in agricultural soils. Sampling was carried out below salmon and trout cages in farms located in lakes and in the sea in the South of Chile during 2002-2003. Manure was analyzed for macronutrients, micronutrients and heavy metals. Results showed a high variability between samples and differences between sea and lake manure. Dry matter contents were low averaging c. 12-15%. Manures showed low OM contents with values <c. 15% and a neutral pH (c. 7.0). Both manures had low total N contents with values of <0.9%, more than 75% of which was in the organic form. Lake manure showed high contents of P (1.56%), Ca (3.89%), Fe (27,948 ppm), Mn (446 ppm), Al (31,789 ppm), As (5.13 ppm), Cd (1.04 ppm), Cr (18.8 ppm), Ni (12.3 ppm), Pb (3.5 ppm) and Zn (393 ppm). Sea manure had high contents of Mg (1.65% ppm), K (0.63%), Na (11.8%) and Cu (89 ppm). Salmonid manure had low nutrients and heavy metal contents and a potential use in agricultural soils, which could reduce the risks of water pollution on water from fish farming.

Animals↗
PubMed2006

Improving rock phosphate availability through feeding, mixing and processing with composting manure.

The objective of this study was to improve the availability of phosphorus (P) from rock phosphate (RP) through feeding, mixing and composting manure. The experiment was conducted as a 3 x 2 split-plot design. Manure was collected from 12 Boran steers (200+/-4.5 kg live weight) fed a basal diet of Napier grass (Pennisetum purpureum) at 2.5% body weight on a dry matter (DM) basis. The main plot treatments were (i) manure from steers supplemented with 113 g Busumbu rock phosphate (BRP) per day (FBRP), (ii) manure from steers not supplemented with BRP, feces mixed with 113 g BRP per day (MBRP) and (iii) manure from steers not supplemented with BRP and feces not mixed with BRP (CONT). The sub-plots comprised composting the manure either (i) mixed with 440 g of wheat (Triticum aestivum L.) straw per kg fresh feces (WS) or (ii) without straw (WOS). The manure was composted in 200 L plastic bins for 90 days. After 90 days, P availability was evaluated (i) by aerobic laboratory incubation at 25 degrees C for 1, 2, 4, 8, 12, and 16 weeks and (ii) by greenhouse agronomic evaluation study using maize (Zea Mays L.) as the test crop in either a humic Nitosol or an Andosol. In the laboratory incubation study, resin P was higher (p<0.05) for the WS compost than for the WOS compost; values were higher (p<0.05) for the Andosol than for Nitosol and followed the order of FBRP-WS, Andosol>FBRP-WS, Nitosol>MBRP-WS, Andosol>MBRP-WS, Nitosol>FBRP-WOS, Andosol>FBRP-WOS, Nitosol. In the greenhouse evaluation, maize crops in the WS compost had higher (p<0.05) biomass yield than the reference fertilizer, triple super phosphate, (173% versus 196%; Andosol and Nitosol, respectively). The biomass yield and P uptake relative agronomic effectiveness (RAE) for WS compost was also higher (p<0.05) than that of WOS compost (184 versus 3+/-0.8 and 242 versus 162+/-0.2, WS and WOS, biomass yield and P uptake, respectively). Nitosol biomass yield and P uptake RAE were also higher (p<0.05) than for the Andosol (99 versus 88+/-0.8 and 332 versus 72+/-0.2, Nitosol and Andosol, biomass yield and P uptake, respectively). The results show that P-enriched composting in the presence of wheat straw significantly increased P availability and increased plant growth. However, in terms of plant growth, there was no additional benefit of first feeding the RP to steers before composting the manure because most of the RP fed seem to have been utilized by the animal.

Manure↗
PubMed2004

Assessment of manure phosphorus export through turfgrass sod production in Erath County, Texas.

A best management practice (BMP) for exporting manure phosphorus (P) in turfgrass sod from the North Bosque River (NBR) watershed in central Texas was assessed using a geographic information system (GIS). The NBR watershed has a mandate to reduce the total annual P load to the NBR by 50% as a result of total maximum daily load regulation. Since dairy waste applications to fields are identified as the major nonpoint source of P to the river, innovative BMPs, such as export of manure P in turfgrass, will be needed to achieve the 50% reduction. However, methods are needed to evaluate the feasibility of these innovative management practices prior to their implementation. A geospatial database of suitable turfgrass production sites was developed for Erath County using GIS. Erath County largely encompasses the upper portion of the NBR watershed. Information from field experiments, production practices, and ground-truthing was used to search, analyze, and verify a geospatial database developed from national and regional sources. The integration and analyses of large databases supports the search by turf producers for sites suitable for turfgrass sod production in Erath County. In addition, GIS enables researchers and regulators to estimate manure P exports and reduced P loading due to implementation of the manure export BMP on a county scale. Under optimal conditions 198,000 kg manure P yr(-1) could be used and 114,840 kg manure P yr(-1) exported from the NBR watershed through implementation of a system using dairy manure to produce turfgrass sod. This is the equivalent of the manure P applied from 10,032 dairy cows yr(-1) and exported from 5808 dairy cows yr(-1). Application of GIS to large-scale planning and decision-making transcends traditional field-scale applications in precision agriculture.

Agriculture↗
PubMed2007

Anaerobic biogasification of undiluted dairy manure in leaching bed reactors.

Dry anaerobic digestion of high solids animal manure is of increasing importance since conventional slurry digestion is not an effective system for these manures. The investment costs for large-size reactors, costs for heating these reactors, handling, dewatering, and the disposal of the digested residue decrease the benefits of conventional slurry anaerobic digestion for high solids animal manure. Even though leaching bed reactors (LBR) constitute a promising option for dry anaerobic biogasification of animal manure, no study is cited in the literature for animal manure, excluding a single study on cattle waste which utilized a similar concept in a different experimental set-up, namely a packed bed digester. Therefore, this work was undertaken to investigate the anaerobic biogasification of undiluted dairy manure in LBRs. To this purpose anaerobic leaching bed reactors (ALBR) packed with a mixture of dairy manure, anaerobic seed and wood powder/chips were operated. The ALBRs were fed with water, and the leachate that was collected from their effluents was subjected to biochemical methane potential (BMP) experiments to determine the biogas production. The results revealed that LBRs can successfully be applied to anaerobic digestion of undiluted dairy manure with around 25% improvement in biogas production relative to conventional (slurry) anaerobic digesters.

Anaerobiosis↗
PubMed2005

A bench-scale aeration study using batch reactors on swine manure stabilization to control odour in post treatment storage.

A bench-scale study on swine manure stabilization for odour control was conducted using batch aeration reactors. In trial 1, two aeration lengths, i.e., 0.5 and 4.0 day, were used under uncontrolled ambient temperature that increased gradually over the experimental period. While in trial 2, a 16.0-day aeration scheme was employed under constant 17 degrees C. An airflow rate of 1.2L/s/m(3) was used for both trials to aerate batch reactors containing finishing pig manure with initial total solids (TS) levels ranging from 0.5 to 4.0%. Manure stabilization during the 90-day post-treatment storage was evaluated by the changes in organic materials, nitrogen and volatile fatty acids (VFA). The odour generation potential in the treated manure was determined by the changes in VFA. Up to 827 mL of liquid was lost due to aeration related foaming. The reductions in total volatile solids (TVS), 5-day biochemical oxygen demand (BOD(5)), total Kjeldahl nitrogen (TKN) and VFA during storage were improved when aeration length increased. Low solids levels offered a more advantageous circumstance for manure stabilization and odour control. Biodegradation of organic matter, removal of nitrogen, and breakdown of VFA would increase with increasing ambient temperature. VFA removals in manure under 16.0-day aeration were higher than those under 0.5- and 4.0-day aeration; however, VFA regeneration started to exceed its consumption on day 20 (4 days after the aeration treatment). BOD(5) was the best estimate of VFA concentration in the aerated manure during storage. The 4.0-day aeration scheme was sufficient to stabilize manure to effectively assuage odour generation potential during the 90-day storage under increasing ambient temperature conditions.

Animals↗
PubMed2003

Bacterial antibiotic resistance levels in Danish farmland as a result of treatment with pig manure slurry.

Resistance to tetracycline, macrolides and streptomycin was measured for a period of 8 months in soil bacteria obtained from farmland treated with pig manure slurry. This was done by spread plating bacteria on selective media (Luria Bertani (LB) medium supplemented with antibiotics). To account for seasonal variations in numbers of soil bacteria, ratios of resistant bacteria divided by total count on nonselective plates were calculated. Soil samples were collected from four different farms and from a control soil on a fifth farm. The control soil was not amended with animal manure. The occurrence of tetracycline-resistant bacteria was elevated after spread of pig manure slurry but declined throughout the sampling period to a level corresponding to the control soil. Higher load of pig manure slurry yielded higher occurrence of tetracycline resistance after spreading; however, the tetracycline resistance declined to normal occurrence defined by the tetracycline resistance occurrence in the control soil. Concentrations of tetracycline in soil and in pig manure slurry were measured using HPLC. No tetracycline exceeding the detection limit was found in soil samples. Manure slurry concentrations of tetracycline for three of the farms were 42, 81 and 698 microg/l, respectively. For streptomycin and macrolides, only minor variations in resistance levels were detected. Results obtained in this study thus indicate that tetracycline resistance levels in soil are temporarily influenced by the addition of pig manure slurry. The results indicate also that increased amount of pig manure slurry amendment may result in increased levels of tetracycline resistance in the soil.

Agriculture↗
PubMed2001

Pig manure vermicompost as a component of a horticultural bedding plant medium: effects on physicochemical properties and plant growth.

This experiment was designed to characterize the physical, chemical and microbial properties of a standard commercial horticultural, greenhouse container, bedding plant medium (Metro-Mix 360), that had been substituted with a range of increasing concentrations (0%, 5%, 10%, 25%, 50% and 100% by volume) of pig manure vermicompost and to relate these properties to plant growth responses. The growth trials used tomatoes (Lycopersicon esculentum Mill.), grown in the substituted media for 31 days under glasshouse conditions, with seedling growth recorded in 20 pots for each treatment. Half of the tomato seedlings (10 pots per treatment) were watered daily with liquid inorganic fertilizer while the other half received water only. The percentage total porosity, percentage air space, pH and ammonium concentrations of the container medium all decreased significantly, after substitution of Metro-Mix 360 with equivalent amounts of pig manure vermicompost; whereas bulk density, container capacity, electrical conductivity, overall microbial activity and nitrate concentrations, all increased with increasing substitutions of vermicompost. The growth of tomato seedlings in the potting mixtures containing 100% pig manure vermicompost was reduced, possibly as a result of high soluble salt concentrations in the vermicompost and poorer porosity and aeration. The growth of tomato seedlings was greatest after substitution of Metro-Mix 360 with between 25% and 50% pig manure vermicompost, with more growth occurring in combinations of pig manure vermicompost treated regularly with a liquid fertilizer solution than in those with no fertilizer applied. Some of the growth enhancement in these mixtures seemed to be related to the combined effects of improved porosity, aeration and water retention in the medium and the high nitrate content of the substrate, which produced an increased uptake of nitrogen by the plant tissues, resulting in increased plant growth. When the tomato seedlings were watered daily with liquid inorganic fertilizer, substitution of Metro-Mix 360 with a very small amount (5%) of pig manure vermicompost resulted in a significant increase in the growth of tomato seedlings. Such effects could not be attributed solely to the nutritional or physical properties of the pig manure vermicompost. Therefore, it seems likely that the pig manure vermicompost provided other biological inputs, such as plant growth regulators into the container medium, that still need to be identified fully.

Animals↗
PubMed2004

Effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure.

Cattle manure from stock bedded on straw was aerobically composted under ambient conditions, turning with either a tractor-mounted front-end loader or a rear discharge manure spreader. Three composting experiments, each of approximately four months duration, were conducted to investigate the effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure. Manure stacks of 12-15 m(3) initial volume were constructed in separate 5 x 5 m concrete compartments. Experiment 1 (January-April 1999) compared manure heaps turned once (T1) or three times (T3) using a front-end loader with an unturned static (S) control manure stack. Experiment 2 (June-September 1999) compared the same treatments as Experiment 1. Experiment 3 (September-December 1999) compared T1 and T3 turning regimes using a front end loader with turning by a rear-discharge spreader (TR1 and TR1T2) for more effective aeration of the manure. Turning took place at 6 weeks for the one turn treatments, and after 2, 6 and 10 weeks for the three turn treatments. Leachate losses were dominated by NH(4)-N during the first three weeks of composting, after which time NH4-N and NO3-N concentrations in leachates were approximately the same, in the range 0-20 mg N l(-1). The concentrations of both NH4-N and NO3-N in leachate were higher after turning. Molybdate-reactive P concentrations in leachate tended not to be significantly influenced by turning regime. Gaseous losses of NH3 and N2O rose quickly during the initial phases of composting, peaking at 152 g N t(-1) d(-1) for the T3 treatment. Mean NH3 emission rate (25-252 g N t(-1) d(-1)) for the first two weeks of Experiment 2 conducted during the period June-September were an order of magnitude greater (1-10 g N t(-1) d(-1)) than Experiment 3, conducted during the colder, wetter autumn period (September-December). Nitrous oxide emission rates ranged between 1-14 g N t(-1) d(-1) and showed little influence of turning regime. Total N and P concentrations in turned (T) and static (S) manure were elevated at the end of all experiments, due to loss of dry matter. Mean total N losses were 30.4% (T1) and 36.8% (T3) and total P losses 28.2% (T1) and 27.4% (T3).

Agriculture↗
PubMed2006

Free Fatty acids and sterols in swine manure.

Free fatty acids and sterols were assessed in fresh manure and anaerobic lagoon sludge from swine production facilities in North Carolina. Eight free fatty acids and five sterols were identified and quantified in both manure and sludge samples. Compound identification was performed by gas chromatography/mass spectroscopy (GC-MS), and compound quantities were determined by gas chromatography after solid phase extraction with a 50:50 mixture of diethyl ether and hexane. The free fatty acids occurring in greatest abundance in both fresh manure and lagoon sludge were palmitic, oleic, and stearic. Free fatty acid content in fresh manure ranged from approximately 3 microg g(-1) dry weight (dw) to over 45 microg g(-1) dw. In lagoon sludge, free fatty acid content ranged from about 0.8 microg g(-1) dw to nearly 4 microg g(-1) dw. Coprostanol and epicoprostanol were the sterols in largest concentrations in fresh manure and lagoon sludge samples. Total sterol content ranged from approximately 0.5 microg g(-1) dw to around 11 microg g(-1) dw in fresh manure and from 3.5 microg g(-1) dw to almost 9 microg g(-1) dw in lagoon sludge. Fresh manure and lagoon sludge both had high levels of inorganic cations (e.g., Ca, Mg, Fe) capable of binding free fatty acids and forming insoluble complexes, thereby potentially reducing fatty acid biodegradation. In anaerobic lagoons, sterols are an organic fraction of sludge that are resistant to bacterial degradation. In the case of fresh manure, fatty acids could represent a potential source of energy via the manufacture of biodiesel fuel, if efficient means for their extraction and transesterification can be devised.

Agriculture↗
PubMed2006

Ammonium-nitrogen transformation and nitrogen retention in broiler manure supplemented with a soil amendment containing nitrifying bacteria.

The effect of a soil amendment on ammonium nitrogen transformation and nitrogen retention in broiler manure was evaluated. Prior to incubation, broiler manure was mixed with autoclaved soil or non-autoclaved soil in different ratios to make 1 kg mixtures; broiler manure:non-autoclaved soil=9:1, 5:5, and 1:9 or broiler manure:autoclaved soil=9:1, 5:5, and 1:9. The non-autoclaved soil treatment reduced either numerically or significantly NH(4)(+)-N concentration compared to the autoclaved soil treatment during the 8-wk incubation. Total-N concentration of the non-autoclaved soil treatments was lower than the autoclaved soil treatments from 4 to 8 wk. The lowest manure to non-autoclaved soil treatment (M:S=1:9) had considerably more nitrite and nitrate; however, the higher ratio manure to non-autoclaved soil treatments (M:S=9:1 and 5:5) had slightly higher total nitrite and nitrate levels compared to the same ratio of autoclaved soil treatments. The moisture level of the 9:1, 5:5, and 1:9 M:S treatments were approximately 70, 45, and 30%, respectively. The results indicated that nitrifying bacteria in the non-autoclaved soil reduced the ammonium nitrogen concentrations of poultry manure by converting NH(3) or NH(4)(+) to NO(2)(-) or NO(3)(-). However, the higher moisture levels in treatments with greater manure to soil ratios (M:S=9:1 and 5:5) created anaerobic conditions that allowed for denitrification and greater N losses.

Agriculture↗
PubMed2003

Effects of bioreactor temperature and time on odor-related parameters in aerated swine manure slurries.

Previous studies have linked odor generation from swine manure to some characteristics of the liquid manure such oxidation-reduction potential (ORP), five-day biochemical oxygen demand (BOD5), volatile fatty acids (VFAs), and predominant microbial population. This study investigated the effect of bioreactor temperature and time on the aforementioned parameters during aeration of swine manure. Five reactors (13 1 capacity) loaded with swine manure and maintained at temperatures of 5, 10, 15, 20, and 25 degrees C, were supplied with air for 15 days to maintain aerobic conditions. Large fluctuations in ORP (-120 to 360 mV) were observed in the first seven days of aeration, which stabilized thereafter regardless of the bioreactor temperature. The percentage removal of VFAs and BOD5 in the manure significantly increased from 0.0% on day one to 87.8% and 65.3%, respectively, on day nine, and remained relatively constant thereafter. The mean percentage of VFAs and BOD5 removed also increased significantly with an increase in the bioreactor temperature. The VFAs and BOD5 removal increased by approximately 25% and 35%, respectively, in going from 5 to 25 degrees C, during the 15 days of aeration. Both VFAs and BOD5 in the manure were significantly correlated with ORP, aerobic bacteria, and anaerobic bacteria. The data suggested that continued aeration for seven days at 20 or 25 degrees C was sufficient for significant reduction of odor precursors (VFAs and BOD5) and in stabilization of swine manure. A linear correlation of 0.97 between VFAs and BOD5 indicated that the two parameters can be used interchangeably as indicators of odor release potential in swine manure.

Air Pollutants↗
PubMed2006

UV inactivation of bacteria in raw and pretreated liquid swine manure.

The study was conducted to investigate the effectiveness of ultraviolet (UV) irradiation for inactivating coliform bacterial indicators in liquid swine manure samples using a laboratory-scale, low-pressure UV collimated beam apparatus. Raw liquid swine manure was brought from the field and stored at 4 'C for preliminary settling for 24 hours, which was followed by alum treatment in a jar test apparatus. Both pre-settled and alum-treated supernatants were filtered separately through different pore-sized polycarbonate membrane filters. The unfiltered and filtered pre-settled and alum-treated supernatant samples were exposed to a range of UV fluences (i.e., doses) to determine the fluence-response relationship. After preliminary settling, alum treatment, and membrane filtration, UV absorbance values of undiluted swine manure samples at 254 nm varied between 4.0 and 4.2 cm(-1) with total suspended solids concentrations of 800 to 1,800 mg l(-1). Total coliforms were reduced by 2 - to 2.5-log10 at UV fluences of 80 to 100 mJ cm(-2). Relatively small log reductions (< 0.5-log10) were observed at lower fluences (below 20 mJ cm(-2) ) in undiluted manure samples. To reduce the UV absorbance of liquid swine manure, raw manure was diluted 1:50 and 1:10 with deionized water in subsequent experiments. Almost complete inactivation (> 4 to 5 log10) was achieved at UV fluences of 20 mJ cm(-2) or higher in the swine manure samples diluted to 1:50. Based on these findings, it was proposed that UV inactivation of coliform in the undiluted liquid swine manure was limited by association of bacterial cells with particulate matter of less than 10 microm in size. Dilution may have disrupted and reduced the association between the bacteria and this fine particulate matter resulting in better dispersion and more complete inactivation by UV.

Alum Compounds↗
PubMed2002

Precipitation of swine and cattle manure phosphorous using limestone dust.

The effectiveness of SPS and PULPRO, fine limestone dusts, in precipitating swine and dairy manure phosphorous (P) was determined in the laboratory. Both manures were sieved before being treated with limestone, to reproduce the treatment of mechanically separated manure and to observe the precipitation effect of limestone without that of the large manure solid particles. P precipitation was optimized by varying precipitation conditions (propeller blade speeds, mixing time and limestone levels) and limestone particle size. P precipitation was optimized using a propeller blade mixing speed of 0.3 m s(-1) for at least 5 minutes, using 3% limestone (dry limestone mass over wet manure mass). In terms of particle size, PULPRO 20 (limestone with a particle size of 0.02 mm) produced the most P precipitation and the smallest volume and mass of sludge, as compared to PULPRO 10, PULPRO 3 and SPS (limestone with a particle size of 0.01, 0.003 and 0.3 to 0.003 mm, respectively). For both 9.5% TS (total solids) dairy and 8.8% TS swine manure, mechanical separation followed by limestone precipitation concentrated 90% of manure TS and TP in a sludge volume representing 45% of the initial raw manure mass.

Animals↗
PubMed2004

Escherichia coli contamination of vegetables grown in soils fertilized with noncomposted bovine manure: garden-scale studies.

In this study we tested the validity of the National Organic Program (NOP) requirement for a > or =120-day interval between application of noncomposted manure and harvesting of vegetables grown in manure-fertilized soil. Noncomposted bovine manure was applied to 9.3-m2 plots at three Wisconsin sites (loamy sand, silt loam, and silty clay loam) prior to spring and summer planting of carrots, radishes, and lettuce. Soil and washed (30 s under running tap water) vegetables were analyzed for indigenous Escherichia coli. Within 90 days, the level of E. coli in manure-fertilized soil generally decreased by about 3 log CFU/g from initial levels of 4.2 to 4.4 log CFU/g. Low levels of E. coli generally persisted in manure-fertilized soil for more than 100 days and were detected in enriched soil from all three sites 132 to 168 days after manure application. For carrots and lettuce, at least one enrichment-negative sample was obtained < or =100 days after manure application for 63 and 88% of the treatments, respectively. The current > or =120-day limit provided an even greater likelihood of not detecting E. coli on carrots (> or =1 enrichment-negative result for 100% of the treatments). The rapid maturation of radishes prevented conclusive evaluation of a 100- or 120-day application-to-harvest interval. The absolute absence of E. coli from vegetables harvested from manure-fertilized Wisconsin soils may not be ensured solely by adherence to the NOP > or =120-day limit. Unless pathogens are far better at colonizing vegetables than indigenous E. coli strains are, it appears that the risk of contamination for vegetables grown in Wisconsin soils would be elevated only slightly by reducing the NOP requirement to > or =100 days.

Animals↗