Liquid Fraction Of Manure Research Articles

In the quest for sustainable management of liquid fraction of manure - Insights from a life cycle assessment

To mitigate the risk of eutrophication and minimize adverse environmental impacts, surplus manure in nitrate-vulnerable zones is frequently divided into a liquid and solid fraction. Managing the liquid fraction (LF) typically presents a greater challenge due to its substantial volume. This study aimed to assess the environmental impacts by region and trade-offs of managing surplus LF with inventory data from pilot facilities using a life cycle assessment (LCA). The LF-treatment technologies assessed were (i) nitrification-denitrification (NDN) with field application of effluent (ii) NDN with ammonia stripping and nitric acid scrubbing as a pre-treatment step followed by polishing in constructed wetlands, and (iii) nutrient up-concentration using vacuum evaporation and/or membrane filtration.The LCA results suggested that 60 to 80 % of the environmental impacts occurred locally. Nutrient up-concentration from LF via membrane filtration (reverse osmosis) and vacuum evaporation indicated a better environmental performance, albeit with high uncertainty when compared to the other scenarios. Although ammonia stripping-scrubbing showed environmental benefits, these were offset by high environmental burdens from fugitive N2O emissions and energy demand during NDN. Furthermore, the study identified that managing the effluent after NDN, a source of potassium (K), requires a nuanced approach from policymakers. Firstly, when K fertilization requirements are not met, direct land application of the effluent as a fertigation source can be a viable option. This minimizes the need for synthetic K fertilizer production and its ensuing freshwater ecotoxicity impacts. However, tertiary treatment of NDN effluent via constructed wetlands can be considered to prevent deterioration of soil from the influx of K. Policymakers are encouraged to engage with local stakeholders to tailor solutions based on these trade-offs. Furthermore, future research should focus on the implications of K on soil quality as well as the life span of nutrient up-concentration technologies for LF.

Влияние навозных стоков на почвенные фототрофные микроорганизмы

Soil phototrophic microorganisms (algae, cyanobacteria) play a very important role in functioning of anthropogenic systems. They take an active part in soil self-purification by directly absorbing biogenic elements, as well as by stimulating the activity of mineralizing microorganisms at the expense of disengaged oxygen. The research was carried out at a plough field with sod-podzol soil situated near a large pig-breeding farm. Neutralization took place due to natural microbiological processes during the time of disgorging the liquid fraction in the lagoons. Long-term application of manure runoff from pig-breeding farms into plough soil had an impact on species diversity of phototrophic microorganisms, which was considered in the research. Groups of species tolerant to the impact formed in the soil in course of long-term application of liquid manure fraction. The influence of long-term runoff of manure from pig breeding farms on specious diversity of soil phototrophic microorganisms was assessed. In plough soils affected by liquid manure runoff a group of species tolerant to this impact has formed. Their basis is represented by green algae: Klebsormidium flaccidum, K. nitens, Chlorococcum infusionum, Chlorella vulgaris, as well as by the heterocyst-free cyanobacteria Phormidium autumnale and the diatom alga Hantzschia amphioxys. On the surface of plough soil these species make microscopically marked films, i. e. soil “blooming” takes place. General species diversity of microphototrophs in soil of the experimental site is lower than that of the control site. Jaccard coefficient of the experimental and control sites of the field is 47.8%. Nitrogen-fixing cyanobacteria are not represented in the microphototrophic community; it indicates that the natural microcoenosis is damaged in the plough soils and nitrogen content is high.

Quantifying Antibiotic Distribution in Solid and Liquid Fractions of Manure Using a Two-Step, Multi-Residue Antibiotic Extraction.

Antibiotic distribution and analysis within liquid and solid fractions of manure are highly variable due to each compound's respective physiochemical properties. This study developed and evaluated a uniform method extracting 10 antibiotics from 4 antibiotic classes (tetracycline, sulfonamides, macrolides, and β-lactam) from unprocessed manure, solid-liquid separated manure, and composted solids. Through systematic manipulation of previously published liquid chromatography tandem mass spectrometry methods; this study developed an extraction protocol with optimized recovery efficiencies for varied manure substrates. The method includes a two-step, liquid-solid extraction using 10 mL of 0.1 M EDTA-McIlviane buffer followed by 10 mL of methanol. Antibiotics recoveries from unprocessed manure, separated liquids, separated solids, and heat-treated solids using the two-step extraction method had relative standard deviations < 30% for all but ceftiofur. Total antibiotic recoveries were 67-131% for tetracyclines, 56% for sulfonamide, 49-53% for macrolides, and 1.3-66% for β-lactams. This is the first study to use one protocol to assess four classes of antibiotics in liquid and solid manure fractions. This study allowed for more precise risk assessment of antibiotic transport in manure waste stream applied to fields as a liquid or solid compost.

Quantifying Antibiotic Interactions in Solid and Liquid Fractions of Manure Using a Two-Step, Multi-Residue Antibiotic Extraction

Quantifying Antibiotic Interactions in Solid and Liquid Fractions of Manure Using a Two-Step, Multi-Residue Antibiotic Extraction

Plant uptake of nitrogen adsorbed to biochars made from dairy manure

The conversion of dairy waste with high moisture contents to dry fertilizers may reduce environmental degradation while lowering crop production costs. We converted the solid portion of screw-pressed dairy manure into a sorbent for volatile ammonia (NH3) in the liquid fraction using pyrolysis and pre-treatment with carbon dioxide (CO2). The extractable N in manure biochar exposed to NH3 following CO2 pre-treatment reached 3.36 g N kg−1, 1260-fold greater extractable N than in untreated manure biochar. Ammonia exposure was 142-times more effective in increasing extractable N than immersing manure biochar in the liquid fraction containing dissolved ammonium. Radish and tomato grown in horticultural media with manure biochar treated with CO2 + NH3 promoted up to 35% greater plant growth (dry weight) and 36–83% greater N uptake compared to manure biochar alone. Uptake of N was similar between plants grown with wood biochar exposed to CO2 + NH3, compared to N-equivalent treatments. The available N in dairy waste in New York (NY) state, if pyrolyzed and treated with NH3 + CO2, is equivalent to 11,732–42,232 Mg N year−1, valued at 6–21.5 million USD year−1. Separated dairy manure treated with CO2 + NH3 can offset 23–82% of N fertilizer needs of NY State, while stabilizing both the solid and liquid fraction of manure for reduced environmental pollution.

Towards a methodology for recovering K‐struvite from manure

AbstractBACKGROUNDThis study provides a methodology for recovering two essential macronutrients (potassium and phosphorus) from the liquid fraction of manure. This methodology paves the way for K‐struvite recovery from manure by determining the suitable operational conditions (pH and temperature).RESULTSThe theoretical operational conditions were established by modelling and experimentally adjusted with manure, achieving the highest recoveries (80% of P‐recovery) at pH 10 and 38 °C when using a 10% manure solution. Then, the suitable operational conditions were evaluated using 0–10–50–100% manure solutions. The lowest percentages of manure (0–10%) favoured the co‐precipitation of other products besides K‐struvite (magnesium phosphate and magnesium hydroxide); and at the highest percentages of manure (50–100%), all the phosphate was recovered as K‐struvite, but also the co‐precipitation of magnesium hydroxide due to the Mg/P molar ratio applied (Mg/P = 2). Suspended particles acted as nuclei for heterogeneous nucleation and favoured the aggregation of crystals resulting in a star‐asterisk form.CONCLUSIONThe viability of the process was demonstrated, this study being the first proof‐of‐concept of K‐struvite recovery from complex waste streams. © 2017 Society of Chemical Industry

Method development for the analysis of ionophore antimicrobials in dairy manure to assess removal within a membrane-based treatment system

Ionophore antimicrobials are heavily used in the livestock industries, both for preventing animal infection by coccidia protozoa and for increasing feed efficiency. Ionophores are excreted mostly unmetabolized and are released into the environment when manure is land-applied to fertilize croplands. Here, an analytical method was optimized to study the occurrences of five ionophore residues (monensin, lasalocid, maduramycin, salinomycin, and narasin) in dairy manure after solid-liquid separation and further treatment of the liquid manure by a membrane-based treatment system. Ionophore residues from the separated solid manure (dewatered manure) and suspended solids of manure slurry samples were extracted using ultrasonication with methanol, followed by sample clean-up using solid phase extraction (SPE) and subsequent analysis via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The use of an ethyl acetate and methanol (1:1 v:v) mixture as an SPE eluent resulted in higher recoveries and lower method quantitation limits (MQL), when compared to using methanol. Overall recoveries from separated solid manure ranged from 73 to 134%. Liquid manure fractions were diluted with Nanopure™ water and cleaned up using SPE, where recoveries ranged from 51 to 100%. The developed extraction and LC-MS/MS methods were applied to analyze dairy manure samples subjected to an advanced manure treatment process involving a membrane-based filtration step (reverse osmosis). Monensin and lasalocid were detected at higher concentrations in the suspended solid fractions (4.40–420 ng/g for lasalocid and 85–1950 ng/g for monensin) compared to the liquid fractions (<MQL – 132 ng/mL for monensin). Monensin residues remained in liquid manure treated with reverse osmosis where residual concentrations were reduced to near 8 ng/mL.

Long-term alternative dairy manure management approaches enhance microbial biomass and activity in perennial forage grass

Removing solids from liquid dairy manure slurry reduces manure phosphorus (P) and increases the available (mineral) fraction of nitrogen (N) but also decreases the organic matter content of the manure. While this novel treatment reduces environmental concerns associated with excess N and P application to soils, it may also reduce microbial biomass and activity in soil. This study evaluated the long-term effects of this alternative manure treatment compared to more typical nutrient applications in a perennial grass sward (tall fescue, Festuca arundinacea Schreb.) on soil microbial biomass, community composition, hydrolytic enzyme activity, and forage yield. Nutrient treatments for this long-term field experiment in Agassiz, British Columbia, Canada were started in 2003. The treatments included liquid dairy manure slurry, liquid dairy manure with solids removed, commercial fertilizer, a combination of fertilizer and dairy manure, and a control. All treatments were applied at 400–600 kg total N ha−1 year−1 in four equal doses. Soil microbial community composition (phospholipid fatty acid analysis) and activity (hydrolytic enzyme activity) were determined several times during the 2013 and 2014 growing seasons to a depth of 15 cm. Time of sampling (date) had a strong influence on microbial biomass, community composition, and activity, while the response to soil properties and yield was more varied. All manure treatments (dairy manure slurry, liquid fraction, and the combination) increased microbial biomass (by 19–32%) and the potential activity of cellulose-degrading enzymes (by 31–47%) compared to commercial fertilizer and unamended plots. The commercial fertilizer and liquid fraction lowered fungal/bacterial ratios compared with both whole manure and unamended plots. Our results indicate that separating the solid from the liquid fraction of manure, to improve crop yield and reduce P loading, did not reduce microbial community size and activity and that all manure treatments increased microbial biomass and activity compared to mineral fertilizer application.

Can Phosphate Salts Recovered from Manure Replace Conventional Phosphate Fertilizer?

Pig farming produces more manure than can reasonably be spread onto surrounding fields, particularly in regions with high livestock densities and limited land availability. Nutrient recycling offers an attractive solution for dealing with manure excesses and is one main objective of the European commission-funded project “BioEcoSIM”. Phosphate salts (“P-Salt”) were recovered from the separated liquid manure fraction. The solid fraction was dried and carbonized to biochar. This study compared the fertilizing performance of P-Salt and conventional phosphate fertilizer and determined whether additional biochar application further increased biomass yields. The fertilizers and biochar were tested in pot experiments with spring barley and faba beans using two nutrient-poor soils. The crops were fertilized with P-Salt at three levels and biochar in two concentrations. Biomass yield was determined after six weeks. Plant and soil samples were analysed for nitrogen, phosphorus and potassium contents. The P-Salt had similar or even better effects than mineral fertilizer on growth in both crops and soils. Slow release of nutrients can prevent leaching, rendering P-Salt a particularly suitable fertilizer for light sandy soils. Biochar can enhance its fertilizing effect, but the underlying mechanisms need further investigation. These novel products are concluded to be promising candidates for efficient fertilization strategies.

Effect of permeate flux in a membrane SBR (MSBR) treating the liquid fraction of manure

Effect of permeate flux in a membrane SBR (MSBR) treating the liquid fraction of manure

Measured versus modeled methane emissions from separated liquid dairy manure show large model underestimates

Liquid manure in storage is a significant and poorly quantified source of methane (CH4). A micrometeorological technique was used to measure CH4 emissions from stored liquid manure on a dairy farm with approximately 146 milking cows and a screw-press solid-liquid separator. Higher than expected CH4 emissions were observed from the liquid manure fraction in the concrete storage tank likely due the high biodegradability of the liquid manure fraction when a long retention time coincided with high temperature. Almost all of the annual CH4 emissions occurred when both manure volume and temperature were high during the five-month period from July to November. In Year 1, 85% of annual emissions occurred from July to September, with 53% occurring in August. In Year 2, 93% of annual emissions occurred from July to November, with 30% occurring in October and November (combined). Removing manure in early fall reduced CH4 emissions substantially: we observed 21% lower annual emissions when manure was removed in early fall (33Mg CH4 in Year 1: September removal) compared to removal in late fall (42Mg CH4 in Year 2: end of November). Comparisons between measured and modeled CH4 emissions showed that both the IPCC methane conversion factor (0.17) for cool climates (10°C or less), and the USEPA model, underestimated annual emissions by up to 60%. We calculated CH4 conversion factors ranging from 0.58 to 0.89 using the measured VS loading rate both with and without VS in the sludge that remained after emptying. Our results suggest that farmers can substantially reduce CH4 emissions by removing manure in late summer and early fall.

Enhancing Extraction and Detection of Veterinary Antibiotics in Solid and Liquid Fractions of Manure

Analysis of veterinary antibiotics in separated liquid and solid fractions of animal manures is vital because of wide variations in the composition of agriculturally applied manure. Differentiation of antibiotic concentrations is important between liquid and solid manures, as their sorption onto the solid fraction depends on physicochemical properties of each antibiotic and manure composition (e.g., organic content, pH) and because each fraction may be treated and reused differently. Here, an efficient and sensitive method for the analysis of 22 veterinary antibiotics in the liquid and solid fractions of manure is reported. Tetracycline (TC), macrolide, and sulfonamide antibiotics were extracted from liquid manure by liquid-liquid extraction (LLE) with methanol following acidification with acetic acid. Extraction from solids was performed by sonication with acetonitrile, methanol, and 0.1 M EDTA-McIlvaine buffer. Cleanup of extracts was achieved by solid-phase extraction with hydrophilic-lipophilic balance (HLB) cartridges or tandem amino (NH2) and HLB cartridges. Quantification of antibiotics was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) under wrong-way-round (WWR) ionization for sulfonamides and TCs and right-way-round ionization for macrolides. Recoveries of 58 to 94.7% and 62 to 94.3% were obtained in liquid and solid manure, respectively. Method detection limits range from 1.2 to 12 ng L and 0.5 to 7.9 μg kg dry wt. in liquids and solids, respectively. This method allows for extraction and analysis of both mobile antibiotics in liquid phase and hydrophobic antibiotics adsorbed on the solids. Without separate analysis, antibiotic concentrations may be improperly estimated by analyzing whole manure, as reported in many studies to date.

Environmental Impact Assessment (EIA) of Effluents from Constructed Wetlands on Water Quality of Receiving Watercourses

The amount of animal manure produced in Flanders—Belgium by intensive animal farming generates a surplus that needs to be treated in order to achieve quality objectives set by the Nitrates Directive (91/676/EEC) and the European Water Framework Directive (2000/60/EU). After the physical separation and biological nitrification/denitrification processes, the liquid fraction of manure can be cost-efficiently and effectively treated by constructed wetlands (CWs). However, current discharge criteria limits do not evaluate whether nutrient loads from specific point sources (such as CWs) affect the water quality of their receiving waterway. Thus, we investigated whether a site-specific analysis, based on local environmental conditions, would yield more relevant discharge thresholds. In the present study, a standardized framework was developed for environmental impact assessment (EIA) of effluents from CWs on the water quality of receiving watercourses. This framework was tested as a case study on a manure treatment installation located in Langemark—Belgium. The effect of different impact scenarios on water quality and flow of the effluent and the receiving waterway was studied. Standardized EIA guidelines and sensitivity analyses were applied to determine the expected impacts of total nitrogen (TN), total phosphorous (P), chlorides (Cl−) and sulphates (SO4 2−) on the receiving watercourse. From this study, we concluded that the methodology currently applied requires adaptation when assessing the discharge from wetlands as current estimations of impact are overly conservative when compared with actual impact. In addition, results showed that expected impact might be mitigated by differentiating discharge limits between dry and wet periods.

Manure management practices on biogas and non-biogas pig farms in developing countries – using livestock farms in Vietnam as an example

This survey was carried out to study animal manure management on livestock farms with biogas technology (biogas farms) and without (non-biogas farms) in the areas surrounding the Vietnamese cities Hanoi and Hue. The objective of the study was to assess the contribution of biogas production to a better environment as well as to recognize the problems with livestock manure management on small-scale farms. On all the farms included in the study more than one manure management technology was used, i.e. composting, separation of manure, biogas production and discharge of liquid manure to recipients such as public sewers or ponds. On biogas farms, most of the manure collected was used for bio-digestion. The farmers used the fermented manure (digestate) as a source of nutrients for crops, but on more than 50% of the interviewed biogas farms digestate was discharged to the environment. On non-biogas farms, manure was in the form of slurry or it was separated into a liquid and a dry-matter-rich solid fraction. The solid fraction from separation was used for composting and the liquid fraction usually discharged to the environment. The survey revealed that there is a need to improve methods for transporting the manure to the field, as transportation is the main barrier to recycling the liquid manure fraction. Farmers in developing countries need financial and technical support to install biogas digesters and to overcome the problems involved in utilizing the manure. Information about how to pre-treat manure before adding it to the digester is urgently needed. At present too much water is used, and the high volume of slurry reduces the retention time and is a disincentive for transporting and applying the digestate to fields. The users need to be informed about the risk of loss of methane to the environment, how to prevent cooker corrosion and the discharge to recipients. In addition, the study reveals that in developing countries manure management legislation needs to be tightened to control environmental pollution.

Leaching of nitrate and phosphorus after autumn and spring application of separated solid animal manures to winter wheat

AbstractAnimal slurry can be separated into solid and liquid manure fractions to facilitate the transport of nutrients from livestock farms. In Denmark, untreated slurry is normally applied in spring whereas the solid fraction may be applied in autumn, causing increased risk of nitrate and phosphorus (P) leaching. We studied the leaching of nitrate and P in lysimeters with winter wheat crops (Triticum aestivum L.) after autumn incorporation versus spring surface application of solid manure fractions, and we compared also spring applications of mineral N fertilizer and pig slurry. Leaching was compared on a loamy sand and a sandy loam soil. The leaching experiment lasted for 2 yr, and the whole experiment was replicated twice. Nitrate leaching was generally low (19–34 kg N/ha) after spring applications of mineral fertilizer and manures. Nitrate leaching increased significantly after autumn application of the solid manures, and the extra nitrate leached was equivalent to 23–35% of total manure N and corresponded to the ammonium content of the manures. After spring application of solid manures and pig slurry, only a slight rise in N leaching was observed during the following autumn/winter (&lt;5% of total manure N). Total P leaching was 40–165 g P/ha/yr, and the application of solid manure in autumn did not increase P leaching. The nitrogen fertilizer replacement value of solid manure N was similar after autumn and spring application (17–32% of total N). We conclude that from an environmental perspective, solid manure fractions should not be applied to winter wheat on sandy and sandy loam soils under humid North European conditions.

Enhanced methods for conditioning, storage, and extraction of liquid and solid samples of manure for determination of steroid hormones by solid-phase extraction and gas chromatography–mass spectrometry

Hormones are among the highest-impact endocrine disrupters affecting living organisms in aquatic environments. These molecules have been measured in both wastewater and sewage sludge. Analytical techniques for such matrices are well described in the literature. In contrast, there is little information about the analysis of hormones in animal waste. The objectives of this study were, first, to propose a method for conditioning swine manure samples (addition of formaldehyde, separation of the solid and liquid phases, and duration of storage) in order to determine hormones in the liquid fraction of manure by solid-phase extraction (SPE) coupled with gas chromatography-mass spectrometry (GC-MS). Our results showed that analysis of hormones was affected by matrix changes which occurred during freezing and thawing and after addition of formaldehyde, an additive frequently used to preserve environmental samples. Thus, our results argue for the conditioning of samples without formaldehyde and for separating the solid and liquid fractions of manure before freezing. Second, this study reports on the use of a liquid extraction method coupled with SPE and GC-MS analysis for determination of hormones in the solid fraction of manure. Under the conditions selected, hormone recoveries were between 80 and 100%. Finally, the optimized method was used to quantify hormones in both liquid and solid fractions of swine manure from different breeding units. High levels of estrone and α-estradiol were found in samples whereas β-estradiol was detected in smaller amounts. Estriol and progesterone were mainly found in manure from the gestating sow building whereas testosterone was detected in manure from male breeding buildings.

Nutrient value, odour emission and energy production of manure as influenced by anaerobic digestion and separation

Crop fields can be fertilised by application of manure because manure contains fertilising elements such as N and P, and organic matter that enhances soil physical properties. However, application of manure may also cause P and N pollution of surroundings, odour emission and waste of energy. A solution may be to apply an improved liquid manure fraction resulting from manure separation and anaerobic digestion. As previous studies have only focused on the factors individually, we carried out here a system analysis with the aim of optimising all the factors simultaneously. We tested three solid-liquid separations on raw manure and manure pre-digested in a biogas reactor, with the separation treatments being coagulation, flocculation and filtration, which differed mainly with respect to coagulant volume, and the N:P ratio of the products was measured. The NH3 and odour emission was determined from the liquid fractions during storage and after soil application, while the energy produced at anaerobic digestion of the solid fractions was measured. Our results show that energy production at digestion increased with decreasing coagulant volume, but was largely unaffected by anaerobic digestion whether performed both before and after or only after separation. Odour generation was reduced by pre-digestion. With increasing coagulant volume and without pre-digestion, the nutrient value of the liquid fraction was improved the most, as shown by an increase in the N/P ratio of the liquid fraction and by a decrease in NH3 emissions from stores and fields. The data proved that mechanical separation of raw manure, added coagulant and polymer, followed by anaerobic digestion of the solid fraction was the optimum strategy from a whole animal manure management perspective. The coagulant volume can be adjusted to favour either nutrient value and NH3 emission, or energy production.

Integrated Control Strategy for Processes in Fattening Pig Systems

This paper describes the development of a control strategy for indoor climate conditions and the water evaporation from liquid manure fraction using a simulation model of a fattening pig production system. The manure produced in this system is first separated. the solid fraction is composted and water from the liquid fraction is evaporated. Different control strategies are evaluated on their operational energy costs and of the achieved dry matter content of the liquid fraction. The manipulated and design variables are ventilation flow, heat supply and the choice between ventilation with outdoor air (direct ventilation) or with air conditioned in soil embedded tubes (indirect ventilation).

Anaerobic manure treatment under extreme temperature conditions

Usually anaerobic treatment of manure is performed as one stage fermentation under mesophilic (30-35°C) or moderate thermophilic (50-55°C) conditions, with the aim to stabilize organic material for the use of digested manure as a fertilizer. The present study was conducted to develop a new approach for manure treatment, which concerned the sanitation of manure and saving energy for its treatment. Laboratory scale experiments were performed on the digestion of cattle and pig manure under psychrophilic conditions (5-20°C) and extreme thermophilic (55-82°C) conditions. Specifically, we were interested in the digestive activities of microbial populations under low and high temperature conditions. Long-term adaptation (or selection) of active psychrophilic microbial communities is essential to perform sufficient manure treatment at low temperatures. Results of this investigation indicated the development and accumulation of a specific microbial populations at high and at low temperatures in both cattle and pig manure. An acclimated methanogenic microbial community active at 5°C was obtained after 1.5-years incubation of cattle manure at low temperatures, prior to digestion under mesophilic conditions. Fermentation under high temperature conditions resulted in the development of a thermophilic acidogenic microbial populations, with the observed accumulation of volatile fatty acids in the liquid fraction of manure. Thus, a two-step anaerobic manure treatment is proposed in which the sanitation of manure and saving energy present: i) acidogenic fermentation at high temperature, ii) separation for solid and liquid fractions, iii) treatment of liquid manure fraction under low temperature conditions.

Anaerobic manure treatment under extreme temperature conditions

Usually anaerobic treatment of manure is performed as one stage fermentation under mesophilic (30-35°C) or moderate thermophilic (50-55°C) conditions, with the aim to stabilize organic material for the use of digested manure as a fertilizer. The present study was conducted to develop a new approach for manure treatment, which concerned the sanitation of manure and saving energy for its treatment. Laboratory scale experiments were performed on the digestion of cattle and pig manure under psychrophilic conditions (5-20°C) and extreme thermophilic (55-82°C) conditions. Specifically, we were interested in the digestive activities of microbial populations under low and high temperature conditions. Long-term adaptation (or selection) of active psychrophilic microbial communities is essential to perform sufficient manure treatment at low temperatures. Results of this investigation indicated the development and accumulation of a specific microbial populations at high and at low temperatures in both cattle and pig manure. An acclimated methanogenic microbial community active at 5°C was obtained after 1.5-years incubation of cattle manure at low temperatures, prior to digestion under mesophilic conditions. Fermentation under high temperature conditions resulted in the development of a thermophilic acidogenic microbial populations, with the observed accumulation of volatile fatty acids in the liquid fraction of manure. Thus, a two-step anaerobic manure treatment is proposed in which the sanitation of manure and saving energy present: i) acidogenic fermentation at high temperature, ii) separation for solid and liquid fractions, iii) treatment of liquid manure fraction under low temperature conditions.