scholarly journals Nutrient losses from cattle co-digestate slurry during storage

2016 ◽  
Vol 47 (2) ◽  
pp. 94 ◽  
Author(s):  
Francesca Perazzolo ◽  
Gabriele Mattachini ◽  
Fulvia Tambone ◽  
Aldo Calcante ◽  
Giorgio Provolo

Among environmental issues related to intensive livestock activity, emissions to air from manure management are of increasing concern. Thus the knowledge of the effect of treatment application on subsequent emissions from manure is required to assess the environment impact of management solutions. This work addresses the effect of anaerobic digestion and phase separation on emissions during storage by studying nitrogen losses from lab-scale stores and field pilot-scale stores of a co-digestate cattle slurry and its respective separated fractions. Lab-scale experiment was carried in temperature-controlled room where each fraction (untreated, separated liquid and separated solid) was stored in duplicate for a period of 32 days in 30 L vessel. Pilot-scale experiment was carried out both during the cold season and during warm season for 90 days of storage. In both experimentations samples of the manure were analysed periodically for total Kjeldahl nitrogen (TKN), total ammonia nitrogen, dry matter and volatile solids and pH. These analyses allow estimating nitrogen losses in different storage conditions. Effects of mechanical separation and season were assessed by ANOVA (Wilcoxon test, P<0.05). In temperature controlled conditions nitrogen losses measured account for 13% and 26% of TKN for unseparated and separated slurries respectively. In field conditions during cold season nutrient losses were limited. On average unseparated and separated slurries lost respectively 6.8% and 12.6% of their initial TKN content. Much higher were the TKN losses from the slurries examined in warm season where losses raised up to 40% of the initial TKN content. Generally mechanical separation increases nutrient losses, but the differences were not significant in field conditions. The results highlighted that nutrient losses, in particular the nitrogen ones, can be considerable especially during summer storage. The latter, in case of separated slurries, are mainly related to the liquid fraction, which is responsible for up 92% of the losses. When phase separation after anaerobic digestion is used, mitigation options, as covers or slurry acidification, are advisable in order to limit the negative environmental impact.

2013 ◽  
Vol 68 (4) ◽  
pp. 948-955 ◽  
Author(s):  
Wei Qiao ◽  
Zhibiao Yin ◽  
Wei Wang ◽  
Jing Wang ◽  
Zhongzhi Zhang

A pilot process of thermal hydrolysis combined with an expanded granular sludge bed reactor (EGSB) was carried out to evaluate pretreated sludge liquor into biogas conversion, process stability, and energy input/output balance. Approximately 25% of suspended solids of sludge were liquefied into aqueous phase during thermal hydrolysis pretreatment, which resulted in chemical oxygen demand (COD) concentration of 20.0 to 35.0 g/L. A mesophilic EGSB reactor was operated for 206 days treating pretreated liquor. Under an organic loading rate of 11.0 kg COD/(m3·d) and hydraulic retention time of 60 h, COD conversion efficiency was maintained at 63%. The energy from biogas provided 80% of that demand for heating pretreatment. Dewatered sludge after thermal hydrolysis could be incinerated with municipal solid waste in an industrial-scale incinerator. Total energy production from combined biogas anaerobic digestion and sludge incineration, treating 1.0 kg raw sludge with moisture content of 82%, was 2419 kJ. The energy demand of thermal hydrolysis pretreatment was 340 kJ.


2021 ◽  
pp. 105148
Author(s):  
Thomas Schubert ◽  
Irem Ergin ◽  
Fiona Panetta ◽  
Jörg Hinrichs ◽  
Zeynep Atamer

2021 ◽  
Vol 13 (10) ◽  
pp. 1884
Author(s):  
Jingjing Hu ◽  
Yansong Bao ◽  
Jian Liu ◽  
Hui Liu ◽  
George P. Petropoulos ◽  
...  

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.


2010 ◽  
Vol 150-151 ◽  
pp. 753-757 ◽  
Author(s):  
Xiong Hao Li ◽  
Yong Jie Xue ◽  
Min Zhou

This paper discussed the feasibility of unburned and non-autoclaved, steam cured bricks prepared by FGD byproducts from coal-fired power plants. The results show that FGD byproduct, aggregates, cementious materials and water could be used to prepare bricks during the process of stir and compaction under natural cure and steam cured condition. S4 and Z2 are the optimum design mixture composition. The maximum compressive strength and saturation coefficient are 28.7 MPa and 96.7%. FGD byproducts do no harm to environment and a pilot-scale experiment demonstrates that bricks made with FGDA can meet the MU10 level bricks technical requirement.


2005 ◽  
Vol 27 (1-2) ◽  
pp. 255-280 ◽  
Author(s):  
Genevieve LeMoine ◽  
James Helmer ◽  
Bjarne Grønnow

Abstract Late Dorset dwellings from two sites on Little Cornwallis Island (Nunavut) illustrate the diversity of architectural forms from this period. Ten architectural features are described. They include five tent rings, ascribed to warm season occupations, and five rectangular semi-subterranean houses with axial features, including one exceptionally well-preserved example, ascribed to cold season occupations. Variations in size, number of hearths, and construction techniques are examined and the use of both types of structures to house multiple nuclear families is suggested.


2007 ◽  
Vol 55 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Eli Ana Traversim Gomes ◽  
Viviane Severiano dos Santos ◽  
Denise Rivera Tenenbaum ◽  
Maria Célia Villac

Much time and resources have been invested in understanding plankton dynamics in Guanabara Bay (Brazil), but no attention has been devoted to the protozooplankton. To fulfill this lacuna, abundance and composition of protozooplankton were investigated from January to December - 2000 in fortnightly surface water samplings at two distinct water quality sites (Urca - closer to the bay entrance, more saline and cleaner waters; Ramos - inner reaches, hypereutrophic waters). The density at Urca (10³ - 10(5) cell.l-1) was one to three orders of magnitude lower than at Ramos (10(4) - 10(5) cell.l-1). A seasonal trend for nanoplankton and protozooplankton was more evident at Urca, but both sites had lower densities during the colder period. Small heterotrophic dinoflagellates (20-30 mm) were dominant in over 50% of the samples. The protozooplankton abundance and composition reflected the distinct trophic conditions states found at the bay. During the wet-warm season, non-oligotrich ciliates were representative of Ramos site with Gymnodiniaceae dinoflagellates, while tintinnids and heterotrophic dinoflagellates were predominantly found at Urca mainly during the dry-cold season. This first descriptive study towards the understanding of the intricate relationships among the microbial food web components reveals that protozooplankton can be a good indicator of water quality conditions at the bay.


2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.


1993 ◽  
Vol 28 (2) ◽  
pp. 27-34 ◽  
Author(s):  
G. Boari ◽  
I. M. Mancini ◽  
E. Trulli

Sanitary landfills of municipal solid waste (MSW) might be used to reduce the storage volume required at plants giving year-round treatment of olive oil mill effluent (OME). A landfill in the methanogenic stage could act as an anaerobic filter and reduce the pollutional load of the OME while also acting as a temporary storage tank. In the present work, a lysimeter in pilot scale was used to simulate a cell of a sanitary landfill. It was filled with MSW screened by a 80 mm mesh sieve mixed to municipal sludge. Results show that when OME was spread on the top of the lysimeter at a loading rate not exceeding 0.4 kgCOD/d/m3 of reactor steady methanogenic activity was maintained in the layers of refuse and a 70% removal of COD was obtained in the OME leachate collected. Higher loading rates reduced methanogenic activity and COD removal efficiency. Nevertheless, the OME collected from the bottom of the landfill was more easily treated by anaerobic digestion than was the raw OME.


2015 ◽  
Vol 15 (3) ◽  
pp. 1411-1420 ◽  
Author(s):  
T. F. Bidleman ◽  
L. M. Jantunen ◽  
H. Hung ◽  
J. Ma ◽  
G. A. Stern ◽  
...  

Abstract. Air samples collected during 1994–2000 at the Canadian Arctic air monitoring station Alert (82°30' N, 62°20' W) were analysed by enantiospecific gas chromatography–mass spectrometry for α-hexachlorocyclohexane (α-HCH), trans-chlordane (TC) and cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = peak areas of (+)/[(+) + (−)] enantiomers), where EFs = 0.5, < 0.5 and > 0.5 indicate racemic composition, and preferential depletion of (+) and (−) enantiomers, respectively. Long-term average EFs were close to racemic values for α -HCH (0.504 ± 0.004, n = 197) and CC (0.505 ± 0.004, n = 162), and deviated farther from racemic for TC (0.470 ± 0.013, n = 165). Digital filtration analysis revealed annual cycles of lower α-HCH EFs in summer–fall and higher EFs in winter–spring. These cycles suggest volatilization of partially degraded α-HCH with EF < 0.5 from open water and advection to Alert during the warm season, and background transport of α-HCH with EF > 0.5 during the cold season. The contribution of sea-volatilized α-HCH was only 11% at Alert, vs. 32% at Resolute Bay (74.68° N, 94.90° W) in 1999. EFs of TC also followed annual cycles of lower and higher values in the warm and cold seasons. These were in phase with low and high cycles of the TC/CC ratio (expressed as FTC = TC/(TC+CC)), which suggests greater contribution of microbially "weathered" TC in summer–fall versus winter–spring. CC was closer to racemic than TC and displayed seasonal cycles only in 1997–1998. EF profiles are likely to change with rising contribution of secondary emission sources, weathering of residues in the environment, and loss of ice cover in the Arctic. Enantiomer-specific analysis could provide added forensic capability to air monitoring programs.


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