The Physical Properties of Compost

Agnew, J.; Leonard, J.J.

doi:10.1080/1065657x.2003.10702132

Cited by 223 publications

(121 citation statements)

References 50 publications

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“…One function of litter is to absorb and store water from excreta and drinking-system spillage until the water can be evaporated and removed from the shed by the ventilation system. The amount of water in litter has been found to affect microbial activity (Bessei, 2006;Eriksson De Rezende et al, 2001;Himathongkham et al, 1999;Wadud et al, 2012), thermal insulation (Agnew and Leonard, 2003), ammonia emissions (Miles et al, 2011), odour emissions (Clarkson and Misselbrook, 1991;Murphy et al, 2014) and friability (Bernhart and Fasina, 2009).…”

Section: Introductionmentioning

confidence: 99%

Water activity of poultry litter: Relationship to moisture content during a grow-out

Dunlop

McAuley

Blackall

et al. 2016

Journal of Environmental Management

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Keywords:Broiler Meat chicken Equilibrium relative humidity (ERH) Wet litter Water absorption isotherms a b s t r a c t Poultry grown on litter floors are in contact with their own waste products. The waste material needs to be carefully managed to reduce food safety risks and to provide conditions that are comfortable and safe for the birds. Water activity (A w ) is an important thermodynamic property that has been shown to be more closely related to microbial, chemical and physical properties of natural products than moisture content. In poultry litter, A w is relevant for understanding microbial activity; litter handling and rheological properties; and relationships between in-shed relative humidity and litter moisture content. We measured the A w of poultry litter collected throughout a meat chicken grow-out (from fresh pine shavings bedding material to day 52) and over a range of litter moisture content (10e60%). The A w increased non-linearly from 0.71 to 1.0, and reached a value of 0.95 when litter moisture content was only 22e33%. Accumulation of manure during the grow-out reduced A w for the same moisture content. These results are relevant for making decisions regarding litter re-use in multiple grow-outs as well as setting targets for litter moisture content to minimise odour, microbial risks and to ensure necessary litter physical conditions are maintained during a grow-out. Methods to predict A w in poultry litter from moisture content are proposed.Crown

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Section: Introductionmentioning

confidence: 99%

Water activity of poultry litter: Relationship to moisture content during a grow-out

Dunlop

McAuley

Blackall

et al. 2016

Journal of Environmental Management

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“…Aerobic composting is a widely used technique for solid waste treatment, the equipment for composting is developing rapidly [4][5][6][7]. In recent years, some studies focused on changes in biochemical indicators [5,8], maturity [4], stability of compost products [6], and effects of product cultivation [9]. Domestic and foreign scholars conducted a series of studies on the theory and practice of solving the long-time fermentation problem of conventional composting, similar to adding the biological agent to accelerate decomposition during the composting process [10].…”

Section: Introductionmentioning

confidence: 99%

Comparison and Evaluation of Co-composting Corn Stalk or Rice Husk with Swine Waste in China

Gao

Zhou

Wang

et al. 2015

Waste Biomass Valor

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An experimental composting system was employed to study the effect of different proportions of corn stalk, rice husk and swine waste on composting efficiency and final compost quality. Three dry mass ratios were designed with biological agent addition as blank contrast. After 84 days of a static aerobic composting process, full-scale comparison was investigated in maturity, organic nutrient and sanitarian properties. The results showed that the treatment of corn stalk co-composting with swine waste at 1:1.5 ratio with the addition of a biological agent was the first to achieve maturity and had a higher level of organic fertiliser quality, and hygienic indicators of the compost product were satisfied within the relevant standards for harm. Meanwhile, the effect of the biological agent on acceleration of degradation was verified in corn stalk composting. This study found rice husk compost did not reach ideal high temperature. The maturity effect of the final product was relatively poor. Except the treatment of rice husk mixing swine manure at 1:2 ratio with biological agent, other treatments of rice husk had lower and lesseffective products, no positive effect was observed in the rice husk compost. At the end of this paper some suggestions were given to develop new approaches for rice husk utilisation and reduce the cost of corn stalk co-composting.

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“…A specific composting process is influenced by the nature of the treated waste, and specifically its physical characteristics (Agnew and Leonard, 2003).…”

Section: Introductionmentioning

confidence: 99%

Effect of initial physical characteristics on sludge compost performance

Trémier¹,

Teglia²,

Barrington³

2009

Bioresource Technology

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To develop an active microbial activity quickly developing stabilizing thermophilic temperatures during the composting of wastewater sludge, the bulking agent (BA) plays a major role in establishing the recipe structure, exposed particle surface area and porosity. To optimize the biodegradation of a sludge compost recipe, the objective of this paper was to study the effect and interaction of initial moisture content (MC) and BA particle size distribution. Three 300 L insulated laboratory composters were used to treat two series of ten (10) recipes with different combinations of MC and BA particle size distribution. Using a BA to wastewater sludge dry mass ratio of 1/ 6, the ten (10) recipes were repeated using two BA, residues recycled from a commercial sludge composting plant and crushed wood pallets. Each four week trial monitored O 2 uptake, temperature, compost consolidation and airflow distribution. The Central Composite Factor Design method produced a model from the results estimating the impact of a wider range of MC and BA particles size distribution. The MC directly affected the total O 2 uptake and therefore organic matter biodegradation. The BA particle size distribution influenced compost consolidation with a MC crossed effect. Both BA particle size distribution and MC influenced compost airflow dispersion. Composting was optimized using the BA consisting of recycled green waste residues with particle size of 20 to 30 mm and a 55 % MC. The predictive models suggested the need for further optimization of sludge and wood residue composting recipe.

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The Physical Properties of Compost

Cited by 223 publications

References 50 publications

Water activity of poultry litter: Relationship to moisture content during a grow-out

Water activity of poultry litter: Relationship to moisture content during a grow-out

Comparison and Evaluation of Co-composting Corn Stalk or Rice Husk with Swine Waste in China

Effect of initial physical characteristics on sludge compost performance

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