Recycling Pig Slurry Solid Fraction Compost as a Sound Absorber

Abstract

The aim of this investigation was to determine the physical and acoustical properties of compacts made from composted pig slurry solid fraction (SF) in order to assess the potential to recycle this agricultural waste as a sound absorber. The compacts were obtained by compression. The physical parameters investigated were bulk density, durability, and particle size distribution. The acoustical features of the compacts were studied with an impedance tube device in order to verify the acoustic absorption coefficient. Two composts were prepared: pig SF compost without a bulking agent (SSFC) and pig SF compost with wood chips as a bulking agent (WCC). The study's results indicated that compost particles dimension played a key role in the physical and acoustical properties of the compacts: the smaller the particles, the higher the physical and acoustical properties of the compacts. The densification process increased the bulk density of the investigated composts up to 690 kg m −3 for SSFC and 660 kg m −3 for WWC, with, respectively, medium (77.9%) and low (66.5%) durability. The addition of woody bulking agent significantly reduced the absorption coefficient: the best results, in terms of potential use as a sound absorber, were observed for compacts made from composted pig slurry solid fraction without the addition of wood chips.

Gaseous Emissions after Soil Application of Pellet Made from Composted Pig Slurry Solid Fraction: Effect of Application Method and Pellet Diameter

“…The experiment was carried out using two different composts: pig solid fraction compost (SSFC) and wood chips compost (WCC) obtained by mixing 8000 kg of pig solid fraction with 2400 kg of wood chips derived from park maintenance. The procedures for obtaining SSFC and WCC were fully described in a previous study conducted by Pampuro et al [26].…”

Adding Phosphate Fertilizer and Apple Waste to Pig Manure during Composting Mitigates Nitrogen Gas Emissions and Improves Compost Quality

“…The appropriate disposal practices of pig manure are becoming more important for the Chinese government and livestock industry. Composting is an effective method due to its simplicity and low cost for the disposal of pig manure, and the end compost could be used as a soil additive, organic fertilizer, and sound absorber (Pampuro et al, 2017(Pampuro et al, , 2018Sáez et al, 2017). However, with the degradation of organic matter (OM), significant amounts of nitrogen (N) gases, such as ammonia (NH 3 ) and nitrous oxide (N 2 O), are emitted, which could result from low-quality compost and may also increase atmospheric pollution (Awasthi et al, 2017a;Gabhane et al, 2012).…”

Effect of Densification Conditions on Specific Energy Requirements and Physical Properties of Compacts Made from Hop Cone

“…Signals from the load cells and displacement transducer are processed using a pc-based acquisition system (DS-NET with BR8 module, Dewesoft, Trbovlje, Slovenia) able to acquiring up to 10 ks s −1 . See Pampuro et al [11,23] and Cavallo and Pampuro [12] for more details of the equipment.…”

“…As highlighted in many studies [19,23,28], compacts density plays a key role in determining handling and storage procedures to preserve their integrity.…”

“…As highlighted by Tabil and Sokhansanj [18] and by Kaliyan and Vance Morey [9], durability indicates the ability of densified material to withstand shear and impact force during handling, storing and transportation. Many authors [12,18,19,23,31,32] considered durability value high when the value is higher than 80%, medium when the value is in the range 70-80%, and low when the value is lower than 70%. Low compacts durability is typically not appreciated as it can cause problems such as health hazard and inconvenient environment for the workers due to the production of fines during handling, transport and storage [33].…”