Particle Size Distribution in Municipal Solid Waste Pre-Treated for Bioprocessing

Abstract

While it is well known that particle size reduction impacts the performance of bioprocessing such as anaerobic digestion or composting, there is a relative lack of knowledge about particle size distribution (PSD) in pre-treated organic material, i.e., the distribution of particles across different size ranges. PSD in municipal solid waste (MSW) pre-treated for bioprocessing in mechanical–biological treatment (MBT) was researched. In the first part of this study, the PSD in pre-treated waste at two full-scale MBT plants in the UK was determined. The main part of the study consisted of experimental trials to reduce particle sizes in MSW destined for bioprocessing and to explore the obtained PSD patterns. Shredders and a macerating grinder were used. For shear shredders, a jaw opening of 20 mm was found favourable for effective reduction of particle sizes, while a smaller jaw opening rather compressed the wet organic waste into balls. Setting the shredder jaw opening to 20 mm does not mean that in the output all particles will be 20 mm or below. PSD profiles revealed that different particle sizes were present in each trial. Using different types of equipment in series was effective in reducing the presence of larger particles. Maceration yielded a PSD dominated by very fine particles, which is unsuitable for composting and potentially also for anaerobic digestion. It was concluded that shredding, where equipment is well selected, is effective in delivering a material well suited for anaerobic digestion or composting.

Characterization of Gosa Municipal Solid Wastes at Abuja, Nigeria

“…Size distribution was determined using the sample D. Sample D was sub-divided into eight groups according to the composition. The sample was visually inspected on a tray and a tape rule was used to measure the approximate dimensions for the components that were elongated, flat, irregular and were poured into coarse sieves of apertures 300 mm to 10 mm according to procedures described by Yang (2007) & Zhang et al (2019. The set of sieves were manually shaken for about 10 mins period and classified according to procedures in ASTM E 11, ( 2019) and (ANSI/ASAE S424.1, (2003).…”

“…Size distribution of various components in solid waste is important to match feed to input opening of the handling, recovery and processing machines. Size distribution can be used to determine quality, to establish degree of shredding and grinding, as well as useful to determine size range to minimize losses via removal of oversize and undersize to sustain maximum efficiency (Zhang et al 2019).…”

Underutilised Resources in Urban Environments

“…Table 1 shows that there are interlinkages between circular economy and renewable energy schemes. Seven out of the ten publications address solid wastes and their potential valorisation as part of circular economy schemes [3][4][5][6][7][8][9], which can be material recycling or energetic valorisation. Source-segregated waste destined for energetic valorisation is considered a source of renewable energy; four out of the seven manuscripts which address solid wastes are closely linked to renewable energy, and therefore fall into both categories of circular economy and renewable energy.…”

“…Better characterisation of a valuable urban material is also the topic of interest in the publication of Zhang et al [9]. Their work focuses on the organic fraction of municipal solid waste.…”

Effect of Particle Size on the Hydraulic Characteristics of Mechanically and Biologically Treated Waste

“…e waste (<50 mm) is biologically treated and later landfilled after decreasing the particle size to less than 20 mm through mechanical sieving and biological recycling. Zhang et al [8] obtained different grain size distribution of MBT waste (from UK) with different shredding treatment. Kuehle-Weidemeier [9] found the uniformity coefficients of MBT waste (from Germany) with particle size ranges of 0-60, 0-40, and 0-20 mm to be 50, 123, and 192, respectively.…”