Thermochemical Pretreatments of Organic Fraction of Municipal Solid Waste from a Mechanical-Biological Treatment Plant

Abstract

The organic fraction of municipal solid waste (OFMSW) usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT) plant, in order to pre-hydrolyze the waste and improve the organic matter solubilisation. To study the solubilisation yield, the increments of soluble organic matter have been measured in terms of dissolved organic carbon (DOC), soluble chemical oxygen demand (sCOD), total volatile fatty acids (TVFA) and acidogenic substrate as carbon (ASC). The process variables analyzed were temperature, pressure and NaOH dosage. The levels of work for each variable were three: 160–180–200 °C, 3.5–5.0–6.5 bar and 2–3–4 g NaOH/L. In addition, the pretreatment time was also modified among 15 and 120 min. The best conditions for organic matter solubilisation were 160 °C, 3 g NaOH/L, 6.5 bar and 30 min, with yields in terms of DOC, sCOD, TVFA and ASC of 176%, 123%, 119% and 178% respectively. Thus, predictably the application of this pretreatment in these optimum conditions could improve the H2 production during the subsequent Dark Fermentation process.

Enhancement of Volatile Fatty Acids Production from Food Waste by Mature Compost Addition

“…Without addition of mature compost, only 27.4% increase in sCOD was observed while 46.8%, 44.5%, and 48.6% increase in sCOD was monitored when 2.5%, 3.5%, and 4.5 % mature compost was added. These indicated that, with the addition of mature compost, hydrolytic enzymes were introduced into the fermentation broth with the aim to increase the hydrolytic rate [25,26]. These results were also consistent with the study by Fdez.-Güelfo et al [27] who tested the biological pretreatment of OFMSW using mature compost and reported that 2.5% v / v was enough to increase the sCOD by roughly 50%, which was the indicator of the solubilization yield in that study.…”

Bio-Compost Behaviour as Soil Additive by Food Waste Pretreatment on the Growth of Abelmoschus esculentus L.: A Systematic Review

“…From the study by Kullavanijaya and Chavalparit (2020), the cellulose content of the sample is has degraded. Studies have been found that the best organic matter solubilization was achieved using thermochemical pretreatments when NaOH/L is used as an alkaline agent (Álvarez-Gallego et al, 2015).…”

Towards Sustainable Carbon Return from Waste to Industry via C2-Type Molecular Unit

“…Waste recycling involving thermochemical treatment is a universal approach and an important component of a circular economy [ 1 , 2 , 3 , 4 ]. Pyrolysis is an efficient way of waste recycling, allowing the recovery of valuable feedstock from waste [ 5 , 6 ]. The key advantage of pyrolysis [ 7 ] and thermochemical methods [ 8 ] is their versatility and applicability to various types of processed materials, including mixtures of these materials.…”