Feasibility Study on Windrow Co-composting to Recycle Industrial Eggshell Waste

Abstract

The main objective of this study was to evaluate the feasibility of recycling large quantities of industrial eggshell waste through turned windrows composting in order to obtain a value-added soil improver. For that, four different formulations were tested to produce stable composts with adequate properties to be further used for agronomic applications such as amendment in soils with acid characteristics and/or with low calcium concentration. The eggshell waste is mainly an inorganic animal by-product, and thus its co-composting was conducted with farm wastes (horse and chicken manures) and grass clipping. The windrows were aerated periodically and monitored during 50 days regarding temperature, moisture, pH, conductivity, and carbon/nitrogen ratio (C/N). The thermophilic phase lasted for 10-20 days. At the end, moisture, pH, electrical conductivity, organic matter, C/N ratio, and toxic heavy metals (Cd, Cr, Pb, Cu, Ni, Zn) were determined. The microbiological assessment involved total mesophilic heterotrophic bacteria, total coliform bacteria, thermotolerant coliform bacteria, E.coli and spores of sulphite-reducing clostridia. The assessment of maturity based on germination index and stability by using Dewar selfheating test and respirometry showed that all the composts were mature and stable, with adequate properties for agronomic applications. This study evidenced that large quantities (up to 30 % in weight) of eggshell waste may be converted into calcium-rich marketable compost by thermophilic windrows composting.

Composting of Biowaste Generated in University Canteens and Rural Households: Converting Waste into a Valuable Product

“…This process is essential in waste management systems to reduce and reuse the biowaste generated, for example, the waste generated in university canteens and household biowaste [21]. In practice, this process mimics nature by transforming biowaste into a natural fertilizer or soil improver, with benefits to soil conditions [22,23].…”

Replacement of hydroxyapatite from chicken eggshell waste for ceramic properties improvement

“…Although some chicken eggshell waste can be used for animal feed, lots of chicken eggshells are also waste 6 . Most chicken eggshell waste is eliminated by disposal in landfill sites without any treatment that can pollute and degrade our environment 7 . The chicken eggshell waste consists of a protein‐rich membrane covered with hard shell.…”

“…6 Most chicken eggshell waste is eliminated by disposal in landfill sites without any treatment that can pollute and degrade our environment. 7 The chicken eggshell waste consists of a protein-rich membrane covered with hard shell. The protein-rich membrane can activate microorganisms and create an undesirable smell and some allergies.…”

Co-composting of eggshell waste in self-heating reactors: Monitoring and end product quality

“…The maximum temperatures achieved were 65°C, but after 11 weeks the end product compost was still immature. Quina et al (2013) studied the feasibility of composting industrial eggshell waste and others ABP (horse and chicken manure) using the indigenous microbial population of the mixture. The temperature profiles attained maximum values of 50°C, but mature composts with adequate properties for agronomic applications were obtained after 50 days.…”