Reuse and Recycling of Waste from the Filtering of the Food Industry in the Construction Sector
Authors: Belmonte Isabel Miñano , Parra Carlos , López Carlos Rodríguez , Saorin Francisco Javier Benito , Meroño Elvira Carrión , Torres José María Mateo 
Published: December 2024

Objective: Diatoms are a serious environmental and economic problem. They are by-products that after an industrial process cannot be used. The volumes generated are large, and the cost of their deletion is disproportionate. Being able to grant them another use or use in any productive activity is a highly desirable objective, directly for waste generators and indirectly for potential users of the waste as a lower cost alternative raw material than the Conventional. For this reason, and because of the large volume of national production in Spain, large quantities of diatomaceous are generated, filled and useless, without another useful life. With the use of recycled diatoms, a dual environmental benefit occurs on the one hand, the replacement of part of cement, and on the other hand, the disposal of industrial waste, which would not have to be deposited in controlled landfills.

Theoretical Framework: In this work, experimental research is reported on the use of natural and recycled diatomaceous earth, from the filtering of wine, oil and beer, whose purpose is to give added value to a by-product that today constitutes a waste, whose reuse is very limited and generally constitutes a problem to manage them. Diatoms are a serious environmental and economic problem because they are a by-product that after industrial processes cannot be used. The volumes generated are substantial, and the cost of their disposal is disproportionate. Being able to give them another use or use in a productive activity is a highly desirable objective, directly for the generators of the waste and indirectly for the potential users of it as an alternative raw material of lower cost than the conventional one.

Method: The present work studies the effect on the properties of a Portland cement when additions of recycled and natural diatoms are incorporated. The properties evaluated were: compressive strength, capillary absorption, chloride permeability and carbonation. To this end, five batches of conventional concrete have been manufactured, one of reference and the rest with a percentage of substitutions of 5% of Portland cement with natural and recycled diatoms, all of them with 242 kg/m3 of cement (CEM I 42.5 R).

Results and Discussion: Portland cements added with diatoms have high mechanical properties, with the mechanical resistance to compression with the use of diatoms from the recycling of wine and beer (5% replacement) being up to 16% higher than the reference concrete and a structure of low permeability (lower capillary absorption coefficient).

Research Implications: It has been proven that replacing a percentage of Portland cement with natural pozzolans (diatoms) can considerably improve the properties of concrete. Last but not least, diatomaceous earths can be used as a partial replacement for Portland cement to reduce both the cost of concrete and the CO2 emissions that are made during cement production. However, diatomaceous earths are not frequently used in the construction industry

Originality/Value: This study proposes that the properties of conventional Portland cement can be improved with natural and recycled diatomite, which is a naturally occurring pozzolan used in filtration in industrial sectors. Diatomite is a sedimentary and biogenic material formed from the accumulation of algae shells that have become fossilized due to the deposition of silica in diatom skeletons.