Please click Additional Files below to see the full abstract

Amaya, Alejandro

Dupont, Capucine

Garcia, Hector

Ponte, Florencia

English

Engineering Conferences International

PRODUCTION AND CHARACTERIZATION OF BIOCHAR FROM INDUSTRIAL SLUDGE FOR POTENTIAL AGRONOMIC USE  Florencia Ponte, UPM / UTEC (UPM Biofore Company / University of Uruguay) florencia.ponte@upm.com Alejandro Amaya, UDELAR (Chemistry University of Uruguay) Hector Garcia, IHE/UTEC (Institute for water education/ University of Uruguay) Capucine Dupont, IHE Delft (Institute for water education)   Key Words: Biochar, sludge, pulpmill, waste management, soil amendment.  In Uruguay, as in most countries with mild weather conditions, soil resources play a determining role in the economy. In most of this country's deterioration of natural resources due to inefficient agricultural production system is observed. Soils under this treatment their productive capacity, mainly due to the reduction of their organic matter content. (2,3) Innovative technologies are developed to prevent soil degradation, restore soil fertility, and sequester carbon. One of the most attractive strategies is the incorporation of organic matter obtained from sludge from industrial and/or domestic wastewater treatment plants. (2,4) However, to incorporate sludge into soils, a previous treatment is necessary to stabilize the sludge, inactive the pathogens content, and reduce the amount of water. That can be achieved by using several sludge treatment processes such as anaerobic digestion, sludge composting and thermochemical sludge treatment, among others. (1,3) Biochar produced during the thermochemical decomposition of biomass both reduces the amount of carbon emitted into the atmosphere, as well as introduces an environment-friendly replacement for activated carbon and other carbon materials. Biochar application to soils is being considered to sequester carbon while concurrently improving soil functions. (1,2,4,5) According to previous studies, biochar provides numerous benefits as a physical soil conditioner, including: i) improves the porosity and infiltration of the soil; ii) increases the resistant to erosion; iii) introduces macro, micronutrients, and organic matter to the soil; iv) help to improve the physicochemical properties of the soil (pH, cation exchange capacity, etc.) and v) improves the biological properties of the soil increasing the activity of the microbial communities. (4, 5, 6,7). Our project aims at recovering wastes from a Eucalyptus pulp mill and convert them into biochar, a new product with potential soil amendment features. The project directly contributes, to promote the objectives of circular economy, strengthening sustainable models with low carbon emissions.  Since this work is carried out in collaboration with a pulp mill company, the raw sludge, analytical determinations, and potential applications of the obtained final products follow the good practices guidelines stated by the company.   The results obtained in this evaluation, would be scale up into both pilot and full scale. Three different wastes from a pulp mill were used as a raw material to produce biochar as follows: i) crushed bark from the wood handling area; ii) primary sludge from the industrial wastewater treatment plant (WWTP); and iii) bio sludge from the WWTP. (Figure 1) The experimental conditions of this evaluation were based on the structure and composition of the raw materials given by elemental and proximate analysis. For the pyrolysis trials a 4kg capacity rotating cylindrical reactor was used, with controlled temperature in an inert nitrogen atmosphere. (Figure 2) Pyrolysis conditions like the heating rate, the residence time, the cooling rate, and the process temperature were defined based on the preliminary TGA results conducted on the raw materials. The optimum temperature for obtaining both the largest removal of volatiles and the highest fixed carbon content for all samples was approximately 400° C. Therefore, the pyrolysis reactions were carried out at that temperature. Once the biochar was obtained, it was characterized. The biochar characterization determines their potential application recovering such a resource either in the industry, or in the environment. Physicochemical determinations were carried out to determine the characteristics of the obtained biochar; the obtained biochar was compared to other biochar obtained from different raw materials.  Physicochemical determinations included: thermogravimetry analysis, textural characterization, water soluble content, among others. In addition, scanning electron microscopy (SEM) with X-rays diffraction determinations were performed to determine the structure and morphology of the biochar. Next steps include the assessment of the produced biochar in different soils and crops (pot trials). In this overall research concept is successful, the conversion from a linear production system to a circular production system will be achieved. Optimizing carbon capture on productive landscapes by implementing practices that are known to improve the rate at which CO2 is removed from the atmosphere and stored in plant material and/or soil organic matter; that is, introducing an example of carbon farming. (8)       Reference  1- L.A.C. Tarelho, T. Hauschild, A.C.M. Vilas-Boas, D.F.R. Silva, M.A.A. Matos, Biochar from pyrolysis of biological sludge from wastewater treatment, Energy Reports,Volume 6, Supplement 1, 2020. 2- Méndez, M. Terradillos, G. Gascó, Physicochemical and agronomic properties of biochar from sewage sludge pyrolysed at different temperatures, Journal of Analytical and Applied Pyrolysis, Volume 102, 2013.  3- Mustafa K. Hossain, Vladimir Strezov, K. Yin Chan, Artur Ziolkowski, Peter F. Nelson, Influence of pyrolysis temperature on production and nutrient properties of wastewater sludge biochar, Journal of Environmental Management, Volume 92, Issue 1, 2011. 4- Kainulainen, A.; Rossi, L.; Gareis, C.; Nipuli, J.; Reuna, S. & Heinonen, M. Recycling carbon, nitrogen and phosphorous from municipal wastewater by combining nutrient recovery and pyrolysis. Proceedings of Sludge Management in Circular Economy (SMICE), Rome, May 23rd–25th 2018. 5- Jorge JA, Camargo OA, Valladares JMAS. Condiçao físicas de um Latossolo VermelhoEscuro quatro anos após aplicaçao de lodo de esgoto e calcário. Revista Brasileira de Ciência do Solo, 15: 237-240. 1991. 6- Marciano CR. Incorporação de resíduos urbanos e as propriedades físico-hídricas de um Latossolo Vermelho-Amarelo [Tesis doctorado]. Piracicaba: Escola Superior de Agricultura «Luiz de Queiroz». Universidade de Sao Paulo. 93p.1999. 7- Leoni C, Ghini R. Sewage sludge effect on management of Phytophthora nicotianae in citrus. Crop Protection, 25: 10-22. 2006.10. Dos Santos I, Bettiol W. Effect of sewage sludge on the rot and seedling damping-off of bean plants caused by Sclerotium rolfsii. Crop protection, 22: 2003. 8- Carbon site Institute. What is carbon farming? Published 2021- From: https://www.carboncycle.org/what-is-carbon-farming  Figure 1 – Illustration of the origin of the raw materials used from Kraft Pulp mill process. Crushed bark from woodhandling area; sludges from wastewater treatment plant.  Figure 2- 4kg capacity rotative Pyrolysis reactor.  

Production and characterization of biochar from industrial sludge for potential agronomic use

https://dc.engconfintl.org/cgi/viewcontent.cgi?filename=0&article=1063&context=biochar_iii&type=additional

Production and characterization of biochar from industrial sludge for potential agronomic use

Abstract

Similar works

Full text

Available Versions

Engineering Conferences International