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an official journal of: published by:
Editor in Chief: RAFFAELLO COSSU

BIOCHAR PRODUCTION FROM WASTE BIOMASS: CHARACTERIZATION AND EVALUATION FOR AGRONOMIC AND ENVIRONMENTAL APPLICATIONS

  • Frantseska-Maria Pellera - School of Environmental Engineering, Technical University of Crete, Greece
  • Panagiotis Regkouzas - School of Environmental Engineering, Technical University of Crete, Greece
  • Ioanna Manolikaki - School of Environmental Engineering, Technical University of Crete, Greece
  • Evan Diamadopoulos - School of Environmental Engineering, Technical University of Crete, Greece

Released under CC BY-NC-ND

Copyright: © 2021 CISA Publisher


Abstract

This study focused on the valorization of different types of waste biomass through biochar production at two pyrolysis temperatures (400 and 600°C). The different feedstocks being used included three materials of municipal origin, specifically two types of sewage sludge and the organic fraction of municipal solid waste, and three materials of agroindustrial origin, specifically grape pomace, rice husks and exhausted olive pomace. The scope of the research was to characterize the resulting materials, in order to evaluate their possible uses in agronomic and environmental applications. Biochar characterization included the determination of several physical and chemical parameters, while germination assays were also carried out. Under the investigated conditions, both pyrolysis temperature and feedstock type appeared to significantly affect biochar characteristics, leading to the production of versatile materials, with many different possible uses. Specifically, results implied that biochars of both municipal and agroindustrial origin have the potential to effectively be used in applications including the improvement of soil characteristics, carbon sequestration, the removal of organic and inorganic contaminants from aqueous media, and the remediation of contaminated soil, with the degree of suitability of each material to each specific use being estimated to differ depending on its particular characteristics. For this reason, with these characteristics in mind, before proceeding to larger scale applications a cautious selection of materials should be conducted.

Keywords


Editorial History

  • Received: 12 Mar 2021
  • Revised: 26 Nov 2021
  • Accepted: 26 Nov 2021
  • Available online: 19 Dec 2021

References

Agrafioti, E., Bouras, G., Kalderis, D., & Diamadopoulos, E. (2013). Biochar production by sewage sludge pyrolysis. Journal of Analytical and Applied Pyrolysis, 101, 72-78.
DOI 10.1016/j.jaap.2013.02.010

Ahmad, M., Lee, S.S., Dou, X., Mohan, D., Sung, J.K., Yang, J.E., & Ok, Y.S. (2012). Effects of pyrolysis temperature on soybean stover-and peanut shell-derived biochar properties and TCE adsorption in water. Bioresource Technology, 118, 536-544.
DOI 10.1016/j.biortech.2012.05.042

Ahmad, M., Rajapaksha, A.U., Lim, J.E., Zhang, M., Bolan, N., Mohan, D., Vithanage, M., Lee, S.S., & Ok, Y.S. (2014). Biochar as a sorbent for contaminant management in soil and water: A review. Chemosphere, 99, 19-23.
DOI 10.1016/j.chemosphere.2013.10.071

Ahmedna, M., Johns, M.M., Clarke, S.J., Marshall, W.E., & Rao, R.M. (1997). Potential of agricultural by‐product‐based activated carbons for use in raw sugar decolourisation. Journal of the Science of Food and Agriculture, 75(1), 117-124.
DOI 10.1002/(SICI)1097-0010(199709)75:1<117::AID-JSFA850>3.0.CO;2-M

Aller, M.F. (2016). Biochar properties: Transport, fate, and impact. Critical Reviews in Environmental Science and Technology, 46(14-15), 1183-1296.
DOI 10.1080/10643389.2016.1212368

Al-Wabel, M.I., Al-Omran, A., El-Naggar, A.H., Nadeem, M., & Usman, A.R.A. (2013). Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes. Bioresource Technology, 131, 374-379.
DOI 10.1016/j.biortech.2012.12.165

APHA. (1992). Method 2540G. Standard Methods for the Examination of Water and Wastewater

ASTM D1762-84 (2004). Standard Test Method for Chemical Analysis of Wood Charcoal. ASTM International, West Conshohocken, PA, 2004

ASTM E897-88 (2004). Standard Test Method for Volatile Matter in the Analysis Sample of Refuse-Derived Fuel. ASTM International, West Conshohocken, PA, 2004

Belyaeva, O.N., Haynes, R.J., & Sturm, E.C. (2012). Chemical, physical and microbial properties and microbial diversity in manufactured soils produced from co-composting green waste and biosolids. Waste Management, 32(12), 2248-2257.
DOI 10.1016/j.wasman.2012.05.034

Buss, W., Graham, M.C., Shepherd, J.G., & Mašek, O. (2016). Risks and benefits of marginal biomass-derived biochars for plant growth. Science of the Total Environment, 569–570, 496-506.
DOI 10.1016/j.scitotenv.2016.06.129

Buss, W., & Mašek, O. (2014). Mobile organic compounds in biochar–a potential source of contamination–phytotoxic effects on cress seed (Lepidium sativum) germination. Journal of Environmental Management, 137, 111-119.
DOI 10.1016/j.jenvman.2014.01.045

Cao, X., & Harris, W. (2010). Properties of dairy-manure-derived biochar pertinent to its potential use in remediation. Bioresource Technology, 101(14), 5222-5228.
DOI 10.1016/j.biortech.2010.02.052

Chen, B., Zhou, D., & Zhu, L. (2008). Transitional adsorption and partition of nonpolar and polar aromatic contaminants by biochars of pine needles with different pyrolytic temperatures. Environmental Science & Technology, 42(14), 5137-5143.
DOI 10.1021/es8002684

Chen, T., Zhang, Y., Wang, H., Lu, W., Zhou, Z., Zhang, Y., & Ren, L. (2014). Influence of pyrolysis temperature on characteristics and heavy metal adsorptive performance of biochar derived from municipal sewage sludge. Bioresource Technology, 164, 47-54.
DOI 10.1016/j.biortech.2014.04.048

Coates, J. (2000). Interpretation of Infrared Spectra, A Practical Approach. Encyclopedia of Analytical Chemistry, 12, 10815-10837.
DOI 10.1002/9780470027318.a5606

Colantoni, A., Evic, N., Lord, R., Retschitzegger, S., Proto, A.R., Gallucci, F., & Monarca, D. (2016). Characterization of biochars produced from pyrolysis of pelletized agricultural residues. Renewable and Sustainable Energy Reviews, 64, 187-194.
DOI 10.1016/j.rser.2016.06.003

Domene, X., Enders, A., Hanley, K., & Lehmann, J. (2015). Ecotoxicological characterization of biochars: Role of feedstock and pyrolysis temperature. Science of the Total Environment, 512-513, 552-561.
DOI 10.1016/j.scitotenv.2014.12.035

EBC (2012). 'European Biochar Certificate - Guidelines for a Sustainable Production of Biochar.' European Biochar Foundation (EBC), Arbaz, Switzerland. http://www.european- biochar.org/en/download. Version 6.3E of 14th August 2017

EC. European Commission. Directive 86/278/EEC on the protection of the environment and in particular of the soil. When sewage sludge is used in agriculture, 2009. https://eur-lex.europa.eu/eli/dir/1986/278/2009-04-20

Elkhalifa, S., Al-Ansari, T., Mackey, H.R., & McKay, G. (2019). Food waste to biochars through pyrolysis: A review. Resources, Conservation and Recycling, 144, 310-320.
DOI 10.1016/j.resconrec.2019.01.024

Enders, A., Hanley, K., Whitman, T., Joseph, S., & Lehmann, J. (2012). Characterization of biochars to evaluate recalcitrance and agronomic performance. Bioresource Technology, 114, 644-653.
DOI 10.1016/j.biortech.2012.03.022

EUROSTAT (2020). Available at: https://ec.europa.eu/eurostat (last visited on 8/7/2020)

Fountoulakis, M.S., Drakopoulou, S., Terzakis, S., Georgaki, E., & Manios, T. (2008). Potential for methane production from typical Mediterranean agro-industrial by-products. Biomass and Bioenergy 32, 155-161.
DOI 10.1016/j.biombioe.2007.09.002

Fryda, L., Visser, R., & Schmidt, J. (2019). Biochar replaces peat in horticulture: environmental impact assessment of combined biochar & bioenergy production. Detritus, 5, 132-149.
DOI 10.31025/2611-4135/2019.13778

Gai, X., Wang, H., Liu, J., Zhai, L., Liu, S., Ren, T., & Liu, H. (2014). Effects of feedstock and pyrolysis temperature on biochar adsorption of ammonium and nitrate. PLoS ONE, 9(12), 1-19.
DOI 10.1371/journal.pone.0113888

Gell, K., van Groenigen, J.W., & Cayuela, M.L. (2011). Residues of bioenergy production chains as soil amendments: Immediate and temporal phytotoxicity. Journal of Hazardous Materials, 186(2-3), 2017-2025.
DOI 10.1016/j.jhazmat.2010.12.105

Gómez, N., Rosas, J.G., Cara, J., Martínez, O., Alburquerque, J.A., & Sánchez, M.E. (2016). Slow pyrolysis of relevant biomasses in the Mediterranean basin. Part 1. Effect of temperature on process performance on a pilot scale. Journal of Cleaner Production, 120, 181-190.
DOI 10.1016/j.jclepro.2014.10.082

Gunarathne, V., Ashiq, A., Ramanayaka, S., Wijekoon, P., & Vithanage, M. (2019). Biochar from municipal solid waste for resource recovery and pollution remediation. Environmental Chemistry Letters, 1-11.
DOI 10.1007/s10311-019-00866-0

Hossain, M.K., Strezov, V., Chan, K.Y., Ziolkowski, A., & Nelson, P.F. (2011). Influence of pyrolysis temperature on production and nutrient properties of wastewater sludge biochar. Journal of Environmental Management, 92(1), 223-228.
DOI 10.1016/j.jenvman.2010.09.008

IBI (2015). Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil. International Biochar Initiative, Version 2.1, (November 23rd 2015). https://www.biochar-international.org/wp-content/uploads/2018/04/IBI_Biochar_Standards_V2.1_Final.pdf

Ibn Ferjani, A., Jeguirim, M., Jellali, S., Limousy, L., Courson, C., Akrout, H., Thevenin, N., Ruidavets, L. Muller, A., & Bennici, S. (2019). The use of exhausted grape marc to produce biofuels and biofertilizers: Effect of pyrolysis temperatures on biochars properties. Renewable and Sustainable Energy Reviews, 107, 425-433.
DOI 10.1016/j.rser.2019.03.034

Inguanzo, M., Domı́nguez, A., Menéndez, J.A., Blanco, C.G., & Pis, J.J. (2002). On the Pyrolysis of Sewage Sludge: The Influence of Pyrolysis Temperature on Biochar, Liquid and Gas Fractions. Journal of Analytical and Applied Pyrolysis, 63(1), 209-222.
DOI 10.1016/S0165-2370(01)00155-3

Intani, K., Latif, S., Islam, M. S., & Müller, J. (2018). Phytotoxicity of corncob biochar before and after heat treatment and washing. Sustainability (Switzerland), 11(1).
DOI 10.3390/su11010030

Jimoh, O. A., Otitoju, T. A., Hussin, H., Ariffin, K. S., & Baharun, N. (2017). Understanding the precipitated calcium carbonate (PCC) production mechanism and its characteristics in the liquid–gas system using milk of lime (MOL) suspension. South African Journal of Chemistry, 70, 1-7.
DOI 10.17159/0379-4350/2017/v70a1

Jin, H., Capareda, S., Chang, Z., Gao, J., Xu, Y., & Zhang, J. (2014). Biochar pyrolytically produced from municipal solid wastes for aqueous As(V) removal: Adsorption property and its improvement with KOH activation. Bioresource Technology, 169, 622-629.
DOI 10.1016/j.biortech.2014.06.103

Kah, M., Sun, H., Sigmund, G., Hüffer, T., & Hofmann, T. (2016). Pyrolysis of waste materials: Characterization and prediction of sorption potential across a wide range of mineral contents and pyrolysis temperatures. Bioresource Technology, 214, 225-233.
DOI 10.1016/j.biortech.2016.04.091

Lee, C.W., Mahendra, S., Zodrow, K., Li, D., Tsai, Y.C., Braam, J., & Alvarez, P.J.J. (2010). Developmental phytotoxicity of metal oxide nanoparticles to Arabidopsis thaliana. Environmental Toxicology and Chemistry: An International Journal, 29(3), 669-675.
DOI 10.1002/etc.58

Leontakianakos, G., Baziotis, I., Papandreou, A., Kanellopoulou, D., Stathopoulos, V.N., & Tsimas, S. (2015). A comparative study of the physicochemical properties of Mg-rich and Ca-rich quicklimes and their effect on reactivity. Materials and Structures/Materiaux et Constructions, 48(11), 3735-3753.
DOI 10.1617/s11527-014-0436-y

Li, D.-C., & Jiang, H. (2017). The thermochemical conversion of non-lignocellulosic biomass to form biochar: A review on characterizations and mechanism elucidation. Bioresource Technology, 246, 57-68.
DOI 10.1016/j.biortech.2017.07.029

Li, H., Dong, X., da Silva, E.B., de Oliveira, L.M., Chen, Y., & Ma, L.Q. (2017). Mechanisms of metal sorption by biochars: Biochar characteristics and modifications. Chemosphere, 178, 466-478.
DOI 10.1016/j.chemosphere.2017.03.072

Lu, H., Zhang, W., Wang, S., Zhuang, L., Yang, Y., & Qiu, R. (2013). Characterization of sewage sludge-derived biochars from different feedstocks and pyrolysis temperatures. Journal of Analytical and Applied Pyrolysis, 102, 137-143.
DOI 10.1016/j.jaap.2013.03.004

Luo, F., Song, J., Xia, W., Dong, M., Chen, M., & Soudek, P. (2014). Characterization of contaminants and evaluation of the suitability for land application of maize and sludge biochars. Environmental Science and Pollution Research, 21(14), 8707-8717.
DOI 10.1007/s11356-014-2797-8

Manolikaki, I.I., Mangolis, A., & Diamadopoulos, E. (2016). The impact of biochars prepared from agricultural residues on phosphorus release and availability in two fertile soils. Journal of Environmental Management, 181, 536-543.
DOI 10.1016/j.jenvman.2016.07.012

Mitchell, K., Trakal, L., Sillerova, H., Avelar-González, F.J., Guerrero-Barrera, A.L., Hough, R., & Beesley, L. (2018). Mobility of As, Cr and Cu in a contaminated grassland soil in response to diverse organic amendments; a sequential column leaching experiment. Applied Geochemistry, 88, 95-102.
DOI 10.1016/j.apgeochem.2017.05.020

Mukherjee, A., Zimmerman, A.R., & Harris W. (2011). Surface chemistry variations among a series of laboratory-produced biochars. Geoderma, 163(3-4), 247-255.
DOI 10.1016/j.geoderma.2011.04.021

Mumme, J., Getz, J., Prasad, M., Lüder, U., Kern, J., Mašek, O., & Buss, W. (2018). Toxicity screening of biochar-mineral composites using germination tests. Chemosphere, 207, 91-100.
DOI 10.1016/j.chemosphere.2018.05.042

Nasir, M., Rahmawati, T., & Dara, F. (2019). Synthesis and characterization of biochar from crab shell by pyrolysis. IOP Conference Series: Materials Science and Engineering, 553(1).
DOI 10.1088/1757-899X/553/1/012031

Nieto, A., Gascó, G., Paz-Ferreiro, J., Fernández, J. M., Plaza, C., & Méndez, A. (2016). The effect of pruning waste and biochar addition on brown peat based growing media properties. Scientia Horticulturae, 199, 142-148.
DOI 10.1016/j.scienta.2015.12.012

Oh, T.-K., Choi, B., Shinogi, Y., & Chikushi, J. (2012). Characterization of biochar derived from three types of biomass. J. Fac. Agric. Kyushu Univ., 57(1), 61-66

Oleszczuk, P., & Hollert, H. (2011). Comparison of sewage sludge toxicity to plants and invertebrates in three different soils. Chemosphere, 83(4), 502-509.
DOI 10.1016/j.chemosphere.2010.12.061

Pariyar, P., Kumari, K., Jain, M. K., & Jadhao, P.S. (2020). Evaluation of change in biochar properties derived from different feedstock and pyrolysis temperature for environmental and agricultural application. Science of the Total Environment, 713, 136433.
DOI 10.1016/j.scitotenv.2019.136433

Pellera, F.-M., & Gidarakos, E. (2015). Effect of dried olive pomace – derived biochar on the mobility of cadmium and nickel in soil. Journal of Environmental Chemical Engineering, 3(2), 1163-1176.
DOI 10.1016/j.jece.2015.04.005

Pituello, C., Francioso, O., Simonetti, G., Pisi, A., Torreggiani, A., Berti, A., & Morari, F. (2015). Characterization of chemical–physical, structural and morphological properties of biochars from biowastes produced at different temperatures. Journal of Soils and Sediments, 15(4), 792-804.
DOI 10.1007/s11368-014-0964-7

Rajkovich, S., Enders, A., Hanley, K., Hyland, C., Zimmerman, A.R., & Lehmann, J. (2012). Corn growth and nitrogen nutrition after additions of biochars with varying properties to a temperate soil. Biology and Fertility of Soils, 48(3), 271-284.
DOI 10.1007/s00374-011-0624-7

Randolph, P., Bansode, R.R., Hassan, O.A., Rehrah, D., Ravella, R., Reddy, M.R., Watts, D.W., Novak, J.M., & Ahmedna, M. (2017). Effect of biochars produced from solid organic municipal waste on soil quality parameters. Journal of Environmental Management, 192, 271-280.
DOI 10.1016/j.jenvman.2017.01.061

Rehrah, D., Reddy, M.R., Novak, J.M., Bansode, R.R., Schimmel, K.A., Yu, J., Watts, D.W., & Ahmedna, M. (2014). Production and characterization of biochars from agricultural by-products for use in soil quality enhancement. Journal of Analytical and Applied Pyrolysis, 108, 301-309.
DOI 10.1016/j.jaap.2014.03.008

Rehrah, D., Bansode, R.R., Hassan, O., & Ahmedna, M. (2016). Physico-chemical characterization of biochars from solid municipal waste for use in soil amendment. Journal of Analytical and Applied Pyrolysis, 118, 42-53.
DOI 10.1016/j.jaap.2015.12.022

Rucińska-Sobkowiak, R. (2016). Water relations in plants subjected to heavy metal stresses. Acta Physiologiae Plantarum, 38.
DOI 10.1007/s11738-016-2277-5

Rybova K., Burcin B., Slavik, J. (2018). Spatial and non-spatial analysis of socio-demographic aspects influencing municipal solid waste generation in the czech republic. Detritus, 1(1), 3 -7.
DOI 10.26403/detritus/2018.2

Shen, Z., Zhang, Y., McMillan, O., Jin, F., & Al-Tabbaa, A. (2017). Characteristics and mechanisms of nickel adsorption on biochars produced from wheat straw pellets and rice husk. Environmental Science and Pollution Research, 24(14), 12809-12819.
DOI 10.1007/s11356-017-8847-2

Singh, B., Dolk, M.M., Shen, Q., & Camps-Arbestain, M. (2017). Biochar pH, electrical conductivity and liming potential. In Biochar: A Guide to Analytical Methods, Balwant Singh, et al. (Eds), Csiro Publishing, Clayton, Australia, 23-38.
DOI 10.1071/9781486305100

Song, W., & Guo, M. (2012). Quality variations of poultry litter biochar generated at different pyrolysis temperatures. Journal of Analytical and Applied Pyrolysis, 94, 138-145.
DOI 10.1016/j.jaap.2011.11.018

Stefaniuk, M., & Oleszczuk, P. (2015). Characterization of biochars produced from residues from biogas production. Journal of Analytical and Applied Pyrolysis, 115, 157-165.
DOI 10.1016/j.jaap.2015.07.011

Stylianou, M., Christou, A., Dalias, P., Polycarpou, P., Michael, C., Agapiou, A., Papanastasiou, P., & Fatta-Kassinos, D. (2020). Physicochemical and structural characterization of biochar derived from the pyrolysis of biosolids, cattle manure and spent coffee grounds. Journal of the Energy Institute, 93(5), 2063-2073.
DOI 10.1016/j.joei.2020.05.002

Suliman, W., Harsh, J.B., Abu-Lail, N.I., Fortuna, A.-M., Dallmeyer, I., & Garcia-Perez, M. (2016). Influence of feedstock source and pyrolysis temperature on biochar bulk and surface properties. Biomass and Bioenergy, 84, 37-48.
DOI 10.1016/j.biombioe.2015.11.010

Tag, A.T., Duman, G., Ucar, S., & Yanik, J. (2016). Effects of feedstock type and pyrolysis temperature on potential applications of biochar. Journal of Analytical and Applied Pyrolysis, 120, 200-206.
DOI 10.1016/j.jaap.2016.05.006

Taherymoosavi, S., Verheyen, V., Munroe, P., Joseph, S., & Reynolds, A. (2017). Characterization of organic compounds in biochars derived from municipal solid waste. Waste Management, 67, 131-142.
DOI 10.1016/j.wasman.2017.05.052

Tan, X., Liu, Y., Zeng, G., Wang, X., Hu, X., Gu, Y., & Yang, Z. (2015). Application of biochar for the removal of pollutants from aqueous solutions. Chemosphere, 125, 70-85.
DOI 10.1016/j.chemosphere.2014.12.058

Taskin, E., de Castro Bueno, C., Allegretta, I., Terzano, R., Rosa, A.H., & Loffredo, E. (2019). Multianalytical characterization of biochar and hydrochar produced from waste biomasses for environmental and agricultural applications. Chemosphere, 233, 422-430.
DOI 10.1016/j.chemosphere.2019.05.204

Trakal, L., Raya-Moreno, I., Mitchell, K., & Beesley, L. (2017). Stabilization of metal(loid)s in two contaminated agricultural soils: Comparing biochar to its non-pyrolysed source material. Chemosphere, 181, 150-159.
DOI 10.1016/j.chemosphere.2017.04.064

Tran, H. N., You, S. J., & Chao, H. P. (2016). Effect of pyrolysis temperatures and times on the adsorption of cadmium onto orange peel derived biochar. Waste Management & Research, 34(2), 129-138.
DOI 10.1177/0734242X15615698

Uchimiya, M., Klasson, K.T., Wartelle, L.H., & Lima, I.M. (2011). Influence of soil properties on heavy metal sequestration by biochar amendment: 1. Copper sorption isotherms and the release of cations. Chemosphere, 82(10), 1431-1437.
DOI 10.1016/j.chemosphere.2010.11.050

US EPA (1986). Method 9081. Cation exchange capacity of soils (sodium acetate)

Wang, Y., Xiao, X., & Chen, B. (2018). Biochar Impacts on Soil Silicon Dissolution Kinetics and their Interaction Mechanisms. Scientific Reports, 8(1), 1-11.
DOI 10.1038/s41598-018-26396-3

Yao, Y., Gao, B., Inyang, M., Zimmerman, A.R., Cao, X., Pullammanappallil, P., & Yang, L. (2011). Biochar derived from anaerobically digested sugar beet tailings: Characterization and phosphate removal potential. Bioresource Technology, 102(10), 6273-6278.
DOI 10.1016/j.biortech.2011.03.006

Yargicoglu, E.N., Sadasivam, B.Y., Reddy, K.R., Spokas, K. (2015). Physical and chemical characterization of waste wood derived biochars. Waste Management, 36, 256-268.
DOI 10.1016/j.wasman.2014.10.029

Yi, S., Gao, B., Sun, Y., Wu, J., Shi, X., Wu, B., & Hu, X. (2016). Removal of levofloxacin from aqueous solution using rice-husk and wood-chip biochars. Chemosphere, 150, 694-701.
DOI 10.1016/j.chemosphere.2015.12.112

Zeng, X., Xiao, Z., Zhang, G., Wang, A., Li, Z., Liu, Y., Wang, H., Zeng, Q., Liang, Y., & Zou, D. (2018). Speciation and bioavailability of heavy metals in pyrolytic biochar of swine and goat manures. ournal of Analytical and Applied Pyrolysis, 132, 82–93.
DOI 10.1016/j.jaap.2018.03.012

Zhao, S.-X., Ta, N., & Wang, X.-D. (2017). Effect of temperature on the structural and physicochemical properties of biochar with apple tree branches as feedstock material. Energies, 10(9), 1293.
DOI 10.3390/en10091293

Zhang, K., Sun, P., Faye, M.C.A., & Zhang, Y. (2018). Characterization of biochar derived from rice husks and its potential in chlorobenzene degradation. Carbon, 130, 730-740.
DOI 10.1016/j.carbon.2018.01.036