Evaluation of Cashew Gum (Anacardium occidentale) as a biocoagulant in water treatment
DOI:
https://doi.org/10.47236/2594-7036.2025.v9.1808Keywords:
Biocoagulants, Green chemistry, Water treatmentAbstract
To make water treatment more sustainable and economical, biopolymers have been studied as biocoagulants. These materials demonstrate excellent results when compared to conventional coagulants and flocculants. Cashew gum emerges as an alternative due to its properties such as abundance, easy isolation, and non-toxicity. This study aimed to evaluate the efficiency of cashew gum as a biocoagulant and flocculant in synthetic cloudy water, comparing its performance with the conventional coagulant aluminum sulfate in cloudy water with kaolin. The effectiveness of the isolated and combined substances was analyzed in a jar-test apparatus simulating the coagulation/flocculation stage. Turbidity and pH measurements were taken to determine the efficiency, optimal concentrations, and sedimentation time of the process. The tests demonstrated that the gum has an efficiency of approximately 90% over a wide pH range, with the combined materials, using a dosage of 2 mg/L of Cashew Gum, it was possible to reduce the amount of aluminum sulfate by 52%, requiring 12 mg/L for a removal of 98.43% of turbidity. Furthermore, sedimentation time was halved when cashew gum was applied in conjunction with aluminum sulfate, requiring 10 minutes to achieve a residual turbidity of 3.1 UNT, with an efficiency of 97.5%. It can be concluded that cashew gum is highly efficient in removing turbidity and can act as a flocculant, reducing the amount of metal coagulant required and the process time.Downloads
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ANG, W. L.; MOHAMMAD, A. W. State of the Art and Sustainability of Natural Coagulants in Water and Wastewater Treatment. Journal of Cleaner Production, v. 262, p. 121267, 2020. https://doi.org/10.1016/j.jclepro.2020.121267. DOI: https://doi.org/10.1016/j.jclepro.2020.121267
BRASIL. Portaria GM/MS nº 888, de 4 de maio de 2021. Brasília, DF. Ministério da Saúde, [2021]. Disponível em: https://bvsms.saude.gov.br/bvs/saudelegis/gm/2021/prt0888_07_05_2021.html
BRATBY, J. Coagulation and Flocculation in Water and Wastewater Treatment. 1ed. IWA Publishing, Reino Unido, 2016. 538p.
CHIAVOLA, A. et al.Combined Experimental-Modeling Approach for Turbidity Removal Optimization in a Coagulation–Flocculation Unit of a Drinking Water Treatment Plant.” Journal of Process Control, v. 130, p.103068-103077, 2023. https://doi.org/10.1016/j.jprocont.2023.103068. DOI: https://doi.org/10.1016/j.jprocont.2023.103068
CHUA, S. C. et al. Optimized Use of Ferric Chloride and Sesbania Seed Gum (SSG) as Sustainable Coagulant Aid for Turbidity Reduction in Drinking Water Treatment. Sustainability, v. 12, p. 2273-2285, 2020. DOI: https://doi.org/10.3390/su12062273
FREITAS, T. K. F. S. Review of Utilization Plant-Based Coagulants as Alternatives to Textile Wastewater Treatment. Textile and Clothing Technology. In: MUTHU, S. S. Detox Fashion: Waste Water Treatment. 1 ed. Singapore: Springer, 2018. P. 27-79. https://doi.org/10.1007/978-981-10-4780-0_2. DOI: https://doi.org/10.1007/978-981-10-4780-0_2
HASNAIN, M. S. et al. Extraction and Characterization of Cashew Tree (Anacardium Occidentale) Gum; Use in Aceclofenac Dental Pastes. International Journal of Biological Macromolecules, v. 116, p. 1074-1081, 2018. https://doi.org/10.1016/j.ijbiomac.2018.05.133. DOI: https://doi.org/10.1016/j.ijbiomac.2018.05.133
HU, C. Y. et al. Treatment of Highly Turbid Water Using Chitosan and Aluminum Salts. Separation and Purification Technology, v. 104, p. 322-326, 2013. https://doi.org/10.1016/j.seppur.2012.11.016. DOI: https://doi.org/10.1016/j.seppur.2012.11.016
IGWEBE, C. A et al. Prediction and optimisation of coagulation-flocculation process for turbidity removal from aquaculture effluent using Garcinia kola extract: Response surface and artificial neural network methods. Cleaner Chemical Engineering, v. 4, p. 100076-100091, 2022. DOI: https://doi.org/10.1016/j.clce.2022.100076
JIANG, J. Q. The Role of Coagulation in Water Treatment. Current Opinion in Chemical Engineering, v. 8, p. 36-44, 2015. https://doi.org/10.1016/j.coche.2015.01.008. DOI: https://doi.org/10.1016/j.coche.2015.01.008
KIM, S.; et al. Solubilization of Cashew Gum from Anacardium Occidentale in Aqueous Medium. Carbohydrate Polymers, v. 199, p. 205-209, 2018. https://doi.org/10.1016/j.carbpol.2018.07.022. DOI: https://doi.org/10.1016/j.carbpol.2018.07.022
KLEIN, J. M. et al. Preparation of Cashew Gum-Based Flocculants by Microwave- and Ultrasound-Assisted Methods. International Journal of Biological Macromolecules, v. 107, p. 1550-1558, 2018. https://doi.org/10.1016/j.ijbiomac.2017.09.118. DOI: https://doi.org/10.1016/j.ijbiomac.2017.09.118
LAPOINTE, M.; BARBEAU, B. Understanding the Roles and Characterizing the Intrinsic Properties of Synthetic vs. Natural Polymers to Improve Clarification through Interparticle Bridging: A Review. Separation and Purification Technology, v. 231, p. 115893, 2020. https://doi.org/10.1016/j.seppur.2019.115893. DOI: https://doi.org/10.1016/j.seppur.2019.115893
LIM, V. H. et al. Comparison of cationic flocculants with different branching structure for the flocculation of negatively charged particles coexisting with humic substances. Journal of Environmental Chemical Engineering, v. 10, p. 108478, 2022. DOI: https://doi.org/10.1016/j.jece.2022.108478
LIMA JÚNIOR, R. N.; ABREU, F. O. M. S. Natural Products Used as Coagulants and Flocculants for Public Water Supply: A Review of Benefits and Potentialities. Revista Virtual de Quimica, v. 10 (3), p. 709-735, 2018. https://doi.org/10.21577/1984- 6835.20180052 DOI: https://doi.org/10.21577/1984-6835.20180052
LIMA JÚNIOR, R. N. et al. Chitosan and carboxymethylchitosan as a high turbidity water biocoagulantes. Journal of Renewable Materials, v. 8, p. 1489-1504, 2020. https://doi.org/10.32604/jrm.2020.011629 DOI: https://doi.org/10.32604/jrm.2020.011629
LUGO, L. et al. Implementation of Modified Acacia Tannin by Mannich Reaction for Removal of Heavy Metals (Cu, Cr and Hg).Water (Switzerland), v. 12 (2), p.352-362, 2020. https://doi.org/10.3390/w120203 DOI: https://doi.org/10.3390/w12020352
LYU, F. et al. Efficient and Fast Removal of Pb 2+ and Cd 2+ from an Aqueous Solution Using a Chitosan/Mg-Al-Layered Double Hydroxide Nanocomposite. Journal of Colloid and Interface Science, v. 539, p.184-193, 2020. https://doi.org/10.1016/j.jcis.2018.12.049. DOI: https://doi.org/10.1016/j.jcis.2018.12.049
MISHRA, S.; KUNDU, K. Synthesis, Characterization and Applications of Polyacrylamide Grafted Fenugreek Gum (FG-g-PAM) as Flocculant: Microwave vs Thermal Synthesis Approach. International Journal of Biological Macromolecules, v. 141, p. 792-808, 2019. https://doi.org/10.1016/j.ijbiomac.2019.09.033. DOI: https://doi.org/10.1016/j.ijbiomac.2019.09.033
PAIVA JÚNIOR, José Ribamar. Nanopartículas por Complexação Polieletrolítica à Base de Goma do Cajueiro Modificada/Quitosana para Encapsulamento do Acetato de Timila. 2020. Dissertação (Mestrado em Química) – Departamento de Química, Universidade Federal do Ceará, Fortaleza -CE, 2020.
POLIZZI, S. et al. Neurotoxic Effects of Aluminium among Foundry Workers and Alzheimer’s Disease. NeuroToxicology, v. 23, p. 761-764, 2002 https://doi.org/10.1016/S0161-813X(02)00097-9. DOI: https://doi.org/10.1016/S0161-813X(02)00097-9
RIBEIRO, A. J. et al. Gums’ Based Delivery Systems: Review on Cashew Gum and Its Derivatives. Carbohydrate Polymers, v.147, v. 188-200, 2016. https://doi.org/10.1016/j.carbpol.2016.02.042. DOI: https://doi.org/10.1016/j.carbpol.2016.02.042
RODRIGUES, J. F.; PAULA, R. C. M.; COSTA, S. M. O. Métodos de Isolamento de Gomas Naturais: Comparação Através da Goma do Cajueiro (Anacardium occidentale L). Polímeros: Ciência e Tecnologia, v. 3, n. 1, p. 31-36, 1993.
SILVA, M. T. et al. Cashew gum as future multipurpose biomacromolecules. Carbohydrate Polymers, v. 347, p. 122749-122770, 2025. https://doi.org/10.1016/j.carbpol.2024.122749 DOI: https://doi.org/10.1016/j.carbpol.2024.122749
THOMPSON, F. et al. Severe Impacts of the Brumadinho Dam Failure (Minas Gerais, Brazil) on the Water Quality of the Paraopeba River. Science of the Total Environment, v. 705, p. 1-6, 2020. https://doi.org/10.1016/j.scitotenv.2019.135914. DOI: https://doi.org/10.1016/j.scitotenv.2019.135914
YANG, R. et al. A Review on Chitosan-Based Flocculants and Their Applications in Water Treatment. Water Research, v. 95, p. 59-89, 2016. https://doi.org/10.1016/j.watres.2016.02.068. DOI: https://doi.org/10.1016/j.watres.2016.02.068
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