Main Article Content
The study determined flocculation activity of mucilage extracted from dragon fruit peel (Hylocereus undatus) and its ability in reducing synthetic coagulant polyaluminium chloride (PAC) used in coagulation – flocculation process to remove turbidity of different types of water. Investigated waters were turbid waters made from kaolin suspension (KS), suspension of river water with hill soil (FW), and To Lich river water (TL). Turbidity removal was assessed in a sequent coagulation and flocculation model using PAC and mucilage extracted from dragon fruit peel in Jar-tests. Optimal coagulation conditions of PAC with PAC dosage of 20-50 mg/L and pH range of 6-8 regardless of water types and resulted in maximum turbidity removal of about 98%. In order to obtain a comparable turbidity removal, 50%-68% of the required PAC was reduced if mucilage was used. The presence of mucilage enhanced turbidity removal of PAC by 13-22% total efficiency. Mucilage extracted from dragon fruit peel has shown its flocculation ability and its potential as a green material in water treatment.
Y. T. Wu, Recent Advancement of Coagulation-flocculation and its Application in Wastewater Treatment, Ind. Eng. Chem. Res., Vol. 55, No. 16, 2016, pp. 4363-4389, https://doi.org/10.1021/acs.iecr.5b04703.
 S. Choy, M. Prasad, Y. Wu, N. Raman, A Review on Common Vegetables and Legumes as Promising Plant-based Natural Coagulants in Water Clarification, Int. J. Environ. Sci. Technol, Vol. 12, 2015, pp. 367-390, https://doi.org/10.1007/s13762-013-0446-2.
 S. Polizzi, E. Pira, M. Ferrara, M. Bugiani, A. Papaleo, R. Albera, S. Palmi, Neurotoxic Effects of Aluminium Among Foundry Workers and Alzheimer’s Disease, Neurotoxicology, Vol. 23, 2002, pp. 761-774, http://doi.org/10.1016/S0161-813X(02)00097-9.
 C. Rudén, Acrylamide and Cancer Risk – Expert Risk Assessments and the Public Debate, J. Food Chem, Toxicol, Vol. 42, 2004, pp. 335-349, https://doi.org/10.1016/J.Fct.2003.10.017.
 G. Vijayaraghavan, T. Sivakumar, A. Kumar, Application of Plant Based Coagulants for Wastewater Treatment, Int J Adv Eng Res Stud, Vol. 1, No. 1, 2011, pp. 88-92.
 M. Sciban, M. Klaˇsnja, M. Antov, B. ˇskrbic, Removal of Water Turbidity by Natural Coagulants Obtained from Chestnut and Acorn, Bioresour, Technol, Vol. 100, 2009, pp. 6639-6643, http://doi.org/10.1016/j.biortech.2009.06.047.
 C. Lee, J. Robinson, C. Fong, A Review on Application of Flocculants in Wastewater Treatment, Industrial & Engineering Chemistry Research, Vol. 92, No. 6, 2014, pp. 489-508, https://doi.org/10.1016/J.Psep.2014.04.010.
 R. Sanghi, B. Bhattacharya, A. Dixit, V. Singh, Ipomoea dasysperma Seed Gum: an Effective Natural Coagulant for the Decolorization of Textile Dye Solutions, J. Environ. Manage, Vol. 81, 2006, pp. 36-41, https://doi.org/10.1016/j.jenvman.2005.09.015.
 D. M. Trung, B. T. T. Hương, N. V. C. Ngan, Application of Bioflocculant in Improving the Quality of Sea Food Processing Wastewater, Ho Chi Minh City University of Education Journal of Science, Vol. 6, No. 84, 2016, pp. 134-146
 P. T. P. Trinh, N. T. H. Tham, N. T. Quang,
N. T. T. Trang, D. M. Trung, Application of Bioflocculant in Treatment of Sea Food Processing Wastewater, Thu Dau Mot University Journal of Science, Vol. 2, No. 27, 2016, pp. 9-17
 V. H. Thi, H. Hung, L. M. Khanh, Study on the Use of Moringa’s Seed (Moringa oleifera) to Clarify Water in Vietnam, Hue University Journal of Science, Vol. 75a, No. 6, 2012, pp. 153-164 (in Vietnamese).
 B. Jamilah, C. Shu, M. Kharidah, M.Dzulkifly,
A. Noranizan, Physico- chemical Characteristics of Red Pitaya (Hylocereus polyrhizus) Peel, International Food Research Journal, Vol. 18, 2011, pp. 279-286.
 S. Ismail, N. Mahiddin, S. Praveena, The Used of Dragon Fruit Peels as Eco-Friendly Wastewater Coagulants, Asian J Agri & Biol, Vol. 6, Special Issue, 2018, pp. 112-117.
 W. Willats, P. Knox, J. Mikkelsen, Pectin: New Insights Into an Old Polymer Are Starting to Gel. Trends in Food Science & Technology, Vol. 17, 2006, pp. 97-104, https://doi.org/10.1016/j.tifs.2005.10.008.
 P. Tang, C. Wong, K. Woo, Optimization of Pectin Extraction From Peel of Dragon Fruit (Hylocereus polyrhizus), Asian Journal of Biological Sciences, Vol. 4, No. 2011, pp. 189-195, http://doi.org/10.3923/ajbs.2011.189.195.
 F. D. Mello, C. Bernardo, C. Dias, L. Bosmuler,
J. Meira, E. Amante, L.c Bileski, Evaluation of the Chemical Characteristics and Rheological Behavior of Pitaya (Hylocereus undatus) Peel, Fruits, Vol. 69, 2014, pp. 381-390, https://doi.org/10.1051/fruits/2014028.
 L. T. H. Oanh, L. T. Nhat, D. T. Van, P. V. Quang, N. V. Anh, N. H. Huan, Mucilage Extracted from Dragon Fruit Peel (Hylocereus Undatus) as Flocculant for Treatment of Dye Wastewater By Coagulation and Flocculation Process, Internaltional Journal of Polymer Science 2020, No. 7468343, 2020, http://doi.org/10.1155/2020/7468343.
 T. N. Le, D. T. Van, P. V. Quang, N. V. Anh, N. H. Huan, L. T. H. Oanh, Removal of Pollutants from Disperse Black Dye Wastewater by Mucilage from Dragon Fruit Peel, Vietnam Journal of Science and Technology, Vol. 58, No. 5, 2020, pp. 613-622, http://doi.org/ 10.15625/2525-2518/58/5/15169.
 K. Anastasakis, D. Kalderis, E. Diamadopoulos, Flocculation Behavior of Mallow and Okra Mucilage in Treating Wastewater, Desalination, Vol. 249, 2009, pp. 786-791, https://doi.org/10.1016/j.desal.2008.09.013.
 Z. Yang, B. Gao, Q. Yue, Y. Wang, Effect of pH on the Coagulation Performance of Al-based Coagulant and Residual Aluminum Speciation During the Treatment of Humic Acid-kaolin Synthetic Water, Journal of Hazardous Material, Vol. 178, 2010, pp. 596-603, http://doi.org/10.1016/j.jhazmat.2010.01.127.
 Z. Chen, B. Fan, X. Peng, Z. Zhang, J. Fan,
Z. Luan, Evaluation of Al30 Polynuclear Species in Polyaluminum Solutions as Coagulant for Water Treatment, Chemosphere, Vol. 64, 2006,
pp. 912-918, http://doi.org/10.1016/J.Chemosphere.2006.01.038.
 M. Miller, J. Fugate, O, Craver, A, Smith, B, Zimmerman, Toward Understanding the Efficacy and Mechanism of Opuntica Spp. as a Natural Coagulant for Potential Application in Water Treatment, Environ. Sci. Technol, Vol. 42, 2008, pp. 4274-4279, https://doi.org/10.1021/Es7025054.
 G. Cruz, J. Ramírez, L. Lagunas, L. Torres, Rheological and Physical Properties of Spray Dried Mucilage Obtained from Hylocereus Undatus Cladodes, Carbohydrate Polymers, Vol. 91, No. 1, 2013, pp. 394-402, https://doi.org/10.1016/j.carbpol.2012.08.048.