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The adsorption of methylene blue dye from water onto longkong waste peel has been investigated under various experiment conditions. Batch experiments were conducted to determine the effect of pH, initial dye concentration, contact time, adsorbent dose and temperature. The equilibrium time was found to be 205 min at the optimum pH of 7. The capacity of adsorption was improved with increasing of initial dye concentration and temperature. In contrast, as the mass of adsorbent increased, a decrease in the adsorption capacity was obtained. For isotherm study, the adsorption data of longkong peel was best fitted to Freundlich model. The kinetics of adsorption followed the pseudo second order model. Thermodynamic parameters such as, enthalpy, entropy and free energy changes were evaluated. The adsorption process was exothermic and spontaneous.
 T. W. Seow and C. K. Lim, “Removal of dye by adsorption: A review,” International Journal of Applied Engineering Research, vol. 11, no. 4, pp. 2675–2679, 2016.
 M. A. Mohammed, A. Shitu, and A. Ibrahim, “Removal of methylene blue using low cost adsorbent: A review,” Research Journal of Chemical Sciences, vol. 4, no. 1, pp. 91–102, 2014.
 V. K. Gupta and Suhas, “Application of low-cost adsorbents for dye removal-A review,” Journal of Environmental Management, vol. 90, no. 8, pp. 2313–2342, 2009.
 A. A. N. Moghaddam, G. D. Najafpour, A. A. Ghoreyshi, and M. Mohammadi, “Adsorption of methylene blue in aqueous phase by fly ash, clay and walnut shell as adsorbents,” World Applied Sciences Journal, vol. 8, no. 2, pp. 229–234, 2010.
 M. N. Ahmed and R. N. ram, “Removal of basic dye from waste water using silica as adsorbent,” Environmental Pollution, vol. 77, pp. 79–86, 1992.
 A. Sayal, V. K. Bulasara, and S. Barman, “A study on synthesis of zeolite and removal of amido black dye of azoreactive dtes on mesoporous minerals,” Dyes and Pigments, vol. 62, pp. 49–60, 2004.
 B. H. Hameed, A. L. Ahmad, and K. N. A. Latiff, “Adsorption of basic dye (methylene blue) onto activated carbon prepared from rattan sawdust,” Dyes and Pigments, vol. 75, pp. 143–149, 2007.  V. Chairgulprasert, N. Poonchuay, and K. Sahwang, “Rubber wood ashes as adsorbents for methylene blue dye removal: Isotherm, kinetics and thermodynamics studies,” presented at the 2016 Pure and Applied Chemistry International Conference (PACCON 2016), Bangkok, Thailand, 2016.
 V. Chairgulprasert, N. Madlah1, R. Pohmueyae, and N. Madmanang, “Removal of lead(II) ion in water by adsorbents from Pithecellobium dulce,” KKU Science Journal, vol. 44, no. 1, pp. 189–200, 2016.
 M. Rafatulah, O. Sulaiman, R. Hashim, and A. Ahmad, “Adsorption of methylene blue on low cost adsorbents: A review,” Journal of Hazardous Materials, vol. 177, pp. 70–80. 2010.
 R. E. Paull. (2016, Feb.). The commercial storage of fruits, vegetables, and florist and nursery stocks. Washington, DC. [Online]. Available: http://www.ba.ars.usda.gov/hb66/087/longkong.pdf
 Sabah. (2004, Nov.). Langsat, Duku, Duku-Langsat and Dokong. Malaysian Agriculture Department, Malaysia [Online]. Available: http://www.sabah.gov.my/tani/english/crop langsat.htm (November 14, 2004).
 V. Chairgulprasert, B. Krisornpornsan, and A. Hamad, “Chemical constituents of the essential oil and organic acids from longkong (Aglaia dookkoo Griff.) fruits,” Songklanakarin Journal of Science and Technology, vol. 28, no. 2, pp. 321–326, Mar.–Apr. 2006.
 M. Tilaar, W. L. Wih, A. S. Ranti, S. M. Wasitaatmadja, Suryaningsih, F. D. Junardy, and Maily, “Review of Lansium domesticum Corrêa and its use in cosmetics,” Boletin Latinoamericano y del Caribe de Plantas Medicinales y Aromaticas, vol. 7, no. 4, 2008.
 K. Heyne, Tumbuhan Berguna Indonesia, 2nd ed. Jakarta: Departemen Kehutanan, 1987, pp. 1126–1128.
 J. F. Morton, Fruits of Warm Climates. Miami, Florida: Julia F. Morton, 1987, pp. 201–203.
 I. Lichanporn, V. Srilaong, C. Wongs-Aree, and S. Kanlayanarat, “Postharvest physiology and browning of longkong (Aglaia dookkoo Griff.) fruit under ambient conditions,” Postharvest Biology and Technology, vol. 52, pp. 294–299, 2009.
 E. W. M. Verheij and R. E. Coronel, Plant Resources of South-East Asia No.2 Edible Fruits and Nuts. Wageningen, Netherlands: Pudoc, pp. 186–190, 1992.
 A. A. Abia and E. D. Asuquo, “Kinetics of Cd2+ and Cr3+ sorption from aqueous solution using mercaptoacetic acid modified and unmodified oil plam fruit fibre (Elaeis guinensis) adsorbents,” Tsinghua Science and Technology, vol. 12, no.4, pp.485–492, Aug. 2007.
 Y. S. Al-Degs, M. I. El-Barghouthi, A. H. El-Sheikh, and G. M. Walker, “Effect of solution pH, ionic strength, and temperature on adsorption behavior of reactive dyes on activated carbon,” Dyes and Pigments, pp. 1–8, 2007.
 D. Feng and A.ich, “Adsorption of heavy netals by biomaterials derived from the marine alga Ecklonia maxima,” Hydrometallurgy, vol. 73, pp. 1–10, 2004.
 M. A. Hashem, “Adsorption of lead ions from aqueous solution by okra waste,” International Journal of Physical Sciences, vol. 2, no. 7, pp. 178–184, 2007.
 W. Hassan, U. Farooq, M. Ahmad, M. Athar, and M. A. Khan, “Potential biosorbent, Haloxylon recurvum plant stems, for the removal of methylene blue dye,” Arabian Journal of Chemistry, vol. 10, pp. S1512–S1522, May 2017.
 E. L. Abd, “Adsorption, kinetic and equilibrium studies on removal of basic dye from aqueous solutions using hydrolyzed oak sawdust”, Desalination and Water Treatment, vol. 6, pp. 252–268, 2009.
 P. K. Malik, “Use of activated carbons prepared from sawdust and rice husk for sorption of acid dyes: A case study of acid yellow 36,” Dyes and Pigments, vol. 56, pp. 239–249, 2003.
 D. Pathania, S. Sharma, and P. Singh, “Removal of methylene blue by adsorption onto activated carbon developed from Ficus carica bast,” Arabian Journal of Chemistry, vol. 10, pp. S1445–S1451, Feb. 2017.
 S. Liang, X. Guo, N. Feng, and Q. Tian, “Isotherms, kinetics and thermodynamic studies of adsorption of Cu2+ from aqueous solutions by Mg2+/K+ type orange peel adsorbent,” Journal of Hazardous Materials, vol. 174, no. 1–3, pp. 756–762, Feb. 2010.
 Z. A. AlOthman, M. A. Habila, R. Ali, A. A. Ghafar, and M. S. E. Hassouna, “Valorization of two waste streams into activated carbon and studying its adsorption kinetics, equilibrium isotherms and thermodynamics for methylene blue removal,” Arabian Journal of Chemistry, vol. 7, pp. 1148–1158, 2014.
 N. Ünlü and M. Ersoz, “Adsorption characteristics of heavy metal ions onto a low cost biopolymeric sorbent from aqueous solutions,” Journal of Hazardous Materials, vol. 136, pp. 272–280, 2006.
 S. Lagergren, “About the theory of So-Called adsorption of soluble substances” Kungliga Svenska Vetenskapsakademiens Handlingar, vol. 24, no. 4, pp. 1–39, 1898.
 Y. S. Ho and G. Mckay, “Sorption of dye from aqueous solution by peat” Chemical Engineering Journal, vol. 70, no. 2, pp. 115–124, 1998.
 I. Langmuir, “The adsorption of gases on plane surface of glass, mica and platinum,” Journal of the American Chemical Society, vol. 40, no. 9, pp. 1361–1403, 1918.
 H. Z. Freundlich, “Over the adsorption in solution,” The Journal of Physical Chemistry A, vol. 57, pp. 385–471, 1906.
 M. I. Temkin and V. Pyzhev, “Kinetics of ammonia synthesis on promoted iron catalyst,” Acta Physicochimica URSS, vol. 12, pp. 327–356, 1940.
 M. G. B. H. Ismail, C. N. Weng, H. A. Rahman, and N. A. Zakaria, “Freundlich isotherm equilibrium equations in determining effectiveness a low cost absorbent to heavy metal removal in wastewater (leachate) at Teluk Kitang landfill, Pengkalan Chepa, Kelantan, Malaysia,” Journal of Geography and Earth Sciences, vol. 1, no. 1, pp. 1–8.
 A. Akgerman and M. Zardkoohi, “Adsorption of phenolic compounds on fly ash,” Journal of Chemical & Engineering Data, vol. 41, pp. 185–187, 1996.
 Y. S. Ho, D. A. J. Wase, and C. F. Forster, “Kinetic studies of competitive heavy metal adsorption by sphagnum moss peat,” Environmental Technology, vol. 17, pp. 71–77, 1996.
 A. O. Dada, A. P.Olalekan, A. M. Loatunya, and O. Dada, “Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms studies of equilibrium sorption of Zn2+ unto phosphoric acid modified rice husk,” Journal of Applied Chemistry, vol. 3, no. 1, pp. 38–45, 2012.
 A. Javaid, R. Bajwa, U. Shafique, and J. Anwar, “Removal of heavy metals by adsorption on Pleurotus ostreatus,” Biomass and Bioenergy, vol. 35, pp. 1675–1682, 2011.
 M. A. Hanif, R. Nadeem, H. N. Bhatti, N. R. Ahmad, and T. M. Ansari, “Ni(II) biosorption by Cassia fistula (Golden Shower) biomass,” Journal of Hazardous Materials, vol. 139, pp. 345–355, 2007.
 J. Anwar, U. Shafique, W. Zaman, M. Salman A. Dar, and S. Anwar, “Removal of Pb(II) and Cd(II) from water by adsorption on peels of banana,” Bioresource Technology, vol. 10, pp. 1752–1755, 2010.
 M. Kazempour, M. Ansari, S. Tajrobekhar, M. Majdzadeh, and H. R. Kermani, “Removal of lead, cadmium, zinc and copper from industrial waste water by carbon developed from walnut, hazelnut, almond, pistachio shell and apricot stone,” Journal of Hazardous Materials, vol. 150, pp. 322–327.
 D. Djordjevic, D. Stojkovic, N. Djordjevic, and M. Smelcerovic, “Thermodynamics of reactive dye adsorption from aqueous solution on the ashes from city heating station,” Ecological Chemistry and Engineering S, vol. 18, no. 4, pp. 527–536, 2011.
 F. Liu, J. Chen, A. Li, Z. Fei, Z. Zhu, and Q. Shang, “Properties and thermodynamics of adsorption of benzoic acid onto xad-4 and a water-compatible hypercrosslinked adsorbent,” Chinese Journal of Polymer Science, vol. 21, no. 3, pp. 317–324, 2003.
 Z. Zawani, A. C. Lugman, and C. Y. S. Thomas, “Equilibrium, kinetics and thermodynamic studies: Adsorption of remazol black 5 on the palm kernel snell activated carbon (PKS-AC),” European Journal of Scientific Research, vol. 37, no. 3, Jan. 2009.
 A. Özcan, E. M. Öncü, and A. S. Özcan, “Kinetics, isotherm and thermodynamic studies of adsorption of acid blue 193 from aqueous solutions onto natural sepiolite,” Colloids and Surfaces A, vol. 277, pp. 90–97, 2006.