Journal of the Taiwan Institute of Chemical Engineers 61 (2016) 306–315 Contents lists available at ScienceDirect Journal of the Taiwan Institute of Chemical Engineers journal homepage: www.elsevier.com/locate/jtice Equilibrium, kinetic and thermodynamic studies of a new potential biosorbent for the removal of Basic Blue 3 and Congo Red dyes: Pineapple (Ananas comosus) plant stem Siew-Ling Chan a , Yen Ping Tan a,∗ , Abdul Halim Abdullah a , Siew-Teng Ong b a Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia b Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak Darul Ridzuan, Malaysia a r t i c l e i n f o Article history: Received 2 July 2015 Revised 13 November 2015 Accepted 12 January 2016 Available online 12 February 2016 Keywords: Pineapple plant stem Adsorption Basic Blue 3 Congo Red Batch Study a b s t r a c t The waste management becomes particular nowadays and waste conversion into valuable materials is one of the promising alternative capable of reducing the resource depletion rate. The performance of lignocel- lulosic residues, pineapple plant stem (PPS) for cationic (Basic Blue 3, BB3) and anionic (Congo Red, CR) dyes removal has been evaluated in a batch process, using different parameters such as, pH, contact time, agitation rate, initial dye concentration and sorbent dosage. The kinetics of both dyes sorption fitted well with pseudo-second order kinetic model. Boundary layer effect and intraparticle diffusion models were applied to study the rate-limiting step. The isotherm data of BB3 could be well described by Freundlich model (r 2 = 0.998) whilst high coefficient of determination of CR obtained from Langmuir (r 2 = 0.999) and Temkin (r 2 = 0.996) models. The maximum sorption capacities for BB3 and CR were found to be 58.983 and 11.966 mg g −1 , respectively under a favourable sorption process. The BB3 and CR adsorption on PPS was found to be exothermic. The result suggests that PPS has higher affinity on cationic than anionic dye. The promising regeneration capability of PPS using acid, implied PPS was a potential biosorbent for BB3 removal. © 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved. 1. Introduction In textile industry, large amount of effluent is discharged from dyeing and finishing processes whereby 10–15% of dyes are esti- mated to be lost in the effluent [1]. The requirement to minimise residual dyes in the effluent becomes a major public concern due to the stringent restriction and regulation has been established on industrial effluents. Although wastewater undergoes conventional wastewater treatment before being discharged into aquatic sys- tems, a low concentration of dyes remaining in the effluent wa- ter along with other chemical substances can affect the aesthetic and transparency of water stream [2]. Besides, dyes discharged into the aquatic system not only reduce the dissolved oxygen concen- tration but also affect the aquatic ecosystem resulted from the tox- icological properties of dyes, since most of the dyes are known to be toxic, carcinogenic and mutagenic toward the aquatic life [3–5]. With the prediction of freshwater shortages in the future due to climate change, treated effluent becomes second water source for ∗ Corresponding author. Tel.: +60 389466789. E-mail address: typ@upm.edu.my, yptan100@gmail.com (Y.P. Tan). non-potable usage in industrial, businesses and household sectors. The colour removal process thus becomes one of the crucial steps to ensure the quality of the reclaimed water, but additional proce- dures in the textile effluent treatment inevitably increase the cost of overall treatment and cause harmful secondary pollution. Pineapple (Ananas comosus), belongs to Bromeliaceae family, is a perennial monocotyledons plant with terminal inflorescences and a terminal multiple fruit [6]. Pineapple plant only fruits once in the whole lifecycle, but slips and suckers produced from the mother stem are basically used as commercial vegetative propa- gation. Therefore, the stems, the leaves and the roots are served as pineapple residues after vegetative shoots were removed from the mother stem. Nowadays, pineapple becomes the third most important commercial tropical fruit crop in the world. Pineapple production in Malaysia is about 316,000 tons for the year 2013 [7], whereby a large scale of the plantation has cultivated on peat soil. About 13 tons per hectare of pineapple residues are pro- duced in every growing season [8], and these residues on the peat soil are recycled by in situ burning after the harvest, subse- quently attributed to global warming by carbon sequestration [9]. Alternatively, pineapple residues can be removed by shredding or plowing before subsequent replanting. However, the use of heavy http://dx.doi.org/10.1016/j.jtice.2016.01.010 1876-1070/© 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.