Highly Efficient Removal of Acid Red-17 and Bromophenol Blue Dyes From Industrial Wastewater Using Graphene Oxide Functionalized Magnetic Chitosan Composite Saima Sohni, 1,2 Kashif Gul, 2 Faiza Ahmad, 2 Imtiaz Ahmad, 2 Adnan Khan, 2 Nouman Khan, 2 Sher Bahadar Khan 3 1 Institute of Chemical Sciences, University of Peshawar, Peshawar, Pakistan 2 Environmental Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang 11800, Malaysia 3 Center of Excellence for Advanced Materials Research (CEAMR) and Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia In present study, magnetic chitosan-graphene oxide composite ( m … C x -GO) has been synthesized and used for the removal of two common textile dyes; acid red-17 (AR-17) and bromophenol blue (BPB). The effect of var- ious parameters including pH (2–8), time (10–100 min), adsorbent dosage (2–10 mg), initial dye concentration (2–30 lg mL 21 ) as well as temperature (303, 313, and 323 K) was investigated. The point of zero charge of composite was determined using pH drift method in an attempt to better understand the adsorption process. Present work revealed fast adsorption kinetics with removal efficiency of around 79 and 97% for AR-17 and BPB, respectively, under optimized conditions. Besides, equilibrium relationships were studied using Langmuir and Freundlich models. Thermodynamic analysis uncovered the spontaneous and endothermic nature of dye-composite interation. Synthesized mate- rial showed profound stability after five successive adsorption-desorpion cycle of reuse. Importantly, spiked real water samples were used to check the suitability of composite adsorbent for practical appli- cations. High % recoveries were obtained which indi- cated that complex matrix presented insignificant interference effects. Also, comparative study revealed that composite material offers superior performance for the removal of dyes relative to precursors (C x , Fe 3 O 4 nanoparticles, GO). Improvement in removal effi- ciency of synthesized composite toward selected dyes can be attributed to intrinsic qualities of C x and incor- porated functionalities; exceptionally high surface area as well as excellent mechanical properties of GO and convenience of magnetic separation because of Fe 3 O 4 nanoparticles . POLYM. COMPOS., 00:000–000, 2017. V C 2017 Society of Plastics Engineers INTRODUCTION Water permeates all aspects of life on Earth by provid- ing vital services for human health, livelihood and well- being. [1] Globally, it is estimated that over 10,000 differ- ent dyes and pigments are consumed by different indus- tries, including textile, food, cosmetics, leather, plastic, paper, and printing, among others. Textile industries in particular consume substantial quantities of water, dyes, and other toxic chemicals. [2] The effluents released from these industries are rich in dyes due to their high water solubility, some of which are known to be non- biodegradable, carcinogenic, and mutagenic. As one of the major sources of water pollution, these effluents pose a serious threat to aquatic life, human health and environ- ment if discarded untreated. [3] At the same time, drastic increase in the demand for dyes and organic pigments has aggravated current status of environment, estimated to grow 6% per annum to $19.5 billion by 2019 (“World Dyes & Organic Pigments Market,” 2015). [4] Conse- quently, wastewater treatment and recycling has become immensely challenging and researchers are actively involved in exploring new, rapid, efficient, and cost effec- tive ways for remedying polluted environment. [5] Over the years, several wastewater treatment methods have been designed for the decontamination of wastewater from textile industries. Dyes, in principle, are recalcitrant Correspondence to: K. Gul; e-mail: kashifpkh@upesh.edu.pk Additional Supporting Information may be found in the online version of this article. DOI 10.1002/pc.24349 Published online in Wiley Online Library (wileyonlinelibrary.com). V C 2017 Society of Plastics Engineers POLYMER COMPOSITES—2017