Chrysanthemum indicum microparticles on removal of hazardous Congo red dye using response surface methodology

International Journal of Industrial Chemistry (2018) 9:305–316 https://doi.org/10.1007/s40090-018-0160-5 RESEARCH Chrysanthemum indicum microparticles on removal of hazardous Congo red dye using response surface methodology J. Chukki1 · S. Abinandan2 · S. Shanthakumar1 Received: 19 June 2018 / Accepted: 8 November 2018 / Published online: 17 November 2018 © The Author(s) 2018 Abstract Biomass-derived adsorbents have been intensively studied due to their competence in reducing pollutants with conventional methods. Flowers are used as source in medicine, cosmetics and even as adsorbents for pollutant abatement. In this study, the microparticles from Chrysanthemum indicum were used as adsorbent for reducing the Congo red dye concentration from synthetic solution. Batch trials were evaluated to understand the influence of factors and optimization was carried out using central composite design. Maximum reduction (84.1%) achieved under the optimized settings of pH (1.0), adsorbent dose (300 ppm), stirring speed (150 rpm), and contact time (75 min) at initial dye concentration (150 ppm at 30 °C). Microparticle size ensured with surface morphology of the adsorbent using electron microscopy and functional groups was studied using infrared spectroscopy techniques, respectively. Regression coefficient (R2) value was obtained as 0.956 which indicates that the predicted values were in good agreement with their corresponding experimental values for the Congo red dye adsorption. Based on the investigation, it is inferred that the Chrysanthemum indicum flower has the potential for Congo red dye reduction from aqueous solution. Keywords Congo red dye · Chrysanthemum indicum · Adsorption · Central composite design Introduction Several industries extensively use synthetic dyes and generate a large volume of dye effluent. This dye effluent contains enormous salt and organic content and they are less biodegradable. Discharge of these dyes into natural water system without the treatment results in ecological imbalance [1–4]. Synthetic dyes are resistance to the physicochemical reaction and have thermal and optical stability due to the complex aromatic structure [5, 6]. By conventional methods, it is challenging to treat the wastewater which contains dyes [7, 8]. Azo dyes account for 60–70% of total dye consumption in many industries [7]. Congo red (CR) is the synthetic anionic azo dye [9] and the effluent had to be adequately treated and discharged into the environment, otherwise it can metabolize into benzidine, which is a human carcinogen * S. Shanthakumar 1 Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology (VIT), Vellore 632014, India 2 Eco Tech Labs Private Limited, Chennai 600032, India [10]. CR dye contains complex aromatic structure which complicates the treatment process. It has thermal and optical stability, and resistance to biodegradation and photodegradation [11]. CR dye is used for staining purpose and as a pH indicator in the laboratory. It is also used for detecting bacteria, amyloidosis diagnosis and to treat protein folding disorders, dermatological disorders, neurodegenerative diseases, etc. However, CR dye causes allergic reactions and it is a cytotoxic, genotoxic, hematotoxic, neurotoxic, as well as mutagenic substance [12, 13]. Generally, chemical oxidation, ozonisation, membrane filtration, ion exchange or electrochemical techniques are the different methods used to treat dye-contaminated wastewater. Adsorption is proved to be the best method compared to all other technologies due to its less capital outlay. Detailed literature review shows that various adsorbents were used for Congo red dye removal from wastewater, which includes polypyrrole–polyaniline nanofibers [14], modified zeolites [2], sugarcane bagasse [15], aniline propyl silica xerogel [16], tamarind fruit shell [17], acrylamide–sodium dodecyl sulfate layered double hydroxides [18], mesoporous Z rO2 fibers [19], ammonium aluminum carbonate hydroxide-nickel hydroxide composite [20], zinc oxide–alumina composite [21], nickel cobaltite 13 Vol.:(0123456789) 306 International Journal of Industrial Chemistry (2018) 9:305–316 [22] and Funalia trogii [23]. However, some of these are not effective for the anionic dye. The biosorbent (Chrysanthemum indicum) belongs to Asteraceae family and are known as Indian chrysanthemum which are widely used for decoration purposes [24, 25]. Further, the literature review indicates that Chrysanthemum indicum flowers (CIF) which are used in this study as an adsorbent for CR dye removal have not yet been studied previously. In India, CIF is generally used for the ornamental purpose and the regular return of CIF is 16.7 tons/hectare that is reported in our previous study [26]. The main aim deals with CIF ability as an adsorbent to treat synthetic CR dye wastewater. CCD is widely adapted to observe the effect of individual process factors and their interactive effects. Table 1  Level of independent variables and experimental range Independent variables Design vari- Range and levels ables −1 0 pH Adsorbent dose(g/L) Initial dye conc. (mg/L) RPM Contact time (min) Temperature (°C) F1 F2 F3 F4 F5 F6 Percentage reduction = [( 4 2 100 100 60 25 6 3 150 150 75 30 +1 8 4 200 200 90 35 ] ) Ci − Cf ∕ Ci × 100, where Ci, Cf are the initial and final dye concentrations (mg L−1), respectively. Materials and methods Experimental design Microparticles In tradition method of adsorption, variable response effect is studied by varying one variable at a time, ending up in large experimental trails associated with high time consumption process without representing the interaction effect between factors. Therefore, RSM is considered as one of the most useful methods for optimizing the process and portray the influence by several parameters [27, 28]. The experimental trails are carried out based on the quadratic equation (Eq. 1) between the independent variable and coefficients of central composite design (CCD), as expressed below: CIF was obtained from the native marketplaces of Vellore district, Tamil Nadu, India and meticulously washed to remove dust and dirt particles. Petals were collected and dried and powdered using a domestic mixer. This powder was sieved. Particles of size less than 100 microns were further used as an adsorbent. Physical characteristics of the microparticles are presented elsewhere [26]. (1) where y is the response (yield), µ is the response function, c is the error, and F1, F2, F3 … Fn are the independent process parameters. y = 𝜇0 + 𝜇1 F1 + 𝜇2 F2 + ⋯ + 𝜇n Fn ± c, Dye Congo red (CR) dye ( C32H22N6Na2O6S2; MW- 696.665; λmax = 497 nm) working derivative solutions made appropriately by diluting the stock solution (1 mg mL−1) with double distilled water. Adsorption experiment Experimental trials were carried based on the procedure mentioned in our previous studies [26]. 250-mL (...truncated)