Photodegradation of Malachite Green by Immobilization of Titanium Dioxide on Glass Plates

The effects of pH, contact time, initial dye concentration, numbers of dip coating, light sources and repetitive usage of dip-coated TiO2 were studied in batch experiments in order to investigate the photodegradation efficiency of malachite green in aqueous solution by using titanium dioxide, TiO2 immobilized on glass plates. The photodegradation of malachite green was found to be more effective at lower initial dye concentration. Kinetic studies showed good correlation coefficient for a pseudo-first order kinetic model. The removal of malachite green was dependent on the TiO2 loading where the percentage removal of malachite green was 92.15, 94.28 and 98.43 % for 5, 10 and 15 number of TiO2 dip-coating, respectively. Among the three light sources used, sunlight possessed the highest removal efficiency with 100 % of removal of dye in 6 h of irradiation. The degradation of malachite green was enhanced in basic solution compared with acidic solution due to the amphoteric property of TiO2. The decolourization efficiency was found to be decreased after each repetitive usage of dip-coated TiO2 glass plates. However, the immobilized TiO2 still displayed a good performance in the removal of malachite green.

Low Cost Adsorbents for Sustainable Dye Containing-Wastewater Treatment

Dyes are coloured substances that can be applied to various substrates such as textile materials, leather, paper and hair. The usage of dyes has continuously increased in many industries but the removal of this pollutant remains as a problematic issue as they are generally stable to light and oxidizing agents and are resistant to aerobic digestion. This literature review paper provides and lists several low cost adsorbents to serve as an alternative method for dye removal. Adsorption using low cost materials can be viewed as a sustainable treatment process because most of these materials are of naturally occurring, locally available and inexpensive materials. This paper covers an overview of dyes waste treatments for 5 years period, from 2008-2012. Some of the noteworthy adsorbents include agricultural byproducts, industrial waste and natural clay materials. Besides, the combination processes involving adsorption and other methods was also discussed

Tartaric Acid Modified Rice Hull as a Sorbent for Methylene Blue Removal

Problem statement: Improper dye discharge from various industries such as textile, paper, cosmetic and plastics into receiving streams can be one of the sources towards water pollution. The release of these effluents not only causes various disruptions in the ecosystems, but also poses hazard effect as most of the dyes are highly toxic, mutagenic and carcinogenic in nature. Approach: To prepare an inexpensive and efficient sorbent by chemically modifying rice hull for the removal of Methylene Blue (MB) which is predominantly used in coloring acrylic fiber. Batch experiments were carried out for the removal of MB from aqueous solution by using Tartaric Acid Modified Rice Hull (TARH). Parameters studied include effect of pH, contact time, initial dye concentration and agitation rate and sorption isotherm. Results: From the results, the percentage uptake of MB increased with increasing contact time and agitation rate. Based on the linear regression correlation coefficient, R2, the system under study is more appropriately described by the pseudo-second order model. Maximum sorption capacity calculated from the Langmuir model is 25.0 mg g-1 for MB. Conclusion: The study has shown the effectiveness of TARH in the removal of MB, a basic dye from synthetic solutions. © 2010 Science Publications

Utilization of Fruits Peel as A Sorbent for Removal of Methylene Blue

The potential of using fruits skin as a low cost sorbent in the removal of methylene blue from aqueous solution was studied. The sorption behaviour of various fruits skin for methylene blue was carried out as a function of pH, contact time, concentration of methylene blue and sorption isotherms. The sorption process was rapid with high percentage of uptake taking place within the first 1 h, regardless of its initial concentration. Different kinetic models were selected to interpret the experimental data. The sorption process conformed to Langmuir isotherm and maximum sorption capacities for methylene blue were 56.50, 34.97, 50.51, 48.54, 48.31 and 78.74 mg/g for mangosteen\u27s analyze and explain experimental data obtained. It was found that application of pseudo-second order kinetics provides better correlation of the experimental data than the pseudo-first order model for the different systems studied

Removal of Hazardous Heavy Metals From Aqueous Environment by Low-Cost Adsorption Materials

The rapid growth of the human population and industrialization in the world has indirectly increased environmental problems such as water, air and land pollution. Amongst all, heavy metals can be considered as the most problematic pollutants. Numerous efforts have been attempted to minimize the impact of heavy metals. This chapter discusses the recent developments and technical applicability of different treatment methods for heavy metal removal. The adsorption process using various low-cost materials as the potential alternative for heavy metal removal is being highlighted and summarized

Equilibrium Studies for the Removal of Basic Dye by Sunflower Seed Husk (Helianthus annuus)

The sorption characteristics of sunflower (Helianthus annuus) seed husk (SSH) to remove Methylene Blue (MB) from aqueous solution under batch conditions have been investigated. Sorption of MB was found to be pH, concentration and agitation dependent. The kinetics of sorption was rapid with 80% sorption taking place within the first 60 min regardless of its initial concentration. The fast attainment of equilibrium implying the biosorbent could be suitable for continuous flow system. Using the pseudosecond order kinetics model, the predictive model for MB sorbed at time t (qt) with the initial concentration of (Co) is given by qt = Cot/[0.0607Co + 2.0762 + (0.0012Co + 5.1949)t]. Results indicated that the predicted uptakes of MB agreed closely with experimental values obtained. The experimental data fitted well to Langmuir isotherm model with the correlation coefficient of 0.9860 and maximum monolayer sorption capacity of 45.25 mg/g

Papaya (Carica Papaya) Seed as a Low-cost Sorbent for Zinc Removal

The potential of using papaya seed as a sorbent for the removal of Zn from aqueous solution was investigated. The sorption characteristics of the sorbent was studied under various experimental conditions, such as pH, contact time, concentration of Zn(II), agitation rate and sorbent’s particle size. The equilibrium data have been studied using Langmuir, Freundlich and Brunauer-Emmett-Teller equations. The best correlation was obtained using Langmuir isotherm with the regression coefficient value of 0.9799 and maximum sorption capacity of 19.88 mg/g. The effective pH for the maximum uptake of Zn(II) was at pH 5.0. An increase in percentage uptake of Zn(II) can be observed with increasing contact time and agitation rate. Decrease in sorbent particle size led to an increase in the sorption of Zn(II) and this could be explained by an increase in surface area and hence binding site. Equilibrium was attained around 60 min indicating this sorbent could be a potential material for continuous flow system

Utilization of Fruits Peel as A Sorbent for Removal of Methylene Blue

The potential of using fruits skin as a low cost sorbent in the removal of methylene blue from aqueous solution was studied. The sorption behaviour of various fruits skin for methylene blue was carried out as a function of pH, contact time, concentration of methylene blue and sorption isotherms. The sorption process was rapid with high percentage of uptake taking place within the first 1 h, regardless of its initial concentration. Different kinetic models were selected to interpret the experimental data. The sorption process conformed to Langmuir isotherm and maximum sorption capacities for methylene blue were 56.50, 34.97, 50.51, 48.54, 48.31 and 78.74 mg/g for mangosteen\u27s analyze and explain experimental data obtained. It was found that application of pseudo-second order kinetics provides better correlation of the experimental data than the pseudo-first order model for the different systems studied

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

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 lignocellulosic 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 (r2 = 0.998) whilst high coefficient of determination of CR obtained from Langmuir (r2 = 0.999) and Temkin (r2 = 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

Batch isotherm and thermodynamic studies of pineapple (Ananas comosus) plant stem as agricultural biosorbent for the removal of Basic Blue 3 and Congo Red dyes

There are considerable amount of dyes to be discharged in the effluent from dyeing and finishing processes in the textile industry. The discharged dyes are known to be toxic, carcinogenic and mutagenic toward the aquatic system. A low concentration of dyes in the effluent can affect the aesthetic and transparency of water stream. Remaining dyes in the effluent necessitated colour removal along with the stringent restrictions and regulations established. Agricultural waste generally is preferred due to its cost-effective and good performance in adsorption. Pineapple plant stem (PPS) is one of the agricultural residues after shoots transplantation. Utilisation of PPS in dyes removal not only can remediate textile wastewater but also reduce the agricultural waste management problem in Malaysia. In the present study, the performance of pineapple plant stem for cationic (Basic Blue 3, BB3) and anionic (Congo Red, CR) dyes removal has been evaluated in a batch process. The isotherm equilibrium studies indicated that BB3 could be well described by Freundlich model (R² = 0.999) while high correlation values of CR obtained from Langmuir (R² = 0.999) and Temkin (R² = 0.997) models. The maximum sorption capacities for BB3 and CR were found to be 59.52 and 11.92 mg g¯¹, respectively under a favourable sorption process. The dependency of BB3 and CR adsorption on temperature was validated by van’t Hoff equation. The effect of temperature on the BB3 and CR removal by PPS was ascertained by studying the temperature-dependence dyes distribution between bulk solution and adsorbent, and the interaction between dyes and adsorbent. Removal of BB3 and CR by PPS was found to be exothermic. The result suggests that PPS has higher affinity on cationic than anionic dye