Removal of Basic and Reactive Dyes by Sorption Using Ethylenediamine-Modified Rice Hull

The effectiveness of using ethylenendiamine modified rice hull (MRH) to remove Basic Blue 3 (BB3) and Reactive Orange (RO16) from single and binary dye solutions was investigated. The optimised modification process was treating 1.00 g of rice hull with 0.02 mol of ethylendiamine (EDA) in a “well stirred” water bath at 80oC for 2 hours. Surface morphology analysis was carried out using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Batch and column studies were performed under various experimental conditions and the parameters studied included pH, contact time, initial concentration, temperature, agitation rate, particle size, sorbent dosage, bed depth, flow-rate and sorption –desorption process. Batch studies reveal that sorption was pH and concentration dependent. The sorption of BB3 and RO16 from single and binary dye solution was found to be endothermic and exothermic, respectively. The kinetics of dye sorption fitted a pseudo-second order rate expression. Maximum sorption capacities calculated from the Langmuir model are 14.68 and 60.24 mg/g for BB3 and RO16, respectively in binary dye solutions. This corresponds to an enhancement of 4.5 and 2.4 folds, respectively, compared to single dye solutions. The dye uptake increased with increasing sorbent dosage. Column studies indicate that breakthrough was bed depth, flow rate and influent concentration dependent. Unusual breakthrough curves were obtained for RO16, with very rapid initial breakthrough followed by complete retention at low flow rate, influent concentration and high bed depth. The breakthrough curves of BB3 followed the typical S shape of packed- bed systems. Theoretical breakthrough curves at different bed depths and flow rates generated by the two parameter mathematical model agreed well with the experimental data of single dye solution of BB3. In sorption-desorption process, BB3 can be recovered completely by eluting the column with 0.5 M H2SO4 and HCl but the column cannot be reused. However the desorption of RO16 from MRH column was unsuccessful. The effect of initial concentrations as well as light source was investigated in the photodegradation of BB3 and RO16 using TiO2 catalyst. Both BB3 and RO16 can be degraded using suspended TiO2, with either UV or sunlight as the light source. In the removal of dyes using a combination of sorption and photodegradation, immobilized MRH and TiO2 were used. The percentage of dye removal increased with increasing irradiation time and the maximum number of dip coatings that can be applied was ten. MRH dip coated with TiO2 appeared to be less efficient to remove dyes compared to separate MRH and TiO2 plates. For all the dye solutions studied, the percentage of dye removal decreased with increasing number of usage of immobilized TiO2. Highest percentage of dyes removal was obtained when MRH/TiO2 glass plates were placed at a distance of 2.2 cm apart with air bubbling between them. In the study of treatment of wastewater from textile industry, optimum pH for the sorption of dyes using MRH was in the range of 2 to 5. Uptake of dye under both batch and continuous flow conditions shows similar behavior as in synthetic solutions. However, photodegradation of the dye from the wastewater was unsuccessful

Utilization of Mango Leaf as A Low-Cost Adsorbent for The Removal of Cu(II) Ions from Aqueous Solution

The potential of mango leaves as a low-cost adsorbent for the removal of Cu(II) ions from aqueous solution was investigated in this study. The influences of pH, contact time, initial metal ions concentration, agitation rate and particle size were studied in batch experiments at room temperature. IR spectrum analysis was employed to study the functional groups of the mango leaves before and after modifications as well as after sorption process. Maximum sorption for metal ion was found to be at pH 5. The adsorption was rapid at the first 5 min of contact time and equilibrium was achieved in 60 min of agitation. Kinetic studies showed good correlation coefficient for a pseudosecond order kinetic model. The uptake was found to increase with higher agitation rate and smaller size of adsorbent. Langmuir and Freundlich, isotherm models were applied to describe the biosorption of Cu(II) ions onto mango leaves. Maximum sorption capacities calculated from the Langmuir model is 15.77 mg/g. The results showed that mango leaves have the potential to be applied as alternative low-cost biosorbent in the remediation of heavy metal contamination in wastewater

A comparison of sorption and photodegradation study in the removal of basic and reactive dyes

A comparative study on the effectiveness of using ethylenediamine modified rice hull (MRH) and titanium dioxide (TiO2) under ultraviolet irradiation to remove both basic and reactive dyes from aqueous solutions was carried out. The sorption characteristics of Basic Blue 3 (BB3) and Reactive Orange 16 (RO 16) by MRH were studied under various experimental conditions. Studies on the sorption of both dyes showed that sorption was pH and concentration dependent. Langmuir equation was employed to model the sorption behavior of MRH. Maximum sorption capacities calculated from the Langmuir model are 3.29 and 24.88 mg/g for BB3 and RO16, respectively. The effect of initial concentrations as well as light source was carried out in the photodegradation of BB3 and RO16. BB3 with concentration of 50 mg/l was totally degraded after 6 hours of contact with TiO2 under UV illumination whereas RO 16 at the same concentration was completely decolorized at illumination time of 5 hours. The decolorizing efficiency decreased with increasing dye concentration and a higher efficiency was obtained under solar light illumination

Removal of basic and reactive dyes using ethylenediamine modified rice hull

Wastewaters from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. Rice hull, an agricultural by-product, was modified using ethylenediamine to introduce active sites on its surface to enable it to function as a sorbent for both basic and reactive dyes. The sorption characteristics of Basic Blue 3 (BB3) and Reactive Orange 16 (RO16) by ethylenediamine modified rice hull (MRH) were studied under various experimental conditions. Sorption was pH and concentration dependent. Simultaneous removal of BB3 and RO16 occurred at pH greater than 4. The kinetics of dye sorption fitted a pseudo-second order rate expression. Increase in agitation rate had no effect on the sorption of BB3 but increased uptake of RO16 on MRH. Decreasing particle size increased the uptake of dyes in binary dye solutions. Equilibrium data could be fitted into both the Langmuir and Freundlich isotherms. Maximum sorption capacities calculated from the Langmuir model are 14.68 and 60.24 mg/g for BB3 and RO16, respectively in binary dye solutions. This corresponds to an enhancement of 4.5 and 2.4 fold, respectively, compared to single dye solutions. MRH therefore has the potential of being used as an efficient sorbent for the removal of both dyes in textile wastewaters

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

Utilization of Quaternized Rice Hull as Low-Cost Adsorbent for The Removal of Congo Red From Aqueous Solution

In this study, the ability of quaternized rice hull to remove Congo Red from synthetic dye solution was investigated. The percentage uptake of Congo Red by quaternized rice hull was close to 50 % and this corresponds to an enhancement of 6.6 folds as compared to natural rice hull. The effect of contact time, kinetic study, sorption isotherm, agitation rate and adsorbent dosage were studied under various experimental conditions. Batch studies revealed that adsorption was depended on contact time and concentration. For Congo Red with the concentration of 50 mg/L, equilibrium was attained around 2 h whereas at higher concentration it requires a longer time. The adsorption of Congo Red onto quaternized rice hull followed pseudo-second order kinetic model with higher correlation coefficients as compared to pseudo-first order kinetic model. The maximum adsorption capacity of quaternized rice hull calculated using Langmuir model is 30.03 mg/g

Utilization of Quaternized Rice Hull as Low-Cost Adsorbent for The Removal of Congo Red From Aqueous Solution

In this study, the ability of quaternized rice hull to remove Congo Red from synthetic dye solution was investigated. The percentage uptake of Congo Red by quaternized rice hull was close to 50 % and this corresponds to an enhancement of 6.6 folds as compared to natural rice hull. The effect of contact time, kinetic study, sorption isotherm, agitation rate and adsorbent dosage were studied under various experimental conditions. Batch studies revealed that adsorption was depended on contact time and concentration. For Congo Red with the concentration of 50 mg/L, equilibrium was attained around 2 h whereas at higher concentration it requires a longer time. The adsorption of Congo Red onto quaternized rice hull followed pseudo-second order kinetic model with higher correlation coefficients as compared to pseudo-first order kinetic model. The maximum adsorption capacity of quaternized rice hull calculated using Langmuir model is 30.03 mg/g

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