Preparation and Characterization of Granular Activated Carbon from Rice Husk for the Treatment of Textile Effluent

This is to prove that this thesis work entitled "Preparation and Characterization of Granular Activated Carbon from Rice Husk for Textile Effluent Treatment" was carried out by Md. of Textile Effluent" has been approved by the Board of Examiners in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering, Khulna University of Engineering and Technology (KUET), Khulna, Bangladesh in January 2011.

PRODUCTION OF ACTIVATEI) CARBON

CHARACTERIZATION OF ACTIVAI'ED CARBON

TREATMENT OF TEXTILE EFFLUENT

DISCUSSION

CONCLUSIONS AND RECOMMENDATIONS

13 4.1 Data for activated carbon produced in large oven Data for activated carbon produced in medium oven 127 B 6.1 Data for activated carbon produced in medium oven 127 C 1.1 Adsorption of color for temperature variation in Pt-Co 133 C 1.2 Adsorption of color for temperature variation in percentage Adsorption of color for variation in contact time 134. D 1.5 Adsorption of color for variation in contact time 138 D 1.6 Adsorption of color for variation in contact time 139 D 1.7 Adsorption of color for variation in contact time 140 D 2.1 Adsorption of color for different adsorption dose 141 D 2.2 Adsorption of color for different adsorption dose 144 D 3.1 Adsorption of color for different adsorption dose and contact time 146.

Table No. Caption of the Tables Page 2.1 Discharge quality standards for classified industries composite textile 8

INTRODUCTION

General
Objective of the Study
The Research Scheme
Structure of the Dissertation
Textile effluent pollution scenario of Bangladesh

Desizing
Bleaching
Neutralization
Dyeing
Printinu

It is also proportional to the product of the influent COD and the specific growth rate. This residual amount is responsible for the coloration of the effluents and cannot be recycled.

Figure 2. 1: Effluent discharge from textile industry outlet (Picture taken from Shoij Garments Ltd

20 Generation of formaldehyde during vacuum extraction has been used in the storage of resin-

Activated Carbon

Preparation of Activated carbon
Classification of Activated carbon
Application of Activated Carbon

Under the electron microscope (Figure 2.3), the high surface structures of activated carbon are revealed. Treatment with activated carbon removes such impurities and restores the electroplating efficiency to the desired level (http://en.wikipedia.org).

Figure 2.4: Schematic activated carbon mode! (http://www.activatecl-carbon.com )

Adsorption

Basic concept
Characteristics of Adsorption
Factors on which Adsorption depends
Types of Adsorption

Phvsisorption or Physical Adsorption

Differences between Physisorption and Chemisorption
Types of adsorption curves
Chemical Composition of Rice Husk

The amount of gas adsorbed depends on the nature of the adsorbent and the gas (adsorbate) to be adsorbed. The extent of adsorption of gases by solids depends on the exposed surface area of the adsorbent. For a given gas and a given adsorbent, the extent of adsorption depends on the pressure of the gas.

For a given adsorbate and an adsorbent, the degree of adsorption depends on the temperature of the experiment. When the chemical forces hold the gas molecules against the surface of the adsorbent, the adsorption is known as chemisorptions. The magnitude of the adsorption depends on the pressure of the gas and the temperature of the experiment for a particular gas and adsorbent.

Figure 2.6: Definition of terms used to describe adsorption phenomena (1-Laque and Nawab, 1974)

General

I)evelopment of furnace and production of Activated Carbon

Characterization of Produced Activated Carbon

Moisture content determination
Volatile content determination
Ash content determination
Fixed carbon determination

Ig activated carbon was taken in a closed porcelain crucible and then the sample was heated in a muffle furnace at about 550 °C for 7 minutes.

Sample preparation

Adsorption studies

100 mL of each test sample was taken in conical streams and 2.0 g of PRHAC was added to each stream. At the specified temperature, the bottles were mixed in an orbital environmental shaker at 200 rpm until the maximum adsorption time was reached. A series of 100 mL volume studies were made in conical flows for optimal dye adsorption.

The contents of the fluxes were subjected to mixing in an orbital shaker at 200 rpm for maximum adsorption time (equilibrium time) at a predetermined optimum temperature.

Column studies

Sample was collected at every 10 minute time interval for 20 and 30 cm bed depths and 5 minute time interval for 10 cm bed depth.

Figure 3.1: Schematic diagram of column setup

Treatment of textile wastewater

Afterwards, the clear effluent from the top of the sedimentation unit was collected for testing. Then the waste water is mixed rapidly for 1 minute and then slowly mixed for 30 minutes. For activated carbon adsorption unit, 8 g of activated carbon was mixed in 100 ml of wastewater for 60 minutes in 40 T.

Figure 3.3: Experimental program of batch test combinations

Fabrication of Furnace

Type A Furnace

The fuel was placed on grain 1-1 through the upper opening and the ash was removed through the lower opening. There was another small 1.27cm diameter hole at the top of the oven where the smoke vent was used. The fuel was placed on the grit through the upper opening and the ash was removed through the lower opening.

There was another small 5.08 cm diameter hole in the top of the furnace that was used as a smoke outlet. There was another small 2 inch diameter hole in the top of the oven. The upper opening was joined to the upper side opening of the furnace. a) Cross section (b) Front view Figure 3.8: Schematic diagram of C-type furnace.

Research framework

General

Production of Activated Carbon

Activated Carbon produced in Type A Furnace
Activated Carbon produced in Type B Furnace

When the process was going on, the smoke produced in the furnace entered the pot through the lower opening and exited through the upper opening which was connected to smoke outlet. When the process was going on, the smoke produced in the oven entered the pot through the bottom. Then the container was closed and sealed and the container was placed in the oven.

As the process took place, the smoke produced in the furnace entered the pot through the lower opening and exited through the upper opening, which was connected to the smoke outlet. Then the container was closed and sealed and placed in the oven. As the process took place, the smoke produced in the furnace entered the pot through the lower opening and went out through the upper opening, which was connected to the smoke outlet.

Figure 4. 1: Temperature variation with time at the production stage

CHARACTERIZATION OF ACTIVATED CARBON

General

SEM Photograph

Effect of temperature on adsorption
Kinetic study
Effect of adsorbent dose and equilibrium study for Isotherm

Adsorption of methylene blue, i.e., decolorization, on activated carbon was investigated at room temperature at 60°C as shown in Figure 5.2. From Figure 5.3 (a) it was seen that, for the 0.05 g PRHAC dose curve, the absorbance of methylene blue increased up to 60 minutes and the rate of absorbance curve was quite straight. It was also seen from Figure 5.3 (h) that, for the 2.25 g PRHAC dose curve, the adsorption of methylene blue dye increased up to 60 minutes and the speed of the absorption curve was quite straight.

Similarly, all the curves with different doses of activated carbon show a similar trend of curves such that the adsorption rate was increased until 60 minutes after the desorption was started. Freundlich adsorption isotherm represents the relationship between the amount of dye adsorbed per mass unit of the adsorbent (x/m) and the concentration of dye remaining in the solution after the adsorption is complete (Ce). This suggests the applicability of the Langmuir model as shown in the graph's equation for the studied system: the results also show monolayer coverage of methylene blue at the outer surface of the activated carbon. a and W are calculated from the slope and the intersection.

Figure 5.1: Cross section images of Raw rice husk, (b) Activated carbon made of rice husk 5.4 Results

General

Tables 6.1 and 6.2 show that the COD value of Desizing washing wastewater was greatly reduced, but the COD value of Enzyme washing wastewater remained the same.

Table 6. 1: Characteristics of textile wastewaters after collection from source

Characteristics of Textile Wastewaters after treating by Activated Carbon

100 ml of textile wastewater was included in each conical flux and 11.0 g of PRHAC was added to each flux. The contents of the fluxes were then subjected to mixing in an orbital shaker at 200 rpm. Tables 6.1 and 6.3 showed that treating PRIIAC reduced approximately 99% color from Enzyme Wash and Desizing Wash wastewater.

Table 6.2 shows the characteristics of same wastewaters which were retain in closed container for 9 months

Comparison of adsorption characteristics between different types activated carbon

The percentage of color removal with different doses of different activated carbon at the optimum temperature and time is shown in Figure 6.2. At a dose of 5 g, a decrease in color can be seen for laboratory grade activated carbon produced (crushed), activated carbon produced (uncrushed). Activated carbon that has been pulverized gives better results than uncrushed activated carbon.

Table 6.4 shows the color unit of treated wastewater after the end of each process. It can be seen from this table that those batch tests which have activated carbon unit have a large color reduction compared to other batch tests which do not have activated carbon unit such as batch test number 5 have a greater color reduction than batch test number 2,3 , 4; the 10-number series test was the highest reduced. It can be seen from this table that PRHAC treated wastewater reduced the highest COD value than other processes.

Figure 6. 1: Change in color after various treatment of Textile vastevater is clearly shown in

DISCUSSION

General

Characteristics of Produced Rice Husk Activated Carbon (PRHAC) and Laboratory grade activated carbon

From Figure F 3.1 it was seen that 10 mg of laboratory grade activated carbon adsorbs approximately 80% methylene blue dye and approximately 100%. From this it was also observed that, as the adsorbing dose of activated carbon increases, the amount of adsorbed color also increases. Comparing the graphs of both PRI-IAC and laboratory grade activated carbon as shown in Figure F 1.1, 2.1 & 3.1, it was seen that the graph trend of both activated carbon was quite similar except the graph for contact time study.

The experimental solution should be placed in a conical flow with a burette for accurate measurement. At the time of placing the cone melter in the water bath, the solution in the cone melter must be below the water level. Activated carbon that absorbs color should be stored in a safe place and can be used to regenerate activated carbon.

Treatment of textile effluent

CONCLUSION AND RECOMMENDATION

General

Conclusion

Recommendation for future work

Color Removal from Textile Effluent Using Hardwood Sawdust as Absorbent", Journal of Chemical Technology and Biotechnology, Wiley, Vol. 34; Use of Industrial ASTC Products as Adsorbents for Dye Removal", Journal of Hazardous Materials, BlOt Treatment of Colored Wastewater from the Textile Industry in Bangladesh using zinc chloride treated indigenous activated carbon. Methodology for Performance Analysis of Textile Purification Plants in Bangladesh''. 2002) “Removal of Congo Red from water by adsorption on activated caron prepared from coconut pith, an agricultural solid waste Renewal of dyes from wastewater using low-cost agricultural by-products”, Science of the Total Environment, Vol Flectrochemical Treatment of Textile Wastewater”, Journal of Water Science Technology, Full.

The Science of the Total Environment, Vol Adsorption studies for the removal of organic substances and heavy metals using low-cost materials", Journal of Environment and Pollution. Journal of Dyes Pigments, Elsevier, Vol Decolorization of secondary treated tannery effluent by adsorption using activated carbon derived from coconut they!!", Proceedings of International Symposium on Southeast Asian Water Environment. 34; The sequestration of PCBs in Lake L-lartwell sediment with activated carbon.", Journal of Water Research.

Production cost analysis

Sample Moisture Content Volatile Content Ash Volatile Content No (%) (including moisture) content (taking into account moisture content of 6%) 5.88. Sample Moisture Content Volatile Content Ash Volatile Content No (%) (including moisture) content (taking into account moisture content of 3%). Moisture content sample I Volatile content - Volatile ash content No (%) (including moisture) content (taking into account moisture content of 1.96%).