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Nadirah Ismail IWA Young Water Professionals 2015

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a powerpoint presentation based on a review paper mainly discussing about the new alternative adsorbent from lignocellulosic materials.

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Nadirah Ismail IWA Young Water Professionals 2015

  1. 1. Removal of Colour From Dyes in Water and Wastewater Using Leaves of Plants as Adsorbents: A Review of Pre-treatment Methods Nadirah Ismail Chemistry Department, Faculty of Science Universiti Teknologi Malaysia IWA Young Water Professionals 2015
  2. 2. William Henry Perkins (1838–1907)  Accidently discovered the first synthetic dye (at 18 y.o)  Aniline purple  From chemicals derived from coal tar  From this grew the highly innovative chemical industry of synthetic dyestuffs
  3. 3. Definition • Coloured substances that when applied to fibers, give them a permanent colour which is able to resist fading upon exposure to sweat, light, water, chemicals, oxidizing agents and microbial attack. Characteristics • Synthetic origin • Complex aromatic structure • Stable in the environment • Metabolites are toxic • Threat to environment and organisms
  4. 4. The Technologies Treatment methods for textile effluents Chemical methods Physical methods Biological methods oxidation ozonation Filtration Coagulation/ flocculation adsorption microbes enzymes
  5. 5. Adsorption  Accumulation of the molecular species at the surface rather than in the bulk of the solid or liquid is termed as adsorption.  The phenomenon of attracting and retaining the molecules of a substance on the surface of a liquid or a solid resulting into a higher concentration of the molecules on the surface is called adsorption.  A chemical process that takes place when adsorbate accumulates on the surface of a solid (adsorbent), forming a molecular or atomic film.  It is a surface phenomenon.
  6. 6.  Simplest  Low capital and operating costs  Rapid kinetics of adsorption and desorption  No sludge production  Can have good physical properties  Adsorbents are easily available
  7. 7. Activated Carbon Well established Capable to adsorb various organics and metals Porous structure High specific surface area = Large sorption capacities *BUT, activated carbon for commercial scale pollutant removal is quite expensive!
  8. 8. Alternative adsorbents “Depleting natural resources, growing environmental awareness and economic considerations are the major driving forces to utilize renewable resources such as biomass for various applications” (Narendra Reddy & Yiqi Yang, Biofibers from agricultural byproducts for industrial applications, 2005)
  9. 9. Low cost alternative adsorbent  Originated from agricultural / domestic/ industrial waste.  Lignocellulosic wastes: plant biomass wastes that are consisted of cellulose, hemicelluloses and lignin.  Such as sawdust, grasses, stalks, nutshells, bagasse, leaves, and peelings.
  10. 10. Alternative Adsorbents Banana stalk Peanut hull Plum kernels Mango seed kernel Coconut husk Neem leaf powder Sugarcane dust Tea waste Rice hull Corn cob Sago waste Degreased coffee beans Banana peel Duckweed Sugar beet pulp Rice bran Orange peel Apricot stone Lemon peel Soybean hull Guava leaf powder Sunflower stalks Jute stick Bamboo dust Almond shell Cotton stalks Raw barley straw Hazelnut shell Rattan sawdust Durian shell
  11. 11. Malachite green Crystal violet Methylene blue Nirgudi leaf, Kammoni leaf, Pineapple leaf Mangifera Indica (Mango) leaf, Calotropis procera leaf Gulmohar leaf, Posidonia oceanica leaf, Pineapple leaf Pineapple leaf Mangifera Indica Calotropis procera Posidonia oceanica Application of plant leaf waste as biosorbent
  12. 12. X-ray Diffraction (XRD) Scanning Electron Microscopy (SEM) Surface area, pore size distribution Fourier transform infrared spectroscopy (FTIR) Tools Characterization of lignocellulosic materials
  13. 13. Physical treatment WASH – DRY – CRUSH - SIEVE Pre-treatment methods
  14. 14. Chemical pretreatment Formaldehyde Sulphuric acid Hydrochloric acid Nitric acid Sodium hydroxide Formaldehyde has been applied to Sargassum binderi to avoid organic leaching that may lead to secondary pollution that might devastate the biosorption process (Pei et al., 2009). The chemical treatments enhanced the adsorption kinetics of Reactive Red 228 compared to untreated Posidonia oceanica (Ncibi et al., 2007).
  15. 15. In the case of Posidonia oceanica, four types of chemical treatments were introduced i.e. modification with 0.2 M nitric acid, 0.2 M phosphoric acid, sodium hypochloride and 30% (v/v) hydrogen peroxide (Ncibi et al., 2007).
  16. 16.  With chemical modification, adsorbent will experience good enhancements in pores.  When tea waste being treated with 0.5M NaOH, gap between pores like honeycomb shape was observed under scanning electron microscope (Nasuha and Hameed, 2011). COVERED WITH MB
  17. 17. Physicochemical pre-treatments  Another activation route that could give improved leaves’ pore structure  Involves the chemical agents such as alkali and mechanical actions.  Milling or extrusion of lignocellulosic biomass with the aid of alkali.  Mainly to destroy lignin structure
  18. 18. (d) Wash Dry Grind & Sieve
  19. 19. Chemical treatment of adsorbent  Methanol to remove inorganic and organic matter from the surface of sorbents. Deionized water Acid treatment Methanol
  20. 20. Adsorption experiments Adsorbent saturated with dye (Reactive Red 198)
  21. 21.  Untreated leaves has relatively smooth surface while the physico-chemically treated leaves exhibits rougher surfaces.  Therefore, was proved to be a good activating agent to develop high surface area adsorbent
  22. 22. Lignocellulosic materials
  23. 23. Adsorption pH of adsorbate Adsorbent Dosage Contact time Factors affecting dye adsorption onto adsorbent
  24. 24. High solution pH solution results in an increase in the percentage of cationic dye removal because the positive charge on the solution interface will decrease and the adsorbent surface appears negatively charged. At higher solution pH, electrostatic repulsion is found between the negatively charged surface and dye molecules, thus decreasing the adsorption capacity and percentage removal of anionic dyes pH Low pH solution results in an increase in the percentage of anionic dye removal because of the electrostatic attraction between anionic dye and the positive surface charge of the adsorbent pH
  25. 25. In general, the dye removal percentage is increasing with the increase of the adsorbent dosage When excess adsorbent dosage is used, a significant portion of the adsorption sites remain unsaturated. This obviously leads to low specific adsorption capacity. Dosage When the adsorbent dosage was lowered, the number of active sites saturated with dyes increased; therefore, specific uptake also increased Dosage
  26. 26. At higher contact time, the rate of adsorption decreases, gradually leading to equilibrium due to decrease in total adsorbent surface area and less available binding sites The decrease in dye removal with time may be due to aggregation of the dye molecules around the adsorbent particles. Time
  27. 27. Plant leaves-based adsorbent offers many attractive features such as outstanding adsorption capacity for many dyes, low in costing and environmental friendly. FUTURE RESEARCH: Investigation of these materials with real industrial effluents, recovery of used plant leaves-based adsorbent, regeneration study and continuous flow study. It offers significant advantages over currently available adsorbent and in addition contribute to agricultural waste minimization strategy. Conclusions Thank You