Coagulation using ecofriendly natural coagulant

D. Vasudevan (833012)

K. Gopalakrishna (7221686)

English

Loughborough University Institutional Repository

- 28th WEDC Conference Kolkata (Calcutta), India, 2002 - SUSTAINABLE ENVIRONMENTAL SANITATION AND WATER SERVICESCoagulation Using Ecofriendly Natural Coagulants D. Vasuoevan & K. Gopalakrisbna I InoiaIN THE HIERARCHY of human needs, clothing has the second top most priority next to food. Dyeing units discharge highly coloured waste water. These waste water prior to discharge should comply with standards prescribed as per the water (prevention and control of pollution ) Act 1974 as amended in 1988 framed by the government of India, so as to prevent the receiving water bodies from pollution. Biologial treatment processes are found to be ineffective for removing colour from the effluent. Consequently effluent after biological treatment may contain appreciable amount of colour. Discharge of highly coloured waste in to natural water bodies prevents photosynthetic activity. In addition many dyes may be micro toxic to the organisms and may cause destruction of aquatic biota. It is thus imperative that colour must be removed from the effluent before disposal. Conventional metal coagulants such as alum, and iron salts are proved to be effective in the removal of colour, from the dyeing effluent but with limited success because of some disadvantages. (i) Production of a large sludge volume which do not readily settle, making the process slow and expensive, (ii) Effectiveness in coagulating only a few dyes and (iii) Increase ofTDS in the treated effluent. Use of natural coagulants in conjunction with the conventional coagulants would improve the efficiency of treatment and reduce the cost of treatment. The objective herein, is to study the performance of natural coagulants nirmali (strychnos potatrum) seed, Drumstick (moringa oleifera) seed, Tamarind (tamarindus indica) seed, and chitosan in removing colour from the dyeing effluent, also in conjunction with conventional (metal) coagulant alum. The characteristics of the composite waste water generated from a moderately maintained and reasonably managed textile processing industry as follows. 1. pH 8.0-10.0 2. TDS - 5000-10000 mg/I3. TSS 100-700 mg/14. BOD 50-550 mg/.15. COD - 250-8000 mg/16. Chorides 100-500 mg/17. · Sulphates 50-300 mg/18. Sodium as Na+ - 200-1000 mg/1Nirmali Seed - Nirmali seed (strychonospotatorum) is commonly known as "clearing nut". Strychonos potatorum is one of the group of trees which belong to the family of loganiaceae and grows profusely in various parts of India and south-east Asia. The seed has been recognized for its medicinal properties. Moringa Oleifera Seed - It is a seed of a tropical plant Moringa oleifera belonging to the family of Moringaceae. Moringa oleifera is the most widespread species which grows quickly at low altitudes in the whole tropical belt including arid zones. It is generally known in the developing world as a vegetable, a medicinal plant, and a source of vegetable oil. Tamarind seed - It is seed of a tree species Tamarindus indica. Tamarindus indica seed is a naturally occurring non ionic polyectrolyte. Chitosan - Chitosan is derived from chitin. It is the second most abundant organic material on earth and is found in the exoskeletons of arthropods such as insects and spiders, some fungi, and in crustaceans such as crabs, shrimp and fishes. Preparation of S ynthetic Dye solution - The dye effluents for the experimental work were prepared synthetically in the laboratory. This was done by adding dyes with a concentration of 25 mg/I and 150 mg/I in the soft water. The sample was heated for 60 minutes at an interval of 20 minutes. Common salts (NaCl) was added. Which acts as an exhausting agent in the dyeing operations, finally to a salt concentration of 2.5 gm/lit. Direct, acid, and reactive dyes were used for the study. Prepared samples were poured in containers and allowed to settle for 12 hours. After settling the supernatant was taken for the experiment. Color removal studies were conducted for the following dyes. SL Commercial Type of Maximum Application No. name dye wavelength of Dyes stuff lmax 1 ATUL-Acid Fast Red Acid 507.0 Wool,Nylon Dye (C.I. Acid red S 8) and Silk 2. Erio Orange II HST (H/ C) Acid 484.5 Wool,Nylon Dye (C.I. Acid and Silk Orange 7(2))3. ATliL Direct Brown MR Direct 411.5 Yarn 4. ATUL Direct bordeux BW Direct 513.0 Yarn 5. Procion TBlue MGN Reactive 616.5 Cloth VASUDEVAN and GOPAL\KRISHNA the use of the Nirmali Seed as a Coagulat Aid". Indian Journal of Environmental Health". Vol VII pp 165-176. 3. Bhole. A.G. (1990). "Performance Studies of a few NaturalCoagulants". Journal of Indian Water Works Association. Pp81-83.4. Karthikeyan. J. and Niranjan P. (1992). "Colour Removal fromDye Effluent by Chemical Coagulation I-Acid and Directdyes". Indian Journal of Environmental Protection. Vol 12.No. 7. Pp 497-502:5. Muyibi S. An and L. M. Evison (1995). "Optimizing PhysicalParameters affecting Coagulation of Turbid Water withMoringa oleifera Seeds" Water Research Journal. Vol. 29 No.12pp. 2689-2695.6. Niranjan P. and I<arthikefan J. (1992). "Colour Removal fromDye Effluent by Chemical Coagulation IJ-Basic and Dispersed Dyes". Indian Journal of Environmental Protection. Vol 12. No. 8.0 pp 599-603. 7. Sen A. K. and K. R. Bulusu (1962). Effectiveness of NirmaliSeed as Coagulant and Coagulant Aid". Indian Journal ofEnv:1ronmental Health". No. 4, pp 232-244.D. VASUDEVAN, Post Graduate Student, Dept. of GvilEngineering, IIT Madras, Chennai, Asst. Engineer,Tamil Nadu Pollution Control Board, Chennai.K Gopalakrishna, Assistant Professor, Environmental Engineering, Dept. of Civil Engineering, IIT Madras, Chennai. 

Coagulation using ecofriendly natural coagulants

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Coagulation using ecofriendly natural coagulants

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