Title of Invention

"AN IMPROVED PROCESS FOR THE PREPARATION OF IMPROVED VISCOSE EFFUNT OF RAYON PULP "

Abstract

The present invention provides an improved process for the preparation of improved viscose effluent of rayon pulp having reduced amount of total dissolved solids (TDS), chemical oxygen demand (COD), and coloring matter characterized in that two steps treatment of said effluent with mixture of transition metal salt and oxide of alkaline earth metal and group III A metal followed by combination of ion exchange resins , which comprises mixing a viscose effluent with a flocculating agent selected from a mixture of a salt of transition metal, alkaline earth metal and group III A metal with oxide of alkali or alkaline earth metal , for a period ranging from 1-10 minutes , at temperature ranging 25 -30 ° C, allowing the effluent to settle for a period ranging from 5-30 minutes, separating the supernatant, contacting the supernatant with a mixture of ion exchange resin such as here in described ,for a period ranging from 5-30 minutes, allowing it to settle and separate the supernatant to obtain the desired improved viscose effluent.

Full Text

This invention relates to an improved process for the preparation of improved viscose effluent of rayon pulp having reduced amount of total dissolved solids (IDS), chemical oxygen demand (COD), and coloring matter . This invention particularly relates to a process for reduction of total dissolved solids (TDS), chemical oxygen demand (COD), and coloring matter from viscose effluent of ryon pulp waste. According to literature the COD, TDS and color of viscose solution may be attributed to the presence of lignin, hemicellulose, xanthate, resin, wax, fat and acids like propionic, acetic etc. and other coloring substances from the raw material like Eucalyptus, Jute and Bamboo used for making pulp. The presence of above mentioned materials can affect pulp properties of rayon. The quality of the pulp plays a very important role in the manufacture of viscose. Certain specifications such as lower percentage of alpha cellulose and higher percentage of lignin, makes the viscose deep in color, which characteristically affect rayon grade fibers. Lignin may be defined as an amorphous polyphenolic material arising from an enzyme-mediated dehydrogenative polymerization ' of three phenylpropanoid monomers, of coniferyl, sinapyl and p-coumaryl alcohols. Lignin (from the Latin, wood) is after cellulose, the principal constituent of woody structure of higher plants which in part is deposited in xylem cell walls, and in part located in intercellular spaces. Lignin is not easily biodegradable and the presence of it influences the viscose process in the following ways: 1. It reduces the reactivity of cellulose, including it's swelling and solubility properties. If the amount of lignin is more in the bulk, the solubility of xanthate will be less resulting in poor filterability of viscose. 2. It hinders the aging of alkali cellulose. 3. It increases the hardness of the fiber. 4. The amount of lignin present in it decides the deepness of the color of viscose effluent. During xanthation process side products such as trithiocarbonate and sodium carbonate are formed according to the following equation : 3CS2 + 6NaOH-» 2Na2CS3 + Na2CO3 + 3H2O The formation of the side products are not desired as they increase the TDS of viscose and affects stability of viscose and also harmful gases are evolved from thiocarbonate during spinning. Almost 20-30% CS2 is consumed in the formation of thiocarbonate, which indirectly affects the xanthate ester formation. Until past two three decades or so large amount of colored effluents containing lignin and other organics imparting high COD, TDS and color were discarded into natural stream and waterways as dilute aqueous solutions, which is not tolerated now. In order to conform to environmental quality guidelines a number of primary and secondary treatment systems are installed. The treatment systems comprise clarifiers to » remove 85 wt.% of suspended solids, aerated lagoons, trickling filters, modified biological systems to remove most of the solids and toxicity with reduction of BOD and COD but very little removal of color and TDS. Ultrafiltration has also been tried and found futile to remove TDS as well as color completely. In the prior art the following methods are used to remove COD, TDS and color of viscose solution in rayon industry. Several methods hitherto used are described in brief herein below: Purifying solutions from rayon production spinning bath. Bochkareva, O. M; Salizhenko, D. A.; Eifer, I. Z; Shimko, I. G. (USSR). U.S.S.R. SU 1171424 Al 7 Aug 1985 From: Otkrytiya, Izobret. 1985, (29), 98. (Russian). (Union of Soviet Socialist Republics). CODEN: URXXAF. CLASS: ICM: C02F001-26. APPLICATION: SU 83-3662282 3 Nov 1983. DOCUMENT TYPE: Patent CA Section. 60 (Waste Treatment and Disposal) Section cross-reference(s): 38, CA 104:55798 Bochkareva et al have purified wastewaters from a rayon spinning bath by evapn., crystn. of the NajSO^ and recombination of the mother liquor with the wastewater. Amine removal from the wastes is increased and the water cycle closed by letting the solns. stand and settle after evapn., conducting the NajS04 crystn. in the lower layer, and treating the upper layer with an org. solvent, a halogen deriv. of a satd. hydrocarbon in a 1:2-4 ratio, and letting 2 layers form again by standing. The aq. layer is recycled to the initial spinning bath soln., and the org. layer treated with a 0.4-0.8% soln. of alkali in a 10:1 to 1:1 ratio, and the resultant alk. soln. then added to the soln. for producing rayon. Reverse osmosis plant design for recovery of sodium sulfate from rayon mill spent liquor: an illustration. Devmurari, C. V.; Chandorikar, M. V. (Cent. Salt Mar. Chem. Res. Inst, Bhavnagar, India). Desalination, 48(3), 331-7 (English) 1983. CODEN: DSLNAH. ISSN: 0011-9164. DOCUMENT TYPE: Journal CA Section: 40 (Textiles) Section cross-reference^): 48, CA 100:122611 Devmurai et al have described a method to det. the time av. product flux of the cellulose acetate [9004-35-7] membrane.Using this data, it is shown how to calc. the required membrane area for a given capacity reverse osmosis tubular plant to cone, the rayon mill spent liquor to the required level of the concn. hike. The important factors for plant design are also briefly discussed. Reduction of pollution from viscose fiber plants by processing waste into microcrystalline cellulose. Koch, Stanislaw; Rybicki, Zbigniew; Struszczyk, Henryk (TZWCh "Wistom", Pol.). Wlokna Chem., 11(3), 280-92 (Polish) 1985. CODEN: WLCHDF. ISSN: 0208-7499. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products) Section cross-reference(s): 40, 60, CA 104:188428 Koch et al have found that environmental pollution related to rayon manuf. can be reduced by manufg. microcryst. cellulose [9004-34-6] from the cellulosic wastes, e.g., mercerization wastes, xanthation wastes, waste viscose, and waste rayon. The technol. is based on acid hydrolysis of the wastes. Purifying wastewaters from viscose production. Vorzonin, V. A.; Osipov, G. P.; Osipov, S. G. (Kalinin Polytechnic Institute, USSR). SU 1204577 Al 15 Jan 1986, U.S.S.R. (Russian). (Union of Soviet Socialist Republics). CODEN: URXXAF. CLASS: ICM: C02F001-58. APPLICATION: SU 82-3448368 4 Jun 1982. DOCUMENT TYPE: Patent CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 37, CA 104:212660 Vorzonin et al have purified wastewaters from rayon prodn. by adding to them a Ca silicate material such as a slate sol, peat sol, or vermiculite, with the relative contents of the components CaO:SiO2:A12O3:SO3:Fe2O3:MgO:Na2O:K2O:P2O5 equal to (2.0-2.4):(3.0-4.0):(1.0-1.5):(1.0-1.2):(1.2-1.6):(1.2-1.5):(2.0-2.4):(1.0-1.4):(1.0-1.4), mixing in 2 stages by circulating the mixture in a closed loop, and in the 2nd stage also blowing air through, and then removing the resultant precipitate. Environment and effluent treatment. Sundaram, P. (South India Viscose Ltd., Sirumugai 641 302, India). Trans. SAEST, 20(2-3), 107-9 (English) 1985. CODEN: TSETA6. ISSN: 0036-0678. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference^): 40, 43, CA 104:74273 Sundaram et al have found that wastewater treatment at an industrial complex (a pulp plant, a rayon plant, a staple fiber plant, and a polynosic stable film plant) in India is divided into primary, chem., and biol. treatment stages. The primary treatment includes equalization and neutralization of raw wastewater with simultaneous aeration. The chem. treatment includes coagulation and clarification of suspended solids in the wastewater. The biol. treatment consists of org. matter removal in aerated lagoons. The treated water is discharged to a river 1 km away. Treatment reduces suspended solids from 360 to 680 to 30 ppm. In addn., spent liquor, after use in the digesters, is coned, and burned in special boilers Biological elimination of heavy metals in industrial wastewaters. Plahl-Wabnegg, F.; Kroiss, H. (Inst. Wasserguete Landschaftswasserbau, Tech. Univ. Wien, Vienna A-1040, Austria). GWF, Gas- Wasserfach: Wasser/Abwasser, 125(9), 424-6 (German) 1984. CODEN: GWWAAQ. ISSN: 0016-3651. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 102:11725 Plahl-Wabnegg et al have described that heavy metals are removed from industrial wastewaters during anaerobic treatment due to pptn. by the HjS generated by SO42~ reducing bacteria. In lab scale tests, Zn concns. in viscose fiber factory wastewater were decreased from 60-100 to Reverse osmosis (RO) was evaluated in treatment of spinning bath and washing effluent stream for water/chem. reclamation, along with pollution abatement has been described by Basu & Moulik. Initial membrane evaluation was carried out in a RO test loop having 1 mm* feed channel height, and 0.60 cm2 flow cross sectional area with cellulose diacetate membrane (CDA), and thin film amide composite membrane (PA-300). Under varying flow rates (NRe 500-8500), concn. polarization modulus was pronounced at low concn. of Na2SO4 soln.(2%), whereas it was lower at higher concn. (12%) for flow rates up to NRe = 3500. At higher flow rates, polarization modulus was more or less const., and was 1.075-1.10 depending upon feed concn. and type of membranes used. Mass transfer coeffs. calcd. from the exptl. results showed good agreement with the predicted data. A new process for recycling zinc-containing wastewaters from the viscose industry as an example of a low-waste/no-waste technology. Schubert, Manfred; Lachmann, Stephan (Sekt. Verarb. Verfahrenstech., TU Dresden, Dresden, Ger. Dem. Rep.). Wiss. Z. Tech. Univ. Dresden, 34(1), 133-36 (German) 1985. CODEN: WZTUAU. ISSN: 0043-6925. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 103:146567 Schubert et al have described a new multistage process for zero-discharge treatment of Zn-contg. wastewaters from rayon manuf. consists of several pH regulation-pptn., flotation, and floe sepn. stages, yielding a treated water and a Zn slurry for recycling. Regeneration of sodium cation-exchange filters by preliminarily purified wastewaters. Shimko, I. G.; Romanova, T. A; Tolstov, V. N.; Malyar, E. I; Lyubina, R. B. (USSR). Khim. Volokna, (6), 18-19 (Russian) 1984. CODEN: KVLKA4. ISSN: 0023-1118. DOCUMENT TYPE: Journal CA Section: 61 (Water) Section cross-reference(s): 40, 60, i CA 102:67167 Shimko et al have shown that the pretreated waste-water from rayon manufg., contg. £8g NaSO4/L, and similar model solns. to be effective as NaCl solns. in regeneration of the cation exchanger KC1-2-8 [11118-20-0]. Wastewater pretreatment, including neutralization, flotation, settling, quartz filtration, and C filtration, removed most of the surfactants, suspended substances, Zn, S, Fe, H2SO4, and COD without removing NaSO4 and alky. The exchanger working capacity for softening water is restored to 40-50% of theor. The resin had no gypsum pptn. even after 150 filtration-regeneration cycles. Use of pretreated wastewater eliminated the need for NaCl and decreased concns. of salts and Cl- in receiving waters. Wastewater treatment. (Unitika Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 59032996 A2 22 Feb 1984 Showa, 4 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: 1C: C02F003-12. APPLICATION: JP 82-141279 13 Aug 1982. DOCUMENT TYPE: Patent CA Section: 60 (Waste Treatment and Disposal), Ca 101:78338 The M/S Unitika Ltd. Japan have described the treatment which is characterized by treatment of an org. wastewater after mixing it with a neutralized primary effluent from rayon n&dn. Thus, wastewater from nylon prodn"' was/clild. with water and the primary effluent from rayon prodn., aerated, and settled. The effluent contained 5-10 ppm BOD. Anaerobic treatment of viscose wastewater. Kroiss, H.; Plahl-Wabnegg, F.; Svardal, K. (Inst. Wasserguete Landschaftswasserbau, TU-Wien, Vienna A-1040, Austria). Water Sci. Technol., 17(1), 231-9 (English) 1985. CODEN: WSTED4. ISSN: 0273-1223. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 43, CA 103:41901 Kroiss et al have described a method for removal of Zn, S042", and org. matter from limestone-neutralized viscose manufg. wastewater by anaerobic treatment in an upflow reactor and subsequent activated-sludge treatment. SO42~reducing bacteria produce S2", which causes Zn to ppt. COD removals were 40-50% in the anaerobic stage, and final effluent Zn concns. were Regeneration of the KU-2-8 resin by coagulation baths of rayon fiber production. Romanova, T. A.; Vishnyakova, E. V.; Kachalkova, E. V. (USSR). Khim. Volokna, (6), 9-10 (Russian) 1984. CODEN: KVLKA4. ISSN: 0023-1118. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 102:66833 Romanova et al have described that settling baths from a textile plant, contg. H2SO4 136- 153, Na2SO4 195-253 g/L, and org compds. (COD 1640-2070 mg OT/L), were useful instead of 10% H2SO4in desorption of Zn from ion exchanger KU-2-8 [111 18-20-0], used in removing metals from rayon manufg. wastewaters. Baths from another plant with higher org. compd. concns. (COD 5661) were initially less effective in removing Zn; but absorption of org. compds. by the resin decreased in later regenerations and restored absorption capacity for Zn was the same for baths from both plants. Complex conversion of biomass. IL Microbiological degradation of cellulose materials. Simionescu, C. I.; Popa, V. I.; Rusan, Viorica; Stoleriu, A.; Rusan, M; Dragomir, B. (Inst. Chim. Macromol. "Petru Poni", lasi, Rom.). Rev. Padurilor-Ind. Lemnului, Celul. Hirtie, [Ser] Celul. Hirtie, 31(4), 169-72 (Romanian) 1982. CODEN: RPLHDX. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products) Section cross-reference(s): 7, 16, 60, CA 98:181309 The degrdn. of filter paper, CM-cellulose [9004-32-4], and rayon-fiber waste by Aspergillus niger and Trichothecium roseum was studied by Simionescu et al . Pretreatment with aq. alkali increased the crystallinity of the rayon-fiber waste and lowered its accessibility to enzymic attack, whereas the alkali pretreatment decreased the crystallinity of the cellulosic materials and increased their accessibility to enzymic attack. T. roseum Exhibited specificity for the rayon fibers, and A. niger exhibited specificity for cellulosic materials. Gas chromatog. showed liberation of sufficient glucose in the culture media from the degrdns. to provide 0.6 g EtOH [64-17-5]/mL media by fermn. Medium for wastewater treatment. Ida, Hiroaki; Fujii, Masahiro; Haruta, Toshio (Unitika Ltd. , Japan). Fr. Demande FR t 2497118 Al 2 Jul 1982, 11 pp. (French). (France). CODEN: FRXXBL. CLASS: 1C: B01D039-16; C02F001-28; C02F003-06. APPLICATION: FR 81-24153 23 Dec 1981. PRIORITY: JP 80-186297 27 Dec 1980; JP 81-43332 24 Mar 1981. DOCUMENT TYPE: Patent CA Section: 60 (Waste Treatment and Disposal), CA 97:133029 Ida et al have showed that the wastewater treatment medium for removal of suspended solids contained spherical clumps of fibers formed by dispersion, agitation, and entanglement of discontinuous fiber added to the wastewater. Thus, the addn. to a rotating device with 1 m diam. contg. water at normal temp, of 1 kg rayon fibers of 10 deniers (31 m diam.) cut to 20 mm length and rotation of the device at 30 turns/min for 30 min resulted in fiber clumps of 10-30 mm diam. Basic trends in development of low-efficient and effluent-free productions of rayon fibers. Shimko, I. G.; Shmatova, V. V.; Gritskova, I. V.; Zinina, A. P.; Urusov, A. A.; Shibalina, V. V.; Trubachev, V. F. (Nauchno-Proizvod. Ob'edin. "Khimvolokna", USSR). Khim. Prom-st, Ser.: Okhr. Okruzhayushchei Sredy Ratsion. Ispol'z. Prir. Resur., (4), 32 pp. (Russian) 1981. CODEN: KPSRDL. DOCUMENT TYPE: Journal CA Section: 40 (Textiles) Section cross-reference(s): 61, CA 96:53636 Shimko et al have explained that redn. of water consumption by recycling and using (in xanthation) the wastewaters left after prewashing of viscose filter presses and a complex wastewater treatment (purifn. and desalination) system providing low-effluent or effluent-free prodn. of rayon fibers. Recent technology in wastewater treatment. Inoue, Gennosuke (Water Re-use Promot. Cent., Japan, Tokyo 107, Japan). Kagaku Sochi, 33(10), 27-30 (Japanese) 1991. CODEN: KASOB7. ISSN: 0368-4849. DOCUMENT TYPE: Journal; General Review CA Section: 60 (Waste Treatment and Disposal), CA 115:262432 Inoue has presented a review with 8 refs. on wastewater treatment by biol. processes, membrane sepn., ozonization, UV irradn., ion exchange, and dephosphorization by crystn. Removal of nonionic surfactants from rayon-manufacturing wastewater. Ivkina, T. M.; Barabash, N. D.; Shashkova, T. N. (USSR). Tekhnol. Fiz.-Khim. Ochistki Prom. Stochnykh Vod: Anal. Kontrol Protsessov Ochistki, 35-8. Edited by: Genkin, V. E. VNTI VODGEO: Moscow, USSR. (Russian) 1990. CODEN: 57CSA8. DOCUMENT TYPE: Conference CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 115:14740 Ivkina et al have shown the removal of PEG-35 and Berol-Visco-314 nonionic surfactants from wastewater from rayon manuf. by coagulation with activated silicic acid, silicotungstic acid, or polyacrylamide. The use of activated silicic acid gave surfactant removal efficiencies of 29.6-85.9% depending on the type of wastewater treated. The best results were obtained at pH 2.6-2.8. Surfactant removal efficiencies of 80% were obtained with silicotungstic acid. Treatment with activated silicic acid and A12(SO4)3 or polyacrylamide was ineffective. The use of activated silicic acid is the most economical and is recommended. Wastewater treatment in rayon manufacture by treatment of local effluents. Shimko, I. G.; Sagadeeva, L. V.; Makarova, N. A.; Sukhikh, V. G.; Kashaeva, L. M. (USSR). Khim. Volokna, (5), 10-11 (Russian) 1988. CODEN: KVLKA4. ISSN: 0023- 1118. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 109:236223 Shimko et al have shown that wastewaters from rayon fiber manuf, contg. 459.2 mg SiOf'/L, are dild. with municipal effluents and treated by the activated-sludge process to give outlet SjO32- concns. of 7.5 mg/L. The recommended max. concn. of SzOj2' in effluents undergoing activated-sludge treatment is 400 mg/L. Internal recycling of the SjC^'contg. stream is recommended for optimum wastewater management. A protess for the detoxification and decolorization of effluents from rayon and paper pulp mills. Parameswaran, Pillai Sivasankar Pillai (India). Indian IN 158181 A 20 Sep 1986, 8 pp. » (India) CODEN: INXXAP. CLASS: ICM: C02C001-40. APPLICATION: IN 83-MA114 23 May 1983. DOCUMENT TYPE: Patent CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40,43, CA 107:64246 Parameswaran et al have described that effluents from rayon and paper pulp mills are decolorized and detoxified by pptn. with the sulfates, chlorides, nitrates, or hydroxides of rare earth elements (Ce, La, Nd, Pr, Sm) together with the sulfate, chloride, or nitrate of Fe, Al, or Cr or their mixts. with a polyelectrolyte material e.g., polyacrylamide or polyglucosamine). A typical effluent 1 L was treated with a rare earth chloride 1.0%, 0.5 mL, 1% aq. A12(S04)3 soln. 2 mL, and 0.5% polyglucosamine 0.25 mL. The soln. was stirred, settled for 30 min, and filtered yielding an effluent with pH 6.0, color (Hazen units) 10, and total solids 100 ppm. Use of Trilon B for cleaning of filter materials in wastewater treatment systems Shimko, I. G.; Gens, A. M; Chernetskii, E. K.; Biryukova, N. I. (USSR). Khim. Volokna, (2), 54-5 (Russian) 1987. CODEN. KVLKA4. ISSN: 0023-1118. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 43, CA 106:219045 Shimko et al have illustrated that, in the treatment of viscose manufg. wastewaters by CaO neutralization and filtration to remove Zn, the deposits of Ca compds. occurring on the quartz sand filters can be removed by washing with a trilon B (I) [64-02-8] soln. I can be recovered from the wash water and reused. Study'of wastewater treatment in viscose fiber production. Chen, Liang; Lin, Shaoning; Huang, Runa (China Textile University, Shanghai 200051, Peop. Rep. China). Shanghai Huanjing Kexue, 13(8), 15-18,4 (Chinese) 1994. CODEN: SHUKE9. ISSN: 1000-3975. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 43, CA 125:40790 The treatment included aeration for removing sulfide, pptn. by alkalies for removing Zn, and oxidn.-coagulation for removing org. substances (COD). The removal rates were 99, 98, and 81.37%, resp which was described by Chen et al. Optimal anaerobic digestion of high BOD waste with an acclimatized and fresh seed culture combination. Rajor, A.; Kothari, R. M.; Garg, R. P. (Civ. Eng. Dep., Thapar Inst. Eng. Technol., Patiala 147 001, India). Int. J. Environ. Pollut, 2(1-2), 64-75 (English) 1992. CODEN: IJVLEN. ISSN: 0957-4352. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 40, CA 120:143055 With rising energy costs and increasing environmental pollution, this paper looks at how treatment of biol. waste is emerging as a cost effective soln. towards both these problems. Treatment of coned, effluents from rayon manuf. is described by Rajor et al. Anaerobic digestion of zinc-containing sludge. Czermak, P.; Guenther, G. K.; Zielke, R. (Fachhochsch. Giessen-Friedberg, FB TG- Biotechnol., Giessen W-6300, Germany). Bioforum, 15(9), 284-7 (German) 1992. CODEN: BFRME3. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 43, CA 118:175065 The possibility is shown of anaerobic digestion of sludge from biol. treatment of rayon manufg. wastewater despite its high ZnS (£20%) and NaS04 contents this has been described by Czermak et al. » Separation of color-bearing lignin rayon and pulp mill effluents using pretreated effluent from sulfate route titanium dioxide plants. Parameswaran, Pillai Sivasankar (India). Indian IN 170361 A 21 Mar 1992, 14 pp. (India). CODEN: INXXAP. CLASS: ICM: C02F001-52. APPLICATION: IN 87-MA623 27 Aug 1987. DOCUMENT TYPE: Patent CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products) Section cross-reference(s): 60, CA 120:33204 Parameswaran et al have shown that color-bearing lignin from rayon and pulp mill effluents is sepd. by pptn. with waste liquor from sulfate route titanium dioxide plant contg. FeSO4, Ti(SO4)2, and H2SO4 followed by settling and sepg. the ppt. by conventional means, wherein the waste liquor is pretreated to reduce the free acid content to a level of 0-7% by reacting with Fe, mill scales, bauxite ore, lime sludge or magnesite ore. Pollution control in viscose rayon industry through recovery of zinc from effluent. Upadhyay, Rajeev; Pandey, G. N. (U.P. Pollut. Contr. Board, Janakpuri 257, India). J. Ind. Pollut. Control, 8(1), 1-9 (English) 1992. CODEN: JIPCE4. ISSN: 0970-2083. DOCUMENT TYPE: Journal CA Section: 54 (Extractive Metallurgy) Section cross-reference^): 38, 60, CA 118:151419 To recover Zn from viscose rayon effluent 3 methods, i.e., chem( pptn"., ion exchange, and solvent extn., were tested by Upadhyay and Pande^ Exptl/results showed the chem. pptn. was the most effective and economic method. Max. Zn recovery was obtained at pH 9.2. Industrial scale Zn recovery may not be much profitable, but is suitable for India. Removal of N-methyl-morpholine N-oxide from aqueous solutions such a cellulose processing wastewater Astegger, Stefan; Firgo, Heinrich; Wolschner, Bernd (Lenzing Aktiengesellschaft, Austria). Eur. Pat. Appl. EP 488988 Al 3 Jun 1992, 9 pp. DESIGNATED STATES: R: BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, ML, SE. (European Patent Organization). CODEN: EPXXDW. CLASS: ICM: C02F001-28. ICS: DO 1FO13-02. APPLICATION: EP 91-890271 11 Nov 1991. PRIORITY: AT 90-2401 26 Nov 1990. DOCUMENT TYPE: Patent CA Section: 60 (Waste Treatment and Disposal) Section cross- reference^): 43, CA 117:239122 Astegger et al have treated wastewaters containing N-methyl-morpholine N-oxide, e.g., from spinning baths, by adsorption with alumina, silica, or coal (grain size In hitherto known processes main drawbacks are the use of acidic media which involves corrosion problems, filtration problems due to colloidal particles and incomplete removal of organics as well as inorganic matter in the effluent water and color due to organics mainly lignin and mellanoidin. The objective of the resent invention is to provide an improved process for the reduction of total dissolved solids (TDS), chemical oxygen demand and colouring matter from viscose effluent of rayon pulp waste. The process of the present invention removes COD, color and TDS simultaneously at room temperature from rayon pulp effluents thus saving energy cost, the operation does not involve any use of mineral acid thus, avoiding corrosion problems. The process involves two steps viz. flocculation with mixture transition metal salt and oxide of alkaline earth metal followed by the use of combination of ion exchange resins. The resins used in the process can be regenerated with known methods. There is continued interest on development of new improved process for removal of color, lignin and other organic and inorganic matter produced in the xanthation process of rayon pulp. It is a well known fact that lignin and color in such types of effluents are not easily biodegradable and hence, have disposal problems in the natural environment. Accordingly the present invention provides an improved process for the preparation of improved viscose effluent of rayon pulp having reduced amount of total dissolved solids (TDS), chemical oxygen demand (COD), and coloring matter characterized in that two steps treatment of said effluent with mixture of transition metal salt and oxide of alkaline earth metal and group III A metal followed by combination of ion exchange resins , which comprises mixing a viscose effluent with a flocculating agent selected from a mixture of a salt of transition metal, alkaline earth metal and group III A metal with oxide of alkali or alkaline earth metal, for a period ranging from 1-10 minutes , at temperature ranging 25 -30 ° C, allowing the effluent to settle for a period ranging from 5-30 minutes, separating the supernatant, contacting the supernatant with a mixture of ion exchange resin such as here in described ,for a period ranging from 5-30 minutes, allowing it to settle and separate the supernatant to obtain the desired improved viscose effluent. In one of the embodiments of the present invention, the flocculating agent used is a mixture of salt of transition metal, alkaline earth metal and III A group with oxide of alkali or alkaline earth metal selected from the group consisting of sodium, potassium, magnesium and calcium. In one of the embodiments of the present invention, the salt used is selected from sulphate, chloride and nitrate. In another embodiment of the present invention, the transition metal and III A group metal used is preferably iron and aluminium respectively. In yet another embodiment of the present invention, the mixture of resins used is a mixture of two or more commercially available resin selected from the group consisting of 120, IR 400 MB 106, Gel A23, ADS 600, Indion 840 and Indion 930 A. » In yet another embodiment of the present invention, the mixture of resins used is preferably a mixture of Indion 840 and Indion 930 A. In yet another embodiment of the present invention, the mixture of the ion exchange resins used is in 1:1 proportion (v/v). In still another embodiment of the present invention the contact time of resin mixture with the supernate obtained from the first step is preferably in the range of 10-15 minutes. In one of the features of the present invention all the operations of the process were carried out at ambient temperature without any use of mineral acid. In the feature of the present invention after the first step of the effluent treatment, significant reduction of color and COD was observed for all the three effluent samples tested. In another feature of the present invention, after the second step of the effluent treatment using ion exchange resins, the dark brown color of the effluent samples changed to almost colorless to straw color within 30 minutes. It was also observed that the COD and IDS values were reduced to a great extent. In another feature of the present invention, all the operations of the process were carried out at room temperature without use of mineral acids. In another feature of the present invention the resin mixture used in the process could be regenerated with known methods and reused. The process of the present invention is described hereinbelow with reference to the examples which are illustrative only and should not be construed to the limit of scope of the present invention in any manner. Example -1 100 ml solution of the viscose effluent samples viz. Sample-I (COD- 13,967 ppm and IDS 19,300 ppm & pH - 3.8), Sample-H (COD -30,474 ppm and IDS 24,780 ppm & pH - 2.0) and Sample-in (COD 1580.9 ppm and IDS 3400 ppm & pH - 7.23) were taken separately in 250ml conical flasks to which a flocculent comprising a mixture of metal salts aluminum sulphate, ferrous sulphate and calcium chloride(0.1g) in 7:2:1 proportion and an oxide of alkaline earth metal viz.calcium oxide ( 1.0 to 2.0g) was added and mixed thoroughly and allowed to settle in 100ml measuring cylinder for 30 minutes at room temperature. The supernatant solutions thus obtained were analyzed for their COD, TDS and color reduction using spectrophotometer at 480 nm after adjusting the pH of the sample to ~ 8.0 . The analytical data for Sample-I, Sample-II and Sample-Hi observed was as follows : (Table Removed) Example - 2 100 ml supernatant samples obtained after first treatment as mentioned in Example -I, of viscose effluent viz. Sample-I, Sample-II and Sample-in of pH ~ 12.0 were taken separately in 250 ml conical flasks to which a mixture of ion exchange resins (Indion -840 & Indion - 930 A 10% each v/v) was added and stirred on magnetic stirrer at room temperature for 10 minutes. The decanted solution was analyzed for COD, IDS and color reduction as in Example No.-l. (Table Removed) Example- 3 100 ml supernatant samples obtained after first treatment as mentioned in Example -1, of viscose effluent viz. Sample-I, Sample-II and Sample-Ill of pH - 12.0 were taken separately in 250ml conical flasks to which a mixture of ion exchange resins (Indion -840 & Indion - 930 5% each v/v) was added and stirred on magnetic stirrer at room temperature for 10 minutes. The decanted solution was analyzed for COD, TDS and color reduction as in Example 1 & 2. (Table Removed) Example -4 100 ml supernatant samples obtained after first treatment as mentioned in Example -1, of viscose effluent viz. Sample-I, Sample-II and Sample-in of pH - 12.0 were taken separately in 250ml conical flasks to which a mixture of ion exchange resins (Indion -840 & Indion - 930 2.5% each v/v) was added and stirred on magnetic stirrer at room temperature for 10 minutes. The decanted solution was analyzed for COD, TDS and color reduction as in Example 1, 2 & 3. (Table Removed) Example - 5 100 ml supernatant samples obtained after first treatment as mentioned in Example -1, of viscose effluent viz. Sample-I, Sample-II and Sample-III of pH ~ 12.0 were taken separately in 250ml conical flasks to which a mixture of ion exchange resins (Indion - 840 & Indion - 930 10% each v/v) was added and stirred on magnetic stirrer at room temperature for 30 minutes. The decanted solution was analyzed for COD, TDS and color reduction as in Example 1,2,3 & 4. (Table Removed) Advantages of the invention : The present process has following advantages such as it removes COD , color and TDS simultaneously at room temperature from rayon pulp effluents thus saving energy cost, the operation does not involve any use of mineral acid thus, avoiding corrosion problems. The process involves two steps viz. flocculation with mixture transition metal salt and oxide of alkaline earth metal followed by the use of combination of ion exchange resins, The resins used in the process can be regenerated with known methods. We Claim: 1. An improved process for the preparation of improved viscose effluent of rayon pulp having reduced amount of total dissolved solids (TDS), chemical oxygen demand (COD), and coloring matter characterized in that two steps treatment of said effluent with mixture of transition metal salt and oxide of alkaline earth metal and group III A metal followed by combination of ion exchange resins , which comprises mixing a viscose effluent with a flocculating agent selected from a mixture of a salt of transition metal, alkaline earth metal and group III A metal with oxide of alkali or alkaline earth metal, for a period ranging from 1-10 minutes , at temperature ranging 25 - 30 ° C, allowing the effluent to settle for a period ranging from 5-30 minutes, separating the supernatant, contacting the supernatant with a mixture of ion exchange resin such as here in described ,for a period ranging from 5-30 minutes, allowing it to settle and separate the supernatant to obtain the desired improved viscose effluent. 2. An improved process as claimed in claim 1 wherein alkaline earth metal used is selected from the group comprising of sodium, potassium, magnesium and calcium. 3. An improved process as claimed in claims 1 & 2 wherein the salt used is selected from sulphate, chloride and nitrate. 4. An improved process as claimed in claims 1 - 3 wherein the transition metal and group III A metal used is preferably iron and aluminium respectively. 5. An improved process as claimed in claims 1 to 4 wherein the ion resins used is a mixture of two or more commercially available macro porous corsslinked polystyrene or styrene resins. 6. A process as claimed in claims 1 to 5 wherein the mixture of the ion exchange resins used is in 1 : 1 proportion (v/v) of polystyrene : styrene resins. 7. A process as claimed in claims 1 to 7 wherein the contact time of resin mixture with the supernatant obtained from the first step is preferably in the range of 10 - 15 minutes. 8. An improved process for the preparation of improved viscose effluent of rayon pulp having reduced amount of the total dissolved solids (IDS), chemical oxygen demand (COD), and coloring matter substantially as herein described with reference to the examples.

Documents:

1079-del-2000-abstract.pdf

1079-del-2000-claims.pdf

1079-del-2000-correspondence-others.pdf

1079-del-2000-correspondence-po.pdf

1079-del-2000-description (complete).pdf

1079-del-2000-form-1.pdf

1079-del-2000-form-19.pdf

1079-del-2000-form-2.pdf

1079-del-2000-form-3.pdf