Decolorizing dye wastewater using chitosan

A prototype decolorization unit has een developed to test the feasibility of using chitosan to absorb dyes from effluents. Nine different dyes are tested. It seems that molecular size is the key factor - small, low-molecular-weight dyes sorb best on chitosan. Dyes with metal in their structure do not appear to sorb any better than their n..

Removal and speciation of transition metal ions in textile dyeing wastewaters

Effluent from textile dyeing processes contains products of decomposed dye and unused intact dyes, some of which contain heavy metals. Therefore, free ionic metal and complexed metal, as well as products from the decomposition of the organic part of the dyes, are present in the effluent. Chelating resins provide a method of speciation of ..

Treatment of effluent from a textile process house-towards zero discharge

The technical and economic features of an effluent treatment system for dealing with discharge from a bleaching/dyeing/printing facility are discussed. A combination of reverse osmosis and solar evaporation with recycling is envisaged, enabling approximately 75 of the water to be recycled, which is highly beneficial in areas where water i..

Waste minimization in synthetic textiles process house

Waste reduction at source is considered as a means for protecting the environment from various types of effluents released in wet processing. The techniques examined in this report inclued: quality control of dyes and chemicals; inventory management; conservation and optimezation of dyes and chemicals; modifications to the processes used;..

Troubleshooting: a litany of solved problems

Some 50 case histories of dyeing and finishing problems and their solutions, some dating back 30-40 years, are presented.

Environmentally-friendly processing - a challenge to technologists and specialty chemical manufacturers

The text of the Prof. G.M. Nabar Endowment Lecture 1991-1992 is reproduced. Prohibited chemicals are analysed and the restrictions on noxious substances in effluents are discussed. Various processing stages are considered from the environmental standpoint (sizing/desizing; recovery and re-use of sizing agent). The replacement of pentachlo..

Treatment of textile wastewater by electrochemical method

The treatment of dyeing finishing effluents by an electrochemical method is discussed. Results are evaluated in terms of colour (trubidity) and chemical oxygen demand reductions. The method is shown to be quite effective and is highly competitive as an alternative way of treating textile effluent.

Removal of colour from effluents using polyamide/epichlorohydrin/cellulose polymer. III. Use in anionic dye removal in a batch process

Polyamide/epichlorohydrin/cellulose (PAE-Cell) can absorb substantial quantities of several direct dyes and acid dyes from aqueous solutions using a batch process. PAE-Cell polymers are shown to exhibit better capacity than some types of commercial activated carbon. For a previous part see abstract 93W/03414.

Far-sighted research on the needs of the textile industry and the environment

The development over the past ten years of environmentally-responsible chemical auxiliaries for the textile industry at Krefeld's Chemische Fabrik Stockhausen is described. The various programmes in place and measures taken to combat effluent pollution and safeguard the environment are briefly outlined.

Air in dyeing machines - new perspectives

The emergence of microfibres has led to a new set of problems which cannot easily be solved on conventional dyeing machines, therefore, is necessary. Thies GmbH has developed the Luft-roto system using aerodynamics which is described.