The effluent from the Textile Dyeing Industries generally consists of high amount of inorganic salts like sodium sulphate or sodium chloride. For the purpose of treating this effluent, first Evaporation, then Crystallization of Salts and thereafter centrifuging is done to dewater the salt output from crystallizer. A combination of Industrial Evaporators like Falling film Evaporator, Forced Circulation Evaporator and the Industrial Dryers like Agitated Thin Film Dryer, Fluid Bed Dryer etc are used. Other auxiliary techniques such as centrifuging are also employed.

The effluent containing high amount of inorganic salts is preheated and then it enters the multiple effects falling film evaporator for further concentration. In the evaporation process where the concentration is done to a level close to the saturation point of the salt present.

After concentration in the falling film evaporator, we get a concentrated stream of effluent which can be then further fed to the evaporative/cooling crystallizer where evaporation/cooling encourage the crystallization process.

Finally, the output from the crystallizer centrifuged to separate the salts from the stream. The salt after centrifuging can further be dried using a Fluid Bed Dryer.

SCHEME FOR EFFLUENT TREATMENT FOR TEXTILE/DYEING INDUSTRY:

The effluent from the bulk drug industries generally consists of high organic content thereby making the effluent as high COD effluent. For the purpose of treating this effluent, Evaporation and Drying methods are used. A combination of Industrial Evaporators like Flash Evaporator, Falling film Evaporator, Forced Circulation Evaporator and the Industrial Dryers like Agitated Thin Film Dryer, Fluid Bed Dryer etc are used. Other auxiliary techniques such as centrifuging, filtration, incineration are also employed. But the condensate water generated after condensation of the vapours formed in evaporation process of this particular effluent tends to carry the volatile organic compounds thereby increasing the COD of condensate water and making it unfit for use/disposal. The COD of the condensate water can be brought down by rectification/ carbon treatment or aeration with a high pressure blower for prolonged periods.

The effluent containing high amount of organics is preheated and then high heated using steam as heating media and then it enters into flashing chamber where due to flash evaporation, the maximum quantity of low boiling organics leave the effluent stream and their vapours are condensed into a condenser. This condensed vapours can be incinerated in an incinerator for making the facility a complete zero pollution plant.

The output liquid stream from the flashing chamber enters the multiple effect falling film evaporator for further concentration. After concentration in the falling film evaporator, we get a concentrated stream of effluent which can be then further concentrated or dried in different types of evaporators and dryers depending upon the actual composition of the individual stream.

Finally, whole of the effluent is converted into solid/sludge form so that it can be disposed using various ways like land filling.

SSPs strong background and its Research Team at the Research & Development Centre tried and tested various techniques to bring down the COD of this condensate water so that it can be used back in the industry/ discharged with COD limits well within the range as specified by the Pollution Control Boards.

The concept of effluent treatment, by means, of a collective effort, has assumed reasonable gravity by being especially purposeful for cluster of small scale industrial units. Common Effluent Treatment Plant (CETP) not only help the industries in easier control of pollution, but also act as a step towards cleaner environment and service to the society at large. Small scale industries, by their very nature of job- cannot benefit much from economies of scale and therefore the burden of installing pollution- control equipment, falls heavy on them.

The concerted approach of joint or common effluent treatment provisions has many advantages. Wastewater of individual industries often contain significant concentration of pollutants; and to reduce them by individual treatment upto the desired concentration, become techno- economically difficult The combined treatment provides a better and economical option because of the equalization and neutralization taking place in the CETP.

SSP is one of the most successfull in seting up a project alike these which can handle different type of waste water in a single unit which is economical and need of the hour.