1, printing and dyeing wastewater characteristics

Textile printing and dyeing industry is a large discharge of industrial wastewater, wastewater containing mainly attached to the textile fiber of dirt, grease, salt of the machining process, and all kinds of slurry, dyes, surfactants, additives, such as acid and alkali.

Wastewater is characterized by high concentration of organic compounds, complex components, deep color and varied, pH changes, water and water quality change is large, it is difficult to deal with industrial wastewater. With the development of chemical fiber fabrics, silk and the rise of printing and dyeing finishing requirements raise, polyvinyl alcohol (PVA), rayon alkali solution material, and new dyes, auxiliaries and other difficult degradable organic matter into textile printing and dyeing wastewater, the traditional wastewater treatment technology pose a serious challenge, COD concentration is from the original hundreds of milligrams per liter rose to 3000 ~ 5000mg / L.

Dyeing wastewater with high colority, high COD, especially in recent years according to the foreign market development of mercerized blue, silk black, dark blue, deep blacks and other printing and dyeing process, the printing and dyeing extensive use of sulfur dyes, auxiliaries sulfide etc.. Therefore, wastewater containing large amounts of sulfide, the wastewater must be pre dosing treatment, followed by a series of processing, in order to stabilize discharge standards. Bleaching and dyeing wastewater containing dyestuff, size, surface active agent, this kind of waste water, concentration and chroma are low, if the simple use of physical and chemical processing, water is also in between 100 ~ 200mg / L, chroma also can to meet emissions requirements, but substantially increases the amount of pollution, the higher cost of sludge treatment, easy to cause the secondary pollution, under the current environmental requirements more stringent should give full consideration to the biochemical treatment system and conventional enhanced biological treatment process can meet the processing requirements.

2, design principles

The pollution source management and clean production, from the source control of wastewater discharge, reduce the production of pollutants and emissions;

1, the use of advanced, reasonable, mature and reliable processing technology and equipment for the characteristics of wastewater quality, the maximum possible investment benefit;

2, the use of efficient and stable water treatment facilities and structures, as much as possible to reduce the cost of the project, while combining the production of enterprises, the comprehensive treatment of sewage;

3, the use of more advanced control system, improve the automation level of sewage station, reduce labor intensity, to ensure continuous and stable operation of the sewage treatment system;

4, meet the requirements of the discharge standards, the use of advanced technology and energy-saving equipment, reduce operating costs of sewage treatment;

5, strive to the sewage treatment facilities layout is compact, process flow smoothly, as far as possible to reduce the number of sewage, as far as possible to save land;

6, the use of physical and chemical treatment based, supplemented by a combination of biochemical treatment process;

7, sewage treatment station operation is not caused by the surrounding environment two times;

3, water quality and water

Through the operation experience of similar wastewater, the relevant technical specifications and the local environmental protection department of wastewater treatment after the discharge requirements, the project's water quality indicators are listed as follows: 1:

4, the principle of technology introduction

The sewage pipe collected by the sewage into the grid channel, the removal of water pump units may be blocked and the larger suspended solids after the valve into the aeration tank, in the aeration regulation of the average volume of the tank. In the aeration regulation pool at the end of the set of submersible sewage pump, the wastewater lifting entering the coagulation reaction pool, in mixed coagulation reaction tank through the dosing pump adding different medicament to the pool of different units in the, in under the action of the fungicides, water color, suspended substance to be removed. By mixing coagulation reactor treating the wastewater flowing into dissolved air flotation machine within suspended substance separation, flotation machine effluent into biochemical systems for removal of organic matter and ammonia nitrogen, water after biochemical precipitation reaches the draining standard.

Sedimentation tank discharge of sludge into sludge tank, and then through the sludge is pumped to the plate and frame filter press for sludge dewatering or drying field drying drying treatment.

5, process flow chart