Dye wastewater treatment and reuse technology

1, General Provisions

1.1, for the prevention and control printing and dyeing wastewater pollution of the environment, to guide and standardize the printing and dyeing industry, water pollution control, according to “Water Pollution Prevention Law of the People’s Republic of China”, “decision” of the State Council on a number of issues of environmental protection, textile industry, the overall planning and industrial development policies,in accordance with the principles of the guidance to develop technology policy.

1.2 The policy applies to natural fibers (cotton, wool, silk, linen, etc.), chemical fibers (such as polyester, nylon, acrylic, adhesive, etc.) and natural fiber and chemical fiber raw materials blended in different proportions for the various types oftextile production printing and dyeing wastewater generated in the process.

1.3 dyeing process refers to the physical and chemical treatment of the general term for all types of textile materials (fibers, yarns, fabrics) in the production process, including pre-treatment of textile materials, dyeing, printing and finishing processes, collectively referred to as the dyeing process.

1.4 encourage the printing and dyeing enterprises to adopt cleaner production processes and technology, strictly control the amount of water in its production process, the displacement and production pollution amount.Actively implementing a series of standards of ISO14000 (environmental management), the use of modern management methods, improve environmental management.

1.5 encourage the progress of the technology of the dyeing wastewater, printing and dyeing enterprises should actively adopt advanced technology and mature wastewater treatment technology to achieve a stable discharge.

2, clean production technology

2.1 water conservation technology

2.1.1 transfer printing (anhydrous suitable polyester fabric printing process);

2.1.2 Pigment printing (suitable for cotton, chemical fiber and blended fabric printing and dyeing);

2.1.3 cotton before the cold pad-batch process (suitable for cotton and blended fabrics, less polluting processes);

2.2 reduce pollutant emissions from process

2.2.1 cellulose enzyme washed denim fabric (preferably cotton fabrics less polluting processes);

2.2.2 efficient reactive dyes instead of ordinary reactive dyes (suitable for cotton fabrics, less polluting processes);

2.2.3 starch enzymatic desizing (suitable for cotton fabrics, less polluting processes);

2.3 recycle, reuse process

2.3.1 Ultrafiltration recovery of dye (reduction of suitable cotton fabric dyed using dyes, etc.);

2.3.2 of mercerizing short alkali recovery (suitable for cotton fabric resource recovery and less polluting process);

2.3.3 souring water extracted from lanolin (suitable for wool fabric resource recovery and less polluting process);

2.3.4 terylene artificial silk printing and dyeing process alkali reduction section in waste lye back (suitable for the production of polyester fabric resource recovery and less polluting process);

2.4 disabled dyes and alternative technologies

2.4.1 The phase-out and disabled The dyeing reductant effect, resulting in 22 categories of the 118 kinds of harmful aromatic amines, azo dye.

2.4.2 strictly limited the underwear fabric content of formaldehyde and pentachlorophenol, to protect human health.

2.4.3 promoting the use of easily degradable pulp, restrict or without polyvinyl alcohol refractory slurry.

3, wastewater treatment and pollution prevention

3.1 printing and dyeing wastewater should be based on production processes and quality characteristics of cotton, wool, silk, linen and other printing products, the use of different governance technology roadmap to achieve the discharge standards.

3.2 ban and elimination of backward technology and equipment, pollution is serious and can not achieve a stable discharge of a small printing and dyeing enterprise.

Economies of scale of 3.3 printing and dyeing wastewater treatment project for wastewater handling capacity Q ≥ 1000 tonnes / day.

Encourage the printing and dyeing enterprises to concentrate on regional implementation of professional centralized management., Printing and dyeing enterprises in the region of the normal operation of urban sewage treatment plant wastewater by moderate pretreatment, in line with the urban sewage treatment into the plant water requirements, into the unified treatment of urban sewage treatment plants to achieve the discharge standards.

Printing and dyeing enterprises to focus on the region should adopt the water, electricity, steam and focus on the supply form.

3.4 printing and dyeing wastewater treatment should adopt a combination of comprehensive management of routes of biological treatment and physical and chemical processing technology, not a single physical and chemical processing unit as a stable discharge governance processes.

3.5 cotton woven wool woolen, chemical fiber, artificial silk printing and dyeing products of wastewater generated during processing, should adopt the anaerobic acidification, conventional activated sludge or biological contact oxidation of biological treatment and chemical dosing (coagulation and sedimentation,coagulation and flotation), combining physico-chemical treatment of the photochemical oxidation or biological activated carbon treatment technology roadmap.

3.6 cotton spinning knitting, worsted, wool, silk and other printing products processing wastewater, should adopt the conventional activated sludge or biological contact oxidation, such as biological treatment and chemical dosing (coagulation and sedimentation, coagulation and flotation), physico-chemical treatment methods of photochemical oxidation or biological activated carbon treatment technology combining routes.3.5 listed in route control technology can also be selected according to the actual situation.

3.7 scouring wastewater recycling lanolin should be adopted to deal with, anaerobic biological treatment, aerobic biological treatment and chemical dosing of the combination of treatment technologies routes.Or anaerobic biological treatment, waste water and then mixed with other lower concentrations the aerobic biological treatment and chemical dosing to deal with the combination of treatment technologies routes.

3.8 Hemp retting should be the use of biological enzyme degumming method, the Hemp retting wastewater anaerobic biological treatment method should be adopted, a combination of aerobic biological treatment and physical and chemical methods of control technology route.

Surplus activated sludge or chemical sludge produced in the 3.9-biological treatment or chemical processing required by the concentrated, dehydration (such as mechanical dewatering, natural drying, etc.), and final disposal.Should adopt incineration or landfill for final disposal.

3.10 printing and dyeing production and wastewater treatment machinery and equipment, should take effective noise control measures, and comply with the noise control requirements.Environmental health conditions in the areas of special requirements, should also take measures to combat odor pollution.

3.11 dyeing wastewater treatment process selection should be stable up to the national or local pollutant emission standards.

Encourage the production processes and technologies

4.1 encourage the printing and dyeing enterprise development and application of biological enzyme processing technology; laser spray wax, ink-jet system, the plate-free printing technology; digital printing technology; efficient front processor, intelligent small bath ratio and closed dyeing and other low-pollution production processes and equipment.

4.2 encourage the development of central and western regions and ethnic minority areas with ethnic characteristics, textile production, but are required to meet the appropriate requirements for environmental protection.

4.3 to encourage low water countercurrent washing technology and equipment used in the production process.

4.4 water shortage areas in the production process or part of the production unit, the choice of adsorption, filtration or chemical treatment of advanced treatment technology to improve the re-utilization of waste water and waste water resources.