Simultaneous Treatment Is The Right Way -- Printing And Dyeing Industry: Discussion On Solving Pollution Control Problems

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As we all know, printing and dyeing sludge is

Pollution control in printing and dyeing industry is a long drawn out battle.

In the middle of 2011, sewage disposal has not yet been completed and the printing and dyeing sludge incident has emerged.

According to reports, a few days ago, dujiangzhai village of Ho Cheng street, Foshan City, Guangdong Province, was dumped by more than 60 thousand tons of printing and dyeing sludge.

5 suspects were arrested by the Gaoming District People's Procuratorate for allegedly polluting the environment.

This is also the first application of the "crime of polluting the environment" in the new criminal law, which sounded the alarm for the heavy blow of the state to control environmental pollution.

Where there is printing and dyeing, there will be sewage.

At present, there are many methods of sewage treatment, and the effect is obvious.

However, sludge treatment is much more complicated than sewage treatment, and the difficulty of treatment is also greater.

The sludge incident in Gaoming District made the printing and dyeing industry tighten again.

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The successful experience of some enterprises is worth learning from.

Reporters learned that Zhejiang true love blanket Technology Co., Ltd., using advanced "deep well aeration" technology and equipment, successfully achieved the goal of reducing sludge by half.

The company takes the production of raschel blanket as its main business. According to the traditional process, it is necessary to add lime, ammonium sulphate and other chemical raw materials into the blankets during printing and dyeing. These chemical materials become sludge after being precipitated, which is likely to cause two pollution.

In cooperation with Shanghai Environmental Protection Institute, the company invested about 8000000 yuan in 2010 and successfully launched the leading deep well aeration process in China.

It is understood that the technology imported Japanese advanced sewage treatment process, which has the characteristics of small footprint, low operating cost, and low sludge production. It can directly treat high concentration wastewater and is not affected by temperature changes.

Compared with the conventional aeration method, the deep well aeration process reduces nearly half of the sludge. The treatment cost of 1 tons of wastewater is reduced by 1.2 yuan compared with the original, and the economic benefit is considerable.

Deep well aeration (super deep water aeration) is a process technology which mainly adopts biological treatment and physicochemical treatment as auxiliary technology. It is used as an aeration tank in underground deep wells for activated sludge treatment.

The aeration tank is composed of a downcomer and a riser. The waste water and sludge are introduced into the downcomer, circulated in the well, and the air is injected into the downcomer, and the mixture is discharged from the riser to the solid-liquid separation device.

The biggest feature of the process is that the aeration tank has a deep depth, a high concentration of dissolved oxygen and a strong oxidizing capacity. It can rapidly and efficiently oxidize the organic matter in the waste water to CO2, H2O and other inorganic substances and become harmless.

In addition, the sludge part can be returned to the deep well through the sludge reflux pump, the excess sludge enters the sludge thickening tank, and then concentrated and dehydrated into the next cycle treatment, such as manufacturing industrial cement and other building materials.

According to relevant reports, Shaoxing South Cement Company Limited, a wholly owned subsidiary of Hangzhou building materials group of South Cement Company Limited, successfully explored the new topic of sludge preparation for Eco cement last year.

In the first half of 2011, the company used "dry new production line" to "eat" more than 9000 tons of sludge discharged from nearby printing and dyeing enterprises, becoming a new bright spot for energy saving and emission reduction in Shaoxing and developing circular economy.

It is understood that the technology of sludge preparation of eco cement is the homogenization of wet sludge and raw limestone in proportion. After high temperature calcination, the alkaline gas in clinker is effectively neutralized with acidic substances in sludge, and the harmful substances of heavy metals in sludge are eliminated.

Inorganic components in sludge can replace some raw materials, and the calorific value of sludge is also effectively utilized in clinker calcinations. Therefore, the corresponding coal consumption is reduced, and the effect of energy saving and emission reduction can be achieved.

During the "12th Five-Year" period, energy conservation and emission reduction as an important basic national policy were mentioned at a higher level.

More stringent sewage discharge standards will be implemented in areas where printing and dyeing enterprises are more concentrated in China.

Reporters learned that, recently, a number of provinces and municipalities have issued local standards for pollutant discharge of printing and dyeing enterprises, further improving the threshold for printing and dyeing enterprises to discharge sewage.

For example, the discharge standard of pollutants for textile dyeing and finishing industry promulgated by Fujian province stipulates that by June 1, 2013, COD (chemical oxygen demand) will be 100mg/L for printing and dyeing enterprises, and other indicators will be reduced by more than 50% after reaching 50mg/L.

Shaoxing county will implement the last knock-out system for printing and dyeing industry which fails to meet the emission standards.

The local relevant departments ranked according to the average value of COD concentration of intake pipe sewage every 10 days.

At present, the average profit rate of printing and dyeing industry is also the lowest in the textile industry. The pressure of equipment pformation and environmental management is also the biggest.

Survival is a test of "speed of life and death" for them.

In the printing and dyeing industry under the "dangerous wall", we must actively respond to the pressure of environmental protection, improve our own level of technology pollution control, treat both the symptoms and the symptoms, and attach importance to sewage treatment, and also make a contribution to the use and reduction of sludge, so that we can achieve sustainable development.