Advanced Treatment and Reuse Process of Printing and Dyeing Wastewater

High pollution has always been a pain in the development of the printing and dyeing industry, with pollution mainly concentrated in wastewater, with an annual discharge of 1.8 billion to 2 billion tons, accounting for about 11% of the total national wastewater discharge.

Due to the high concentration, variety, and toxicity of pollutants such as COD and dyes in printing and dyeing wastewater, it is extremely difficult to treat. Currently, the treatment of printing and dyeing wastewater generally faces the challenges of small scale, low reuse rate, and high cost.

At present, the water reuse rate of printing and dyeing wastewater treatment systems on the market is generally around 55%, which is far from enough. To reduce wastewater discharge, the key is to separate water from pollutants.

The special adsorption material developed by Haipu can selectively separate recalcitrant organic compounds from wastewater, and the adsorbed water can meet the discharge standards. Combined with relevant processes, it reduces the cost of outsourcing wastewater treatment and adding new water, and has more obvious economic value. The relevant cases are as follows:

The production process of a textile production, dyeing and finishing, clothing processing and sales enterprise can generate~2500 tons of wastewater per day. The existing wastewater treatment process of the enterprise exceeds the COD standard of the biochemical tail water, which cannot meet the reuse standard.

According to the production needs of the enterprise, Haipu has designed a process for 2000 tons of biochemical wastewater, using our company's special adsorbent and its supporting adsorption process to treat the wastewater, which can meet the requirements of reuse.

Our company conducted multiple batches of adsorption and desorption experiments on the sampled wastewater on site. The specific experimental results are shown in the above figure and the comparison chart before and after treatment is shown below.

From the experimental results, it can be seen that the COD removal rate is stable at over 70%, and the effluent COD is much lower than the customer's requirement (<50mg/L). From the comparison chart before and after treatment, it can be seen that the raw water is brown, the effluent is basically colorless and clear, and most of the organic matter in the wastewater is removed. The experiment proves that Haipu special adsorbent and supporting adsorption method are an effective treatment method for removing COD from wastewater.

A certain enterprise in Shandong requires the COD content in the treated wastewater to be less than 500mg/L. The experimental treatment effect shows that using adsorption treatment can stabilize the COD content in the wastewater to be less than 500mg/L.

While ensuring that customer requirements are met, a certain safety margin is left to effectively prevent water quality fluctuations in the feed wastewater from causing substandard effluent. The adsorption treatment effect of dye wastewater is shown in the table.

The production process of this enterprise generates 100 tons of dye wastewater per day. After adsorption treatment, the COD in the wastewater can meet the discharge requirements. The enterprise has adopted the adsorbent and process package from Jiangsu Haipu Functional Materials Co., Ltd. Currently, the adsorption system is running smoothly.

On site application

Similar to the adsorption method introduced earlier, the basic principle of the Haipu process is to utilize the adsorption performance of the special adsorption material developed by our company to selectively adsorb and enrich COD in wastewater into the adsorption material, resulting in colorless adsorbed water.

Principle of wastewater adsorption

After adsorption saturation, a specific desorption agent is used to desorb the adsorbent material, allowing it to regenerate and resume adsorption, and this process is continuously repeated.

Principle of wastewater adsorption

Compared with other processing methods, Haipu has the following advantages:

1. Efficiently remove organic and colored substances from wastewater to achieve water reuse;

2. Special adsorbent materials have high absorption capacity and high concentration ratio, low equipment investment, and low operating costs;

3. Automated control, easy operation, convenient maintenance, and long service life

The core advantages of Haipu technology

At present, the treatment methods for dye wastewater have their own shortcomings in terms of treatment efficiency and operating costs.

The membrane separation method has problems such as membrane fouling, high membrane cost, fast replacement frequency, and high processing cost.

The disadvantage of extraction method is that it consumes a large amount of extractant, and the separation of extracts is relatively difficult. The cost of treating one ton of water is high, and it cannot continuously process large amounts of water.

Radiation method is an immature technology with high energy consumption and low energy utilization efficiency; In addition, special protective measures are required to avoid the harm of radiation to the human body.

The coagulation method, oxidation method, and biological method cannot meet the government's emission requirements at once and cannot stably meet the emission standards.

The adsorption method can effectively remove organic matter from dye wastewater below the discharge limit, making it an economical and effective method for treating dye wastewater.