Printing and dyeing wastewater purifying flocculating agent, and printing and dyeing wastewater purifying application thereof

Abstract

The invention provides a printing and dyeing wastewater purifying flocculating agent, and a printing and dyeing wastewater purifying application thereof. The flocculating agent meets the environmentally-friendly requirement, and has the technical advantages of excellent decolorizing and purifying effects, realization of fast decolorizing, and high purifying efficiency. The printing and dyeing wastewater purifying flocculating agent comprises a mixture of the following powdery components: N-carboxyethylchitosan, cationic starch and bentonite, wherein a mass ratio of the N-carboxyethylchitosan to the cationic starch is 2:(3-4), and a mass ratio of the bentonite to the N-carboxyethylchitosan is 5:(1-4). The invention provides the printing and dyeing wastewater purifying application of the flocculating agent. The flocculating agent has the advantages of natural degradability, non-toxicity, and low prices of above materials; and the decolorizing rate of the flocculating agent can reach 90% or above when the flocculating agent is mixed with wastewater for only 10 minutes.

Description

technical field

[0001] The invention relates to a purification treatment agent for printing and dyeing wastewater, in particular to a composite flocculation treatment agent for printing and dyeing wastewater. Background technique

[0002] With the development and expansion of the textile industry, the annual discharge of textile printing and dyeing wastewater is as high as several billion tons. The printing and dyeing wastewater has the characteristics of high chroma, complex organic components and low degree of microbial degradation, which brings many difficulties to water purification treatment. . Among them, flocculation is a relatively common method for the decolorization and purification of printing and dyeing wastewater, but the existing flocculation methods are not ideal in terms of purification rate, especially purification efficiency, and have always been a difficult problem in the purification and discharge of printing and dyeing wastewater. Urgent research is need...

Examples

Embodiment 1

[0012] The mixed components of the printing and dyeing wastewater purification flocculant include N-carboxyethyl chitosan, cationic starch and bentonite, wherein,

[0013] Bentonite is preferably purified bentonite. The purification method is as follows: add sodium-based bentonite to water with 20 times the quality of bentonite and stir for 1 hour to form a bentonite suspension. After standing for stratification, remove the supernatant, and the remaining Obtained by drying, grinding, and 200-mesh screening;

[0014] N-carboxyethyl chitosan can be prepared by using the existing N-carboxyethyl chitosan preparation method, and this application has cited a preparation method for N-carboxyethyl chitosan, but this patent application involves N-carboxyethyl chitosan is not limited to this preparation method: Dissolve chitosan in an acrylic acid solution with a mass concentration of 1.5%, prepare a chitosan solution with a concentration of 10%, stir and heat up to 55°C and keep it for...

Embodiment 2

[0019] Mixing component is identical with embodiment 1

[0020] Mix the above-mentioned treated bentonite, N-carboxyethyl chitosan and cationic starch according to the mass ratio of 5:4:6, take 3g and add it to the concentration of 50 mg / L, the volume is 1L of each listed in the table below. For various types of dye wastewater, adjust the pH of the wastewater to 6 with hydrochloric acid, stir for 30 minutes, and then settle for no less than 6 minutes. Take the supernatant to measure the liquid absorbance of the supernatant, and calculate its removal of various types of dyes The results are shown in Table 2:

[0021]

Embodiment 3

[0023] Mixing component is identical with embodiment 1

[0024] The bentonite, N-carboxyethyl chitosan and cationic starch after the above treatment were mixed according to the mass ratio of 5:1:2, and 4 g was added to the following table with a concentration of 50 mg / L and a volume of 1 L. In various types of dye wastewater, adjust the pH of the wastewater to 7 with hydrochloric acid, stir for 30 minutes, and then settle for no less than 6 minutes. Take the supernatant to measure the liquid absorbance of the supernatant, and calculate its specificity for various types of dyes. Removal rate, its result is shown in Table 3:

[0025]

technical field

[0001] The invention relates to a purification treatment agent for printing and dyeing wastewater, in particular to a composite flocculation treatment agent for printing and dyeing wastewater. Background technique

[0002] With the development and expansion of the textile industry, the annual discharge of textile printing and dyeing wastewater is as high as several billion tons. The printing and dyeing wastewater has the characteristics of high chroma, complex organic components and low degree of microbial degradation, which brings many difficulties to water purification treatment. . Among them, flocculation is a relatively common method for the decolorization and purification of printing and dyeing wastewater, but the existing flocculation methods are not ideal in terms of purification rate, especially purification efficiency, and have always been a difficult problem in the purification and discharge of printing and dyeing wastewater. Urgent research is need...

Examples

Embodiment 1

[0012] The mixed components of the printing and dyeing wastewater purification flocculant include N-carboxyethyl chitosan, cationic starch and bentonite, wherein,

[0013] Bentonite is preferably purified bentonite. The purification method is as follows: add sodium-based bentonite to water with 20 times the quality of bentonite and stir for 1 hour to form a bentonite suspension. After standing for stratification, remove the supernatant, and the remaining Obtained by drying, grinding, and 200-mesh screening;

[0014] N-carboxyethyl chitosan can be prepared by using the existing N-carboxyethyl chitosan preparation method, and this application has cited a preparation method for N-carboxyethyl chitosan, but this patent application involves N-carboxyethyl chitosan is not limited to this preparation method: Dissolve chitosan in an acrylic acid solution with a mass concentration of 1.5%, prepare a chitosan solution with a concentration of 10%, stir and heat up to 55°C and keep it for...

Embodiment 2

[0019] Mixing component is identical with embodiment 1

[0020] Mix the above-mentioned treated bentonite, N-carboxyethyl chitosan and cationic starch according to the mass ratio of 5:4:6, take 3g and add it to the concentration of 50 mg / L, the volume is 1L of each listed in the table below. For various types of dye wastewater, adjust the pH of the wastewater to 6 with hydrochloric acid, stir for 30 minutes, and then settle for no less than 6 minutes. Take the supernatant to measure the liquid absorbance of the supernatant, and calculate its removal of various types of dyes The results are shown in Table 2:

[0021]

Embodiment 3

[0023] Mixing component is identical with embodiment 1

[0024] The bentonite, N-carboxyethyl chitosan and cationic starch after the above treatment were mixed according to the mass ratio of 5:1:2, and 4 g was added to the following table with a concentration of 50 mg / L and a volume of 1 L. In various types of dye wastewater, adjust the pH of the wastewater to 7 with hydrochloric acid, stir for 30 minutes, and then settle for no less than 6 minutes. Take the supernatant to measure the liquid absorbance of the supernatant, and calculate its specificity for various types of dyes. Removal rate, its result is shown in Table 3:

[0025]

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