Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for treating acidic wastewater with high arsenic content by using nano TiO2 and recycling arsenic

A technology for arsenic fouling acid and arsenic recovery, applied in the field of environmental science, can solve the problems of large amount of sediment, high arsenic content, high transportation, storage, and processing costs, and achieves the solution of secondary environmental pollution, reduced cost input, and amount of sediment. reduced effect

Inactive Publication Date: 2012-03-21
RES CENT FOR ECO ENVIRONMENTAL SCI THE CHINESE ACAD OF SCI +4
View PDF2 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the wastewater mainly contains trivalent arsenic, the treatment process needs to add an additional oxidant to oxidize the low-valent arsenic to high-valent arsenic to effectively remove it, which will undoubtedly increase the cost of the treatment process
[0014] (2) Arsenic control is not up to standard
The existing process is unstable for the removal of arsenic. The arsenic content in the treated external drainage is often high and contains a large amount of heavy metal ions at the same time. The treated external drainage cannot fully meet the discharge standards.
[0015] (3) The amount of sediment is large, and the cost of transportation, storage and treatment is high
[0016] (4) No continuous treatment method has been established from the removal of arsenic to the recovery of arsenic from wastewater
Although arsenic and heavy metal ions are mostly removed, arsenic is not recycled

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for treating acidic wastewater with high arsenic content by using nano TiO2 and recycling arsenic
  • Method for treating acidic wastewater with high arsenic content by using nano TiO2 and recycling arsenic
  • Method for treating acidic wastewater with high arsenic content by using nano TiO2 and recycling arsenic

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] The wastewater samples were collected from the high arsenic-containing wastewater discharged from the sulfuric acid workshop of a copper smelter. The composition is shown in Table 1. Add lime milk to the wastewater, adjust the pH value to 5, and separate the solid and liquid with a centrifuge. The separated filtrate enters three reaction tanks for step-by-step adsorption, and 30g / L TiO is added to each of the three reaction tanks. 2 The pH value of the adsorbent was adjusted to 7, and the reaction time of each stage of adsorption was 1 hour. In each reaction tank the pH was adjusted to 7, with TiO 2 The adsorbent (30 g / L) was reacted for 1 hour, and after the adsorption reaction was completed, solid-liquid separation was performed. In order to ensure the removal of cadmium, the filtrate obtained after the third-stage adsorption was passed into the fourth reaction tank for adsorption and centrifugation.

[0042] The arsenic concentration and heavy metal concentration ...

Embodiment 2

[0049] After the same wastewater as in Example 1 was treated in the reaction tank, solid-liquid separation was achieved by centrifugation. After testing, the concentration of arsenic and heavy metal ions in the filtrate meets the emission requirements, and the solid after adsorption of arsenic, namely TiO 2 The adsorbent was passed into the alkali elution tank, and 2 mol / L NaOH solution was added (the volume of NaOH added: the volume of wastewater in the reaction tank=1:10), and after stirring and elution for 30 minutes, the solid-liquid centrifugation was performed. TiO after alkaline washing 2 Pass into the reaction tank (1, 2, 3) and reuse it to remove arsenic in wastewater. The eluate containing high concentrations of arsenic enters the arsenic recovery tank.

[0050] Elution rate of arsenic and TiO after regeneration 2 The effect of removing arsenic is shown in Figure 4 and Figure 5 . Figure 4 showed that the average elution rate of arsenic was higher than 70%, i...

Embodiment 3

[0052] The same waste water source and treatment process as Example 1 and Example 2, the eluent containing high-concentration arsenic produced in Example 2 is passed into the arsenic recovery tank, and calcium oxide is added to precipitate arsenic (calcium oxide adds mass: Mass of arsenic in eluent = 1:1). The initial concentration of arsenic in the eluent and the detection results of the concentration of arsenic after adding calcium oxide are shown in Table 3.

[0053] The results show that when the mass ratio of CaO addition to arsenic is 10:1, 96% of the arsenic in the backwash can be recovered, but using 10 times the amount of CaO to recover arsenic will produce more sludge, so in practical applications , using 1 times the dosage of CaO. It can be seen from Table 3 that when the mass ratio of CaO addition to arsenic is 1:1, the average recovery rate of arsenic is 77%, which can not only recover most of the arsenic in the backwash, but also avoid excessive use of CaO. The...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a method for treating acidic wastewater with high arsenic content by using nano TiO2 and recycling arsenic, comprising the following steps of: adjusting the pH value of the wastewater to 5 by using lime milk, and separating the wastewater into a solid and liquid; continuously absorbing a solution with high arsenic content three times by using a nano TiO2 adsorbent, and adjusting the pH value to 7. The adsorbent can be recycled through the elution and regeneration of sodium hydroxide. Meanwhile, arsenic in backwash liquor is recycled through adding calcium oxide. According to the method, trivalent arsenic and heavy metal ions in the wastewater can be effectively removed, the adsorbent can be recycled, almost no waste residues are generated, and meanwhile, the arsenic can be recycled so that the pollution to the environment is reduced and economic benefits are obtained.

Description

a technical field [0001] The present invention is a kind of application of nanometer TiO 2 The invention discloses a method for treating high arsenic polluted acid wastewater and recovering arsenic, belonging to the field of environmental science and technology. Two background technology [0002] Research on arsenic removal from industrial wastewater has received extensive attention in recent years. At present, the main methods for treating arsenic-containing wastewater at home and abroad include precipitation method, flotation method, porous material adsorption method, ion exchange resin method and functional polymer membrane method. Precipitation methods mainly include: neutralization precipitation method, ferrite method, sulfide precipitation method, coagulation method (also known as adsorption colloid precipitation method or carrier co-precipitation method) and electrocoagulation method. Among them, the most widely used method is the high-density sludge method (HDS), w...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C02F9/04C01G28/02C02F1/28C02F101/20
Inventor 景传勇罗婷张麟刘雅娜吕重安
Owner RES CENT FOR ECO ENVIRONMENTAL SCI THE CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com