The Harm of Lead-Containing Wastewater and Its Treatment Technology

Hazards of lead-containing wastewater and its treatment process Lead is often used as a raw material in manufacturing industries such as batteries, electroplating, pigments, rubber, pesticides, and fuels. The acidic wastewater (pH3 = the highest lead concentration) discharged in the lead plate manufacturing process, the lead concentration of the wastewater produced by the electroplating waste liquid is also very high. 1. The hazards of lead-containing wastewater After lead enters the human body, except partly excreted through feces and sweat, the rest After a few hours, it dissolves into the blood and hinders the synthesis of blood, leading to anemia, headache, dizziness, fatigue, drowsiness, constipation and sore limbs; some have a metallic taste in the mouth, as well as arteriosclerosis, peptic ulcer and fundus Bleeding and other symptoms. Children with lead poisoning will have developmental delay, loss of appetite, inconvenient walking, constipation, and insomnia; if they are primary school students, they will also be accompanied by hyperactivity, hearing impairment, inattention, and mental retardation. This is because lead enters the human body After that, it invades the brain nerve tissue through the blood, causing insufficient supply of nutrients and oxygen, causing brain tissue damage, and severe cases may lead to lifelong disability. Especially children are in the growth and development stage, and they are more sensitive to lead than adults. The system has a strong affinity, so the absorption of lead is several times higher than that of adults, and the damage is particularly serious. At present, there is a serious shortage of water resources, and a large amount of industrial water makes the scarce fresh water resources less and less. The discharge of lead battery enterprises Although the wastewater meets the industry discharge regulations, the wastewater still contains a certain concentration of lead, which will still cause great pollution to the water body after being discharged into the water body, endangering people's health. Advanced treatment of lead-containing wastewater can make the post-treatment The waste water is reused by the process, which effectively saves water resources, and at the same time reduces the discharge of lead-containing polluted waste water and protects the environment. Therefore, it is of great significance to carry out advanced treatment of lead-containing waste water. 2. Treatment process of lead-containing waste water 1. One-step purification method At present, there are one-step purifiers integrating concentration, flocculation, sedimentation and filtration processes in the market. For example, the newly-built sewage treatment plant of Shenyang Battery Factory adopts this method, combining neutralization, flocculation, sedimentation and filtration in three steps. For one step, it is completed by a one-step purifier. The one-step purifier occupies less land, saves energy consumption, and is easy to use and operate, but it also has some problems when dealing with lead-containing wastewater: one is that the lead-containing wastewater fluctuates due to pH value fluctuations in the During continuous operation, there will be hysteresis in pH control, and it is not easy to control the appropriate pH value in the precipitation section, which makes the precipitation effect of lead unsatisfactory. The process of entering the coagulation and sedimentation treatment will cause the analysis of the sediment due to the change of pH value; the third is that the concentration of lead in the wastewater will also change during the treatment process, which will make it difficult to control the dosage of the flocculation and sedimentation treatment process , resulting in unstable lead concentration in drainage. 2. Resin adsorption method The resin contains active groups such as hydroxyl, carboxyl, and amino groups, which can chelate heavy metal ions to form cage-shaped molecules with a network structure, so it can effectively adsorb Heavy metals. Among them, chitosan and its derivatives are ideal materials for the treatment of heavy metal wastewater, and many scholars have done a lot of research on this. Wang Ru et al. [1] used industrial grade chitosan (the degree of deacetylation is 83%) as the adsorbent, To remove Pb in aqueous solution, at room temperature, when dealing with Pb solution with a mass concentration of 100mg/L, the best condition is: chitosan The mass concentration of sugar added is 2g/L, the particle size is 20-40 mesh, the pH value is 6-8, and the adsorption time is 15h. Under these conditions, the removal rate of Pb is as high as 997%, and the mass concentration of residual Pb is ≤06mg/L. It has reached the requirements of the national wastewater discharge standard (≤10mg/L). In recent years, a large number of studies on modified chitosan have also appeared. 3. Ion exchange method The ion exchange method is realized by ion exchange between the freely movable ions carried by the exchanger itself and the ions in the treated solution. The driving force for ion exchange is the concentration difference between ions and the affinity of functional groups on the exchanger for ions. In the research on the treatment of some lead-containing wastewater, strong acidic cation exchange resin is used, and when the pH value is 50-52, phosphoric acid resin is used to ion-exchange the discharge water, and the lead content can be reduced to 0.20-0.53mg/L; After the operation and investigation of the ion exchange process and corresponding process conditions, it was found that the wastewater with a lead content of 10 mg/L was treated by ion exchange, and the lead content in the discharged water was 0.14-0.18 mg/L, which reached the national discharge water quality standard [2]. However, the effluent quality of the treated wastewater is unstable, and the water quality of the reused water cannot meet the requirements of the process water used in production, and it also causes secondary pollution of the eluate water. This method is widely used in food and pharmaceuticals. The hazards of lead-containing wastewater and its treatment process The hazards of lead-containing wastewater and its treatment process, according to the size of the water, the pollutants contained in it are different, the treatment process, equipment style and price are also different. For more details or find a unit to deal with, please visit Inquiry on the Shuibao website, if you have lead-containing wastewater treatment needs, please consult Shuibao. Shuibao is a nationwide sewage treatment platform, bringing together well-known environmental protection companies across the country, and has helped tens of thousands of companies find suitable sewage treatment companies.