Conventional treatment: In the secondary treatment of urban sewage, the dosage of about 10-30 mg/L can meet the basic treatment needs according to the effective component of aluminum oxide.
Special case: When the wastewater has high turbidity (such as more than 500 NTU) or contains heavy metals/organic matter, the dosage needs to be adjusted according to laboratory tests, which may exceed 150 mg/L.
Performance of aluminum sulfate
Aluminum sulfate has excellent coagulation performance, and the alum flowers formed are dense and have a fast sedimentation rate. It can effectively remove suspended matter, color substances and some heavy metal ions in sewage. It has significant effects in turbidity removal, decolorization, dehydration, sterilization and deodorization. It has outstanding treatment effects on micro-polluted, low-temperature and low-turbidity raw water, especially suitable for high turbidity sewage.
Precautions for the use of aluminum sulfate:
1) Dissolution control
①Concentration range: It is recommended to control between 10%-30%, and avoid exceeding 50% to make the solution viscous and difficult to stir
②Water temperature: 20-40℃℃ is appropriate. Too high (>60℃℃) will decompose and fail, and too low will affect the dissolution rate.
③ Stirring speed: Mechanical stirring is recommended to be 100-300 rpm. Too fast will easily generate foam and destroy the molecular structure.
2) Dosing management
① Accurate control amount: Adjust according to the turbidity of water quality (domestic sewage is usually 50-100 mg/L). Excessive dosage may cause excessive aluminum ion residue.
② Mixing order: When used in combination with other agents (such as polyacrylamide), aluminum sulfate must be added first and then other agents must be added.
③ Dosing point selection: Prioritize areas with rapid water flow or mixing pools to ensure rapid dispersion.
3) Safety protection
① Personal protection: Wear acid-resistant gloves and goggles during operation to avoid skin contact or inhalation of dust.
② Environmental requirements: Operate in a well-ventilated environment, away from heat sources and direct sunlight.
③ Emergency treatment: Immediately rinse with clean water in case of skin contact; seek medical attention after rinsing eyes; drink warm water to induce vomiting and seek medical attention if ingested.
4) Storage requirements
① Container selection: Use corrosion-resistant materials (polyethylene, stainless steel) to avoid direct contact with metals.
②Storage environment: cool and dry place, away from alkaline substances or oxidants, avoid leakage.
