Microsand (High-Rate Dense Media) Sedimentation Tank FAQ

Q1: What exactly is the difference between a microsand sedimentation tank and a conventional coagulation-sedimentation tank?

The main difference lies in "sand addition": microsand serves as a floc skeleton that adds weight to the flocs, multiplying their settling velocity. This results in high surface loading, a small footprint, strong shock resistance, and the ability to start and stop on demand.

Q2: What pollutants can it remove?

It primarily removes suspended solids (SS), turbidity, and colloidal particles. With phosphorus removal chemicals, it can achieve advanced phosphorus removal. It has essentially no removal capacity for dissolved COD, ammonia nitrogen, or total nitrogen.

Q3: What effluent SS / turbidity levels can be achieved?

Under typical conditions, effluent SS can be stably maintained at ≤ 10 mg/L (with chemicals), with SS / turbidity removal rates of approximately 85%–95% or higher. Actual results depend on water quality and bench test outcomes.

Q4: Can it remove phosphorus? Can it meet Class 1A or stricter limits?

Yes. It is often used as an enhanced unit for chemical phosphorus removal, achieving advanced phosphorus removal with phosphorus removal chemicals. Typical total phosphorus removal rates are approximately 80%–90%, making it a mature combination for upgrading and retrofitting.

Q5: Can it really save a lot of space?

Yes. Thanks to its high surface loading, the microsand sedimentation tank typically has a significantly reduced footprint compared to conventional sedimentation tanks, making it an effective solution when "land is scarce and new tank construction is not possible."

Q6: Is installation complicated? Can it be skid-mounted / mobile?

The equipment is an integrated steel tank structure, installed above ground and ready to use upon connection. Its modular design facilitates parallel expansion, and skid-mounted configurations can be provided as needed.

Q7: Will the microsand be used up after one cycle, resulting in high operating costs?

No. The microsand is recovered by a hydrocyclone and recirculated, with extremely low loss. A single dose can last for long-term operation, requiring only minor replenishment. Daily operating costs are mainly for chemicals and the power consumption of the recovery system.

Q8: Can it operate intermittently? How long after shutdown does it take to meet standards again?

Yes. It is a purely physicochemical process with no biological acclimation period. It achieves effective treatment immediately upon startup and can start and stop on demand, making it ideal for intermittent operation and emergency treatment.

Q9: Is routine maintenance extensive? What is mainly maintained?

Maintenance is relatively simple. The focus is on inspecting the chemical dosing system, microsand recovery pump, and hydrocyclone (watching for wear), as well as periodically replenishing a small amount of microsand.

Q10: My flow rate is small / highly variable. Is it suitable?

Yes. The equipment is modular, and a single unit can be configured for small flow rates. When flow rates fluctuate greatly, its high shock resistance and rapid startup characteristics are actually advantageous.

Q11: How do I determine whether to use it and what size to choose?

We recommend first providing flow rate, water quality (SS, turbidity, total phosphorus, etc.), and site conditions. We can evaluate process suitability and provide selection recommendations. Key parameters should be determined through on-site bench tests.