Low speed desktop centrifugeThrough the core solution of "gradient speed adaptation, dedicated rotor design, and graded separation process", efficient treatment of algae and particulate matter in water samples is achieved, balancing separation efficiency and operational convenience. The specific implementation path is as follows:

1、 Gradient speed regulation, adapted to different particle size separation requirements

The speed adjustment range of low-speed desktop centrifuge (300-5000rpm) can accurately match the settling characteristics of algae and particulate matter. For suspended particles with larger diameters (such as sediment and organic debris, particle size ≥ 50 μ m), low-speed centrifugation at 1000-2000rpm is used to quickly settle the particles to the bottom of the pipe using centrifugal force, avoiding particle breakage caused by high-speed centrifugation; For single-cell algae (such as Chlorella vulgaris and diatoms, particle size 2-20 μ m), a medium speed of 3000-4000rpm is selected. By extending the centrifugation time (5-10 minutes), the algal cells are fully settled while avoiding cell wall rupture and releasing intracellular substances that contaminate the supernatant; For the coexistence of small particles (particle size 1-10 μ m) and algae in a mixed system, gradient speed stepwise centrifugation can be used to remove large particles at low speed first, and then separate algae at medium speed to achieve graded purification.

2、 Specialized rotor and centrifuge tube design to enhance separation efficiency

The equipment is equipped with specialized rotors suitable for water sample processing, such as horizontal rotors and angular rotors, to meet the needs of different separation scenarios. When the horizontal rotor is running, the centrifuge tube is in a horizontal state with a long settling path, which is suitable for the full separation of light particles such as algae; The angular rotor (angle 20 ° -45 °) concentrates centrifugal force, separates quickly, and is suitable for rapid settling of large particles. The centrifuge tube is made of transparent polypropylene (PP) or polycarbonate (PC) material, which is resistant to centrifugal impact and easy to observe the separation effect. The capacity ranges from 15mL to 50mL and is suitable for different water sample volumes. Some centrifuge tubes are equipped with scales and sealing covers, which can accurately measure the volume of the separated supernatant and prevent liquid splashing during centrifugation, thus avoiding cross contamination.

3、 Graded separation process to achieve efficient separation of algae and particulate matter

1. Water sample pretreatment:Low speed desktop centrifugeLet the collected water sample stand for 10 minutes, remove floating debris, and divide it into centrifuge tubes in a quantity of 20-30mL per tube. After balancing, symmetrically place it in the rotor to avoid equipment vibration during centrifugation.

2. Gradient centrifugation operation: Centrifuge at 1500rpm for 5 minutes to remove sediment and large organic debris from the water sample, then pour out the supernatant into a new centrifuge tube; Increase the speed to 3500rpm and centrifuge for 8 minutes to allow the algae cells to settle to the bottom of the tube. At this point, the supernatant is a clear water sample after removing algae and large particles.

3. Post processing steps: After separation is completed, slowly remove the centrifuge tube, pour out the supernatant for retention or further processing. The sediment at the bottom of the tube can be collected as needed (such as algae enrichment for subsequent detection and particulate matter for component analysis), achieving the dual goals of resource recovery and water sample purification.

4、 Optimize operational parameters to ensure separation stability and safety

The optimization of centrifugation time and temperature can improve the separation efficiency. The centrifugation time should be adjusted according to the turbidity of the water sample. When the turbidity is high, it can be extended to 10-15 minutes to ensure complete separation; The temperature should be controlled between 4-25 ℃ to avoid high temperatures causing active algal metabolism or changes in particle properties. The equipment has safety functions such as overspeed protection and imbalance alarm. When the weight deviation of the centrifuge tube exceeds the threshold or the speed is abnormal, it will automatically shut down for protection, preventing equipment damage and sample leakage. In addition, some models support a timed function that can preset the centrifugation time, automatically stop the machine after separation, reduce manual operation intensity, and adapt to batch water sample processing scenarios.