Small-Scale RO System

Step One in Small-Scale Reverse Osmosis System Design: Pretreatment Process

The water purification process adopts a "pretreatment + reverse osmosis" configuration. The pretreatment system includes a multimedia filter and an ultrafiltration (UF) filter. Proper pretreatment is crucial, as it not only significantly extends the service life of the RO membrane, but also largely determines the quality of the final RO permeate.

After passing through the tap water inlet valve, water enters the raw water tank, marking the beginning of the pretreatment phase. A pump draws water into the multimedia filter, which contains quartz sand and activated carbon:

• Quartz sand removes suspended solids.

• Activated carbon removes foreign chemical substances and heavy metals, and also adsorbs residual chlorine.

The multimedia filter requires periodic backwashing, and the backwash water is directed to the concentrate treatment system.

After multimedia filtration, the water flows into the ultrafiltration (UF) filter, which effectively removes fine particles, colloids, bacteria, pyrogens, and organic matter. Solute molecules larger than the membrane pore size are retained. The UF filter also requires backwashing, and the resulting backwash water and concentrate are also sent to the concentrate treatment system.

This completes the pretreatment stage of the system.