The second water plant of the Shen County Urban-Rural Integrated Water Supply Project is located in Liaocheng City, Shandong Province. The raw water source is groundwater from Shen County, with a treatment capacity of 15,000 cubic meters per day (m³/d). The plant uses the DAGUA ecological treatment process system, producing 12,000 m³/d of treated water. This includes 9,000 m³/d from oxidation-resistant ultrafiltration membranes and 7,200 m³/d from low-pressure high-flux nanofiltration membranes, blending the product water at a ratio of 65:35 with raw water. The system meets the new mandatory standards for drinking water hygiene as specified in GB5749-2022. The comparison of raw water pollution and treated water quality is as follows:

· Sulfate (SO4²⁻): Raw water 378 mg/L, treated water ≤ 11-17.9 mg/L

· Sodium (Na⁺): Raw water 460 mg/L, treated water ≤ 61-72.9 mg/L

· Fluoride (F⁻): Raw water 1.92 mg/L, treated water ≤ 0.21-0.26 mg/L

· Total Hardness: Raw water 450 mg/L, treated water ≤ 6-8 mg/L

· TDS (Total Dissolved Solids): Raw water 1500 mg/L, treated water ≤ 480-500 mg/L

Process Flow:Deep well groundwater →Raw water pool →Water pump lifting →

DAGUA ecological treatment process package (self-cleaning security filtration system → ozone pressure oxidation system → oxidation-resistant ultrafiltration membrane system → ultrafiltration product water pool → nanofiltration membrane water pump lifting → low-pressure high-flux nanofiltration membrane system) →Clear water pool