This is the site of Neijiang City Food Waste and Municipal Solid Waste Treatment Plant, with a designed treatment capacity of 270 tons per day. In December 2024, five nanofiltration membranes in the first stage were replaced on-site. The treatment process is as follows: food waste wastewater → pretreatment + anaerobic digestion + UF + NF + RO + reduction material membrane. The nanofiltration membrane system consists of two units: a two-stage design (series + parallel) with a 2+1 membrane housing arrangement, each housing containing five elements. The designed treatment capacity of the nanofiltration system is 200-250 m³ per day, with a designed recovery rate of 80%.
Note: As requested on-site, the effluent quality of the nanofiltration membrane is to be compared with that of the DUPONT membrane as a reference. The intermediate product water data in the chart refers to the HOWIE membrane. The water quality standards are as follows:
Operating data:
Inlet water flow m³/h | Operating pressure MPa | Permeate flow m³/h | Concentrate flow m³/h |
7.68 | 0.55 | 6.14 | 1.54 |
7.72 | 0.52 | 6.17 | 1 |
7.75 | 0.54 | 6.2 | 1.55 |
Water quality testing data:
Water type | COD （mg/L) | NH-N （mg/L) | TN （mg/L) | Hardness （mg/L) |
NF raw water | 353 | 6.98 | 109.5 | 227 |
Permeate1 HOWIE membrane | 58.78 | 0.00 | 78.12 | 32 |
Permeate2 DUPONT membrane | 133.48 | 1.95 | 79.09 | 40 |
