After being steadily treated by the membrane system (UF and
RO), permeate water flow was 2.4 m3/h with a pH value of 7.4–
7.9, a color of 0 degree, a COD of lower than 2.5 mg/L, a
conductivity of 50–200 μs/cm, a total hardness of 2–10 mg/L,
and a total alkalinity of 25–60 mg/L. The results showed that
the membrane permeates could be applied as process water for
dyeing. Moreover, the concentrated stream was obtained with
a pH value of 7.3–8.3, a color of 32 degree, and a COD of 45.7–
97.9 mg/L. The concentrate water could be discharged directly
without additional treatment since it had already met the
discharge standard.