Session 4

Above is permeability trend for months. What can be done recover the permeability ?

• BW

• CEB

• CIP

If micros count is high on UF filtrate, which shall not be done ?

• integrity test

• check pretreatment

• CIP include the filtrate line

• clean sampling point

What to check ?

• CEB chemical dosing

• pretreatment if coagulation + DAF is ok

• if additional CEB helps to recovery

• all above

Which of the following is NOT important for successful and stable operation of PES membrane ?

• coagulation at appropriate dosage

• BW flux and duration

• CEB frequency and pH

• none of above

Which of the followings to be completed prior to commissioning service visit ?

• complete installation of pumps, pipings and T-racks

• completion of loop checks and automation

• associated chemical dosing systems are ready for use

• all above

During start up commissioning, filtrate tank , filtrate line and membrane modules shall be disinfected

• True

• False

What's high pH CEB setting for (1) Non Seawater (2) Seawater

• (1) 20ppm FCl, pH 12

  (2) 20ppm FCl, pH 9.5

• (1) 20ppm FCl, pH 9.5

  (2) 20ppm FCl, pH 12

• both 20ppm FCl, pH 12

• (1) 50ppm FCl, pH 12

  (2) 50ppm FCl, pH 9.5

Which of the following flow ramping timine has more severe impact on UF system recovery ?

• feed flow ramp up during UF train start up and shutdown

• BW flow ramp up and down

• both

Select the best answer : Syringe filter can be handy on site for checking

• (i) SDI of UF filtrate

• (ii) Me3+ residual in UF filtrate

• (iii) if there is any overdosing of coagulant

• (ii) and (iii)

PES membrane chlorine tolerance is about 20-25% of PVDF membrane. Which of following(s) is NOT TRUE ?

• Both PES and PVDF membrane can be CIPed at 1000ppm FCl

• CEB for PES is lower dosage (20ppm) compared to PVDF (250ppm)

• lower dosage of FCl is compensated with higher pH (~12) during CEB and CIP

• recommended UF feed for PES <0.2ppm FCl