STREAMING CURRENT MONITOR FOR COAGULANT OPTIMIZATION IN WATER TREATMENT PLANTS - LAP EXPERIENCE

Transcription

1 STREAMING CURRENT MONITOR FOR COAGULANT OPTIMIZATION IN WATER TREATMENT PLANTS - LAP EXPERIENCE DECEMBER 15, 2015 (TUESDAY) 9.30 am BORNEO WATER & WASTE WATER EXHIBITION 2015

2 PRESENTATION OVERVIEW Introduction (LAP) Coagulation & Flocculation Why Streaming Current? Material & Methodology Streaming Current Technologies Applications Streaming Current for Process Control Result & Conclusion 2

3 INTRODUCTION Perak Water Board ( LAP ) is the sole water provider for state of Perak, Malaysia Production : 1,200 million liters per day (MLD) No. of treatment plant : 46 (operate using conventional treatment method) Raw water sources : River water Borneo Convention Kuching Centre 3

4 WATER TREATMENT PLANT The raw water being treated are mostly from surface waters In recent years, we realized that the water resources has changes in quality & quantity Rapid changes in turbidity causes difficulty in maintaining the optimum dosing of coagulant During raining season, the turbidity do rapidly change cause difficulties in order to maintain optimum dosing of coagulant & chemicals 4

5 Rainfall in Malaysia (November 2014) River water turbidity usually increase after heavy rainfall in the catchment areas. Perak River Water turbidity varies from 20 NTU to more than 1000 NTU Perak River supply almost 40% of total needs Accumulative catchment area about 11,098km 2 ; that area 5 covered 54% of Perak State.

6 Average Rainfall in Ipoh 6

7 Kg Senin WTP BEFORE AFTER Kg Senin WTP Figures shows differences after rainfall in the catchment areas 7

8 PERAK RIVER Kg Senin Water Treatment Plant 8

9 PERAK RIVER (KUALA KANGSAR)

10 PERAK RIVER INTAKE KOTA LAMA KIRI 10

11 1-Jan 10-Jan 19-Jan 28-Jan 6-Feb 15-Feb 24-Feb 5-Mar 14-Mar 23-Mar 1-Apr 10-Apr 19-Apr 28-Apr 7-May 16-May 25-May 3-Jun 12-Jun 21-Jun 30-Jun 9-Jul 18-Jul 27-Jul 5-Aug 14-Aug 23-Aug 1-Sep 10-Sep 19-Sep 28-Sep 7-Oct 16-Oct 25-Oct 3-Nov 12-Nov 21-Nov 30-Nov 9-Dec 18-Dec 27-Dec RAW WATER TURBIDITY (NTU) BWWE 900 PERAK RIVER DAILY MAXIMUM TURBIDITY January February March April May June July August September October November December 11

12 1-Jan 7-Jan 13-Jan 19-Jan 25-Jan 31-Jan 6-Feb 12-Feb 18-Feb 24-Feb 2-Mar 8-Mar 14-Mar 20-Mar 26-Mar 1-Apr 7-Apr 13-Apr 19-Apr 25-Apr 1-May 7-May 13-May 19-May 25-May 31-May 6-Jun 12-Jun 18-Jun 24-Jun 30-Jun 6-Jul 12-Jul 18-Jul 24-Jul 30-Jul 5-Aug 11-Aug 17-Aug 23-Aug 29-Aug RAW WATER TURBIDITY (NTU) BWWE PERAK RIVER DAILY MAXIMUM TURBIDITY JAN- AUGUST January February March April May June July August 12

13 TURBIDITY REMOVAL DOSING OPTIMIZATION

14 COAGULATION Coagulation control has been primary concern to water utilities, engineers and scientists for many years. For the decades, jar test has been conducted to determine optimum dosage of coagulant to achieve the appropriate settling in the sedimentation tank. Streaming current implemented in late 60 s but wasn t widely used, due to reason of its high cost and unstable reliability. Enhancement in rapid electronics technologies lead the development and introduction of microprocessors, streaming current monitor (SCM) become user friendly in operation, reliable and affordable. 14

15 WHY STREAMING CURRENT? JAR TEST Standard method to determine optimum coagulant dosage for water treatment process The result determine by Visual comparison or physical tests ie turbidity & color. The general tendency in most facilities is to overfeed chemicals as a safety precaution The tests provide only a snap shot of plant conditions at the time the samples were collected Chemical dosing unable to 15 respond to rapid change in raw

16 PERAK RIVER WATER (TURBIDITY : 790 NTU) 16

17 WHY STREAMING CURRENT? Fast Response to Changes in Raw Water Streaming Current Monitors provide an early warning to rapid changes in raw water turbidities e.g. storm water influence and allows the adjustment of coagulant chemicals necessary to maintain optimum water quality. Optimize Chemical Usage Operators that control the chemical dosage from jar test & based on years of experience have a tendency to overdose just to be on the safe side. Streaming Current Monitor not only eliminate potential of chemical over use, but SCM can actually help the operator optimize usage to the minimum level required to maintain optimum water quality. In most cases the chemical usage can be reduced with no effect on water quality. 17

18 Streaming Current Monitoring How does the Streaming Current Monitor work? SCM measures the net colloidal and ionic surface charge (positive & negative) of a continuously flowing sample. Streaming Current potential is related to Zeta potential 18

19 OBJECTIVES A streaming current monitor (SCM) is an instrument for measuring the charge that exists on small, suspended particle in liquid A SCM is the only online instrument that can be used to measure coagulated particle stability for the feedback control of coagulant dosage 19

20 MATERIAL & METHOD Perak Water Board has applied the Streaming Current Monitors (SCM) in 20 of the water treatment plants since year 2004 to optimize the coagulant dosage in water treatment process. SCM operates by using electronic sensor to determine charge neutralization after addition of coagulant to the raw water. If the correct coagulant dosage is added to the incoming raw water it should exactly neutralize the negatively charged particles in the raw water. In theory, if the proper coagulant dose and a complete mixing of the chemical has occurred, the SCM will read

21 APPLICATIONS OF STREAMING CURRENT TECHNOLOGIES Municipal and Industrial Water Treatment: Any process using coagulants or polymers to clarify the raw water Aluminium sulphate (alum) / polyaluminium chloride is use for coagulation & flocculation (to clarify the river water) 21

22 For the purpose of this paper, 5 treatment plants which have installed SCM and its automatic system of controlling coagulant dosing along the Perak River are chosen. Map : Fives (5) water treatment plants along the Perak River 1 Kota Lama Kiri (KLK) 25 MLD 2 Sultan Idris Shah 11 (SIS) 272 MLD 3 Kg Senin (KS) 34 MLD 4 Kg Paloh (KP) 76 MLD 5 Teluk Kepayang (TKPYG) 136 MLD 22

23 WTPs ALONG PERAK RIVER Teluk Kepayang SIS II, Parit Kg Senin Kg Paloh

24 1-Jan 13-Feb 28-Mar 10-May 22-Jun 4-Aug 16-Sep 29-Oct 11-Dec 23-Jan 7-Mar 19-Apr 1-Jun 14-Jul 26-Aug 8-Oct 20-Nov 2-Jan 14-Feb 28-Mar 10-May 22-Jun 4-Aug 16-Sep 29-Oct 11-Dec 23-Jan 7-Mar 19-Apr 1-Jun 14-Jul 26-Aug 8-Oct 20-Nov 2-Jan 14-Feb 29-Mar 11-May 23-Jun 5-Aug 17-Sep 30-Oct 12-Dec 24-Jan 8-Mar 20-Apr 2-Jun 15-Jul 27-Aug RAW WATER TURBIDITY (NTU) BWWE PERAK RIVER TURBIDITY (DATA LOJI RAWATAN AIR SULTAN IDRIS SHAH II, PARIT) DAF designed treatmet at 350 NTU (max) 0.0 JanFebMar AprMay JunJulAugSepOctNovDecJanFebMar AprMay JunJulAugSepOctNovDecJanFebMar AprMay JunJulAugSepOctNovDecJanFebMar AprMay JunJulAugSepOctNovDec January February March April May June July August Septembe October November December January February March April May June July August Sept r Date Turbidity

25 PERAK RIVER TURBIDITY (MAXIMUM DAILY) 25

26 STREAMING CURRENT FOR PROCESS CONTROL 26

27 STREAMING CURRENT FOR PROCESS CONTROL How SCM fits into the treatment scheme. 3 important criteria for installation of SCM Sample point strategies Lag time Chemical feed points 27

28 SENSOR LOCATION Mixing Unit Flocculator Settling Basin Filters Sensor The Sample Point for the Sensor should be as close to chemical injection point as possible. The preferred location is directly after the mixing unit. Sample flow through the Sensor should be 1 to 5 GPM. Higher flow rates help to keep the sensor clean 28

29 STREAMING CURRENT CONTROL Mixing Unit Flocculator Settling Basin Filters Sensor Sample Point Well Mixed Quick Response Pump Controller Set Point Defined by Operator Based on Process Performance 29

30 RESULT & DISCUSSION Water Quality before & after the treatment (Turbidity, Fe, Mn) Chemical consumption Treatment plant operation 30

31 31

32 SETTLED WATER 32

33 FILTER (SETTLED WATER) 33

34 TURBIDITY 34

35 35

36 Parame ter Drinking Water Quality Standard (mg/l) Perak River (Average) Fe Mn Al 0.2 nd 36

37 SCM Kota Lama Kiri 37

38 WATER QUALITY Ministry of Health Malaysia selected 5 performance indicators to further enhance continuous quality improvement (Quality Assurance Programme : QAP) Five performance indicators selected are: Residual chlorine (98.15%) E. coli (99.65%) Residual chlorine & E.coli (99.9%) Turbidity (98%) Aluminium (89.8%) Ministry of Health sets yearly target for each indicators 38

39 PERCENTAGE OF COMPLIANCE All fives (5) QAP parameters complied with the standard 39

40 Alum Usage No. Water Treatment Plant 1. Teluk Kepayang Year Installed Liquid Alum (kg) Productio n (m3) 22/04/2004 Year 2003 Ratio (kg/m3) 1,035,817 29,256, Year ,066 33,896, Year ,043,778 36,306, Year 2014 Borneo 14 Convention 16 December Centre ,456,910 46,803, Before After 40

41 Alum Usage No. Water Treatment Plant Year Installed Liquid Alum (kg) Production (m3) Ratio (kg/m3) 2. Kota Lama Kiri 31/12/2004 Year ,834 6,235, Year ,713 6,758, YEAR ,356 10,312, Using increase due to high turbidity Before After 41

42 TREATMENT PLANT OPERATION (TKPYG WTP) NO OF FILTER NO OF FILTERS FREQUENCY OF BACKWASHING (DAYS) WATER USAGE FOR 1 FILTER BEFORE 4 3 DAYS 70 m3 23 AFTER 4 5 DAYS 70 m3 14 DAILY USAGE M3/day/filter 42

43 BENEFITS Better quality of settled water. Maximise filter life span and less water for filter backwashing. Eliminate Aluminium residual issues. 43

44 CONCLUSION The SCM can be a useful tool in coagulant optimization SCM is capable in optimizing the coagulant dosage under fluctuation of raw water turbidity In conclusion streaming current monitor will benefit as follows Improve overall plant performance, consistent and high quality settled & treated water Increased length of the filter runs (consistency of the quality of settled water) 44

45 d THANK YOU