2018 MAY PAC Water Treatment

Transcription

1 2018 MAY PAC Water Treatment

2 Facts about Water Water security is among the top global risks in terms of development impact- WB The world will not be able to meet the sustainable development challenges of the 21st century without improving management and access to reliable water and sanitation services. WB

3 Why Water Treatment Turkana aquifer- can supply whole county with water for 70 years but not fit for drinking without treatment- Too salty Dwindling fresh water sources- and the once available heavily contaminated- Nairobi River 2015 (WHO/UNICEF) Report- 19 million people do not have access to at least basic water WASREB report- Only 53% of the urban population and 49% of the rural population had access to clean water In Nairobi- only 35 % had access to clean water

4 Water contaminants Physical- Suspended sediment and organic material Chemical -nitrogen, salts, pesticides, metals, gases etc. Biological- bacteria, viruses, protozoan, and parasites. Radiological- cesium, plutonium and uranium.

5 Water Treatment Technologies Classification Physical Treatment- Sand filtration, sedimentation, ultrafiltration, Reverse osmosis Chemical Treatment - flocculation and chlorination systems, UV systems, ion exchange systems, Adsorption Biological Treatment- biodegrading of organic matter in Bioreactors WWTP

6 Water Treatment

7 Wide Range- Any water quality

8 Reverse Osmosis (RO)

9 How RO works Every RO must have two streams of water

10 RO membrane construction

11 RO Membrane

12 What RO will remove from your water 99%+ of dissolved salts Particles Colloids Organics Bacteria etc BUT- RO is designed to deal with dissolved salts only. All others must be removed before RO

13 RO design and Performance - Key Parameters Feed Pressure Permeate Pressure Concentrated pressure Feed Flow Permeate Flow Temperature Feed TDS Permeate TDS Concentrate TDS

14 Salt Rejects Tells You how effective the RO membranes are in removing dissolved solids Salt Rejection= Feed Water Conductivity/TDS Permeate water conductivity/tds Feed Water conductivity/tds

15 Salt Rejection Salt Passage %=1 salt Rejection The lower the salt passage the better High salt passage could mean damaged membrane or need for cleaning

16 Recovery Recovery %= Permeate Flow Feed Flow 100 A general rule is the system can be operated at 50%, 75%, and 80-85% recoveries for a single stage, two stage, and three stage systems respectively. % system recovery is often set to maximize permeate flow while preventing precipitation of super-saturated salts within the membrane system Operating temperature, source of feed, composition of feed, feed concentration, and ph can have an effect on the overall recovery

17 Mass Balance Mass balance equation is used to help determine if your flow and quality instrument is reading correctly Feed TDS Feed Flow rate=(permeate TDS Permeate flow rate) + (Concentrate TDS Concentrate Flow rate) A difference of > +/- 10% on both sides of the equation means instruments needs calibration

18 RO Staging

19 RO Staging

20 RO Staging

21 RO Pass- Single Pass

22 RO Pass- Double Pass

23 Typical RO installation

24 RO Pretreatment Proper pretreatment prevents fouling, Scaling and premature membrane failure and frequent cleaning Pretreatment could be chemical, mechanical or both

25 Common Problems Due to Poor Pretreatment Fouling- Contaminants accumulating on the membrane surface Plugging the membrane- Colloidal matter, Organics, Biofilm, media break through Scaling- compounds exceeding solubility limit precipitating on membranes e.g. CaCo3 Chemical Attack by oxidizers e.g. chlorine Mechanical damage- Hard starts and back pressures

26 Pretreatment Solutions for RO Multi media using sand or Glass media. Removes particles down to 20 microns and 10 microns when coagulation is added. Micro Filtration- recommended 5 microns after Multi Media Filter Ultrafiltration- Ideal filtration Antiscalant- Dosed before RO feed pump Chlorination- For preventing bacteria growth. Dosed before media filter SMBS/Carbon- De-chlorination

27 Eco Membranes RO ECO Membranes will increase sustainability efforts for an ECOlogical solution ECO Membranes will provide opportunity to save energy and chemical costs for an ECOnomical solution

28 Reverse Osmosis Application Drinking Water production Fluoride removal- Big Problem in Arusha >1.5 mg/l dental fluorosis Stains, brown teeth, chipping of teeth >6 mg daily intake skeletal fluorosis Deformed bones, Crippling Pain in joints, weakening of bones

29 Examples of Project 12m3/hr RO -Voyager Beach Resort

30 Examples of Project Kenya Breweries 15m3/hr

31 Examples of Project 16m3/hr RO Sultan Palace

32 Examples of Project 3m3/hr Sea Water RO Interland

33 Ultrafiltration UF: membrane process based on size exclusion (physical sieving). Reject particles, colloids, SS, oxidized Fe/Mn, microorganisms... What UF cannot reject: DOM, Non-Oxidized Fe/Mn, Hardness, Salts, dissolved matter in general.

34 Ultrafiltration Fundamentals

35 DOW UF- Products Specs

36 DOW UF- Products Specs VIDEO

37 DOW IntegraPac Concept Our Customers needs Reduce engineering and installation complexity Reduce delivery time Reduce transport and handling cost Compact solutions where there is space constraints Reduce capacity expansion costs More cost effective

38 DOW IntegraPac Concept Features: Minimized Fittings & Materials (Headers integrated in EndCaps) Highly Compact Design (up to 50% weight and footprint reduction vs conventional skids) Plug and Play Lower Cost Solution

39 DOW IntegraPac Concept Features: Filtrate clear tubes for integrity control Module accessibility maintained Modular and Scalable: 6 to /2880 Modules From 500 m3/d to 2,650 m3/d filtrate flow E.g. 14 x 2880: 1,078 m2 filtration surface in 2 m2 footprint Supports shipment by container

40 Application of UF RO Pretreatment Drinking water production Irrigation water production Industrial process water production Waste water post treatment

41 Advantages of UF as Pretreatment to RO Reduce colloidal fouling in RO membranes. Possibility to operate the RO at higher flux. Reduce chemical cleaning frequencies. Enhance life of RO by achieving required RO feed parameters.

42 Dayliff UF Range Can treat murky surface water Suitable for treating water at POU Suitable for remote areas with no power

43 Example of Projects British Army 20m3/hr Drinking water

44 Example of Projects Kijabe Community Drinking Water Project 20m3/hr

45 Dayliff Media Filtration It consists of several layers of filtration media, which differ in particle size

46 Dayliff Media Filtration Pentair Bobbin Wound Filters- Suitable for industrial use high up to 10 bar Fiber Glass Filter- For general filtration low pressure- Up to 2.5 bar Steel Filters- High flow medium pressure application up to 5 bar

47 Dayliff Media- Glass Media This environmentally friendly filter media is made from a glass recycled

48 Glass Media This environmentally friendly filter media made from a glass recycled

49 Glass Media benefits Over Sand More efficient It can remove up to 30% more material and pollutants than sand Keeps cleaner It s less susceptible to bio-fouling, as the product is heat treated surfaces are smooth

50 Glass Media benefits over sand requires less material It s less dense than sand by 15% and therefore uses less water to backwash. 23% less water doesn t degrade It therefore has a longer life span. Upto 10 years, compared to sand 3 years

51 DMI 65

52 DMI 65 The processes that take place in a bed of DMI-65 involve reduction/oxidation (redox). Redox reactions involve a transfer of electrons between species Reduction is the gain of electrons or a decrease in the oxidation state of a molecule, atom or ion. Oxidation is the loss of electrons or an increase in the oxidation state of a molecule, atom or ion. Redox reactions occur simultaneously whereby there cannot be a reduction reaction without an oxidation reaction.

53 DMI 65

54 DMI 65 Feed water Specs

55 DMI 65 USES Reverse Osmosis Protection- Iron and manganese removal Drinking water application Arsenic Removal Food and beverage Irrigation water systems

56 Glass Media This environmentally friendly filter media made from a glass recycled

57 Glass Media benefits Over Sand More efficient It can remove up to 30% more material and pollutants than sand Keeps cleaner It s less susceptible to bio-fouling, as the product is heat treated surfaces are smooth

58 Glass Media benefits over sand requires less material It s less dense than sand by 15% and therefore uses less water to backwash. 23% less water doesn t degrade It therefore has a longer life span. Upto 10 years, compared to sand 3 years

59 Dosing pump Selection A customer has a water treatment system in which he wishes to dose 10 mg NAOH /l in a pipeline with a flow of 6 m 3/h and system pressure of 4 bar His dosing solution of soda lye [NaOH] must be a 25% solution. Which dosing pump should we offer him? Solution; In a 25% [NaOH] solution there is approx. 25 g [NaOH]/100 ml =50 mg [NaOH]/ml=250,000mg/lr. To calculate dosage rate is as follows Dosage rate ( l hr) = (flow rate ( l hr) Required Dose concentration( mg l) solution concentration ( mg l) In our case therefore, Dosage rate = The correct dosing pump is therefore DDE6-10 set at 4% = 0.24 l hr

60 Chemical Mixing Calculation If you are to make a solution in a 100l tank, then to calculate the volume of NaOH to be added into the tank the formula is as below V Dosage in L = required dose concentration ( mg l) Tank Volume in L concentration of stock solution density of the chemical ( g cm 3 ) 10 6 In our case this will be = = l of NaOH

61 Bioliff Waste Water Treatment

62 Bioliff Waste Water Treatment Wastewater treatment is a process used to convert wastewater into an effluent that can be returned to the water cycle with minimal impact on the environment or directly reused Are Septic tank waste water treatment?

63 ECOROCK WWTP Very compact. No need for power. No moving parts. Silent operation. Minimal maintenance. Ease of handling and installation Suitable for domestic applications upto 120PE

64 ECOROCK WWTP

65 SBR WWTP Bioliff SBR wastewater treatment plants use the Sequential Batch Reactor process. SBR process provides for full Carbon and Nitrogen removal - produces high quality effluent. Systems upto 750PE

66 BIOPURE WTTP Features; Modular design allowing scaling up Testing in conformity to EU Norm EN Up to 750PE

67 Thank You!