Development of a Grey Water Treatment System

Transcription

1 Development of a Grey Water Treatment System NW Brown, EPL Roberts, SN Hussain, N De-Les-Heras, P Gaffey, A Gaffey, M Keighley Envirolink NW & IEMA Knowledge Exchange Kings Conference Centre, Manchester 19/1/11

2 Overview Introduction to Arvia Introduction to Grey water The Arvia Process Technical Background Process operation Trial Results Organics Removal Disinfection Residual Chlorination Concluding Comments Questions & Discussion

3 Who are Arvia? Research project at University of Manchester Dr Nigel Brown/Dr Ted Roberts Arvia Technology formed in 2007 Spin-out from University of Manchester Initial VC funding end 2008 Successful follow-on VC funding 2010 Early stage - moving into early commercialisation Series A funding 3 rd Quarter 2011 Strong research link to University

4 What is the Arvia Process? Nyex carbon based adsorbent 3 stage process in a single unit Adsorption Separation Regeneration Adsorption and Destruction of organics Low and trace concentrations Toxic and non-biodegradable Chlorinated preferentially removed Separation of organics from inorganics Reduction in microbiological activity In-situ regeneration of Nyex

5 Recognition & Awards

6 Greywater - Introduction Less water available in SE England than many Mediterranean countries 20% of UK water used Domestically 30% of domestic water used for toilet flushing Greywater is water from showers, baths, basins, washing machines and kitchen sinks (EA 2008)

7 Obstacles to Greywater treatment cost of water is low; only a third of domestic customers have metered water supplies and thus would save money; cost of greywater systems is high and would give long payback periods; there are no regulations covering the quality of recycled water; public health concerns over pathogens within the water; poorly treated greywater deteriorates rapidly when stored.

8 Unit Operations for GreyWater Treatment Solids Removal Dissolve organics and colour Removal Disinfection Residual chlorination

9 Holy Grail of GreyWater Treatment Complete treatment in one unit operation Chemical free Waste free Low energy / Low carbon Unattended operation Minimal maintenance

10 Holy Grail of Water Treatment X Complete treatment in one unit operation? Chemical free Waste free Low energy / Low carbon Unattended operation Minimal maintenance

11 Technical Background

12 Nyex 1000

13 Nyex Characterisation Characteristic Nyex 100 Typical AC Density (g cm -3 ) Bed electrical conductivity (S cm -1 ) GAC PAC Pore volume (mm 3 g -1 ) Surface Area (m 2 g -1 ) Surface area of Nyex > GAC after 18 days operation

14 Phenol Conc. (mg/l) Adsorption Kinetics Time (mins)

15 solid phase equilibriumconcentration (mg/g) Nyex Regeneration Reg (1) Reg (500+) AI Reg (1) AI Reg (500+) e q e C Freundlich AI e q e C Liquid phase equilibriumconcentration (mg/l)

16 Volume % Nyex Physical Attrition Final Initial um

17 Concentration (mg g -1 ) Preferential adsorption (Phenols) phenol chlorophenol Dichlorophenol Trichlorophenol Nyex dose rate (g/100ml)

18 Electrode Processes Water is reduced at the cathode: 2H 2 O + 2e - H 2 + 2OH - At the anode the adsorbed organics are oxidised Equation below is for TCE destruction (complete oxidation) CHClCCl 2 + 4H 2 O 2CO Cl 2 + 9H + + 9e - N.B. Chlorine likely to be present in gaseous & dissolved form, as well as oxidised chlorine species such as hypochlorite

19 The Arvia Process

20 Methods of Operation Batch (higher organic conc) Continuous (low flows) Continuous adsorption/batch regeneration (Under development)

21 Arvia Unit - Batch Effluent Or Raw water Bed of Nyex Stack of electrochemical cells

22 Adsorption Nyex Bed is Lifted & Fluidised Nyex Adsorbs & Concentrates Organics Air

23 Settling Nyex Settles Between Cells

24 Electrochemical Oxidation Gases from oxidised organics (CO 2 /CO/Cl 2 ) H 2 Current Applied Across cells Electrochemical oxidation destroys organics

25 Repeat Treated Water Regenerated Nyex

26 Arvia Unit - Continuous Destroyed pollutants (CO 2 /CO/Cl 2 ) + H 2 Cleaned stream overflows Mixing Electrochemical Oxidation (Destruction) Air flow Recycling of Nyex Effluent feed

27 Arvia Process Units - Batch

28 Arvia Process Units - Continuous

29 Results - Organic Removal

30 Effluents treated Industrial Dyehouse Landfill Ion-exchange regenerant Pulp & Paper Pharmceutical TBT Agri-chemical Pesticides Nuclear Groundwater CL:AIRE Raw waters/nom removal Disinfection and grey water treatment

31 COD (mg/l) Landfill Leachate after biological treatment (50%) Cycles

32 Pulp & Papermill Results Feed from secondary clarifier Colour Reduction over 80% COD Reduction 20% Cationic demand reduction 90% Energy for regeneration 0.5 kwh/m 3 Treatment of warm wastewater (approx 30 o C) for re-use, reducing water heating requirements by nearly 25 o C (min 29 kwh/m 3 ).

33 COD (mg/l) API Conc (mg/l) Pharmaceutical waste API removal (20%) dilution TOC API 135 API Treatment cycle

34 COD (mg/l) Pesticide Wastewater Seed Manufacturer Pilot 40A, 22V, 30Mins Lab 0.6A 22.5 mins Treatment cycle

35 Pesticide Wastewater Seed Manufacturer Before treatment After treatment

36 Groundwater - Petrol station remediation Laboratory scale trial COD mg/l Treatment cycle

37 CL:AIRE Project pesticide removal Determinand Gemini In Gemini SBR In SBR Out ( g/l) Out ( g/l) ( g/l) ( g/l) Dimefox 0.2 < <0.2 Ethofumesate 0.4 < <0.2 Hempa 9.0 < <0.2 Schradan 4.4 < <0.2 Simazine 0.3 < Dicamba Dchloroprop <0.1 <0.1 Mecoprop <0.1 <0.1 PAAH <0.1 <0.1

38 CL:AIRE Project Gaseous discharges Hydrogen conc. low (<0.2%) Organochloro compounds below detectable limits In summary, although there is a certain degree of detection of the pollutants in question, their levels are generally extremely low

39 Results - Disinfection

40 Disinfection -1 Before contact with Nyex

41 Disinfection - 2 Disinfection after contact with Nyex 5 min 10 min

42 Disinfection - 3 e. coli adsorption

43 Disinfection - 4 After regeneration

44 Disinfection - 4

45 Disinfection Mechanisms Direct electrochemical disinfection Electro-chlorination ph

46 Results - Residual Chlorination

47 Free Chlorine Effect of ph

48 Chlorine Organics present

49 Current Developments Installation of 1 st Commercial unit Installation of test unit at Oldham Swimming Pool (with Gaffey Tech Services Ltd) Innovate 10 winner Sustainable grey water treatment Raw Water Treatment Scottish Water

50 Conclusions/Acknowledgements Conclusions Arvia Process could provide simple to operate grey water treatment system Organics/colour removal, Disinfection and Residual Chlorination demonstrated Acknowledgements Co-authors, Arvia Technology, Gaffey Technical Services Ltd and University of Manchester

51 Questions My Questions What scale of system should be designed individual homes, multiple dwellings (eg blocks of flats/estates), hospitals etc? Can small unit be cost effective? Will it be accepted by public? How should system be demonstrated? Whom should Arvia collaborate with? Thank you for your attention Your Questions?

52 Thank you Martin Keighley CEO / Nigel Brown Technical Director martin.keighley@arviatechnology.com / nigel.brown@arviatechnology.com