Formulation of growth media from complex effluent streams

Dr. Robert W. Lovitt

Membranology Ltd

bob.lovitt@membranology.com

Introduction• Membranology  is a spin out involved 

many aspect of membrane technology 

including liquid formulations from 

complex effluent sources

Development of a number of process top p

recover useable materials in solid or

liquid form and chemical intermediates

from waste sourcesWelsh Assembly

Swansea University Group

from waste sourcesWelsh Assembly

Project “SuPERPHA – Systems and

Product Engineering Research for

Polyhydroalkanoates (PHA)”

• .  SPEC

CWATER

Anaerobic digestion, an  energy recovery and resource recovery to make of valuable chemicals?

• Anaerobic digestion (AD), oracidogenic fermentation,

• Traditional treatment, it can beperformed on various solid or liquidsubstrates, such as silage or manureleading to the production of biogasleading to the production of biogas,methane CO2 used in energygeneration.

• Acidogenesis represents one of thestages towards methanogenesis VFAstages towards methanogenesis. VFAare the main soluble compoundsgenerated

• VFA, ammonia, phosphate couldrepresent a sources of valuablerepresent a sources of valuablematerials for chemicals productsprovided they can be recoveredeconomically.

Fig.1. Schematic diagram of AD process

Zacharof & Lovitt, Waste and Biomass Valorisation, 2013

Advantages and commercial benefits of nutrients recovery y•Reduced demand on WWTP as reduced carbonis extracted so reducing costs and energyrequirements of oxidation and CO2 release

•The extraction of reduced carbon (as VFA) forreuse and substitution of VFA’s derived frompetrochemicals reducing reliance on fossil

b f h i l f f bl t i tcarbon for chemicals of favourable nutrients

•Ammonia recovery would save CO2 productionand enhance the formation of a potentiallyvaluable product if in a concentrated formvaluable product if in a concentrated form

•Phosphate is a finite resource is becomingincreasingly expensive (800% rise between 2006to 2008, $50 to $400) with a current value of

Nutrient recovery

, )over $500 per tonne

•Although its production is carbon neutral it’sbeen achieved by mining causing environmentaland social issues.

Fig.2. Schematic diagram of  advantages of the process

Zacharof &Lovitt, Water Science &Technology, Under review, 2014

Membrane Filtration was the chosen

Benefits of membrane technology

Membrane Filtration was the chosen 

recovery methodology•Suitable technology for pre‐treatment and separation•Technology quite well developed but not widely industrially applied for waste processingBenefits of membrane filtration include:

•Physical separation (water does nochange phase)

•No additives (chemicals and/or othermaterials) are added other than when

b f dmembranes are manufactured

•There is a wide range of membraneprocess based on the membrane poresize

•Filtration allows manipulation of thenutrient content, when combined withleaching and acidification using MF orselective separation and concentrationusing subsequent NF and RO processes

Zacharof &Lovitt, Water Science &Technology, Under review, 2014

Fig.3. Schematic diagram of  advantages of filtration

Spiral wound membraneSpiral wound membrane

Hollow fibre filters

Basic processM b S ti i P d i• Membrane Separation is a Pressure driven process

• Microfiltration (MF) 0.2μm pore size

• The large solids are successfully removed through the• The large solids are successfully removed through theuse of a ceramic microfiltration unit , simultaneouslywith the recovery of the nutrients of interest

• Membranes used are Ceramic made of ultrapure alumina(Pall Membralox) able to separate particles in a range ofdifferent sizes varying from 0 2μm(MF)different sizes varying from 0.2μm(MF)

• The flow was configured as cross flow mode

Transmembrane pressure  Osmotic Pressure (iMRT)Cross Flow filtration

⎟⎞

⎜⎛ ΠΔ *PJ

p(N m ̄² ̄)

( )

Flux (J, m3/s)

⎟⎟⎠

⎞⎜⎜⎝

⎛μ+

ΠΔ=

*)RR(PJ

cmViscocity (η,Pa/s)

Membrane resistance  (Rm,m¹̄) Cake resistance(Rc, m ̄¹)

Ceramic membrane w/t housing

Nanofiltration transport processes

Methodology

Picture of the processing systemDiagram of the processing system

Process strategy and resulting effluents

Parameters Agricultural SludgeUntreatedSludge

Microfiltered(0.2μm)Sludge

Anaerobically digested effluentsWater

Sedimentation

Permeate

Total Solids (TS, g/L) 15.13 5.15

Total Suspended Solids (TSS, mg/L)

612.50 <0.1Manipulation

Screening

Microfiltration

Total Dissolved Solids (TDS, mg/L)

7965 7055

pH 8.13 8.25Conductivity (mS/cm) 9.37 8.3

/

Manipulation

Formulated growth media

Nutrients/Chemicals/Ions rich effluentsAlkalinity (mg CaCO3/L) 7500 1875

Zeta Potential (mV) ‐33.25 nd

Sizing (μm) 27.17 <0.2Optical Density (580nm1) 0.86 0.10

C t ti /L /L

Fig.9. Anaerobically digested spent effluents Treatment Strategy

gConcentration g/L g/LAcetic Acid 1.65 1.26Butyric Acid 1.69 1.39Ammonia 34.57 30.95Phosphate 31 91 0 17

Zacharof &Lovitt., Water Science and Technology, 2013

Fig.9. Anaerobically digested spent effluents Treatment Strategy Phosphate 31.91 0.17

Table.2  Anaerobically digested spent effluents treatment results

Current Status

• MF studies • Clarify fluids• Obtain materials from particulates

• Diafiltration / strategies• Acid treatment 

• Range of nutrient products• Costs Utility/  y/

• NF/ RO • Enrichment of various streams • Ammonia / phosphates separation• Fatty acid enrichment also 

demonstrated • Data sufficient to estimate costs ofData sufficient to estimate costs of 

large scale systems• Potential for multistage enrichment 

Fig.8.Nanofiltration unit (CCFP) treatment schemes media formulation

Zacharof et al.Under preparation, 2014

Current StatusC ti E i f MF/UF Pil t S l T i lCosting Exercise  of MF/UF Pilot Scale Trials

Fig.6.KOCH PVDF membrane module  

Fig.5.Ultrafiltration unit provided by Axium processingunit: [1] feed vessel, [2] feed pump, [3] circulating pump, [4] membrane unit , [5] membrane unit, [6] pressure gauge (inlet),[ [7] pressure gauge (outlet), [8] control panel [9]scale and graduatted vessel [10] flow meter [11] regulating valve [12] flow meter

Max. volume capacity: 120  LMax. flow rate: 3000 L/hMax. operating pressure: 6 barMax. operating temperature: 50 °Ccontrol panel [9]scale and graduatted vessel, [10] flow meter [11] regulating valve [12] flow meter 

(circulating part) [13 a, b, c] butterfly valve [14] permeate line [15] thermometer [16] heat exchanger(not shown)

Zacharof et al.Under preparation, 2014

Max. operating  temperature: 50  CpH range : 2.5‐11Total membrane area: 4.4 m2

Parameters Values

Temperature 25°CTransmembrane  Pressure (psi) 5.65pH 7.5Volume (feed) 100 LViscosity (μ, N s m‐1) (water) 8.091

ElectricityElectricityUnits (kW/h) 0.650Cost of Unit (kW/h) (pence,p) 12.5Standing Charge of Electricity usage (day) (pence,p)

18.33

Total Processing Time (h) 2Total Usage of Electricity per processing time  1.30g y p p g(kW)Total Usage of Electricity per day (24h operation) (kW/day)

15.6

Cost of Operation per hour (pence, p) 8.125Cost of Operation per total processing time (pence, p )

16.25

C t f O ti d (24h) ( ) 195 00Cost of Operation per day (24h) (pence,p) 195.00Cost of Operation per day (24h) (pence,p) (including standing charge/day)

213.33

Water (tap)Cost of water per  Unit (m³) (pence,p) 75Total Processing Time (h) 2Total Usage of  water per  Unit (m³)  per processing time 

0.2

Total Usage of  water per  Unit(m³)  per day (24h operation) 

2.4

Cost of Operation per hour (pence, p) 7.5Cost of Operation per total processing time  15(pence, p )Cost of Operation per day (24h) (pence,p) 180

Costing Parameters Agricultural sludgeCurrent case study

Total volume of permeate collected (L) 200 L Total volume of processed feed (L) 250 LTotal NH3‐N recovered at this case (mg/L) 4 87

Recovery costs of phosphate is £1768/t acid extracted systems (1500 mg/> would be more like 

Total NH3 N recovered at this case (mg/L) 4.87

Total PO4‐P recovered at this case (mg/L) 1.85Total NH3‐N recovered at this case  (mg / 200 L) 974Total PO4‐P recovered at this case (mg / 200 L) 370Total NH3‐N recovered at this case  (mg / 1000 L) 4870

£300/tonneAmmonia was calculated at £148.14/t For high NH3 systems > 8000 mg/L

Total PO4‐P recovered at this case (mg / 1000 L) 1850Current case study

Mean Permeate flow at steady state (L/h) 101.61Cost of power and water usage (£/h) 0.34Total time processing time (h) 2

For high NH3 systems >  8000 mg/L cost will be reduced further (<£50 tonne).Cost estimation presented only takes 

Total time processing time (h) 2Operating costs for the total collected permeate (£) 0.68Operating costs per cubic meter of sludge (m3) (£) 2.72

Values of ammonia, phosphate and VFA used in calculating the cost

Total volume of permeate collected (L) 100

into account the operating costs in terms of power and water usage including maintenance (cleaning), without including labour cost, 

Total volume of processed feed (L) 150Total NH3‐N recovered at this case (mg/L) 1746.86Total PO4‐P recovered at this case (mg/L) 154.85Total NH3‐N recovered at this case  (g / 100 L) 1740Total PO4‐P recovered at this case (g / 100 L) 154

transportation as well as cost for the unit construction.The market value of these chemicals (USD 700/tonne for ammonia, USD$ 

[1] Including standard charge of electricity per 24 h

4 (g / ) 154Total NH3‐N recovered at this case  (g / 1000 L) 17400Total PO4‐P recovered at this case (g / 1000 L) 1540Operating costs in terms of N recovered (£/tonne) 148.15Operating costs in terms of P recovered (£/tonne) 1768

400/tonne for phosphate) the costs proposed here, though only estimation, do imply that the recovery of platform chemicals from [ ] Including standard charge of electricity per 24 h.waste sources is a feasible alternative when compared to the petroleum based industry and mining.

Parameters Municipal Wastewater

After SAS1/Post A.D.2 Before SAS/w‐t polymer3

Total Solids (TS, g/L) 16.51 5.40

Total Suspended Solids (TSS, mg/L) 7172.94 2445.48

Total Dissolved Solids (TDS, mg/L) 15579 2031.35

9 27 7 54pH 9.27 7.54

Conductivity (mS/cm) 18.83 2.39

Alkalinity (mg CaCO3/L) 5625 1875

Optical density (580 nm) 0.326 0.316Optical density (580 nm)

Size (μm) 18.51 7.40

Concentration mmol/L

Ammonia (NH4‐N) 44.01 (748 mg/NH3) 62.02

Phosphate (PO4‐P) 14.66 (1407 mg./PO4) 21.80

Potential  recovery costs ammonia (~£300) and PO4 (~£300)

Growth of microorganisms on in vitro media & treated sludgein vitro media & treated sludge

Growth media Nutrient*1

(in vitro)d

Minimised (in vitro)*2

mediaTreated sludge(N:P 36.6:1)

Enriched treated sludge (0.11M 

l )media pH:7.81 glucose)

Micro/sms μ (h‐1)

DT (h) μ(h‐1)

DT (h) μ (h‐1)

DT (h) μ (h‐1)

DT (h)

L.plantarum 0.18 3.83 0.02 31.1 ‐ ‐ 0.45 1.52p

Cl.butyricum 1.49 0.46 0.14 4.94 0.24 2.91 0.38 1.82

E li 0 6 1 15 0 02 38 2 0 65 1 06 0 37 1 81E.coli 0.6 1.15 0.02 38.2 0.65 1.06 0.37 1.81

Schi. limacimum 0.52 1.34 0.69 0.99 0.36 1.91 1.55 0.44

Sacc.cerevisiae 1.37 0.50 0.73 0.94 0.19 3.55 0.34 2.04

*Media recipe: Y E 10 g/L glucose 20 g/L MgSO4 5 g/L KH2PO4 25 g/L pH 5 01

Table 3. Comparative table of growth of 5 microorganisms on different nutrient sources

Zacharof  et al., WIT Transactions on Ecology & the Environment, 2014

Media recipe: Y.E. 10 g/L, glucose 20 g/L, MgSO4 5 g/L, KH2PO4 25 g/L pH 5.01*Minimal media recipe: Tap water, 20 g/L glucose 

End products of Cl.butyricum on i it di & t t d l din vitro media & treated sludge

Growth  Nutrient*1 Minimised (in vitro)*2 Treated sludge Enriched treated sludge media (in vitro)

media

( )media

g(N:P 36.6:1)pH:7.81

g(0.11M glucose)

pH:8.1

Micro/sms Biomass Acetic Butyric  Biomass Acetic Butyric  Biomass Acetic Butyric  Biomass Acetic Butyric (g/L) Acid

(g/L)

yacid(g/L)

(g/L) Acid(g/L)

yacid(g/L)

(g/L) Acid(g/L)

yacid(g/L)

(g/L) Acid(g/L)

yacid(g/L)

Cl.butyricum 1.42 15.43 6.51 0.49 ‐ ‐ 1.44 6.65 1.57 1.46 16.87 2.71

*Media recipe: Y.E. 10 g/L, glucose 20 g/L, MgSO4 5 g/L, KH2PO4 25 g/L pH 5.01/

Table 4. End products of Cl.butyricum

*Minimal media recipe: Tap water, 20 g/L glucose  pH: 7.04

What is the carbon footprint of media generated by this method for platform chemicalsand single cell protein ?

Zacharof et al., Under prepartion, 2014

and single cell protein ?

Nanofiltration Enrichment

Further processing  of the effluents was achieved using Nanofiltration

Nutrients  Acetic acid (mmols/L)

Butyric acid(mmols/L)

(NH4‐N)(mmols/L)

(PO4‐P) (mmols/L)

Flux (L/m2 h)

using Nanofiltration, enrichment of salts additions and pH adjustment were made to

Initial Conc 21.08 15.81 48.99 1.35

Membrane retentates

Treatment : pH 8.5

NF270 29.56 26.54 78.47 36.60 15.40adjustment were made to the process

Many factors that control 

NF270 29.56 26.54 78.47 36.60 15.40

Ratio 1:0.89:2.65:1.23

LF10 53.94 28.38 168.37 40.06 6.00

Ratio 1.82:0.96: 5.69: 1.35ynutrient ratios.• Membrane type• pH

Treatment :NaCl addition (100mM)

NF270 52.62 69.74 17.30

Ratio 1.78:2.35

• Salts

Reverse osmosis can also t t thi t i l

Treatment :NaHCO3 addition (100mM)

LF10 48.27 72.23 11.78

Ratio 1.63:2.44

Zacharof et al., Journal of Cleaner Production, Under review 2014

concentrate this materials Table 6. Formulation of different composition solutions using nanofiltration

NF/RONF/RO

• Nanofiltration membranes reject 70‐98%Nanofiltration membranes reject  70 98% Phosphate– Now devising schemes for calcium phosphate recovery g p p y

• Ammonia up to 80% rejection heavily depended on pHdepended on pH– Concentration limited by osmotic pressure but can membranes can be 

used as hybrid process in enhanced stripping for example

• Fatty acid recovery 80% also pH dependent – Calcium salt recovery/electrochemical recovery

Conclusions• Processes have been developed and are being evaluated economically.

– These process produce a range of novel, environmentally friendly products, fromwastes.

• Full medium formation now needs to be carries out, so tailored media to the needs of our partnerswill be provided.

– Media components derived from wastes allows cyclisation of nutrients solvingproblems associated with nutrient disposal by their incorporation into biomass (PHB,Protein Fats and Carbohydrates platform chemicals)Protein, Fats and Carbohydrates, platform chemicals).

• NF can be used as a method of isolation and recovery of VFA, phosphate and ammonia fromcomplex effluent streams, provided a pre‐treatment scheme that will remove coarse particles, sothe effluents can be easily filtered.

– NF allows subtle formulations components from waste, achieving the dual benefit ofhe isolation valuable chemicals and purifying water

• Further work will be done to economically evaluate the MF/NF/RO process, and its feasibility on thelarge scale and integration in situ (in an AD digester)large scale and integration in situ (in an AD digester)

– Data obtained here will allow economic evaluation of the costs of recovery ofnutrients and organic acids by physical methods of filtration. Energy from the digesterto drive the product recovery process.