Ph.D. Ewa Połom Institute of Chemical Engineering and Environmental Protection Processes THE UTILISATION OF WASTE LACTOSE WITH MEMBRANE TECHNIQUES USAGE

Plan of presentation 1. Introduction 2. Integrated systems of environmental protection 3. Whey as a source of valuable products 4. Membrane techniques proposed for lactic acid LA, manufacturing 5. Zr(IV)/PAA Dynamically formed membranes DMF 6. The scheme of the experimental set-up 7. Statistical examination of experimental results 7. Conclusions

Introduction production process water raw materials energy air pollution main product solid wastes liquid wastes

POLLUTION PREVENTION cleaning strategy cleaner strategy re-userecycling energy recovery deposition Integrated systems of environmental protection

Diary industry main products cheeses yoghurts skim milk Main waste from food processing whey lactose 5% proteins 0,8% minerals and vitamins 0,5% fats 0,3% lactic acid 0,2%

Lactic acid LA stereoisomers Possibilities of LA obtaining : 1.Chemical synthesis from oil-based non renewable resources 2.Biotechnical processes based on fermentation of industrial wastes

The main steps in the process of waste lactose conversion to LA or ethanol Product separation /purification Product concentration Sugar conversion Feedstock preparation

The membranes techniques proposed for LA manufacturing by waste lactose fermentation 1.Prefiltration of solutions before fermentation processes 2.Selection of lactic acid from post -fermentiation solution 3.Conversion of lactic acid salts into lactic acid 4.Purification and concentration of lactic acid solutions Membrane techniqueStage 1Stage 2Stage 3Stage 4 Microfiltration, MFvv Ultrafiltration, UFvv Nanofiltration, NFv Reverse osmosis, ROv Liquid membranes, LMv Membrane extraction, EMv Electrodialysis, EDv MF+ EDVV UF + EDVV UF+ MF + EDvVV EM + EDvv

Fermentation UF MODULE ED UNIT lactic acid sodium lactate post fermentaive solution lactose + lactic acid bacteria Integrated scheme of LA production with product neutralisation

The conception of LA production from whey with continuous product disposal

The characteristic of Zr(IV)/PAA dynamically formed membranes DFM MembraneSupportGel-layerPore radius * / layer thickness ** MF, Ti (IV)Stainles steel tube TiO – 0.05  m * UF, Zr (IV)MF membrane ZrO(OH) 2 10  m ** NF, Zr (IV)/PAA UF membrane PAA 2  m **

DF MEMBRANES Zr(IV)/PAA EMS PHOTOS a) Top view of NF DFM Zr(IV)/PAA surface of PAA layer b) Cross- section of two NF DFM Zr(IV)/PAA layers: ZrO(OH) 2 and PAA K.S. Menon, Thesis, Clemson University, Clemson 1988 DF MEMBRANE Zr(IV)/PAA

The scheme of the experimental set-up ´

Statistical examinations of NF LA solutions experimental results r=0,35–0,05x 1 +0,104x 2 +0,08x 3 –0,09x 4 +0,14x 1 x 4 –0,044x 2 x 4 +0,03x 1 x 2 x 4 +0,03x 2 x 3 x 4 r=0,49–0,027x 1 +0,11x 2 +0,1x 3 –0,077x 4 +0,135x 1 x 4 –0,044 x 2 x 4 –0,061x 3 2 –0,077x 4 2 (1) (2) Forms of obtained polynomial models: SymbolParameter descriptionRange of parameter x1x1 Cross flow velocity1.0 – 2.6 m/s x2x2 pH of feed solution4.0 – 8.0 x3x3 Pressure difference across membrane surface 1.4 – 5.5 MPa x4x4 Concentration of LA in the feed solutions 0.02 – 1.0 mol/l Independent variables description

x 1  u = 1,0 [m/s] x 2  pH = 8,0 x 3  p = 5,52 [MPa] x 4  c LA = 0,02 [mol/l] r max = 0,82 x 1  u = 2,6 [m/s] x 2  pH = 4,0 x 3  p = 1,42 [MPa] x 4  c LA = 0,02 [mol/l] r min  0,02 Values of parameters allow to obtain r max Values of parameters allow to obtain r min Influence of NF process parameters on LA DFM Zr(IV)PAA selectivity

Fermentation of waste lactose connected with lactic acid manufacturing is the best way of whey utilisation which corresponds to the integrated systems of environmental protection rules Employing pressure membrane techniques in utilisation of whey process brings profits from both: environmental and economical points of view Zr(IV)/PAA DFM can be use in LA separation from fermentative solutions and purification of selected product. Conclusions