OVERVIEW OF MEMBRANE PROCESSES FOR OMW TREATMENT. BGU, Prof. Jack Gilron

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1 OVERVIEW OF MEMBRANE PROCESSES FOR OMW TREATMENT BGU, Prof. Jack Gilron

2 The Environmental Impacts of OMWW Threat to aquatic life - The organic load (COD ~ g/l) causes an oxygen availability reduction, promotes algae development & might lead to eutrophication. Also, the high phenolic content ( ~4.2 g/l) might cause intoxication. Discoloring of natural waters The change in color is attributed to the oxidation and polymerization of tannins producing darkly colored polyphenols. Odors - As a result of pungent fermentation methane, hydrogen-sulphide and other gases are released to the open air and cause sever odor nuisance.

3 Most Adapted OMWW Treatment Methods Treatment Advantages Disadvantages Evaporation in open storage ponds: Direct application on soil: Low investment Favourable climatic conditions in Mediterranean countries Requires large pounding areas Produces bad odour for long distances Insect proliferation The concentrate has to be treated Danger to underground water Low investment Infiltration depends on soil properties High nutrient concentration, especially K High mineral salt content Phytotoxicity (polyphenols) Biotechnological transformations: 1. Anaerobic Digestion 2. Activated sludge Production of energy (biogas) Re-use of effluent in irrigation Efficient pollutant reduction Efficient pollutant reduction Suited for industrial-scale oil mills Pre-treatment required High investment costs Complex control process (long acclimation) Destruction of viable antioxidants High investment & operational costs Space requirements Complex control process (long acclimation) Excess sludge

4 Alternative OMWW Treatment Method Treatment Advantages Disadvantages Physicochemical treatments: Membrane applications: Suited for small-size oil mills Optimal pollutants reduction Chemical costs Limited efficiency by single chemical treatment High investment and operational costs Compactness of the units Complex process control Reutilization of the products Fouling process (Niaounakis and Halvadakis, 2006; Caputo et al., 2003; Roig et al., 2006; Kapellakis et al., 2008)

5 OMW and membrane filtration (adapted from Gesan- Guiziou) OMW components Inorganic ions polyphenols COD Oil droplets Bacteria Suspended material m Microfiltration 0.1 m Ultrafiltration 10 kg.mol -1 Nanofiltration 400 g.mol -1 Reverse osmosis 100 g.mol -1 5 Industrial membrane operations

6 Membrane and Membrane Processes Research Group at the University of Genoa developed a OMW treatment process based on two integrated pressure driven membrane process: Microfiltration (MF) and Reverse Osmosis (RO). 1 st step: MF process Two outlet streams: minor volume MF concentrate (by-product for valorization) a main stream - MF permeate (partially depurated OMW for further treatment in RO process) Two outlet streams: 2 nd step: RO process minor volume RO concentrate (polyphenols rich by-product for valorization) a main stream - RO permeate (depurated water for irrigation/reuse) DCCI University of Genoa

7 Portable membrane treatment for water purification and polyphenol recovery MARS UF-NF System Irrigation Hydroxytyrosol Food Industry Pharma/Cosmetic OMWW

8 Membrane Contractor HT Recovery Sys. UF NF System

9 OMWW Polyphenols - Health Anti-oxidant Skin protectant Anti-microbial Anti-aging Oleuropein degradation Products - Polyphenols Anti-viral Anti-atherogenic Anti-cancer Anti-imflammatory

10 Mobile OMWW + Membrane Contractor Pilot Plant OMWW Acidification COD ~ 106g/l Phenol~ 3g/l TP/TOCx100~8% PH 2 NMR~ 99% Final -HT Pure product Preparative HPLC Ultra- Filtration Product B: Food Pharma Additive Starting Material Product A: Semi-purified H2O for Agri COD~10g/l Phenol~0.7 g/l Nano- Filtration Organic Concentrate Phenol~4.5g/l Hydroxytyrosol Enriched Product HT/TOCx100~12% Compost Organic Waste MA-HT-R (MARS -. HT Recovery Sys.)

11 TMP, bar Average permeate flow rate, L/h UF treatment N ` TMP Average flow rate Elapsed time, min

12 J, Flux, L/m2h Sp. Flux, L/m2-h-bar Applied P, bar J, Flux, L/m2h Applied P, bar NF concentration of OMWW (sterlitech) VCF J DP DK5 NF270 J DP VCF DK5 7.1 L/m2-h-bar 0 NF L/m2-h-bar VCF

13 NF selectivity 120.0% 100.0% 80.0% Initial rejection Final rejection RAHAT OMWW after UF DK5 passes only tyrosol and hydroxytyrosol. 60.0% 40.0% 20.0% While >99% pf polyphenols in permeate were hydroxytyrosol, there is still another7 g/l of COD from which to purify it. 0.0%

14 Mem. Contactor Hydroxytyrsol Recovery Sys. Dialysis cell for diffusion rate measurement

15 Capital costs Capital Equipment Euro UF NF MARS Contingency (5%) 9600 Total

16 Operating cost Operating Costs (Euro/year) Electricity (NF + UF) Chemicals (acid, base, cleaning) Membrane replacement 2000 Maintenance 2000 Labor Vehicle rental (2 months) 4000 Facility rental Insurance 800 Total

17 Balance sheet Value of recovered polyphenols that compensates costs 150 /kg Case 1: 70% recovery from NF permeate, Case 2: 50% Recovery from NF Permeate; 70% REC 50% REC Operating costs Phenol value Net Operating Income Annual Return on Investment 41% 20% Operating costs Capital costs (Charged at 10%/year) Phenol value Net Income