2.2.4 Ultrafiltration

The clarified OMWW was ultra-filtered on GM membranes, GK, GH and GE Type (TFM) tubular listed in Table 1 with the cutoff between 100 and 200 kDa, and the recovering of the permeate. The ultrafiltration method is followed by nanofiltration.

#### 2.2.5 Nanofiltration step

The permeate obtained by ultrafiltration is nano-filtered on DK and DL; spiral and tubular membranes type (TFM) listed in Table 1 with the cutoff between 150


PVDF: difluorure de polyvinyl,TFC or TFM: thin-film composite membranes,TFPP: talc filled polypropylene co-polymer,TFPS: thin-film polymer on silicon.

2.3 Schematic description of the pilot plant

DOI: http://dx.doi.org/10.5772/intechopen.90087

Photography of the pilot plant used (Ecosystem S. L Technologies).

FI01: Flow-meter concentrate stream. FI02: Flow-meter permeate stream. E01: concentrate heat exchanger (big). E02: concentrate heat exchanger (small).

Vxx: valves (x = 1, 2, 3, … ., 35).

following [18–21]:

Figure 2.

85

duced the water to be treated.

P01: Volumetric pump. P02: Centrifuge pump.

The pilot plant used is Ecosystem S. L Technologies and described as the

Treatment of Agro-Food Wastewaters and Valuable Compounds Recovery by Column…

F01: Cartridge filters of 50 μm to remove power remaining solids.

S01: Feed tank with the capacity: min 10 liters, max 100 liters where is intro-

M01: Housing for medium size membrane modules, mod. 2540, area 2.51 m<sup>2</sup>

OMMW pre-treated feedstock was stored in a feed tank (FT1) of 100 L. The centrifugal (P1) and volumetric (P2) pumps to drive the wastewater stream over the spiral-wound membrane supplied by osmotic fitted in the housing M1, at a flow rate of 600 L/h. The active membrane area of each module was 2.51 m<sup>2</sup> [18–21]. The maximum one for the used membranes in this work that can be obtained constantly on this system, for the ultrafiltration ("UF"), the nanofiltration ("NF") and the reverse osmosis ("RO") type is reported in Table 2. The membranes are characterized when new by their pure water permeability value mw, the average of the pore size Dp and the maximum operating pressure Pmax. The membrane modules were used under the flux threshold conditions at least of 1000 operating hours. Each module exhibited reduced pure water permeability values compared to new ones. By acting on the regulation valves V1 and V2, it was possible to set a desired operating pressure PExT over the membrane by maintaining a feed constant flow rate with an accuracy of 0.5 bar. The permeate and concentrate streams were cooled down to the feedstock temperature, mixed together and the feedstock composition was maintained constant during each experimental batch run. The temperature was

M02: Housing for small size membrane modules, mod. 1812, area 0.52 m2

.

.

#### Table 1.

Characteristics of membrane modules used.

Figure 1. Schematic of the pilot plant used.

and 400 Da, and at the maximum pressure of 16 Bar. Following this operation is obtained the rich fraction in polyphenols called nanofiltration concentrate. This concentrate is used in the adsorption/desorption tank for the separation of toxic compounds and the recovery of polyphenols of interest. If the operation is pursued we have the reverse osmosis which leads to the production of pure water. The membrane characteristics of this operation are recorded in Table 1 and both Figures 1 and 2 present the installation of the pilot plant used in the membrane treatment.

Treatment of Agro-Food Wastewaters and Valuable Compounds Recovery by Column… DOI: http://dx.doi.org/10.5772/intechopen.90087

Figure 2. Photography of the pilot plant used (Ecosystem S. L Technologies).

### 2.3 Schematic description of the pilot plant

The pilot plant used is Ecosystem S. L Technologies and described as the following [18–21]:

S01: Feed tank with the capacity: min 10 liters, max 100 liters where is introduced the water to be treated.

F01: Cartridge filters of 50 μm to remove power remaining solids.

P01: Volumetric pump.

P02: Centrifuge pump.

M01: Housing for medium size membrane modules, mod. 2540, area 2.51 m<sup>2</sup> .

M02: Housing for small size membrane modules, mod. 1812, area 0.52 m2 .

FI01: Flow-meter concentrate stream.

FI02: Flow-meter permeate stream.

E01: concentrate heat exchanger (big).

E02: concentrate heat exchanger (small).

Vxx: valves (x = 1, 2, 3, … ., 35).

OMMW pre-treated feedstock was stored in a feed tank (FT1) of 100 L. The centrifugal (P1) and volumetric (P2) pumps to drive the wastewater stream over the spiral-wound membrane supplied by osmotic fitted in the housing M1, at a flow rate of 600 L/h. The active membrane area of each module was 2.51 m<sup>2</sup> [18–21].

The maximum one for the used membranes in this work that can be obtained constantly on this system, for the ultrafiltration ("UF"), the nanofiltration ("NF") and the reverse osmosis ("RO") type is reported in Table 2. The membranes are characterized when new by their pure water permeability value mw, the average of the pore size Dp and the maximum operating pressure Pmax. The membrane modules were used under the flux threshold conditions at least of 1000 operating hours. Each module exhibited reduced pure water permeability values compared to new ones. By acting on the regulation valves V1 and V2, it was possible to set a desired operating pressure PExT over the membrane by maintaining a feed constant flow rate with an accuracy of 0.5 bar. The permeate and concentrate streams were cooled down to the feedstock temperature, mixed together and the feedstock composition was maintained constant during each experimental batch run. The temperature was

and 400 Da, and at the maximum pressure of 16 Bar. Following this operation is obtained the rich fraction in polyphenols called nanofiltration concentrate. This concentrate is used in the adsorption/desorption tank for the separation of toxic compounds and the recovery of polyphenols of interest. If the operation is pursued we have the reverse osmosis which leads to the production of pure water. The membrane characteristics of this operation are recorded in Table 1 and both Figures 1 and 2 present the installation of the pilot plant used in the membrane

ID Type of operation Material Pmax Tmax Pore size JX MF (microfiltration) PVDF 12 Tmax 300.00nm JW UF (ultrafiltration) PVDF 12 50°C n.d GM UF TFM 16 50°C 2.00 nm GK UF TFM 16 50°C 1.63 nm GH UF TFM 16 50°C 0.90 nm GE UF TFM 16 50°C 0.63nm DL NF(nanofiltration) TFM 32 50°C 0.65 nm DK NF TFM 32 50°C 0.50 nm AK RO (reverse osmosis) TFPS 70 50°C < 0.1 nm SG RO TFPP 70 50°C < 0.1 nm SC RO TFPP 70 50°C < 0.1 nm PVDF: difluorure de polyvinyl,TFC or TFM: thin-film composite membranes,TFPP: talc filled polypropylene

treatment.

84

Figure 1.

Schematic of the pilot plant used.

co-polymer,TFPS: thin-film polymer on silicon.

Characteristics of membrane modules used.

Table 1.

Sorption in 2020s

set at 20 1°C for all experiments [18, 19, 22]. The pretreatment processes aim to reduce TSS and organic matter by measuring the COD. The results obtained by the authors [18, 19, 22] are shown in Table 2 and are reported as a percentage of the reduction (Δ%). The adsorption step on polymeric resins is applied after the membrane treatment and obtaining the fraction of nanofiltration.
