**4.1 Wastewater assessment**

During the studying period, samples of winery wastewater were taken for laboratory characterization to evaluate their pollutant charge (Table 1). The values of pH ranged from 4 to 8, being this variation mostly dependent on the labor period. The electric conductivity of the wastewater showed no relevant variation in the different sampling periods and the range of registered values is not considered as inhibiting biomass growth.

The highest values of COD were reached during the vintage period, followed by the first racking. These results are in accordance to those previously reported by other authors (Petruccioli *et al.*, 2002). As expected, the highest values of biodegradability (BOD5/COD) were achieved during the vintage period, due to the high concentration of simple molecules, easily metabolized (sugars and ethanol) by microorganisms (Duarte *et al.*, 2004).

Concerning TS and TSS parameters, the results reveal a high variability during the vinification period. Moreover, the TS are significantly higher than TSS, which means that these wastewaters contain, mostly, dissolved organic pollutant charge. However, during 2nd racking the TSS concentration reach the maximum value derived from the presence of tartrate. These solids are often problematic due to the high phenolic load adsorbed.

Although polyphenols and anionic surfactants are important pollutants, it is not expected that they could influence the organic load, since they are present in low concentration. Nevertheless, after the wastewater treatment some compounds known as recalcitrant may remain in the treated effluent, such as the polyphenols that are responsible for colour and the residual COD, this can also be observed by the low biodegradability ratio presented in Figure 17.

Moreover, this type of wastewater has very low levels of nutrients that are essential to microbial growth. For this reason, it is often required the addition of nutrients to guarantee the process of cellular synthesis. Alternatively, it is possible to change some practices at the winery in order to balance this ratio (Oliveira & Duarte, 2010).

The assessment of the water consumption is another key parameter for the successful of the winery wastewater treatment. In one of the monitored wineries the water consumption was evaluated throughout the operation period for two consecutive years. Internal management strategies were implemented to increase efficient water use, such as cleaning methods that aim the water reuse (closed-loop) pressure washing machines, among others. These simple changes showed a saving in water consumption of about 40%.

### **4.2 AMBB treatment**

In this type of seasonal industry, the treatment system must be able to treat the wastewater produced in the vintage period. For this reason, many reactors have an appropriate volume for this stage but over dimensioned during the rest of the year. On the other hand, the high organic load of these wastewaters may promote the excessive growth of biomass, that requires an increase in the air supply (López-Palau *et al*., 2009) and creates problems of sludge generation and disposal.

The adopted strategy in this study is based on sludge reduction, as the production of excess sludge from the wastewater treatment plant is considered one of the serious problems encountered in the aerobic treatments (Liu & Tay, 2001). In this study, an aerobic step alternated with an anoxic one was adopted as a strategy.


Table 1. Physico-chemical characterization of winery wastewater

Winery Wastewater Treatment - Evaluation of the Air Micro-Bubble Bioreactor Performance 401

Fig. 17. Biodegradability indicators of the winery wastewater, in different labour periods

also as biofilm adsorbed to the reactor walls.

Fig. 18. Inoculation of the AMBB with fresh winery wastewater

The bioreactor AMBB was tested in different phases of the wine process and it started in the vintage period (Figure 18-19). The biomass inoculated in this assay was already acclimated to winery wastewater and was maintained in aerobic/anoxic conditions, with insufficient substract. During the AMBB operation the microorganisms grow as suspended biomass but

Table 1. Physico-chemical characterization of winery wastewater

Oxidized matter (m

TS (m

NH4+ (m

P (m

Na (m

M

g (m

Cu (m

Turbidit

SO4 2- (m

y Total Phenols (mg.L-1) 28

g.L-1) 191

Cl- (mg.L-1) 130

Anionic surfactants (m

gMBAS.L-1) 15

g.L-1)\* g.L-1) 6268

TSS (mg.L-1) 523

g.L-1) 0.73

Kjeldahl nitrogen (mg.L-1) 16

g.L-1) 12

g.L-1) 347

K (mg.L-1) 117

g.L-1) 12

Ca (mg.L-1) 39

g.L-1) 0.13

BOD5 (m

Vintage 1st Racking 2nd Racking Bottling pH 5.88

0.92 5.92

±

1.95 5.23

±

2.15 8.42

± ± ± ± ±

5988

± ± ± ± ± ± ± ± ± ± ±

209

± ± ± ± ±

13 7

±

8 4.2

±

3.0 2

62 185

±

129 113

±

56 nd

38 160

±

129 177

±

176 160

11 32

±

15 30

±

14 2

138 635

±

214 3628

±

4225 3.1

0.01 0.21

±

0.13 0.09

±

0.01 nd

15 27

±

31 18

±

5 nd

1 9.4

±

3.0 10

±

1 nd

8 71

±

72 264

±

34 nd

46 218

±

305 234

±

45 nd

8 27

±

22 93

±

82 1.1

8 26

±

19 135

±

71 3.5

0.68 4.5

±

190 866

±

199 3739

± 2.6 - nd

4654 185

4274 3034

±

248 8313

±

8725 2200

2448 4461

±

842 1640

±

1341 988

0.32 0.47

±

0.26 0.23

±

0.09 0.32

2900 3104

±

817 1395

±

1447 580

5310 8025

±

4220 5993

±

4444 1805

279 2036

±

618 3260

±

1666 1265

Conductivit

y (μS cm-1) 1714

COD (mg.L-1) 8942

g.L-1) 4107

BOD5/COD 0.66

Fig. 17. Biodegradability indicators of the winery wastewater, in different labour periods

The bioreactor AMBB was tested in different phases of the wine process and it started in the vintage period (Figure 18-19). The biomass inoculated in this assay was already acclimated to winery wastewater and was maintained in aerobic/anoxic conditions, with insufficient substract. During the AMBB operation the microorganisms grow as suspended biomass but also as biofilm adsorbed to the reactor walls.

Fig. 18. Inoculation of the AMBB with fresh winery wastewater

Winery Wastewater Treatment - Evaluation of the Air Micro-Bubble Bioreactor Performance 403

to the biomass exponential phase. The maximum efficiency obtained (98.6±0.4%) was achieved after 15 days of treatment. These results are comparable with those reported by Beltran de Herédia *et al*. (2005), where they achieve 75% of COD reduction, after 3 days of

In order to minimize the sludge production and the energetic costs during the recirculation of the mixed liquor, the aeration time was reduced. During this assay dissolved oxygen, pH,

Concerning the DO concentration the Figure 21 illustrate the dynamic change of this parameter in the AMBB. During the air supplying, the DO increases until it reaches saturation. The period of time required to reach saturation is directly related to the oxygen transfer rate. The estimation of OTR under different operational conditions has a relevant role to predict the metabolic pathway for microbial growth in aerobic treatments. So, this approach could be interesting for studying the influence of operational conditions on

A dynamic method was used to determine the volumetric mass transfer coefficient, kLa (Table 2). The kLa values were calculated by solving the Equation 2, during the aeration phase and considering that the gas flow and OUR were both constant. In these cases the slope of the *ln* f(DO) *vs* time allows the determination of the oxygen transfer parameter

0.00 5.00 10.00 15.00 20.00 25.00

Time (h)

The results show a decrease in the kLa value during the treatment period (Figure 23). Many factors could influence kLa, including air flow rate, air pressure, temperature, vessel geometry and fluid characteristics. All parameters were kept constant throughout the treatment, except the wastewater composition that varies during the treatment period. More readily biodegradable compounds such as sugars and ethanol are firstly assimilated by microorganisms; the more complex substrates are only degraded at a later stage. Previous

(Figure 22). The kLa values were corrected to 20 ° C, according to equation 6.

treatment.

COD and biomass was evaluated.

volumetric mass transfer coefficient.

0.0

1.0

2.0

3.0

DO (mgL-1)

4.0

5.0

6.0

7.0

Fig. 21. Evolution on pH and DO concentration in the AMBB

Fig. 19. AMBB in the beginning of the treatment

The evolution of COD concentration, biomass and dissolved oxygen was followed. Regarding the biomass evolution, a typical growth curve for batch cultivation was achieved (Figure 20). This curve does not show a lag phase, since biomass was already adapted. The recirculation of the mixed liquor was 20 min hour-1.

Fig. 20. Evolution on COD and biomass concentration in the AMBB

The COD of the winery wastewater ranged between 4.0-8.0 kg COD m-3 but the efficiency was similar for each batch, about 90.0±4.3%, after 6 days of operation. This period is related

The evolution of COD concentration, biomass and dissolved oxygen was followed. Regarding the biomass evolution, a typical growth curve for batch cultivation was achieved (Figure 20). This curve does not show a lag phase, since biomass was already adapted. The

The COD of the winery wastewater ranged between 4.0-8.0 kg COD m-3 but the efficiency was similar for each batch, about 90.0±4.3%, after 6 days of operation. This period is related

VSS (gm -3)

COD

Biomass

Fig. 19. AMBB in the beginning of the treatment

recirculation of the mixed liquor was 20 min hour-1.

COD (g.m-3)

Fig. 20. Evolution on COD and biomass concentration in the AMBB

0 5 10 15 20

Time (days)

to the biomass exponential phase. The maximum efficiency obtained (98.6±0.4%) was achieved after 15 days of treatment. These results are comparable with those reported by Beltran de Herédia *et al*. (2005), where they achieve 75% of COD reduction, after 3 days of treatment.

In order to minimize the sludge production and the energetic costs during the recirculation of the mixed liquor, the aeration time was reduced. During this assay dissolved oxygen, pH, COD and biomass was evaluated.

Concerning the DO concentration the Figure 21 illustrate the dynamic change of this parameter in the AMBB. During the air supplying, the DO increases until it reaches saturation. The period of time required to reach saturation is directly related to the oxygen transfer rate. The estimation of OTR under different operational conditions has a relevant role to predict the metabolic pathway for microbial growth in aerobic treatments. So, this approach could be interesting for studying the influence of operational conditions on volumetric mass transfer coefficient.

Fig. 21. Evolution on pH and DO concentration in the AMBB

A dynamic method was used to determine the volumetric mass transfer coefficient, kLa (Table 2). The kLa values were calculated by solving the Equation 2, during the aeration phase and considering that the gas flow and OUR were both constant. In these cases the slope of the *ln* f(DO) *vs* time allows the determination of the oxygen transfer parameter (Figure 22). The kLa values were corrected to 20 ° C, according to equation 6.

The results show a decrease in the kLa value during the treatment period (Figure 23). Many factors could influence kLa, including air flow rate, air pressure, temperature, vessel geometry and fluid characteristics. All parameters were kept constant throughout the treatment, except the wastewater composition that varies during the treatment period. More readily biodegradable compounds such as sugars and ethanol are firstly assimilated by microorganisms; the more complex substrates are only degraded at a later stage. Previous

Winery Wastewater Treatment - Evaluation of the Air Micro-Bubble Bioreactor Performance 405

trials it was found that the size of the bubble formed, increased throughout the treatment period, which is in agreement with the obtained results. Moreover, it is interesting to observe that the kLa decline follows the degradation kinetics of organic matter, expressed as COD, which corroborate the obtained results. The kLa values obtained in these assays are in the same range that of values achieved by other authors in full-scale aeration tank equipped with fine bubble diffusers and jet loop reactor (Fakeeha *et al.,* 1999; Fayolle *et al*., 2010). In addition, the respirometric activity of microorganisms which are actively growing in the bioreactor can also be measured based on this dynamic method. When the gas supply to the bioreactor is turned off, the DO concentration decreases at a rate equal to oxygen consumption by the respiration process. In this situation the OUR can be calculated from the

Fig. 24. Trendlines adjustment on DO concentration depletion to determine OUR in the

0.0 5.0 10.0

The specific oxygen uptake rate (SOUR) or respiration rate is expressed as milligrams of oxygen consumed per gram of volatile suspended solids per hour. The high SOUR values obtained (Table 2), indicate a high organic load to the existing suspended solids in the

Time (h

)

15

.0 20.0

The SOUR measurements throughout the wastewater treatment showed an initial increase in the SOUR values until reaching a plateau. The Figure 25 shows that after an adaptation period to the treatment system there is a removal of the organic load, expressed as COD rate corresponding to the increment of SOUR rate. This high SOUR rate is due to the high activity of the microbial population to oxidise substrates. These values may be induced by an increased energy requirement stimulated by a famine period, during sludge acclimatisation. The feast/famine phenomenon has been reported by several authors as a strategy on sludge production (Chen *et al*., 2001; Ramakrishna & Viraraghavan, 2005; López-Palau *et al.,* 2009). A similar behaviour was found by Chen *et al*. (2001) during the study of

slope of the DO *vs* time (Figure 24).

AMBB

mixed liquor (MLSS).

0

0.0

1

1.0

2

2.0

3

3.0

DO (mgL-1)

4

4.0

5

5.0

6

6.0

7

7.0

studies indicate that the composition of the fermentation broth influences the oxygen mass transfer, such as glucose that can decrease the kLa, by increasing the viscosity of the medium but on the other surfactants increases this value (Fakeeha *et al.,* 1999). In fact, is practically impossible to determine the exact composition of wastewater, but the compounds mentioned above are always present in this type of wastewater. This decrease in kLa value means that some of the existing compounds in wastewater optimize the oxygen mass transfer during the initial phase of treatment. Indeed, even without being quantified, in all

Fig. 22. Experimental determination of kLa based on DO concentration in the AMBB

Fig. 23. kLa and COD dynamics during wastewater treatment in the AMBB

studies indicate that the composition of the fermentation broth influences the oxygen mass transfer, such as glucose that can decrease the kLa, by increasing the viscosity of the medium but on the other surfactants increases this value (Fakeeha *et al.,* 1999). In fact, is practically impossible to determine the exact composition of wastewater, but the compounds mentioned above are always present in this type of wastewater. This decrease in kLa value means that some of the existing compounds in wastewater optimize the oxygen mass transfer during the initial phase of treatment. Indeed, even without being quantified, in all

Fig. 22. Experimental determination of kLa based on DO concentration in the AMBB

0 20 40 60 80 100 120

Time (s)

0

0.

000

005

010

015

020

025

0.

0.

kLa (s-1)

0.

0.

0.

0.2

0.4

0.6

ln(1-DO/DOsat)

0.8

1

1.2

Fig. 23. kLa and COD dynamics during wastewater treatment in the AMBB

Time (h)

00

0

150

1000

2000

COD (mgL-1)

kLa

COD

3000

4000

5000

0 50 1

trials it was found that the size of the bubble formed, increased throughout the treatment period, which is in agreement with the obtained results. Moreover, it is interesting to observe that the kLa decline follows the degradation kinetics of organic matter, expressed as COD, which corroborate the obtained results. The kLa values obtained in these assays are in the same range that of values achieved by other authors in full-scale aeration tank equipped with fine bubble diffusers and jet loop reactor (Fakeeha *et al.,* 1999; Fayolle *et al*., 2010). In addition, the respirometric activity of microorganisms which are actively growing in the bioreactor can also be measured based on this dynamic method. When the gas supply to the bioreactor is turned off, the DO concentration decreases at a rate equal to oxygen consumption by the respiration process. In this situation the OUR can be calculated from the slope of the DO *vs* time (Figure 24).

Fig. 24. Trendlines adjustment on DO concentration depletion to determine OUR in the AMBB

The specific oxygen uptake rate (SOUR) or respiration rate is expressed as milligrams of oxygen consumed per gram of volatile suspended solids per hour. The high SOUR values obtained (Table 2), indicate a high organic load to the existing suspended solids in the mixed liquor (MLSS).

The SOUR measurements throughout the wastewater treatment showed an initial increase in the SOUR values until reaching a plateau. The Figure 25 shows that after an adaptation period to the treatment system there is a removal of the organic load, expressed as COD rate corresponding to the increment of SOUR rate. This high SOUR rate is due to the high activity of the microbial population to oxidise substrates. These values may be induced by an increased energy requirement stimulated by a famine period, during sludge acclimatisation. The feast/famine phenomenon has been reported by several authors as a strategy on sludge production (Chen *et al*., 2001; Ramakrishna & Viraraghavan, 2005; López-Palau *et al.,* 2009). A similar behaviour was found by Chen *et al*. (2001) during the study of

Winery Wastewater Treatment - Evaluation of the Air Micro-Bubble Bioreactor Performance 407

after a famine period the microorganisms are starved and the substrate utilization rate increases. A treatment system based on this management model seems to be a good approach for winery wastewaters, with the additional advantage of keeping the low amount of sludge. The cause of sludge reduction in this process is not clearly known but the absence of oxygen reduces the growth of strictly aerobic populations and stimulates the facultative bacteria (unpublished results), which have lower specific growth rates. In this sense, as the dominant population is constituted of slow growers that may explain the low sludge yield production. Furthermore, the produced sludge shows low SVI values indicative of easy

The strategy based on low aeration time alternating with anoxic periods allows the treatment of the winery wastewater with lower sludge production but with lower efficiency. In fact, the MLSS achieved in this batch treatment, 1.2 g/L was lower compared with the initial assay. In the management of a wastewater treatment of this nature is necessary to establish a compromise between operating costs and final quality of the treated wastewater,

taking into account the final destination and the legal requirements.

Fig. 25. Evolution of SOUR and COD rates during the batch treatment

In order to evaluate its suitability to be used in crop irrigation the treated wastewater from the AMBB batch assays was physico-chemical characterized. All the analyzed parameters except one were in agreement with EU and Portuguese Legislation (Directive 2000/60/EC, DL n° 236/98) for irrigation use (Table 3). Of particular concern was the sodium adsorption ratio (SAR), the proportion of sodium to calcium and magnesium, which was higher than the permitted parametric value. Probably, some strategies can be applied in winery in order to reduce the problem. Nevertheless, the treated wastewater, normally, is used in irrigation systems to supplement the irrigation water, as an economic additional water supply. Also,

0 20 40 60 80 100 120 140

Time (h)

0.0

0.2

0.4

0.6

COD/COD0

0.8

1.0

1.2

sludge settling.

0.0

SOUR/SOUR0 COD/COD0

0.5

1.0

1.5

SOUR/SOUR0

2.0

2.5


feast/famine growth on activated sludge cultures previously subjected to a famine treatment. This study also indicates that the COD removal ability of the fasted culture is higher than the non-fasted culture.

Table 2. Evolution of the mass transfer parameters OUR, SOUR and kLa values, throughout the treatment

In winery wastewater treatments systems the period prior to vintage is a non-productive period, without wastewater generation. In this sense, the existing biomass in the treatment system is subjected to a famine treatment. Moreover, during harvest the wastewater production has the highest flow rates and organic loadings. According to Chen *et al*., 2001 after a famine period the microorganisms are starved and the substrate utilization rate increases. A treatment system based on this management model seems to be a good approach for winery wastewaters, with the additional advantage of keeping the low amount of sludge. The cause of sludge reduction in this process is not clearly known but the absence of oxygen reduces the growth of strictly aerobic populations and stimulates the facultative bacteria (unpublished results), which have lower specific growth rates. In this sense, as the dominant population is constituted of slow growers that may explain the low sludge yield production. Furthermore, the produced sludge shows low SVI values indicative of easy sludge settling.

The strategy based on low aeration time alternating with anoxic periods allows the treatment of the winery wastewater with lower sludge production but with lower efficiency. In fact, the MLSS achieved in this batch treatment, 1.2 g/L was lower compared with the initial assay. In the management of a wastewater treatment of this nature is necessary to establish a compromise between operating costs and final quality of the treated wastewater, taking into account the final destination and the legal requirements.

COD/COD0

406 Mass Transfer - Advanced Aspects

feast/famine growth on activated sludge cultures previously subjected to a famine treatment. This study also indicates that the COD removal ability of the fasted culture is

> **SOUR (mg O2 (g MLSS. h)-1)**

**kLa.103 (20ºC) (s-1)** 

 **(mg O2 (L.h)-1)** 

 16.6 19.5 11.7 19.8 23.3 19.0 19.5 22.9 14.3 17.6 20.7 20.0 Initial values 20.5 24.1 22.6 20.2 23.8 13.0 18.9 22.2 13.0 19.5 22.9 15.6 19.6 23.1 26.0 21.4 25.2 19.9 20.4 24.0 19.9 Maximum values 28.9 34.0 17.3 32.8 38.6 19.9 32.6 38.4 18.2 31.8 37.4 16.5 29.5 34.7 11.3 32.8 37.4 11.3 14.2 25.1 11.5 21.4 17.9 10.7 Final values 15.2 23.4 8.9 19.9 18.0 8.8 15.3 17.4 8.5 14.8 18.6 8.9 15.8 12.4 9.1 10.5 14.1 5.9 12.0 13.4 7.7 11.4 16.7 6.2

Table 2. Evolution of the mass transfer parameters OUR, SOUR and kLa values, throughout

In winery wastewater treatments systems the period prior to vintage is a non-productive period, without wastewater generation. In this sense, the existing biomass in the treatment system is subjected to a famine treatment. Moreover, during harvest the wastewater production has the highest flow rates and organic loadings. According to Chen *et al*., 2001

higher than the non-fasted culture.

the treatment

 **OUR** 

In order to evaluate its suitability to be used in crop irrigation the treated wastewater from the AMBB batch assays was physico-chemical characterized. All the analyzed parameters except one were in agreement with EU and Portuguese Legislation (Directive 2000/60/EC, DL n° 236/98) for irrigation use (Table 3). Of particular concern was the sodium adsorption ratio (SAR), the proportion of sodium to calcium and magnesium, which was higher than the permitted parametric value. Probably, some strategies can be applied in winery in order to reduce the problem. Nevertheless, the treated wastewater, normally, is used in irrigation systems to supplement the irrigation water, as an economic additional water supply. Also,

Winery Wastewater Treatment - Evaluation of the Air Micro-Bubble Bioreactor Performance 409

stages of treatment might improve the performance of this technology because it allows higher flexibility. The result of feast / famine treatment in sludge should also be exploited,

Moreover, the treated wastewater revealed its suitability to be integrated in the irrigation systems as confirmed by direct toxicity bioassays. This study is expected to contribute to the implementation of an efficient wastewater treatment, intending the preservation of the water resource, the reduction of the wastewater sludge production and the energy safe.

Fundação para a Ciência e a Tecnologia (FCT) – PhD grant SFRH/BD/31653/2006, by finantial support and Quinta da Casaboa, Catapereiro and Herdade da Mingorra where the

Andreottola, G., Foladori P., Ragazzi, M. & Villa, R. (2002). Treatment of winery wastewater

Andreottola, G., Foladori P. & Ziglio, G. (2009). Biological treatment of winery wastewater:

A.P.H.A., A.W.W.A., W.E.F. (1998) *Standard methods for the examination of water and* 

Arienzo, M., Christen, E.W., Quayle, W (2009a). Phytotoxicity testing of winery wastewater

Arienzo, M., Christen, E.W., Quayle, W, Di Stefano, N. (2009b) Development of a Low-Cost

Artiga,P.,Ficara,E.,Malpei,F.,Garrido,J.M. & Méndez,R.,2005. Treatment of two industrial

Beltran de Herédia J., Torregrosa J., Dominguez J.R. and Partido E. (2005). Degradation of

Bolzonella, D. & Rosso, D. (2007). Winery wastewater characterisation and biological

Chen, G., Yip, W., Mo, H., Liu, Y. (2001). Effect of sludge fasting/feasting on growth of

*Research*, Vol. 81, No. 3, pp. 233-241, ISSN 1061-4303.

in sequencing batch bofilm reactor. *Water Science and Technology* Vol. 45, No.12, pp.

an overview. *Water Science and Technology* Vol. 60, No.5, pp. 1117–1125, ISSN 0273-

for constructed wetland treatment. *Journal of Hazardous Materials*, Vol. 169, No. 1,

Wastewater Treatment System for Small-Scale Wineries. *Water Environment* 

wastewaters in a submerged membrane bioreactor. *Desalination*, Vol. 179, pp. 161-

wine distillery wastewaters by the combination of aerobic biological treatment with chemical by Fenton's reagent. *Water Science and Technology*, Vol. 51, No. 1, pp. 167-

treatment options. *Water Science and Technology*, Vol. 56, No. 2, pp. 79–87, ISSN

activated sludge cultures. *Water Research*. Vol. 35, No. 4, pp.1029-1037, ISSN: 0043-

as it is of interest in this type of seasonal industries.

**6. Acknowledgment** 

studies were conducted.

1223.

347–354, ISSN 0273-1223.

*wastewater*, 20ª Ed., USA.

pp. 94-99, ISSN 0304-3894.

169, ISSN 0011-9164.

174, ISSN 0273-1223.

0273-1223.

1354.

**7. References** 

seed germination assays carried out with *Lepidium sativum* were developed for evaluating the effects of water contaminants on germination and seedling growth. The adequacy of the treated wastewater for crop irrigation was evaluated with direct toxicity bioassays, by using cress seeds as indicator No significant differences (*P*=0.05) between batch experiments were registered on germination index (GI). As the cress bioassay is a standard procedure to evaluate the behaviour of crops to water contaminants, data (previously published) evidence the suitability of treated wastewater in relation to crop irrigation, thus minimizing water consumption (Oliveira *et al.,* 2009).


Table 3. Physical and chemical characterization of the treated wastewater and standard parameter
