Conditioning of sewage sludge by prickly pear cactus (Opuntia ficus Indica) juice

Ecological Engineering 70 (2014) 465–469

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Conditioning of sewage sludge by prickly pear cactus (Opuntia ficus Indica) juice H. Betatache a , A. Aouabed a , N. Drouiche b,c,∗ , H. Lounici c,d a

Laboratoire d’Analyses Fonctionnelles des procédés chimiques, Université Saad Dahlab de Blida, Algeria Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE), 2, Bd Dr. Frantz Fanon P.O Box 140, 7 merveilles, Alger, 16038, Algeria c URIE, Ecole Nationale Polytechnique, B.P. 182-16200, El Harrach, Algiers, Algeria d Université Bouira, Pole technologique 10000, Bouira-Algeria b

a r t i c l e

i n f o

Article history: Received 7 April 2014 Received in revised form 4 May 2014 Accepted 23 June 2014 Available online 17 July 2014 Keywords: Coagulation Filtration Opuntia ficus Indica Sludge Conditioning Characterization

a b s t r a c t The possibility of using a plant material, prickly pear cactus, Opuntia ficus Indica, juice (OFIJ), for conditioning the Beni-messous wastewater treatment plant sludge was examined. Optimum dosage of OFIJ was found to be 0.4 g kg−1 of dry matter. The residual turbidity, the dryness of filtration cake and the specific resistance of filtration were found to be 2.5 NTU, 24% and 0.13 × 1012 m kg−1 respectively. The results obtained with OFIJ were compared to those obtained with polyelectrolytes: Chimfloc C4346, a cationic polymer, Sedipur NF 102, a non-ionic polymer and Sedipu AF 400, an anionic polymer, and inorganic conditioners, FeCl3 and Al2 (SO4 )3 . The optimum dosages of those conditioners were found to be 0.4 g kg−1 for OFIJ, 0.8 g kg−1 for Chimfloc C4346, 80 g kg−1 for FeCl3 and 60 g kg−1 for Al2 (SO4 )3 . © 2014 Elsevier B.V. All rights reserved.

1. Introduction The treatment of wastewaters during these last years became a considerable challenge for the current societies. This activity develops another problem: the management of the sewage sludge. The sludge ripped off from clarifiers sustains two successive operations of concentration: the thickening and dehydration. As it stands, the sludge can be hardly concentrated and must be conditioned to improve its treatment. The conditioning of the sludge is usually done with mineral salts, synthetic polymers or with the combination of the two. However, despite their proven effectiveness (Akhtar et al., 2004; Qi et al., 2011), the chemical conditioning has some disadvantages for human health and the ecosystems (Lu, 2002; Bolto and Gregory, 2007) to solve this problem, these last few years another kind of natural reagent have view the day, they have the advantage of

∗ Corresponding author at: Technology of Semi-conductor for the Energetic Research Center, Department of Environmental Engineering, 2, Bd Frantz Fanon BP140 Alger-7-merveilles, Algiers, Algeria. Tel.: +213 21 279880x192; fax: +213 21 433511. E-mail addresses: [email protected], [email protected] (N. Drouiche). http://dx.doi.org/10.1016/j.ecoleng.2014.06.031 0925-8574/© 2014 Elsevier B.V. All rights reserved.

being biodegradable and without risk to public health. In the literature a number of coagulant–flocculants of vegetable, animal or micro-organism sources used in the treatment of natural and waste waters exist. Among these natural coagulants, the Moringa oleifera certainly is the most studied by the scientific community since these coagulant properties have been recognized (Yin, 2010). Since 1999, the coagulation ability of the cactus is highlighted (Diaz et al., 1999), and the different species of Opuntia, reserved to Habit in human food, fodder, medicine and cosmetics (Saenz et al., 2004; Miller et al., 2008) have aroused the interest of researchers in the field of the water treatments. Jing Dong Zhang et al. (Zhang et al., 2006) have seen the turbidity of the water decreased from 104 NTU to less than 5 NTU using powder of Opuntia ficus Indica. Abid et al. (Abid et al., 2009) have used the juice of cactus of this same species to eliminate heavy metals in industrial effluents, and the rate of reduction of chromium (VI) has exceeded 99.5% while the turbidity has decreased from 100 NTU to 2 NTU. Barka et al. (2013) have used the cladodes of the cactus Opuntia ficus Indica as biosorbant to eliminate the methylene blue from the waters. The chitosan and the xanthan are the only animal materials studied for the water treatments (Kadouche et al., 2012a, 2012b; Zemmouri et al., 2012). The cactus Opuntia ficus Indica is native of South America, but it is also found in the arid and semi-arid regions in Africa and Australia as well as in the south of Europe and Asia. The family of

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H. Betatache et al. / Ecological Engineering 70 (2014) 465–469

Fig. 1. FTIR spectra of dried Opuntia ficus Indica’s juice.

cactaces is known for its production of the mucilage. The mucilage is composed mainly of acid galacturonic and different quantities of l-arabinose, d-galactose, l-rhamnose, and d-xylose (Trachtenberg and Mayer, 1980) in addition to the dietary fiber and other mineral elements such as the Ca2+ and K+ whose presence is necessary for the gelatinous properties of mucilage (Sepulveda et al., 2007). The extraction of the mucilage of cactus is done by mixture of water and different organic solvents such as ethanol, acetone, and methanol. In this work, the juice of cactus Opuntia ficus Indica, widely available on the Algerian territory, has been extracted, characterized and then used in the conditioning of sludge. Its coagulant performances were compared to those of cationic, anionic and non-ionic polymers, aluminum sulfate and ferric chloride. The sludge conditioning was followed by dehydration and the following parameters: the specific resistance to filtration (RSF), the turbidity and the dryness were studied during a vacuum filtration.

transported immediately to the laboratory to be used for extraction of juice. The sludge was also conditioned with three synthetic polymers, Chimfloc C4346, Sedipur NF 102 and Sedipur AF 400 (cationic, noionic and anionic), from Cosme Company. 2.2. Coagulants preparation The OFI’s cladodes collected were repeatedly washed with distilled water to remove dirt particles, cut into small pieces and then blended in domestic blender. The crushed cladodes were sieved then in order to obtain the juice which is a green viscous liquid; the amount of juice was dried at 60 ◦ C for 3 days, and the dried powder was stored in a glass bottle for further use and analysis. The rest of the juice was diluted in deionized water to a concentration of 10%. 0.6% (6 g l−1 ) solutions of synthetic polymers and inorganic chemicals were prepared a day before conducting the experiments.

2. Materials and methods 2.3. Chemical analysis of OFIJ 2.1. Coagulants The Opunitia ficus indica used in this study was from Boufarik in the north of Algeria, and the cladodes were picked in March and

Various tests were performed on OFIJ in order to determine its general composition and its potential use as a natural clotting in sludge conditioning.

Table 1 Characteristics of investigated sewage sludge.

Table 2 Characteristics of OFIJ.

Parameter

Unit

Average value

Parameter

pH Conductivity Temperature Turbidity Dry solids Dryness Organic matter Mineral matter SRF

– ms/cm

7.16 3.6 15 30 45.46 4.62 53.01 46.98 1.03 × 1013

pH pHzpc Viscosity Dry matter Organic matter Mineral matter Carbohydrates Galacturonique acid P

◦

C NTU g l−1 % % m kg−1

Unit

Average value

Pa s g l−1 % % g l−1 g l−1 g l−1

4.76 4 0.029 28.6 98.7 1.3 4.109 11.076 0.013

H. Betatache et al. / Ecological Engineering 70 (2014) 465–469

chimfloc C4346

35

sedipurNF400

sedipurAF102

a 23

chimfloc C4346

sedipuAF400

sedipurNF102

22

30

21

25

19

20

Dryness (%)

Residual turbidity (NTU)

a

467

20 15 10

18 17 16 15 14 13 12 11

5

10

0

0

5

10

15

20

25

9

30

0

-1

5

10

Polymers doses (g.Kg )

b 35

15

20

25

30

-1

Polymers doses (g.Kg )

Al2(SO4)3

FeCl3

b

26 24

25

Dryness (%)

Residual turbidity (NTU)

30

20 15

22 20 18

10

16

5

14

0

12

0

20

40

60

80

100

0

40

60

80

100 -1

Chemical conditioners doses (g.Kg )

c c

20

Chemical conditioners doses (g.Kg )

-1

26 24

30

Dryness (%)

Residual turbidity (NTU)

22

25 20 15 10

20 18 16 14 12 10

5

8

0

0,0

0,5

1,0

1,5

2,0

2,5

3,0

0,0

0,5

1,0

1,5

2,0

2,5

3,0

-1

OFIJ doses (g.Kg )

-1

OFIJ doses (g.Kg ) Fig. 2. Effect of various doses of (a) polymers, (b) FeCl3 and Al2 (SO4 )3 , and (c) OFIJ on filtrate turbidity.

FTIR spectral analysis was recorded in IRAffinity-1 spectrometer in the region of 400–4000 cm−1 . The samples were prepared with the powder of OFIJ and KBr under high pressure. Dry, organic and mineral matters were determined by standard methods. Photometric methods were used to determine the content of phosphor. The percentage of protein was obtained using the factor 6.25 with nitrogen content. Total sugars were

Fig. 3. Effect of various doses of (a) polymers and (b) FeCl3 and Al2 (SO4 )3 , (c) OFIJ on dryness.

determined by Dubois method (1956) using d-glucose as standard (Dubois et al., 1956). The content of galacturonic acid was determined by Blumenkrantz and Asboe-Hansen method (1973), using d-galacturonic acid as standard (Blumenkrantz and Asboe-Hansen, 1973). pH and conductivity were measured with Hanna multiparameters.

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a 22 20 18

12

-1

SRF.10 (m.kg )

16 14 12 10 8 6 4 2 0 0

5

10

15

20

25

30

-1

Polymers doses (g.Kg )

b 12

(DS), organic matter (OM), mineral matter (MM) and dryness (S) were determined as reported by Standard Methods (Rodier et al., 2009). pH, conductivity and temperature were measured directly on sludge, and turbidity was measured on filtrate after dewatering process. The sludge collected from the WWTP was passed through a 4.25 mm sieve to remove any gross-sized particles. 500 ml sample of the sludge was poured into a 1000 ml beaker, and the required dosages of conditioners were added. The sludge and conditioner were rapidly mixed using the Jar-test apparatus (Stuart Floculator SW6) at 120 rpm for 20 s, followed by gentle flocculation at 40 rpm for 2 min. To assess coagulation–flocculation effectiveness, a vacuum filtration was conducted on conditioned sludge at the negative pressure of 0.06 MPa, the measurement set consisting of 7 cm diameter Buchner funnel, membrane of 8 ␮m pore size, vacuum pump, and graduated measuring cylinder where the filtrate is collected. The parameters assessed after the dewatering process were specific resistance of filtration (SRF), dryness of filtration cake and turbidity of the filtrate. 3. Results and discussion

10

3.1. Characterization of OFI’s juice -1

SRF (m.Kg )

8

6

4

2

0

0

20

40

60

80

100 -1

Chemical conditioners doses (g.Kg )

c

12

3.2. FTIR analysis 10 8

-1

SRF (m.Kg )

Results of the preliminary analyses are presented in Table 2, and data presented in this table are average of three analyses. From Table 2, we notice that the majority composition of OFIJ is the organic matter. The principal groups of the above constituents are proteins, carbohydrates, lipids, lignins and uronic acids. In this study, we have found that the juice contents are 4.109 g l−1 sugars and 11.076 g l−1 galacturonic acid. The remaining part, 1.3% of mineral matter, consists of mineral elements such as phosphorus 0.013 g l−1 . The zero point charge (pHzpc ) of the natural coagulant was found to be at pH of 4.3. The pHzpc of the biomaterial is one way to understand the coagulation flocculation mechanism. When the pH of the juice is lower than 4.3, the surface of the dried juice of cactus gets positively charged, and the surface of the dried juice of cactus is negatively charged in pH values higher than 4.3.

6 4 2 0 0,0

0,5

1,0

1,5

2,0

2,5

3,0

-1

OFIJ doses (g.Kg ) Fig. 4. Effect of various doses of (a) polymers and (b) FeCl3 and Al2 (SO4 )3 , (c) OFIJ on SRF.

The FT-IR spectra of dried OFIJ in the range 400–4000 cm−1 were taken to obtain information on the nature of functional groups at the surface of the natural coagulant. The spectra presented in Fig. 1 show broad, strong and superimposed bands around 3600–3200 cm−1 which may be due to the over-lapping of O H and N H stretching vibration. The peak at 1714.95 cm−1 is due to of stretching vibration of C O of carboxyl groups. The peak observed at 1574.27 cm−1 is due to the NH deformation of amines. The stretching vibration band at 1387.57 cm−1 is due to the asymmetric stretching of the carboxylic COO double bond of deprotonated carboxylate functional groups (Barka et al., 2013). The absorption peaks around 1231.21 and 1080.74 cm−1 are indicative of P O and P OH stretching vibrations. The peak at 840.1 cm−1 is attributed to S O stretching vibration. Peaks in the region of wavenumbers lower than 700 cm−1 could be attributed to the halogenated stretching. 3.3. Sludge characterization

2.4. Sludge simple and conditioning The stabilized sludge was sampled from Beni-Messous wastewater treatment plant (WWTP); the site is 15 km on the West of Algiers. The samples were stored in obscurity at 4 ◦ C. The general characteristics of the sludge are summarized in Table 1. Dry solids

3.3.1. Turbidity Fig. 2 shows the results concerning the effect the dose of chimfloc C4346, sedipur AF102 and sedipur NF400 (ranged from 2 to 30 g kg−1 of dry matter), FeCl3 and Al2 (SO4 )3 (ranged from 10 to 100 g kg−1 ) and OFIJ (ranged from 0.2 to 2.8 g kg−1 of dry matter)

H. Betatache et al. / Ecological Engineering 70 (2014) 465–469

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on turbidity of filtrate after vacuum filtration. From Fig. 1(a) it could be seen that an increase in chimfloc C4346 and sedipur NF400 concentration results to a decreased turbidity. The better final turbidity occurred when the doses of the two polymers was 8 g kg−1 and 4 g kg−1 respectively for a residual turbidity reaching respectively 1.5 and 3.6 NTU. Above this dosage, the suspensions showed a tendency to re-stabilize. The increasing doses of sedipur AF400 caused an increasing of turbidity. Fig. 2(b) shows that the better turbidity removal occurred when the dose of aluminum sulfate and ferric chloride are respectively 80 and 60 g kg−1 for a residual turbidity reaching 2.2 and 2.5 NTU. Fig. 2(c) shows the efficiency of turbidity removal by the increasing concentration of OFIJ, the turbidity decreased strongly at the first add of bio-coagulant followed by a stationary state a lowest final turbidity was recorded with 2.5 NTU for all OFIJ doses applied.

by the treatment of urban water. The characterization of OFIJ has shown that it is an organic matter. This study was conducted to determine the OFIJ’s ability as natural flocculant for sewage sludge of WWTP. The experiments show that the juice of cactus has promoted the coagulation flocculation of almost all of the sludge causing separation liquid/solid easy to using a filtration process without observing the formation of big flocs. The residual turbidity, the SRF and the dryness obtained are the same of those obtained using chimfloc C4346 and better than those obtained with sedipur NF102 sedipur AF400 and inorganic chemicals, but the bio-material has shown efficiency with more small amount the others conditioners, the optimum dosage of OFIJ was 0.4 g kg−1 of dry matter. Relying on the previous results, the OFIJ could be used as a natural conditioner in sewage sludge treatment.

3.3.2. Dryness Fig. 3 shows the variation of dryness of cake formed during the vacuum filtration; it could be seen that an increase in conditioners dosages caused the increase in dryness of the filtration cake except the anionic polymer sedipur AF400, it caused the decrease of dryness. Further for the concentration of 19 g kg−1 of dry matter, the dryness increased. The conditioning with OFIJ greatly increases the dryness of the sludge, it reached a maximum of 24% for a dose of 0.8 g kg−1 of OFIJ, from a dose of 1.6 g kg−1 of plant material, the dryness begins to decrease and the cakes obtained are more moist and have a viscous appearance; this is due to the increase of OFIJ’s content which is itself a viscous material. Results of dryness closely mirror the decrease in residual turbidity. Cationic, non-ionic polymers, inorganic chemicals and OFIJ occurred in the formation of flocs and elimination of particles which will be restrained during the filtration process in the cake.

References

3.3.3. Specific resistance of filtration (SRF) The specific resistance of filtration is an important parameter to evaluate the efficiency of conditioner during the filtration process. The relationship between conditioners dosage and the SRF is shown in Fig. 4. It could be seen from Fig. 4(a) that the chimfloc C4346 effect on SRF was better than that of sedipur NF102, and the lowest SRF values reached for the two conditioners are 0.3 × 1012 and 4 × 1012 m kg−1 respectively for a concentration of 6 g kg−1 . From Fig. 4(b) the SRF value of 1.3 × 1012 m kg−1 for aluminum sulfate and ferric chloride dosages of 40 and 80 g kg−1 respectively could be noted. The best reduction of SRF was assigned to the plant material, and it reached the value of 0.17 × 1012 m kg−1 for a concentration of 0.4 g kg−1 (Fig. 4(c)). Addition of coagulants causes the release of bound water to colloids; therefore more the concentration of coagulants increased more the cake obtained after filtration will be dry, consisting, porous and less resistant to the filtration. However the anionic polymer sedipur AF400 caused an increase of the RSF due to the formation of a viscous layer on the filter. 4. Conclusion The physico-chemical characterization of the fresh sludge of WWTP has shown that it is of organic nature because it is generated

Abid, A., Zouhri, A., Ider, A., Kholtei, S., 2009. Valorisation d’un nouveau bio-floculant (extrait de cactus) dans le traitement physico-chimique des rejets liquides chargés en cuivre, en zinc et en matiére en suspension. Rev. Energies Renouvelables 12, 321–330. Akhtar, N., Iqbal, J., Iqbal, M., 2004. Removal and recovery of nickel(II) from aqueous solution by loofa sponge-immobilized biomass of Chlorella sorokiniana: characterization studies. J. Hazard. Mater. B 108, 85–94. Barka, N., Ouzaouit, K., Abdennouri, M., 2013. Dried prickly pear cactus (Opuntia ficus indica) cladodes as a low-cost and eco-friendly biosorbent for dyes removal from aqueous solutions. J. Taiwan Inst. Chem. Engineers 44, 52–60. Blumenkrantz, N., Asboe-Hansen, G., 1973. New method for quantitative determination of uronic acids. Anal. Biochem. 54, 481–489. Bolto, B., Gregory, J., 2007. Organic polyelectrolytes in water treatment. Water Res. 24, 2301–2324. Diaz, A., Rincon, N., Escorihuela, A., Fernandez, N., Chacin, E., Forster, C.F., 1999. A preliminary evaluation of turbidity removal by natural coagulants indigenous to Venezuela. Process Biochem. 35, 391–395. Dubois, M., Gilles, K.A., Hamilton, J.K., Rebers, P.A., Smith, F., 1956. Colorimetric method for determination of sugars and related substances. Anal. Chem. 28, 350–356. Kadouche, S., Lounici, H., Benaoumeur, K., Drouiche, N., Hadioui, M., Sharrock, P., 2012a. Enhancement of sedimentation velocity of heavy metals loaded hydroxyapatite using chitosan extracted from shrimp waste. J. Polym. Environ. 20, 848–857. Kadouche, S., Zemmouri, H., Benaoumeur, K., Drouiche, N., Sharrock, P., Lounici, H., 2012b. Metal ion binding on hydroxyapatite (Hap) and study of the velocity of sedimentation. Procedia Eng. 33, 377–384. Lu, Z., 2002. Medicament of Water Treatment. Publishing Company of Chemical Industry, Beijing, pp. 100–102. Miller, S.M., Fugate, E.J., Craver, V.O., Smith, J.A., Zimmerman, J.B., 2008. Toward understanding the efficacy and mechanism of Opuntia spp. as a natural coagulant for potential application in water treatment. Environ. Sci. Technol. 42, 4274–4279. Qi, L., Cheng, R., Wang, H.C., Zheng, X., Zhang, G.M., Li, G.B., 2011. Recycle of alum sludge with PAC (RASP) for drinking water treatment. Desal. Water Treat. 25, 170–175. Rodier J., Legube B., Merlet N., 2009. Analyse de l’eau, 9th ed, Dunod. Saenz, C., Sepulveda, E., Matsuhiro, B., 2004. Opuntia spp. mucilage’s: a functional component with industrial perspectives. J. Arid Environ. 57, 275–290. Sepulveda, E., Saenz, C., Aliaga, E., Aceituno, C., 2007. Extraction and characterization of mucilage in Opuntia spp. J. Arid Environ. 68, 534–545. Trachtenberg, S., Mayer, A., 1980. Biophysical properties of Opuntia ficus indica mucilage. Phytochem. 21, 2835–2843. Yin, C.-Y., 2010. Emerging usage of plant-based coagulants for water and wastewater treatment. Process Biochem. 45, 1437–1444. Zemmouri, H., Drouiche, M., Sayeh, A., Lounici, H., Mameri, N., 2012. Coagulation flocculation test of Keddara’s water dam using chitosan and sulphate aluminum. Procedia Eng. 33, 254–260. Zhang, J., Zhang, F., Luo, Y., Yang, H., 2006. A preliminary study on cactus as coagulant in water treatment. Process Biochem. 41, 730–733.