Tunisian Landfill leachate treatment by anaerobic membrane bioreactor by mcb12915

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									   Tunisian Landfill leachate treatment
   by anaerobic membrane bioreactor


            ,
  Amal Zayen, Fathi Aloui, Firas Fki, Slim Loukil, Mohamed
          Bouaziz, Sami Mnif and Sami Sayadi*

             Bioprocesses Laboratory, Biotechnology Centre of Sfax
                         BP: 1117, 3018, Sfax, Tunisia,
                        E-mail: sami.sayadi@cbs.rnrt.tn
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             Presentation outline
     Introduction
     Landfill leachate characterization
     Objective
     Methanisation performance
     Biomass growth inside the AnMBR
     Organics degradation in the AnMBR
     Filtration performance
     Conclusion

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             Introduction
Landfill leachate
     Rainwater percolation through wastes
     Biochemical processes in waste’s cells
      Inherent water content of wastes
  themselves
     Large amount of organic matter which
  can be biodegradable but also refractory
     biodegradation.
  to biodegradation.
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    Leachate composition vary widely within landfill
      age
                      Recent                 Intermediate           Old
Age (years)           <5                     5-10                   >10
pH                    6.5                    6.5-7.5                >7.5
COD (mg l-1)          >10,000                4000-10,000            <4000
BOD5/COD              >0.3                   0.1-0.3                <0.1
Organic compounds     80% VFA                5-30%VFA + HA          Humic, fulvic acids
Heavy metals          Low-medium                                    Low
Biodgradability       Important              Medium                 Low



Source: S. Renou, et al., Landfill leachate treatment: Review and opportunity, J. Hazard.
Mater. (2007).


    Useful criteria to choose                            a suited treatment
process.
    27/05/2008                                                                      4
  Management of domestic waste in
             Tunisia
     Djebel Chekir is the first controlled
    discharge in Tunisia
     1800 tons of domestic and assimilated
    waste per day coming from great Tunis
          1999.
    since 1999.
    The production of the landfill leachate is
    very high: 100.000 m3/year
         high: 100.


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    Since that, 9 other controlled dumps were created or still
    under construction:




  The treatment of the leachate coming from these
  discharges has become an urgent need.
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    Tunisian solid waste composition
                                      Textile 2%
                          Metals 4%
             Leather                          Others 3%
             and rubber
             2%


 Paper 10%                                                Organic
                                                          matter
                                                          68%



Plastic 11%

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    Landfill leachate characterization

    Parameters                                  Average
    pH (25°C)                                    7.31
    Electrical conductivity (25 °C) (mS cm-1)      46
    COD (g l-1)                                    85
    BOD5 (g l-1)                                   49
    BOD5/COD                                     0.58
    TSS (mg l-1)                                 1970
    VSS (mg l-1)                                 1460
    Total Kjeldhal nitrogen (mg l-1)             3177
    NH4+ (mg l-1)                                2800
    Ca (mg l-1)                                  975.5
    Cu (mg l-1)                                   553
    Fe (mg l-1)                                  67.75
    K (mg l-1)                                   8.02
    Mg (mg l-1)                                  14.37
    Na (mg l-1)                                    20
    Ni (mg l-1)                                  0.935
     Li (mg l-1)                                  0.42
    Pb (mg l-1)                                  1.585
    Hg (mg l-1)                                  2.505
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              Obejectives
    Anaerobic treatment    by    a     jet-
                                       jet-loop
             bioreactor.
    membrane bioreactor.
                            Volume       of    the
                           reactor: 50 l
                            Temperature: 37 °C
                            Cross-flow
                           ultrafiltration
                           membrane: 1 m2 area
                           and 100 kDa cutoff
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   Dilution of the feed solution   reasonable value
      COD.
   of COD.
                                          days.
   Constant Hydraulic retention time of 7 days.
   Increase of OLR by decreasing the dilution
   factor.
   factor.
             Operation period       HRT (d)   OLR (g COD l-    CODf (g l-1)
                                                  1 -1
                                                   d )
             OLR 1              7             2.24 ± 0.35     14.87 ± 0.88
             OLR 2              7             4.66 ± 1.23     30.8 ± 3.15
             OLR 3              7             6.27 ± 0.78     41 ± 3.14




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                                     Methanisation performance

                             7
COD concentration (g l-1)




                                     OLR 1        OLR 2          OLR 3
                             6
                     l




                             5
                             4                                                 COD reactor
                             3                                                 COD permeate
                             2
                             1
                             0
                                 0           50           100     150    200
                                                      Time (d)
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                 200
                              OLR 1    OLR 2              OLR 3
Biogas (l d-1)




                 150

                 100

                   50

                      0
                          0           50          100         150   200
                                               Time (d)


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Biogas yield (l biogas COD removed-1)

                                         0,80
                                                         OLR 1        OLR 2         OLR 3
                                         0,60

                                         0,40

                                         0,20

                                         0,00
                                                     0           50           100    150    200

                                                                        Time (d)


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VFAs concentration (g l-1)

                                  3
                                          OLR 1        OLR2                        OLR 3
                                2,5

                                  2

                                1,5

                                  1

                                0,5

                                  0
                                      0      20   40   60      80      100   120   140     160

                                                            Time (d)


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                   Biomass growth inside the AnMBR
                   4,5
                     4
                   3,5
Biomass (g l-1)




                     3
                   2,5
                     2
                   1,5
                     1
                   0,5
                     0
                         0     20   40   60      80      100   120   140   160

                                              Time (d)
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                         Organics degradation in the AnMBR
Abundance                                                                        Abundance


                                   TIC 070815_3.D\ data.m
                                      :                  s                                                          :
                                                                                                                 TIC 070815_2.D\ data.ms

     2400000                                                                          2400000


     2200000                                                                          2200000


     2000000                                                                          2000000


     1800000                                                                          1800000


     1600000                                                                          1600000


     1400000                                                                          1400000


     1200000                                                                          1200000


     1000000                                                                          1000000


      800000                                                                           800000


      600000                                                                           600000


      400000                                                                           400000


      200000                                                                           200000



                 6.00    8.00   10.00   12.00   14.00    16.00   18.00   20.00                  6.00   8.00   10.00   12.00   14.00    16.00   18.00    20.00
Time-->                                                                          Time-->




 Untreated LFL
 4.387: Phenol; 4.769: Hexanoic acid; 5.587: Heptanoic acid; 5.887: Cyclohexanecarboxylic acid; 6.075: Hexanamide; 6.328:
 Octanoic Acid; 6.540: 2-Piperidinone; 7.463: Benzenepropanoic acid; 7.640: Pyridine; 7.810: 1-Tetradecene; 7.857: Tetradecane;
 7.893: 7-Methylindole; 9.081: 1-Hexadecene; 9.122: Hexadecane; 10.210: E-15-Heptadecenal; 10.245: Octadecane; 10.628:
 Caffeine; 10.898: 1-Docosene; 10.969: Methyl-3-(3,5-diterbutyl-4-hydroxyphenyl) propionate; 10.022: Cyclohexadecane; 11.104:
 Cycloeicosane; 11.798: 7,9-di-tert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione

 Permeate
 9.081: 1-Hexadecene; 9.122: Hexadecane; 10.210: E-15-Heptadecenal; 10.898: 1-Docosene; 11.104: 1-Octadecene; 11.798: 7,9-Di-
 tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione
            27/05/2008                                                                                                                                 19
             Filtration performance
  Feed Reactor Permeate
                          Hydrodynamic operation conditions
                          (transmembrane pressure and cross-
                          flow velocity) were adjusted to have a
                          flux of 2.5 l h-1m-2 .


                           Ultrafiltration membrane:
                             Retains the bacteria inside the MBR
                           avoid wash-out
                              Retains high molecular weight
                           substances increase of the residence
                           time more adapted consortia

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                       Conclusions
  The OLR in the AnMBR was gradually increased from 1 g COD l-1d-1
   to an average of 6.27 g COD l-1d-1.

   At the highest OLR, the biogas production was more than 3 volumes
                               bioreactor.
   of biogas per volume of the bioreactor.

   The MLVSS reached a value of approximately 4 g l-1.

   The MBR achieved a COD removal up to 90% and biogas yield of
                          removed.
   0.4 l biogas per g COD removed.

   It was possible to operate the reactor with a very high loading rate as
    the result of the increase of the solids in the reactor.

    The Ultrafiltration membrane showed a very low flux . The chemical
                                efficiency.
    cleaning didn’t improve its efficiency. This problem can limit the
                                              studied.
    process efficiency and deserve to be well studied.


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