References
  -  S. Sassi, La sédimentation phosphatée au paléocène dans
    le sud et le centre de la Tunisie, (Paleocene Phosphate
    Sedimentation in Southern and Central Tunisia), Thèse de
    doctorat es-Sciences Naturelles, Université de Paris Sud,
    Centre d’Orsay, 1974, p. 292. 
-  H. Rouvier, Géologie de l’extrême Nord tunisien tectonique
    et paléogéographies superposées à l’extrémité orientale de la
    chaine nord-maghrébine, (The Far North Geology of Tunisia
    Tectonics and Paleo-Geography Superimposed on the North-Maghreb Chain Eastern End), Thèse de doctorat Es Science
    Naturelles, Université Pierre et Marie Curie, Analyses des
    Mines et de la Géologie, 29 (1977) 134–165. 
-  H. Belayouni, Etude de la matière organique dans la série
    phosphatée du bassin de Gafsa-Métlaoui (Tunisie), Application
    à la compréhension des mécanismes de la phosphatogenèse,
    (Study of Organic Matter in the Phosphate Series of Gfsa-
    Metlaoui Basin (Tunisia), Application to Understanding
    the Phosphaphatogenesis Mechanisms), Thèse de Doctorat
    es-Sciences, Université d’Orléans, France, 1983, p. 205. 
-  H. Tlemseni, Identification minéralogique géochimique et
    petrophysique des sédiments siliceux (Cherts) de la série
    phosphatée du bassin de Gafsa Metlaoui, (Geochemical
    Petrophysical and Mineralogical Identification of Siliceous
    Sediments (Cherts) of the Phosphate Series from Gafsa Metlaoui
    Basin), DEA Sciences Terre, Université Tunis El Manar, 1990,
    p. 88. 
-  R. Saidi, Etude minéralogique et pétrophysique des cherts
    du bassin de phosphate Gafsa-Metlaoui et perspectives de
    valorisation industrielle (Mineralogical and Petrophysical
    Study of the Cherts Rocks of Gafsa-Métlaoui Basin ans Prospects
    for Indutrial Recovery), Mastère en Géosciences Appliquées
    aux Ressources et Environnements Naturels, Faculté des
    Sciences de Sfax, 2007, p. 91. 
-  M. Henchiri, Les facies siliceux éocène, bassin de Gafsa,
    (Tunisie Méridionale, Sédimentologie, minéralogie, et
    transformation diagénétique (Eocene Silica Facies, Gafsa Basin,
    (Southern Tunisia, Sedimentology, Mineralogy, and Diagenetic
    Transformation), Thèse de Doctorat en Géologie, Université
    Tunis El Manar, 2009, p. 134. 
-  M. Felhi, Les niveaux intercalaires de la série yprésienne du
    basin Gafsa-Métlaoui: Apports de la minéralogie des argiles
    et de la géochimie de la matière organique résiduelle à la
    reconstitution paléo-environnementale (Interbeddeds of the
    Ypresian Series From Gafsa-Metlaoui Basin: Contributions of
    Clay Mineralogy and Residual Organic Matter Geochemistry
    to Paleo-Environmental Reconstitution), Ph.D. Thesis, Sfax
    University, 2010, p. 184. 
-  A. Tlili, M. Felhi, M. Montacer, Origin and depositional
    environment of palygorskite and sepiolite from the Ypresian
    phosphatic series, South-western Tunisia, Clays Clay Miner.,
    58 (2010) 573–581. 
-  A. Tlili, M. Felhi, N. Fattah, M. Montacer, Mineralogical and
    geochemical studies of Ypresian marly clays and silica rocks of
    phosphatic series, Gafsa-Metlaoui basin, south-western Tunisia:
    implication for depositional environment, Geosci. J., 15 (2011)
    53–64. 
-  A. Tlili, R. Saidi, A. Fourati, N. Ammar, F. Jamoussi,
    Mineralogical study and properties of natural and flux
    calcined porcelanite from Gafsa-Metlaoui basin compared
    to diatomaceous filtration aids, Appl. Clay Sci., 55 (2012)
    47–57. 
-  R. Saidi, A. Tlili, A. Fourati, N. Ammar, A. Ounis, F. Jamoussi,
    Granulometric distribution of natural and flux calcined chert
    from Ypresian phosphatic series of Gafsa-Metlaoui basin
    compared to diatomite filter aid, 
 IOP-Conf. Revue, 28 (2012)
    1–8.
-  R. Saidi, M. Felhi, A. Tlili, L. Khlil, A. Fourati, L. Kammoun,
    F. Jamoussi, Depositional environment and stability of the
    porcelanite within the Ypresian phosphatic series of the Gafsa-
    Metlaoui basin, south-western Tunisia, Arabian J. Geosci.,
    8 (2014), doi: DOI:10.1007/s12517-014-1552-2. 
-  A. Haj Ahmed, A. Tlili, Y. Jeddoui, Fossil diatoms from
    endogangue of the Ypresian phosphatic pellets of the Gafsa-
    Metlaoui basin: implication on the origin of biogenic silica
    and depositional environment, Arabian J. Geosci., 8 (2014)
    1077–1087. 
-  J. Essid, R. Saidi, A. Haj Ahmed, M. Felhi, N. Fattah, A. Tlili,
    Characterization, nomenclature and factors controlling the
    stability of quartz and opal CT of Burdigalian and Ypresian
    siliceous rock from Tunisia, J. Afr. Earth. Sci., 155 (2019) 151–160. 
-  R. Saidi, Etude géochimique et minéralogique des niveaux
    de porcelanite du bassin de Gafsa-Métlaoui: Perspectives de
    valorisation dans la filtration industrielle (Geochemical and
    Mineralogical Study of the Porcelanite Levels of the Gafsa-
    Métlaoui Basin: Prospects for Industrial Filtration Recovery),
    Thèse de doctorat en Sciences Géologiques, Université de Sfax,
    2015, p. 320. 
-  F. Chaabani, Dynamique de la partie orientale du Bassin
    de Gafsa-Métlaoui au Crétacé et au Paléogène: Etude
    minéralogique et géochimique de la série phosphatée éocène
    (Tunisie méridionale) (Cretaceous and Paleogene Dynamics
    in Gafsa-Metlaoui Basin Eastern Part: Mineralogical and
    Geochemical Study of the Eocene Phosphate Series (Southern
    Tunisia), Ph.D. Thesis, Université Tunis II, Faculté des Sciences
    de Tunis, 1995, p. 428. 
-  M. Henchiri, Sedimentation, depositional environment and
    diagenesis of Eocene biosiliceous deposits of Gafsa basin
    (southern Tunisia), J. Afr. Earth. Sci., 49 (2007) 187–200. 
-  M. Felhi, A. Tlili, M. Montacer, Geochemistry, petrographic
    and spectroscopic studies of organic matter of clay associated
    kerogen of Ypresian series: Gafsa-Metlaoui phosphatic basin,
    Tunisia, Res. Geol., 59 (2008) 428–436. 
-  API, Agency for the Promotion of Industry and Innovation
    in Tunisia. Les perspectives de développement industriel du
    gouvernorat de Gafsa (The Industrial Development Prospects
    of the Gafsa Governorate), API/CEPI, Tunisia, 2009. 
-  M.E. Tucker, Sedimentary Petrology: An Introduction to
    the Origin of Sedimentary Rocks, 3rd ed., 
 Wiley-Blackwell,
    Hoboken USA, 2001.
-  R.H. Habib, The use of Iraqi porcelanite rocks for purification of
    drinking water Iraqi, J. Sci., 47 (2004) 104–110. 
-  Advanced Minerals, Comparing Conventional Diatomite and
    Capture Filter aids, Advanced Minerals Corporation, Technical
    Note: AMC02, Santa Barbara, 2002. 
-  S. Shatti Salih, Reduction of Escherchia coli in Ablution Lake and
    River Water USING Porcelanite, Master Sci., 2016, p. 181. 
-  K. Jόzwiakowski, M. Gajewska, A. Pytka, M. Marzec,
    M. Gizinska-Gόrna, A. Jucherski, A. Walczowski, M. Nastawny,
    A. Kaminska, S. Barna, Influence of the particle size of carbonatesiliceous
    rock on the efficiency of phosphorous removal
    from domestic wastewater, Ecol. Eng., 98 (2016) 290–296. 
-  D. Leclerc, G. Baluais, Filtration: Introduction, Techniques de
    l’ingénieur, 1981, J3500. 
-  F. Zargouni, Tectonique de l’atlas méridionale de la Tunisie.
    Evolution géométrique et cinématique des structures en
    zone de cisaillement (Tectonic of the Southern atlas Tunisia,
    Geometric and Kinematic Evolution of Structures in Shear
    Zone), Thèse d’Etat, Université Louis Strasbourg, 1985, p. 304. 
-  N. Boukadi, Structuration de l’Atlas de la Tunisie; signification
    géométrique et cinématique des noeuds de la zone
    d’interférences. Structurales au contact des grands couloirs
    tectoniques (Structuring of the Atlas of Tunisia; Geometrical
    and Kinematic Meaning of the Intererence Zone Nodes.
    Structural in Contact With the Great Tectonic Corridors),
    Ph.D. Thesis, Tunis II University, Tunisia, 1994, p. 148. 
-  PF. Burrolet, Contribution à l’étude stratigraphique de la
    Tunisie-centrale (Contribution to the Stratigraphic Study of
    Central Tunisia), Thèse Doct. Es Sciences, Paris, Ann. Mines et
    Géol. Tunis, 1956, p. 350. 
-  P. Fournié, Phosphates et pétroles en Tunisie (Phosphates
    and oils in Tunisia), Mém BRGM Orléans, 24 (1980) 157–165. 
-  M. Henchiri, N. Fattah, Extent of diagenetic transformations
    in severely altered biogenic silica deposits from Tunisia: new
    insights from mineralogy and geochemistry, Arabian J. Geosci.,
    7 (2014) 1179–1186. 
-  A. Haj Ahmed, Contribution à l’étude du contenu minéral
    et organique des phosphates du bassin 
 de Gafsa-Metlaoui:
    Implications paléo-environnementales (Contribution to the
    Study of the Mineral and Organic Composition Phosphates in
    the Gafsa-Metlaoui Basin: Paleoenvironmental Implications),
    Thése de doctorat en Sciences Géologiques, Université de Sfax,
    2017, p. 181.
-  N. Ediz, İ. Bentli, İ. Tatar, Improvement in filtration characteristics
    of diatomite by calcinations, Int. J. Miner. Process.,
    94 (2010) 129–134. 
-  S.S. Ibrahim, A.Q. Selim, Producing a micro-porous diatomite
    by simple classification, calcinations process,
 J. Ore Dress.,
    12 (2010) 24–32.
-  R.O.Y. Breese, Diatomite, D.D. Carr, Ed., Industrial Minerals
    and Rocks, SMME, Colorado, USA, 1994, 
 pp. 397–412.
-  B. Yılmaz, N. Ediz, The use of raw and calcined diatomite in
    cement production, Cem. Concr. Compos., 
 30 (2008) 202–211.
-  S.V. Kouteren, Filters and Absorbents, D.D. Carr, Ed., SMME,
    Colorado, USA, 1994, pp. 497–507. 
-  R. Saidi, A. Tlili, F. Jamoussi, The effect of heating on mineral
    composition and grain size distribution of flux calcined
    porcelanites from the Gafsa-Metlaoui basin, south western
    Tunisia, J. Afr. Earth. Sci., 12 (2016) 189–198. 
-  R. Gören, T. Baykara, M. Marsoğlu, Effects of purification and
    heat treatment on pore structure and composition of diatomite,
    Br. Ceram. Trans., 101 (2002b) 177–180. 
-  S. Martinovic, M. Vlahovic, T. Boljanak, L. Pavlovic, Preparation
    of filter aids based on diatomites, Int. J. Miner. Process.,
    80 (2006) 255–260. 
-  M.F. Albright, H.A. Waterfield, Evaluating Phosphorus-
    Removal Media for Use in On-site Wastewater Treatment
    Systems, (Interim Report), 2010, p. 17. 
-  U.E. Ekpunobi, S.U. Agbo, V.I.E. Ajiwe, Evaluation of the
    mixtures of clay, diatomite, and sawdust for production of
    ceramic pot filters for water treatment interventions using
    locally sourced materials, J. Environ. Chem. Eng., 7 (2019)
    102–791. 
-  S.S. Ibrahim, A.Q. Selim, Heat treatment of natural diatomite,
    Physicochem. Probl. Miner. Process., 48 (2012) 413–424. 
-  C. Costa, A. Velosa, A. Angela Cerqueira, P. Caetano,
    F. Rocha, Characterization of Portuguese diatomites in ordre
    to assesspotential applications, Acta Geodyn. Geomater.,
    15 (2018) 47–56. 
-  O. Hadjadj-Aoul, R. Belabbesa, M. Belkadib, M.H. Guermouche,
    Characterization and performances of an Algerian diatomitebased
    gas chromatography support, Appl. Surf. Sci., 240 (2005)
    131–139. 
-  S.S. Ibrahim, Preparation of wollastonite mineral from Egyptian
    cruminerals, Egypt. Aca. Sci. Res. Technol., 2007. 
-  H. Aguedal, A. Iddou, A. Aziz, A. Shishkin, J. Ločs, T. Juhna,
    Effect of thermal regeneration of diatomite adsorbent on its
    efficacy for removal of dye from water, Int. J. Environ. Sci.
    Technol., 16 (2019) 113–124. 
-  E.H. Oelkers, J. SHOTT, An experimental study of enstatite
    dissolution rates as a function of pH, temperature and
    aqueous Mg and Si concentration, and the mechanism of
    pyroxene/pyroxenoid dissolution, Geochim. Cosmochim. Acta,
    65 (2000) 1219–1231. 
-  O. Şan, C. Özgür, Preparation of astabilized β-cristobalite
    ceramic fromdiatomite, J. Alloys Compd., 484 (2009) 920–923. 
-  M. Al-Wakeel, Characterization and process development
    of the Nile diatomaceous sediment, Int. J. Miner. Process.,
    92 (2009)128–136. 
-  N.S. Zafisah, W.L. Ang, A.W. Mohammad, Cake filtration for
    suspended solids removal in digestate from anaerobic digested
    palm oil mill effluent (POME), Water Conserv. Manage.,
    2 (2018) 5–9. 
-  H. Ahdno, H. Jafarizadeh-Malmiri, Development of a sequenced
    enzymatically pre-treatment and filter 
 pre-coating process to
    clarify date syrup, Food Bioprod. Process., 101 (2017) 193–204.
-  A. Renman, G. Renman, Long-term phosphate removal by
    the calcium-silicate material Polonite in wastewater filtration
    systems, Chemosphere, 79 (2010) 659–664. 
-  WHO, WHO Guidelines for Drinking Water Quality, World
  Health Organization, 2011.