Department Process Engineering

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   libraryUrl => '' (0 chars)

array(3 items)
   0 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=10623, pid=124)
      originalId => protected10623 (integer)
      authors => protected'Derlon, N.; Grütter, A.; Brandenberger, F.; Sutter, A.;
          Kuhlicke, U.; Neu, T. R.; Morgenroth, E.' (137 chars)
      title => protected'The composition and compression of biofilms developed on ultrafiltration mem
         branes determine hydraulic biofilm resistance' (121 chars)
      journal => protected'Water Research' (14 chars)
      year => protected2016 (integer)
      volume => protected102 (integer)
      issue => protected'' (0 chars)
      startpage => protected'63' (2 chars)
      otherpage => protected'72' (2 chars)
      categories => protected'ultrafiltration membrane; biofilm; permeability; hydraulic resistance; compr
         ession; extracellular polymeric substances (EPS)' (124 chars)
      description => protected'This study aimed at identifying how to improve the level of permeate flux st
         abilisation during gravity-driven membrane filtration without control of bio
         film formation. The focus was therefore on understanding (i) how the differe
         nt fractions of the biofilms (inorganics particles, bacterial cells, EPS mat
         rix) influence its hydraulic resistance and (ii) how the compression of biof
         ilms impacts its hydraulic resistance, i.e., can water head be increased to 
         increase the level of permeate flux stabilisation. Biofilms were developed o
         n ultrafiltration membranes at 88 and 284 cm water heads with dead-end filtr
         ation for around 50 days. A larger water head resulted in a smaller biofilm 
         permeability (150 and 50 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</S
         UP> for biofilms grown at 88 cm and 284 cm water head, respectively). Biofil
         ms were mainly composed of EPS (>90% in volume). The comparison of the hydra
         ulic resistances of biofilms to model fouling layers indicated that most of 
         the hydraulic resistance is due to the EPS matrix. The compressibility of th
         e biofilm was also evaluated by subjecting the biofilms to short-term (few m
         inutes) and long-term variations of transmembrane pressures (TMP). A sudden 
         change of TMP resulted in an instantaneous and reversible change of biofilm 
         hydraulic resistance. A long-term change of TMP induced a slow change in the
          biofilm hydraulic resistance. Our results demonstrate that the response of 
         biofilms to a TMP change has two components: an immediate variation of resis
         tance (due to compression/relaxation) and a long-term response (linked to bi
         ofilm adaptation/growth). Our results provide relevant information about the
          relationship between the operating conditions in terms of TMP, the biofilm 
         structure and composition and the resulting biofilm hydraulic resistance. Th
         ese findings have practical implications for a broad range of membrane syste
         ms.' (1903 chars)
      serialnumber => protected'0043-1354' (9 chars)
      doi => protected'10.1016/j.watres.2016.06.019' (28 chars)
      uid => protected10623 (integer)
      _localizedUid => protected10623 (integer)modified
      _languageUid => protectedNULL
      _versionedUid => protected10623 (integer)modified
      pid => protected124 (integer)
   1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=13981, pid=124)
      originalId => protected13981 (integer)
      authors => protected'Klein,&nbsp;T.; Zihlmann,&nbsp;D.; Derlon,&nbsp;N.; Isaacson,&nbsp;C.; Sziva
         k,&nbsp;I.; Weissbrodt,&nbsp;D.&nbsp;G.; Pronk,&nbsp;W.' (131 chars)
      title => protected'Biological control of biofilms on membranes by metazoans' (56 chars)
      journal => protected'Water Research' (14 chars)
      year => protected2016 (integer)
      volume => protected88 (integer)
      issue => protected'' (0 chars)
      startpage => protected'20' (2 chars)
      otherpage => protected'29' (2 chars)
      categories => protected'gravity driven membrane; biofouling; nematodes; oligochaetes; basal layer; f
         lux increase; biological control' (108 chars)
      description => protected'Traditionally, chemical and physical methods have been used to control biofo
         uling on membranes by inactivating and removing the biofouling layer. Altern
         atively, the permeability can be increased using biological methods while ac
         cepting the presence of the biofouling layer. We have investigated two diffe
         rent types of metazoans for this purpose, the oligochaete <I>Aelosoma hempri
         chi</I> and the nematode <I>Plectus aquatilis</I>. The addition of these gra
         zing metazoans in biofilm-controlled membrane systems resulted in a flux inc
         rease of 50% in presence of the oligochaetes (<I>Aelosoma hemprichi</I>), an
         d a flux increase of 119–164% in presence of the nematodes (<I>Plectus aqu
         atilis</I>) in comparison to the control system operated without metazoans. 
         The change in flux resulted from (1) a change in the biofilm structure, from
          a homogeneous, cake-like biofilm to a more heterogeneous, porous structure 
         and (2) a significant reduction in the thickness of the basal layer. Pyroseq
         uencing data showed that due to the addition of the predators, also the comm
         unity composition of the biofilm in terms of protists and bacteria was stron
         gly affected. The results have implications for a range of membrane processe
         s, including ultrafiltration for potable water production, membrane bioreact
         ors and reverse osmosis.' (1316 chars)
      serialnumber => protected'0043-1354' (9 chars)
      doi => protected'10.1016/j.watres.2015.09.050' (28 chars)
      uid => protected13981 (integer)
      _localizedUid => protected13981 (integer)modified
      _languageUid => protectedNULL
      _versionedUid => protected13981 (integer)modified
      pid => protected124 (integer)
   2 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=10568, pid=124)
      originalId => protected10568 (integer)
      authors => protected'Ding,&nbsp;A.; Liang,&nbsp;H.; Li,&nbsp;G.; Derlon,&nbsp;N.; Szivak,&nbsp;I.
         ; Morgenroth,&nbsp;E.; Pronk,&nbsp;W.' (113 chars)
      title => protected'Impact of aeration shear stress on permeate flux and fouling layer propertie
         s in a low pressure membrane bioreactor for the treatment of grey water' (147 chars)
      journal => protected'Journal of Membrane Science' (27 chars)
      year => protected2016 (integer)
      volume => protected510 (integer)
      issue => protected'' (0 chars)
      startpage => protected'382' (3 chars)
      otherpage => protected'390' (3 chars)
      categories => protected'aeration shear; grey water treatment; GDM; fouling resistance; bio-fouling l
         ayer' (80 chars)
      description => protected'Two different aeration regimes were studied in a low pressure gravity driven
          membrane bioreactor without any flushing or (back-) washing. In one reactor
         , the aeration was positioned below the membrane module, thus exposing the m
         embranes to aeration shear stress. A second reactor was operated at low shea
         r stress by placing the aerator in a different compartment. Flux stabilizati
         on at 2.0 L/(m<SUP>2</SUP> h) occurred in the reactor with low shear stress
          while no flux stabilization was observed in the reactor with aeration shear
          stress, resulting in a flux of 0.5 L/(m<SUP>2</SUP> h) after 120 days. The
          thickness of the bio-fouling layer in the reactor with aeration shear was s
         maller (129 vs. 344 µm), which implies that shear stress resulted in a thi
         nner, denser and less permeable bio-fouling layer. The results can be explai
         ned by differences in (1) the morphology of the bio-fouling layer and (2) th
         e EPS contents (proteins and polysaccharides) in the bio-fouling layer. The 
         low-shear system provides a suitable solution for decentralized grey water t
         reatment, or other conditions where maintenance and energy consumption shoul
         d be minimized. Furthermore, the results can contribute to decrease the ener
         gy consumption in MBR systems.' (1246 chars)
      serialnumber => protected'0376-7388' (9 chars)
      doi => protected'10.1016/j.memsci.2016.03.025' (28 chars)
      uid => protected10568 (integer)
      _localizedUid => protected10568 (integer)modified
      _languageUid => protectedNULL
      _versionedUid => protected10568 (integer)modified
      pid => protected124 (integer)