﻿312 
  

  

  AMERICAN 
  HOMES 
  AND 
  GARDENS 
  

  

  August, 
  1907 
  

  

  Bacterial 
  Beds 
  of 
  First 
  and 
  Second 
  Contact 
  at 
  La 
  Madeleine-les-Lille 
  

  

  this 
  process 
  are 
  excellent. 
  Unfortunately 
  it 
  retains 
  some 
  of 
  

   the 
  disadvantages 
  of 
  ordinary 
  irrigation. 
  The 
  quantity 
  of 
  

   water 
  purified 
  is 
  limited 
  to 
  three 
  or 
  four 
  quarts 
  per 
  square 
  

   foot 
  per 
  day, 
  so 
  that 
  the 
  area 
  required 
  for 
  a 
  large 
  city 
  is 
  

   still 
  very 
  great. 
  Besides, 
  sandy 
  soil 
  is 
  not 
  found 
  everywhere. 
  

  

  The 
  results 
  obtained 
  with 
  intermittent 
  filtration 
  suggested 
  

   to 
  the 
  English 
  chemist 
  Dibdin 
  the 
  idea 
  of 
  effecting 
  the 
  decom- 
  

   position 
  of 
  the 
  or- 
  

   ganic 
  matter 
  by 
  the 
  

   action 
  of 
  bacteria 
  in 
  

   specially 
  contrived 
  ar- 
  

   tificial 
  beds, 
  instead 
  

   of 
  allowing 
  the 
  action 
  

   to 
  be 
  controlled 
  by 
  

   the 
  nature 
  of 
  t 
  h 
  e 
  

   ground, 
  as 
  in 
  the 
  

   preceding 
  methods. 
  

   He 
  hoped 
  thus 
  to 
  ac- 
  

   celerate 
  and 
  regulate 
  

   the 
  w 
  o 
  rk 
  of 
  the 
  

   bacteria, 
  and 
  conse- 
  

   quently 
  to 
  purify 
  a 
  

   much 
  larger 
  quantity 
  

   of 
  water 
  in 
  propor- 
  

   tion 
  to 
  the 
  area 
  em- 
  

   ployed. 
  D 
  i 
  b 
  d 
  i 
  n 
  ' 
  s 
  

   first 
  experiments 
  

   were 
  made 
  in 
  1895. 
  

   His 
  artificial 
  bacterial 
  

   beds 
  were 
  composed 
  

  

  of 
  a 
  mixture 
  of 
  coke 
  and 
  burned 
  clay. 
  The 
  water, 
  after 
  

   settling 
  and 
  being 
  decanted, 
  was 
  caused 
  to 
  flood 
  the 
  first 
  

   bed, 
  where 
  it 
  remained 
  two 
  hours. 
  The 
  partially 
  purified 
  

   water 
  then 
  flowed 
  to 
  a 
  second 
  bed, 
  where 
  in 
  two 
  hours 
  more 
  

   it 
  was 
  purified 
  so 
  well 
  that 
  it 
  could 
  safely 
  be 
  allowed 
  to 
  flow 
  

   into 
  streams. 
  After 
  each 
  flooding 
  the 
  beds 
  were 
  exposed 
  to 
  

   the 
  air 
  for 
  four 
  hours 
  to 
  enable 
  the 
  bacteria 
  to 
  multiply. 
  

   But 
  it 
  was 
  discovered 
  that 
  these 
  beds 
  soon 
  became 
  

   clogged 
  with 
  filth, 
  and 
  then 
  required 
  two 
  or 
  three 
  

   weeks' 
  rest 
  to 
  fit 
  them 
  for 
  further 
  service. 
  To 
  

   avoid 
  this 
  inconvenience 
  Cameron 
  conceived 
  the 
  

   idea 
  of 
  interposing 
  between 
  the 
  sewage 
  supply 
  pipe 
  

   and 
  the 
  bacterial 
  beds 
  a 
  series 
  of 
  ditches 
  called 
  

   septic 
  fosses, 
  in 
  which 
  the 
  putrefiable 
  matter 
  in 
  sus- 
  

   pension 
  could 
  be 
  deposited 
  and 
  then 
  dissolved 
  and 
  

   decomposed 
  by 
  anaerobic 
  bacteria.* 
  The 
  water 
  

   which 
  flows 
  from 
  the 
  fosses 
  holds 
  almost 
  no 
  matter 
  

   in 
  suspension, 
  and 
  its 
  dissolved 
  organic 
  matter 
  is 
  

   very 
  easily 
  decomposed 
  by 
  the 
  bacteria 
  of 
  the 
  beds, 
  

   which, 
  consequently, 
  do 
  not 
  become 
  clogged. 
  

  

  The 
  biological 
  processes, 
  as 
  these 
  methods 
  of 
  

   Dibdin, 
  thus 
  modified, 
  are 
  now 
  called, 
  have 
  been 
  

  

  Septic 
  Fosses 
  at 
  La 
  Madeleine-les-Lille 
  

  

  tested 
  at 
  Exeter, 
  Veovil, 
  Manchester 
  and 
  else- 
  

   where. 
  The 
  results 
  obtained 
  have 
  generally 
  been 
  

   good, 
  and 
  the 
  study 
  of 
  these 
  methods 
  has 
  greatly 
  

   developed 
  in 
  the 
  last 
  few 
  years. 
  With 
  the 
  energetic 
  

   and 
  fruitful 
  initiative 
  of 
  Dr. 
  Calmette, 
  director 
  of 
  

   the 
  Pasteur 
  Institute 
  of 
  Lille, 
  and 
  the 
  aid 
  of 
  a 
  

   large 
  subsidy 
  from 
  the 
  national 
  fund 
  for 
  scientific 
  

   research, 
  France 
  has 
  now, 
  in 
  turn, 
  taken 
  up 
  the 
  

   study 
  of 
  the 
  biological 
  methods, 
  and 
  sufficient 
  

   work 
  has 
  already 
  been 
  done 
  to 
  show 
  that 
  these 
  

   methods 
  are 
  very 
  practical 
  and 
  very 
  advantageous. 
  

   Let 
  us 
  see, 
  then, 
  how 
  these 
  methods 
  should 
  be 
  

   applied 
  in 
  practice, 
  in 
  accordance 
  with 
  the 
  investi- 
  

   gations 
  made 
  at 
  the 
  experimental 
  station 
  for 
  the 
  

   purification 
  of 
  water, 
  at 
  La 
  Madeleine-les-Lille. 
  

   Artificial 
  bacterial 
  purification 
  comprises 
  three 
  

   operations: 
  First, 
  the 
  separation 
  of 
  non-putrescible 
  solid 
  

   residuum 
  (sand, 
  stones, 
  fragments 
  of 
  metal, 
  etc.); 
  second, 
  

   the 
  solution, 
  in 
  the 
  septic 
  fosses, 
  of 
  organic 
  matter 
  in 
  sus- 
  

   pension, 
  and 
  its 
  partial 
  conversion 
  into 
  gases; 
  third, 
  the 
  de- 
  

   composition 
  of 
  soluble 
  organic 
  matter 
  in 
  the 
  bacterial 
  beds. 
  

   The 
  first 
  operation 
  is 
  purely 
  mechanical. 
  The 
  sewage 
  

   first 
  traverses 
  a 
  chamber 
  with 
  double 
  gratings 
  which 
  retain 
  

  

  floating 
  bodies, 
  and 
  

   then 
  flows 
  very 
  

   slowly 
  into 
  a 
  cham- 
  

   ber 
  containing 
  a 
  thin 
  

   layer 
  of 
  sand, 
  on 
  

   which 
  the 
  gravel 
  and 
  

   metallic 
  particles 
  are 
  

   deposited. 
  This 
  de- 
  

   posit 
  is 
  removed 
  at 
  

   regular 
  intervals 
  

   with 
  hand 
  or 
  chain 
  

   scrapers. 
  

  

  The 
  water 
  next 
  

   enters 
  the 
  septic 
  

   fosses. 
  These 
  are 
  

   long 
  basins 
  of 
  rect- 
  

   angular 
  cross-section, 
  

   lined 
  with 
  masonry 
  

   and 
  subdivided 
  by 
  in- 
  

   complete 
  transverse 
  

   partitions 
  which 
  

   check 
  the 
  flow 
  of 
  the 
  

   water 
  and 
  facilitate 
  

   deposition 
  of 
  sediment. 
  Their 
  depth 
  is 
  ten 
  or 
  twelve 
  feet, 
  

   their 
  length 
  and 
  width 
  such 
  that 
  they 
  contain 
  one 
  day's 
  out- 
  

   put 
  of 
  the 
  sewer 
  so 
  that 
  each 
  gallon 
  of 
  water 
  occupies 
  twenty- 
  

   four 
  hours 
  in 
  traversing 
  the 
  length 
  of 
  the 
  system, 
  which 
  may 
  

   consist 
  of 
  several 
  parallel 
  fosses 
  or 
  one 
  very 
  long 
  one. 
  The 
  

   fosses 
  discharge 
  by 
  overflow, 
  and 
  are 
  consequently 
  always 
  

   full. 
  The 
  muddy 
  sediment 
  which 
  collects 
  in 
  the 
  bottom 
  of 
  

  

  KB 
  4B 
  

  

  * 
  Bacteria 
  which, 
  unlike 
  the 
  aerobic 
  bacteria~of 
  the 
  filter 
  beds, 
  

   do 
  not 
  require 
  the 
  presence 
  of 
  air. 
  

  

  Bacterial 
  Bed 
  with 
  Fiddian 
  Rotary 
  Distributor 
  at 
  La 
  Madeleine-les-Lille 
  

  

  