8/18/2019 Materials and Methods Biodigestor
2/3
Profesor)es* G'-a)s*+ !la'diaPav.n
Alejandra $edina
#ebrero de /012
$aterials and (et3ods
E4,eri(ent 1+ One sta5e anaerobic di5estion of (ar6et 7aste
Experiment layout
The digester experiments were carried out in four CSTR
laboratory-scale glass
reactors, each one with an eective volume of 1 !" The feeding
and sampling
were reali#ed through a cap in the top plate of the reactor"
$ach reactor was
stirred by a continuous stainless steel stirrer, and temperature
was not
maintained by external devices"
Operation conditions
The reactors were operated in semi-continuous mode with 1
cycle per day% &&
hours of digestion and & hours of decanting, draw o and
feeding" 'naerobic
digestion of mar(et waste was investigated with two dierent )!R,
two
reactors operated with & and two with * g S+!"d, for
constant retention time of
1 days" The RT were maintained by feeding 1 ! of shredded waste
and water
and removing 1 ! of e.uent daily" Steady-state condition is
achieved after
three retention times were met"
E4,eri(ent /+ T7o sta5e anaerobic di5estion of (ar6et 7aste
Experiment layout
Two pilot-scale reactors of dierent volumes were used" The
hydrolysis-
acidi/cation step was carried out in a stainless steel tan( with
an eective
volume of 1 !, and methanogenesis step was performed in a
stainless steel
tan( with an eective volume of & !" The reactors were
stirred by a suction
pump of 1"1 (0 that wor(ed for minutes every 1 minutes"
Temperature was
maintained by a thermal resistance in each reactor" 2eeding was
reali#edthrough the top of the hydrolytic reactor, and sampling was
reali#ed through
valves in the bottom of each tan("
Operation conditions
The reactors were operated in semi-continuous mode with 1
cycle per day"
2eeding was done with an )!R of 3 g S+!"d, an RT of 3 days for
hydrolysis
step and 1 days for methanogenesis step" Temperature was
maintained within
8/18/2019 Materials and Methods Biodigestor
3/3
the mesophilic range" Retention time was achieved by drawing o
&3 !d and
feeding &3 !d of a mix of water and 3 (g of shredded mar(et
waste"
2or both experiments, waste and methods used were the same"
Waste characteristics
The reactor feed was obtained wee(ly from street mar(ets
located near theplant, and consisted in vegetable and fruits waste"
Total solids concentration
was initially 11,&4 with a total volatile solids
concentration of 1,564"
Analytical methods
7iogas production, p, al(alinity and temperature were recorded
on a daily
basis" 8arameters such as total solids 9TS:, volatile solids
9+S:, total suspended
solids 9TSS:, chemical oxygen demand 9C);:, biogas composition,
and +2'
were recorded wee(ly" 2or mar(et waste, TS, +S and C); were
recorded every
wee("
