Agriculture Reference
In-Depth Information
has different range of pH. Sewage sludge as raw material for compost have pH
value 8.1, however, organic fraction of municipal solid waste has pH 7.6 (Manios
2004
). In the early phase of composting pH remain low but during the process, it
increase upto 8.5. It has been reported that the production of lactic acid and acetic
acid in the biomass degradation process leads to lower down the pH in the range
of 4.2-5.5 (Hultman
2009
). Kim et al. (
2004
) found that the pH 7.5 is the ideal pH
for composting process of organic matter decomposition. Sundberg et al. (
2004
)
studied the effect of the temperature and pH (4.6-9.2). On respiration rate ensuring
the early phase of composting in two different composts. The respiration rate was
strongly reduced at 40 °C at pH below 6.0 compared to compost with a higher pH at
lower temperature. The high temperature and low pH is possibly adverse factors in
composting. Low pH confirmed as inhibiting factors in transition from mesophilic
to thermophilic phase in composting.
12.6.2
Temperature
The understanding of the factors influencing decomposition of organic wastes and
performance are the major issues over sustainable waste management practices.
Among all influencing factors temperature encompass prime important characteris-
tic of thermophilic microorganisms active in compost. They are generally variably
observed in the temperature range from 54 to 70 °C (Miyatake and Iwabuchi
2005
).
It was seemingly interested factors that temperature influence rate of mineraliza-
tion and rate of leaching of dissolved organic carbon (DOC) and nitrogen (DON)
(Chodak et al.
2001
). Fierer et al. (
2005
) showed that the temperature sensitivity of
litter decomposition vary depending on litter type and extent of decomposition and
stated that it is the fundamental principle of enzyme kinetics. It is included that the
temperature sensitivity of microbial decomposition is inversely proportional to that
of litter carbon quality. Temperature response of decomposition in both fresh litter
and soil organic matter (SOM) directly related to the chemical composition of the
constituent organic matter, explaining 90 and 70 % of the variance in litter and SOM
respectively (Erhagen et al.
2013
). Miyatake and Iwabuchi (
2006
) investigated the
relationship between temperature and microbial activity in composting using oxy-
gen uptake rate, specific growth rate and enzymatic activity during composting. It
is resulted that the enhancement of specific growth rate and enzymatic activity and
volatile solids reduction induced at 54 °C in composting.
12.6.3
Carbon Nitrogen Ratio
Change in organic C, total N, C:N ratio, activities of cellulose, xylanase and pro-
tease and microbial populations showed a definite role in composting of different
organic waste including sugarcane trash, cattle dung, press mud etc. C:N ratio and
CO
2
evolved from finished compost can be taken as the most reliable indices of
