THERMODYNAMIC STUDIES OF TREATMENT OF WASTEWATER FROM FOOD INDUSTRY, USING POWDERED SNAIL SHELL (PSS)

The thermodynamic studies of the treatment of wastewater from a food industry using
powdered snail shell was done at different temperatures. The change in standard Gibb’s free
energy (∆G0

) of pH has values of -0.109, -0.263, -0.147, 0,and -0.064 kJ/mol respectively,

while the change in standard entropy (∆S0

) and enthalpy (∆H0

) have values of 0.80 and -279.9

kJ/mol respectively. ∆G0

values of alkalinity were -0.359, -0.355, -0.354, -0.344 and -

0.347kJ/mol respectively, its values of ∆S0

and ∆H0 were -0.27 and -26.4 kJ/mol respectively.

Turbidity has ∆G0

values of -0.405, -0.338, -0.322, -0.161 and -0.145 kJ/mol whiles its ∆S0

and ∆H0
values were 1.68and -599.6kJ/mol. The values of ∆G0

of electrical conductivity were

-0.415, -0.587, -0.671, -0.263 and -0.240kJ/mol while its ∆S0
and ∆H0

values were 1.50 and-
591.5kJ/mol respectively. ∆G0

, ∆S0
and ∆H0
values of TS, TSS, TDS, BOD5, COD, DO, NO3-
N, Phosphate, sulphate and Lead were also determined. However Cadmium could not be
computed because it was below the detectable limit. The thermodynamic studies were done at
283K, 292K, 303K, 313K and 333K respectively. Physicochemical characterization of the
wastewater was determined before and after treatment. However the food and mineral
composition of four different species of snail shell were determined, the pH, surface area and
optimum dosage of the powdered snail shell were determined, from the analysis, the giant
African snail shell was chosen and used for the treatment of the wastewater, due to its large
surface area, stability at pH of 4-12 and the ease to produce a fine powder when homogenised.
KEYWORDS: Thermodynamic studies, food industry, powdered snail shell, Temperature
Wastewater.