08-16-2017, 08:46 PM
[attachment=1812]
BIOSORPTION OF METALS
SELECTION OF BIOMASS
While choosing the biomass for metal biosorption, its origin is a major factor .
Biomass can come from, activated sludge or fermentation waste from industries like those of food, diary and starch .
organisms coming from their natural habitats are good sources of biomass.
Fast growing organisms that are specifically cultivated for biosorption purposes
TYPES OF BIOMASS
Agricultural products
Seaweeds
Fungi and Yeast
Bacteria
CASE STUDY:EXPERIMENT WITH ULMUS AND THEIR ASH
PREPARATION OF ULMUS LEAVES
Ulmus leaves were washed with deionized water.
Then laid down to be dried in sunlight for 14 days.
Dry leaves were then ground with electrical grinder.
After being grounded, the leaf particle were sieved with 60 70 mesh sieves (0.2 0.3mm)
Then the leaves were dried at 1000C for 24 hours to be constant weight.
PREPARATION OF ASHES
The Ulmus leaves ash obtained from burning of Ulmus leaves in oven at 5500C for 15 minutes.
Dried leaves were stored in desiccator until used.
PREPARATION OF STOCK SOLUTION
By dissolving the cadmium nitrate in the distilled water.
The concentration range of cadmium in the solution varied between 2 40 mg/l.
For the required PH value diluted and the concentrated H2SO4 and NaOH solution were added.
PROCEDURE
The experiment were carried out in the batch system for the measurement of adsorption capacities.
Each cadmium solution was placed in 1000 ml. beaker and known amount of adsorbent (1g) were added to each beaker.
The beaker were agitated on the jar test equipments at 300 rpm constant mixing rate for 5 300 minutes to ensure equilibrium was reached.
After agitating the solution biosorbent, the biosorbent was removed by filtration through 0.45 m membrane filter and filters.
Using the atomic spectrometry we can analyze the residual cadmium.
ADVANTAGES AND DISADVANTAGES
ADVANTAGES
Cost effectiveness.
High efficiency.
Minimization of chemical/biological sludg,
And regeneration of biosorbent with possibility of metal recovery.
DISADVANTAGES
Early saturation of biomass.
Little biological control over the characteristics of biosorbents.
CONCLUSION
In this case study the removal efficiency of Cadmium was greater than 85%
The adsorption of metal ion on tree leaves reached equilibrium in 60 min.
pH=6-7 and initial concentration of 2mg/L.
Compare ulms leaves and their ash ,ulmus leaves ash is more effective than ulmus leaves
Analyzing all the result bisorption is an effective process for the removal of ions