Which part of this circuit plays the role of filtration?
Please draw the circuit in the standard form next time! 

The opamp is configured as an Integrator in this circuit. The opamp is integrating the input signal rather than amplifying. The bypass capacitors C8,C1,C6 and C7 are filtering unwanted frequencies. TC and C5 are coupling capacitors. They allow only AC signals to pass through and block DC.

Read about: 
1. Operational Amplifier(Opamp) circuits.
2. Bypass capacitors.
3. Coupling capacitors. 

Any decent Analog Electronics book should have all these covered.