A composition is described that comprises an abrasive, and a hydrocarbon containing component that is coupled to the abrasive. The pollutant collecting device includes a hollow tub and a collecting module. A second via is then etched into the dielectric material so as to expose and make the electrode layer available as a top electrode. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.