Disruption typically involves a breakdown in relations between a trustee and the rest of the board or staff, making meetings difficult.
Responsibility for dealing with it rests with the chair, but another board member might be nominated. Either way, all decisions must be recorded.
A meeting should be arranged with the disruptive trustee to discuss their behaviour. It might stem from a feeling of inadequacy because of a lack of knowledge, in which case further induction is needed.
Alternatively, the trustee might decide they should not have taken the appointment. In that case, they should be permitted to step down without recrimination - especially in small charities, where bad feeling surrounding a well-known local figure's departure could have implications for the organisation's reputation.
Whatever the outcome, the dynamic of the board will have been affected. The chair will need to take time at its next meeting to clarify what has happened and either welcome the additional qualities gained by the trustee or mark their departure in a pleasant way.