Company owners and CEOs can do a lot to eradicate bullying and harassment in the workplace. This should be a key mandate given to the Human Resources department. If upper management makes it very clear to everyone that this is one of top priorities for the company, then it can be possible to develop and maintain a bully-free positive work environment.
Most professional HR personnel have training and expertise in this area. If the CEO/Owner of the firm gives a mandate to the HR team about making sure the organization creates and maintains a positive bully-free environment, the professional HR team can typically achieve that goal. They just have to put in appropriate processes and procedures in place so employees are able to openly address any issues that might come up.
If the employees know that if they face any bullying or harassment at work they can approach the HR department and if the HR department follows through with appropriate investigations, most employees will feel good about the company. Maybe the HR department will need to put together some mandatory training for all employees and supervisors so everyone is aware of the company mandate and the associated processes and procedures. But the bottom line is that it all starts with the upper management (i.e., CEO/Owner) making it clear to everyone that bullying/harassment in the workplace will not be tolerated and asks the HR department to make sure the processes are implemented appropriately.