Removing utf8=✓ from Database

I have an API that returns info straight from the database and noticed Rails is storing a utf8 check mark and the authenticity token. What is the best way to remove this before it is saved?

{"achievements":[{"utf8":"✓","authenticity_token":"XDzrmNqNyt6OfhWpAzu3j7LhMd/sRcr/4oLsPxRMrDY=","achievement":"Big Guns",...

An example of the controller code:

def achievements
  if params.include?(:ach)
    @achievement = Achievement.new(params[:ach])
    if @achievement.save
      redirect_to action: :achievements and return
    end
  end
end

Example of the view:

<%= form_tag '', multipart: true do %>
<div class="four columns">Name <input name="ach[achievement]" type="text" ></div>
<div class="five columns">Description <input name="ach[description]" type="text" ></div>
<% end %>