preg_replace to delete something in a special string

preg_replace to delete something in a special string

Hi I tried to delete something in a string. But I don't know ho to make it.
My string:
@trash='test1',value1='test2',@trash='test3',value2='test4'
I want to delete all with @trash for example = @trash='test1',.
Perhaps important is, that of course the value in the example above
"test1" is allways changing.