table.dataTable thead .sorting_asc {
    background-image: url("") !important;
    background-position-x: left !important;
}

table.dataTable thead .sorting {
    background-image: url("") !important;
    background-position-x: left !important;
}

table.dataTable thead .sorting_desc {
    background-image: url("") !important;
    background-position-x: left !important;
}