on closedness of some permutative posemigroup identities

As we know that all non-trivial permutation identities  are not preserved under epimorphisms of partially ordered semigroups.  in this paper towards this open problem, first we show that certain non-trivial identities in conjunction with the permutation identity z_1z_2 cdots z_n=z_{i_1}z_{i_2}cdots z_{i_n}~   (ngeq2) with i_n neq n  ~~[i_1 neq 1]  are preserved under epimorphisms of partially ordered semigroups. further, we extend a result of ahanger and shah which showed that the center of a partially ordered semigroup s is closed in s and show that the normalizer of any element of a partially ordered semigroup s is closed in s.