Dependence of axioms of Zermelo set theory

Question

I'm reading a book about Zermelo–Fraenkel set theory, and I was told that there are a lot of dependence relation among the commonly used axiom system (in the question What axioms does ZF have, exactly? , many examples can be found). But I notice that most of dependence relations are cause by the Replacement Scheme. So I wonder that if only considering the axioms of Zermelo set theory (that is, ZC, or more precisely, the axiom system consisting of Extensionality, Foundation, Comprehension Scheme, Pairing, Union, Infinity, Power Set and Choice), does there still remain any redundant axiom? Thanks in advance.