  The ground state phase diagram is obtained for an antiferromagnetic spin-1
anisotropic biquadratic model. With the help of symmetry and duality
transformations, three symmetry-protected trivial phases and one dimerized
symmetry breaking phase are found. Local and nonlocal order parameters are
identified to characterize these phases. Quantum phase transitions between the
symmetry-protected trivial phases belong to the Gaussian universality class
with central charge c = 1, and quantum phase transitions from the
symmetry-protected trivial phases to the dimerized phase belong to the Ising
universality class with central charge c = 1/2. In addition, the model admits
three characteristic lines of factorized ground states, which are located in
the symmetry-protected trivial phases instead of a symmetry breaking phase, in
sharp contrast to other known cases.
