My sincere apologies for the delay in answering your question. Looks like something might had happened that did not allow the answer to be recorded and saved.
So here it goes again:
Congratulations on your graduation! I hope you are excited to start applying to the real world the knowledge you acquired during all those years of studying. You will soon see that a degree in chemical engineering will open the doors for you in many industries and sectors, as well as in the Environmental field. My recommendation is for you to search opportunities that will allow you to solve problems related to the environment, either by means of a full time work or volunteering. I think that the most important thing will be for you to interact with other Environmental Engineers and Scientists in the field, the lab, or even in the bar. Yes, there are numerous societies and organizations that sponsor networking events and volunteering opportunities that may help you reach your goals (e.g., Engineers without Borders, AIChE, Society of Women Engineers).
The specialization are numerous: hazardous waste management; environmental health and safety; land remediation; water treatment; air pollution; sustainability, groundwater contaminant modeling... Perhaps you should give me a bit more of background to see what your interests are before I make this list comprehensive!