Summarize the following:
An evaporating dish will allow the water and carbon dioxide to slowly evaporate from the crystals. This method will take much longer than boiling off excess water and carbon dioxide, but can be done. Do not transfer any solid baking soda particles into the evaporating dish. A wide/long, shallow dish, like a glass casserole dish, works best. The water will take much longer to evaporate from a deep dish. The evaporation process will take days under standard conditions (room temperature, normal atmospheric pressure, etc.). If you wish to speed up the evaporation, you can place the dish under a heat lamp. As the water evaporates, white sodium acetate crystals will precipitate out of the solution and cling to the dish. Once the water evaporates, the sodium acetate crystals will be stuck to the evaporating dish. Use a razor to scrape the crystals from the dish. Store the crystals in an airtight container such as a ziplock bag.

Summary:
Pour the solution into an evaporating dish. Allow the contaminants to evaporate. Collect the crystals.