Collecting adverbs are provided in this article. The words listed here are commonly found along with the verb collecting in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb COLLECTING.
actually, busily
carefully, constantly
diligently, gradually
hastily, merely
rapidly, simply
systematically
Hope this word list had the collecting adverb you were looking for. In addition to adverbs used with collecting, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.