Characterization of Two Gulf-Area Refinery Secondary Wastewater Treatment Plants to Resolve Hindered Settling Issues

摘要

This paper was generally well written, although the discussions included too much information from literature references, while presenting relatively few data to substantiate the observations made in the text. The focus of the paper was to characterize two petroleum refinery activated sludge processes and to use the information to resolve a hindered settling problem in one of the biological treatment systems. The characterizations included chemical and microbiological information, but the emphasis appeared to be primarily on microorganism identification relating to the apparent presence of filamentous microbes that were found to be more common in the activated sludge process (i.e., Refinery A) that experienced hindered settling. The microbiological evaluations utilized Fluorescence in situ Hybridization (FISH) methodology to identify filamentous bacteria, nitrifying bacteria, and denitrifying bacteria, although it was not clear why the latter two microbial groups were targeted in the study. Learned discussions that appeared to be taken from research literature by well-known investigators (e.g., Jenkins, Wanner, Daigger, and Seviour among others) in the field of filamentous bulking were heavily used throughout the text. However, little of the discussion was directly related to observations associated with petroleum refinery wastewater treatment.