Uppal, O., R. Lees, K. McKeever, and S. Yalvigi.
RemTEC Summit, 7-9 March 2017, Denver, Colorado. Poster, 2017

A comprehensive treatability study of biological land treatment for nitrobenzene (NB), aniline, and diphenylamine (DPA) in soil was conducted to evaluate the feasibility of the biological land treatment application, develop contingent remedial approaches to mitigate the technical obstacles posed for land treatment, and develop data to support the remedial design basis. A full-scale pilot test was implemented to evaluate site specific conditions and confirm design and operational protocols. The lab treatability study consisted of four tasks: (1) soil sampling; (2) bulking simulation; (3) pre-treatment; and (4) land treatment simulation. The pilot test comprised four different test cells with varying contaminant constituents, soil texture (plastic clays, cohesive silts, sands), and bulking agents. The presence of lower permeability soils proved to be a significant challenge. The study yielded an improved understanding of the major contaminants, mainly that NB could not be degraded effectively through reactive chemical oxidation methods or at elevated levels > 2,500 mg/kg through biodegradation. NB and aniline are dissipated via abiotic processes, however, and can be readily degraded under moderate concentrations < 1,500 mg/kg. Elevated aniline > 2,500 mg/kg may pose toxicity to microbes. DPA was confirmed to pose no toxicity at elevated levels and degraded readily. DPA cannot be lost through abiotic processes under ambient temperatures; hence, DPA reduction would solely rely on biodegradation.