Factory legacy pollutants are an increasing concern for waterways as old infrastructure deteriorates and contaminates nearby environments. The Fisherville Mill in Grafton, Massachusetts, USA exemplifies this problem since it has now fallen into disrepair and is leaking Bunker C crude oil into the adjoining Blackstone River, a third order stream. Our research examines how effectively an ecologically engineered system (EES), consisting of anaerobic bacteria environments, fungal microcosms, and aquatic plant environments, can break down petroleum hydrocarbons, specifically aliphatic and polycyclic aromatic hydrocarbons (PAH), in this river environment. Our testing protocol involved taking water samples before and after each filtration stage monthly from June through October 2012. Water samples were analyzed at the Brown University Superfund Research Lab using mass spectrometry to determine aliphatic and PAH concentrations. Post-treatment aliphatic oil concentrations were significantly different from baseline concentrations (p=0.005), with an average reduction of 95.2%. Post-treatment PAH concentrations were also significantly different from baseline concentrations (p=0.001), with an average reduction of 91%. We conclude that this EES provided effective treatment for Bunker C crude oil, even though some filtration stages did not achieve their intended objectives. This type of filtration arrangement might be scaled up for use in larger remediation efforts regarding Bunker C crude oil.

Eutrophication due to excess loading of phosphorus (P) is a leading cause of water quality degradation within the United States. The aim of this study was to investigate P removal and recovery with 12 materials (four calcite varieties, wollastonite, dolomite, hydroxylapatite, eggshells, coral sands, biochar, and activated carbon. This was accomplished through a series of batch experiments with synthetic wastewater solutions ranging from 10-100 mg PO₄-P/ L. The results of this study were used to establish large-scale, calcite-based column filter experiments located in the Rubenstein School of Environment and Natural Resources' Eco-Machine. Influent and effluent wastewater samples were routinely collected for 64 days. Measures of filter performance included changes in pH, percent reduction and mass adsorbed of P. After the columns reached saturation, filter media was analyzed for the mineralogical content by X-ray powder diffraction (XRD). In the batch experiments, P removal and recovery varied among the media and across treatments. The best performing minerals were calcite, wollastonite, and hydroxylapatite. Eggshells, activated carbon, and coral sands also reduced and adsorbed P. The remaining materials had the lowest reductions and adsorption of P. Results from batch experiments informed the design of large column filters within the Rubenstein School of the Environment and Natural Resources' Eco-Machine. Removal and adsorption rates of P by the three column filters were similar. The columns achieved an average P reduction of 12.53% (se = 0.98) and an average P adsorption of 0.649 mg PO₄-P/ kg media (se = 0.03) over a 4-h hydraulic retention time. Paired T-tests showed that P reductions were statistically significant (p-value < 0.05) on the majority of sampling dates until the columns reached saturation. Saturation was reached after 31 days for two of the columns and 36 days for the third column. The filter media consistently buffered the pH of the wastewater to approximately 6.0-7.0 with no indication of diminishing buffer capacity after saturation. XRD analysis was not able to detect any P species within the crystalline structure of the filter media. This research contributes to the understanding of how the selected media perform during P removal and recovery programs, while providing information on the performance of large column filters operating within advanced, ecologically engineered wastewater treatment systems.