Hamid Borazjani

Bioremediation studies at a northern California Superfund site

Abstract Laboratory analysis of land treatment of wood preservative contaminated soils was performed as part of an investigation of remediation alternatives for an EPA Superfund site. Experimental procedure involved 6 different site soils with different supplementary nutrients placed in lined steel boxes, 6′ × 12′ × 5′ deep, and analyzed for among other things creosote pentachlorophenol acclimated and total bacteria populations, polynuclear aromatic hydrocarbons (PAHs), and pentachlorophenol (PCP) with both single and multiple loadings. The best overall percentage reduction occurred where there were moderate initial constituent concentrations and the highest level of manure.

Enhanced Remediation of Pentachlorophenol (PCP)-Contaminated Groundwater by Bioaugmentation with Known PCP-Degrading Bacteria

ABSTRACT The objective of this study was to test whether bioaugmentation with known pentachlorophenol (PCP)-degrading bacteria (Sphingobium chlorophenolicum and Burkholderia cepacia) could enhance remediation of PCP-contaminated groundwater. Groundwater PCP concentrations were determined by US Environmental Protection Agency (EPA) method 3510C and gas chromatography. Gene expression for PCP-degrading enzymes: pentachlorophenol 4-monooxygenase (pcpB; S. chlorophenolicum) and chlorophenol 4-monooxygenase (TftD; B. cepacia) was determined by real-time polymerase chain reaction (RT-PCR) using gene-specific primers. Bioaugmented treatments with S. chlorophenolicum and B. cepacia showed 32% and 49% decrease (p < .05) whereas un-bioaugmented (indigenous) treatment did not show significant decrease (p > .05) in average PCP concentration, respectively, over 72 days. Decreased PCP levels correlated strongly (r = −.82, p < .05) with increased PCP-tolerant bacteria in bioaugmented treatments, whereas no significant correlation was observed (r = −.22, p > .05) in un-bioaugmented treatment. In addition, a decrease in PCP levels also correlated significantly with an increase in gene expression of PCP-degrading enzymes, pcpB (r = −.77044) and TftD (r = −.87905) (p < .05). PCP concentrations decreased and pcpB or TftD expressions were higher in bioaugmented treatments with S. chlorophenolicum (50%, 7-fold) or B. cepacia (67%, 10.7-fold), respectively, than indigenous treatment. Therefore, bioaugmentation with known PCP-degrading bacteria enhanced remediation of PCP-contaminated groundwater than indigenous bacteria alone. Results of this study may provide a more efficient and environmentally friendly technique for on-site remediation of PCP-contaminated groundwater.

Effects of Composting On Removal of Nitrogen, Phosphorus, and Potassium from Sawdust Amended with Chicken Litter

A six month study evaluated composting affects on nitrogen (N), phosphorus (P), and potassium (K) leaching from hardwood and furniture sawdust amended with 20% and 30% chicken litter. Toxicity Characteristic Leaching Procedure (TCLP) was obtained from substrates. Moisture was provided through precipitation, and the substrate was aerated once or twice per week, depending on the amount of rainfall. Samples were collected at 45 day intervals for analysis. A significant reduction in N and K concentrations occurred for all amended compost by day 180. Hardwood substrate matured quicker than furniture compost based on a radish seed germination test. Toxicity reduction occurred in every treatment by day 180. Chicken litter control showed the best overall weight loss; however, its toxicity levels were still much higher on day 180.

Efficacy of Pentachlorophenol in Biodiesel versus Diesel

Abstract Pentachlorophenol (PCP) is widely used as a wood preservative for utility poles and other wood products. It has been proposed that a modified PCP carrier system based on a diesel/biodiesel mixture should be used in place of the conventional diesel/KB3 carrier, but questions exist as to whether this modified carrier system can provide the same service life as wood products treated with PCP/diesel/KB3. The main objective of this research was to evaluate the comparative decay resistance of wood treated with carrier formulations containing either diesel/KB3 or diesel/biodiesel. A 2-year efficacy study using an accelerated soil contact decay test was initiated to compare the performance of southern yellow pine wood treated with the conventional diesel/KB3 carrier and a modified diesel/biodiesel carrier, both with and without PCP. The residual hydrocarbon levels, PCP reduction, toxicity, and leaching of PCP of the samples remained approximately at the same level for treatments with similar PCP retentio...

Treatment of Bio-Oil Refinery Storm Water by a Simulated Constructed Wetland: A Sustainable Management Alternative

Abstract Contaminated storm-water discharge is a growing concern in the United States owing to a steady increase of harmful pollutants entering freshwater sources. This study remediated contaminated storm-water runoff from a bio-oil conversion facility through a simulated constructed wetland. A six-phase series of constructed wetlands was contaminated with varying dilution levels of bio-oil process water. The study concluded that there was a significant decrease in biological oxygen demand (BOD) and microtoxicity over a 10-day remediation cycle within the constructed wetlands for the lower levels of contaminated storm water. The higher levels of contamination changed very little in total volume of pollution. A comparative screening of the bacterial community within the wetlands during the contamination process showed a similar trend in species richness and composition for the first three phases of contamination. There was a shift in richness and diversity for the final three phases of contamination after ...

Co-Composting of Steam-Pressed Scrim Lumber Process Water

Steam-pressed scrim lumber (SPSL) involves crushing small diameter trees into mats that are coated with adhesive and pressed into boards. Water from the crushing process contains a high biological oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS). This water must be remediated before it can be discharged into public water systems. A 6-month study was conducted to evaluate the effectiveness of co-composting of the process water with wood waste and chicken manure as a method of remediation. Wood waste from the SPSL pilot facility in Shuqualak, Mississippi, was ground into small particles. This material was composted using four treatments: with or without added manure plus deionized (DI) water or process water to adjust moisture content. The compost end products for all treatments were evaluated for relative toxicity, weight loss, maturity, and suitability as a container substrate to grow plants. Additional testing determined the toxicity of compost leachate and evaluated th...

Biopiling of creosote contaminated soil

Abstract An abandoned wood-treating facility in south Mississippi was the site of a year-long field-scale study. The facility produced creosote-treated railroad cross-ties and marine pilings, and released creosote wastes into the environment for almost forty years. The magnitude of contamination through soil contact, accidental spills, and disposal of creosote wastes in unlined disposal pits was great. Bioremediation of organic compounds has been successfully employed at many sites, however physical factors can be rate limiting. biopiling enhances aerobic catabolism of creosote by injection of air into piles of contaminated soil. The objectives of this study were to evaluate the effectiveness of forced air injection, addition of kenaf, and application of Cladosporium sp. fungus in enhancing creosote biodegradation and to determine if biopiling could be considered for future remediation at similar sites. Creosote contaminated soil was excavated and mixed to construct 12 study piles, 4 m long×3 m wide×1 m high, in three randomized blocks of four treatments, namely controls, vented, vented with 1% kenaf (by volume) and vented with 1% kenaf and Cladosporium sp. Sampling was at 45 day intervals for one year, and soil samples were extracted according to EPA method 3540 and analyzed for 17 selected PAHs and by EPA method 8100. An overall decrease in concentration occurred from day 0 to 360 for all treatments with the majority of decrease occurring by day 45, with PAH concentrations reaching a stable plateau after day 90. Surprisingly, no significant differences existed between treatments at day 360 from any group of PAHs. If the rapid degradation rates evident at the beginning of the study could be maintained, then biopiling would be the treatment of choice at many creosote contaminated sites.