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The nano forms of the metals molybdenum oxide (MoO3), nickel oxide (NiO) and lithium oxide (Li2O) are finding wide application in advanced technologies including batteries and fuel cells. We evaluated soil responses to nanoMoO3, nanoNiO, and nanoLi2O as some environmental release of the materials, either directly or following the land application of biosolids, is expected. Using Drummer soil (Fine-silty, mixed, superactive, mesic Typic Endoaquolls), we evaluated the impacts of the three nanometals on soil gas (N2O, CH4, and CO2) emissions, enzyme activities (β-glucosidase and urease), and microbial community structure (bacterial, archaeal, and eukaryal) in a 60 day microcosms incubation. Soil treated with nanoLi2O at 474 μg Li/g soil, released 3.45 times more CO2 with respect to the control. Additionally, β-glucosidase activity was decreased while urease activity increased following nanoLi2O treatment. While no clear patterns were observed for gas emissions in soils exposed to nanoMoO3 and nanoNiO, we observed a temporary suppression of β-glucosidase activity in soil treated with either metal. All three domains of microbial community were affected by increasing metal concentrations. This is the first evaluation of soil responses to nanoMoO3, nanoNiO, or nanoLi2O.

Anthropogenic water use and reuse represent major components of the water cycle. In the context of climate change, water reuse and recycling are considered necessary components for an integrated water management approach. Unplanned, or de facto, indirect water reuse occurs in most of the U.S. river systems, however, there is little real-time documentation of it. Despite the fact that there are national and state agencies that systematically collect data on water withdrawals and wastewater discharges, their databases are organized and managed in a way that makes it challenging to use them for water resource management analysis. The ability to combine reported water data to perform large scale analysis about water use and reuse is severely limited. In this paper, we apply a simple but effective methodology to complete a time series watershed-scale analysis of water use and unplanned indirect reuse for the Wabash River Watershed. Results document the occurrence of indirect water reuse, ranging from 3% to 134%, in a water-rich area of the U.S. The time series analysis shows that reported data effectively describe the water use trends through nine years, from 2009 to 2017, clearly reflecting both anthropogenic and natural events in the watershed, such as the retirement of thermoelectric power plants, and the occurrence of an extreme drought in 2012. We demonstrate the feasibility and significance of using available water datasets to perform large scale water use analysis, describe limitations encountered in the process, and highlight areas for improvement in water data management.

A feasible and readily available source of hydrogen-producing acetogens (HPAs) was developed by obtaining microflora D83 dominated by butyrate-oxidizing HPAs through enrichment and subculture of anaerobic sludge with the use of butyric acid. The effect of bioaugmentation of D83 both on methane production through glucose fermentation and molasses wastewater treatment was evaluated. At a bacterial number-to-activated sludge ratio of 1:9, inoculation of microflora D83 could enhance methane yield and production rate from glucose by a factor of 2.1 and 2.0, respectively. In treatment of normal molasses wastewater, chemical oxygen demand (COD) removal efficiency improved from 75.6% to 88.2%, and the accumulated methane yield and methane yield obtained through COD removal increased by a factor of 2.3 and 2.0, respectively. Hydrogen-producing acetogenesis is apparently a rate-limiting step in methanogenesis because bioaugmentation of HPAs during methane production improved not only hydrogen-producing acetogenesis but also hydrolysis/acidogenesis and methanogenesis. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

The degradation and distribution of bisphenol A (BPA), bisphenol S (BPS) and bisphenol AF (BPAF) were evaluated in dilute anaerobic sludge slurries amended with a single bisphenol or a mixture of all three and maintained under methanogenic conditions over a 28-d period. No significant degradation of the bisphenols was observed in methane-generating microcosms. Rapid sorption to sludge particles was the primary removal process with sorption observed: BPAF > BPA > BPS. Several other trace organic chemicals of concern in the sludge were detected using quadrupole time of flight mass spectrometry. Of those detected, triclosan and triclocarban had sufficiently high intensities to quantify changes over the 28-d period in the bisphenol-amended microcosms. Similar to the bisphenols, triclosan and triclocarban concentrations also did not significantly change over the 28-d period with concentrations quantified at 2021 ± 627 and 1864 ± 769 μg/kg dry weight, respectively. Findings exemplify that methane-generating microcosms do not appear conducive to significant degradation of trace organics of concern in anaerobic sludge digesters. HighlightBisphenol A, S and AF as well as triclocarban and triclosan are not degraded under methane producing conditions.Removal from the liquid is through sorption to sludge particles and not biodegradation.Methane producing conditions are not suitable for achieving significant biodegradation of organics of concern. Bisphenol A, S and AF as well as triclocarban and triclosan are not degraded under methane producing conditions. Removal from the liquid is through sorption to sludge particles and not biodegradation. Methane producing conditions are not suitable for achieving significant biodegradation of organics of concern.

Aerobic biodegradation of 8:2 fluorotelomer stearate (FTS) and 8:2 fluorotelomer citrate triester (TBC) was evaluated in a forest soil in closed bottle microcosms. Loss of parent, production of 8:2 fluorotelomer alcohol (8:2 FTOH), which is released along with stearic acid (SA) by microbial ester linkage, and subsequent metabolites from FTOH degradation were monitored for up to 7months. Soil microcosms were extracted with ethyl acetate followed by two heated 90/10 v/v acetonitrile/200mM NaOH extractions. Cleavage of the ester linkage in the 8:2 FTS occurred (t1/2∼28d), producing 8:2 FTOH and various levels of subsequent metabolites. Quantifying the generation of SA from ester cleavage in FTS was complicated by the natural production and degradation of SA in soil, which was probed in an additional FTS and SA study with the same soil that had been stored at 4°C for 12months. In the latter study, FTS degraded faster (t1/2∼5d) such that SA production well above soil background levels was clearly observed along with rapid subsequent SA degradation. Cold storage was hypothesized to enrich fungal enzymes, which are known to be effective at hydrolytic cleavage. 8:2 TBC biotransformation was slow, but evident with the production of PFOA well above levels expected from known FTOH residuals. Slower degradation of TBC compared to FTS is likely due to steric hindrances arising from the close proximity of three 8:2 FT chains on the citrate backbone limiting the enzyme access.

Methane fermentation process can be restricted and even destroyed by the accumulation of propionate because it is the most difficult to be anaerobically oxidized among the volatile fatty acids produced by acetogenesis. To enhance anaerobic wastewater treatment process for methane production and COD removal, a syntrophic propionate-oxidizing microflora B83 was obtained from an anaerobic activated sludge by enrichment with propionate. The inoculation of microflora B83, with a 1:9 ratio of bacteria number to that of the activated sludge, could enhance the methane production from glucose by 2.5 times. With the same inoculation dosage of the microflora B83, COD removal in organic wastewater treatment process was improved from 75.6% to 86.6%, while the specific methane production by COD removal was increased by 2.7 times. Hydrogen-producing acetogenesis appeared to be a rate-limiting step in methane fermentation, and the enhancement of hydrogen-producing acetogens in the anaerobic wastewater treatment process had improved not only the hydrogen-producing acetogenesis but also the acidogenesis and methanogenesis. Open image in new window

Fullerene C60 nanoparticles are being used in broad range of applications. It is important to assess their potential impacts in the environment. We evaluated the effects of C60 introduced as aqueous suspensions of nC60 aggregates of different particle size or via organic solvents on soils with different organic matter contents in this study. Impacts of the application were evaluated by measuring total microbial biomass, metabolic activity and bacterial community structure. Results show that nC60 aggregates, introduced as an aqueous suspension, had size-dependent effects on soil bacterial community composition in the low organic matter system, but induced minimal change in the microbial biomass and metabolic activity in soils with both high and low organic matter contents. Fullerene C60, co-introduced via an organic solvent, did not influence the response of soil microbes to the organic solvents. Our results suggest that nC60 aggregates of smaller size may have negative impact on soil biota and soil organic matter may play a key role in modulating the environmental effect of nanomaterials.

A fundamental lack of data on the potential impacts of carbon based nanomaterials on natural ecosystems currently exists. The gap between what we know about environmental impacts and new products that may contain nanomaterials continues to get wider especially related to knowledge about nanocomposites. In this paper we present ideas and concerns about the current state of knowledge on nanomaterials in the environment and present a number of points about what recent work has provided us about the novel materials.

Nanoparticles are being used in many commercial applications. We describe the toxicity of two commercial silver (Ag) nanoparticle (NP) products, NanoAmor and Sigma on Pimephales promelas embryos. Embryos were exposed to varying concentrations of either sonicated or stirred NP solutions for 96 h. LC(50) values for NanoAmor and Sigma Ag NPs were 9.4 and 10.6 mg/L for stirred and 1.25 and 1.36 mg/L for sonicated NPs, respectively. Uptake of Ag NPs into the embryos was observed after 24 h using Transmission Electron Microscopy and Ag NPs induced a concentration-dependent increase in larval abnormalities, mostly edema. Dissolved Ag released from Ag NPs was measured using Inductively Coupled-Mass Spectrometry and the effects tested were found to be three times less toxic when compared to Ag nitrate (AgNO(3)). The percentage of dissolved Ag released was inversely proportional to the concentration of Ag NPs with the lowest (0.625 mg/L) and highest (20 mg/L) concentrations tested releasing 3.7 and 0.45% dissolved Ag, respectively and percent release was similar regardless if concentrations were stirred or sonicated. Thus increased toxicity after sonication cannot be solely explained by dissolved Ag. We conclude that both dissolved and particulate forms of Ag elicited toxicity to fish embryos.

Multi-phase extraction (MPE) is commonly used at petroleum-contaminated sites to volatilize and recover hydrocarbons from the vadose and saturated zones in contaminant source areas. Although primarily a physical treatment technology, the induced subsurface air flow can potentially increase oxygen supply and promote aerobic biodegradation of benzene, toluene, ethylbenzene, and xylenes (BTEX), the contaminants of concern at gasoline-contaminated sites. In this study, real-time PCR enumeration of aromatic oxygenase genes and PCR-DGGE profiles were used to elucidate the impact of MPE operation on the aquifer microbial community structure and function at a gasoline-contaminated site. Prior to system activation, ring-hydroxylating toluene monooxygenase (RMO) and naphthalene dioxygenase (NAH) gene copies were on the order of 106 to 1010 copies L−1 in groundwater samples obtained from BTEX-impacted wells. Aromatic oxygenase genes were not detected in groundwater samples obtained during continuous MPE indicating decreased populations of BTEX-utilizing bacteria. During periods of pulsed MPE, total aromatic oxygenase gene copies were not significantly different than prior to system activation, however, shifts in aromatic catabolic genotypes were noted. The consistent detection of RMO, NAH, and phenol hydroxylase (PHE), which catabolizes further oxidation of hydroxylated BTEX metabolites indicated the potential for aerobic biodegradation of dissolved BTEX during pulsed MPE.

Subsurface injection of oxygen-releasing materials (ORMs) is frequently performed at petroleum-contaminated sites to stimulate aerobic bioremediation of benzene, toluene, ethylbenzene, and xylenes (BTEX). In this study, qPCR enumeration of aromatic oxygenase genes and PCR-DGGE profiles of bacterial 16S rRNA genes were combined with groundwater monitoring to determine the impact of ORM injection on BTEX bioremediation at a gasoline-contaminated site. Prior to injection, BTEX concentrations were greater than 3 mg/L and DO levels were typically lessthan 2 mg/L, butphenol hydroxylase (PHE) and ring-hydroxylating toluene monooxygenase (RMO) genes were detected in impacted wells indicating the potential for aerobic BTEX biodegradation. Following injection, DO increased, BTEX concentrations decreased substantially, and PHE and RMO genes copies increased by 1-3 orders of magnitude. In addition, naphthalene dioxygenase (NAH) and xylene monooxygenase (TOL) genes were intermittently detected during periods of increased DO. Following depletion of the ORM, DO decreased, BTEX concentrations rebounded, and oxygenase genes were no longer detected. Temporal changes in PCR-DGGE microbial community profiles reflected the dynamic changes in subsurface conditions. Overall, the combination of chemical and geochemical analyses with quantification of aromatic oxygenase genes demonstrated that injection stimulated BTEX biodegradation until the ORM was depleted.

Growing environmental concerns, coupled with public pressure and stricter regulations, are fundamentally impacting the way companies design and launch new products across the world. Companies are recognising that implementing design for environment (DfE) in their product development process provides opportunities both for improving environmental aspects of a product and for enhancing the product competitiveness. Therefore, integrating environmental and business aspects for decision-making during DfE consideration are crucial in the product design process. The environmental aspect of the product is captured by the lifecycle assessment, and the result is directly introduced to the selection of DfE strategies followed by the multi-criteria decision-making process, in order to integrate business aspects. The proposed method may help the company systematically develop appropriate and profitable design for environment strategies for their product systems.

Monitoring groundwater benzene, toluene, ethylbenzene, and xylene (BTEX) concentrations is the typical method to assess monitored natural attenuation (MNA) and bioremediation as corrective actions at gasoline-contaminated sites. Conclusive demonstration of bioremediation, however, relies on converging lines of chemical and biological evidence to support a decision. In this study, real-time PCR quantification of aromatic oxygenase genes was used to evaluate the feasibility of MNA at two gasoline-impacted sites. Phenol hydroxylase (PHE), ring-hydroxylating toluene monooxygenase (RMO), naphthalene dioxygenase (NAH), toluene monooxygenase (TOL), toluene dioxygenase (TOD), and biphenyl dioxygenase (BPH4) genes were routinely detected in BTEX-impacted wells. Aromatic oxygenase genes were not detected in sentinel wells outside the plume indicating that elevated levels of oxygenase genes corresponded to petroleum hydrocarbon contamination. Total aromatic oxygenase gene copy numbers detected in impacted wells were on the order of 106–109 copies L−1. PHE, RMO, NAH, TOD, and BPH4 gene copies positively correlated to total BTEX concentration. Mann–Kendall analysis of benzene concentrations was used to evaluate the status of the dissolved BTEX plume. The combination of trend analysis of contaminant concentrations with quantification of aromatic oxygenase genes was used to assess the feasibility of MNA as corrective measures at both sites.

Because of the bioaccumulation of penta- and tetrapolybrominated diphenyl ether (PBDE) flame retardants in biota,the environmental biotransformation of decabromodiphenyl ether (BDE-209) is of interest. BDE-209 accounts for more than 80% by mass of PBDE production and is the dominant PBDE in sediments. Most sediments are anaerobic and reports of microbial reductive dehalogenation of hydrophobic persistent organohalogen pollutants are numerous. Reductive debromination of BDE-209 in the environment could provide a significant source of lesser-brominated PBDEs to biota. Moreover, a recent study showed that BDE-209 debrominates in sewage sludge, and another demonstrated that some halorespiring bacteria will debrominate BDE-209. To determine whether reductive debromination of BDE-209 occurs in sediments, parallel experiments were conducted using anaerobic sediment microcosms and a cosolvent-enhanced biomimetic system. In the biomimetic system, reductive debromination occurred at rates corresponding to bromine substitution levels with a BDE-209 half-life of only 18 s compared with a halflife of almost 60 days for 2,2',4,4'-tetrabromodiphenyl ether. In sediment, the measured debromination half-life of BDE-209 was well over a decade and was in good agreement with the predicted value obtained from the biomimetic experiment. Product congeners were predominantly double para-substituted. BDE-209 debrominated in sediment with a corresponding increase in nona-, octa-, hepta-, and hexa-PBDEs. Nine new PBDE congeners appeared in sediment from reductive debromination. Given the very large BDE-209 burden already in sediments globally, it is important to determine whether this transformation is a significant source of lesser-brominated PBDEs to the environment.

Increasing demands for freshwater make it necessary to find innovative ways to extend the life of our water resources, and to manage them in a sustainable way. Indirect water reuse plays a role in meeting freshwater demands but there is limited documentation of it. There is a need to analyze its current status for water resources planning and conservation, and for understanding how it potentially impacts human health. However, the fact that data are archived in discrete uncoordinated databases by different state and federal entities, limits the capacity to complete holistic analysis of critical resources at large watershed scales. Humans alter the water cycle for food production, manufacturing, energy production, provision of potable water and recreation. Ecosystems services are affected at watershed scales but there are also global scale impacts from greenhouse gas emissions enabled by access to cooling, processing and irrigation water. To better document these issues and to demonstrate the utility of such an analysis, we studied the Wabash River Watershed located in the U.S. Midwest. Data for water extraction, use, discharge, and river flow were collected, curated and reorganized in order to characterize the water use and reuse within the basin. Indirect water reuse was estimated by comparing treated wastewater discharges with stream flows at selected points within the watershed. Results show that during the low flow months of July–October, wastewater discharges into the Wabash River basin contributed 82 to 121% of the stream flow, demonstrating that the level of water use and unplanned reuse is significant. These results suggest that intentional water reuse for consumptive purposes such as landscape or agricultural irrigation could have substantial ecological impacts by diminishing stream flow during vulnerable low flow periods.

Decabromodiphenyl ether (BDE-209) is a major component of a commercial flame retardant formulation; however, there is limited information on the fate of BDE-209 in the environment, including metal oxide mediated degradation. Laboratory experiments were conducted to investigate the birnessite (delta-MnO(2))-promoted debromination of BDE-209 in tetrahydrofuran (THF)-water systems as well as catechol solutions. Up to 100% (0.1044 micromol initial charge) of BDE-209 disappeared upon reaction with birnessite in THF/H(2)O (4:6-9:1). The formation of aqueous Br(-) from BDE-209 reduction was determined and up to 16 mole% of initial bromine was released over the course of the reaction indicating approximately 1.7 Br-C bonds were reduced per BDE-209 molecule. The distribution of debrominated congeners, however, indicated a much greater extent of debromination for some products than what was inferred from an average bromine mass balance. The produced congeners varied from tetra- to nona-bromodiphenyl ether, including BDE-47 and -99, during the 24 h reaction. Experiments with deuterated water indicated that water was not the major hydrogen donor in the reduction but rather THF provided the reducing power. This conclusion was supported by the presence of succinic acid, which was produced from oxidation of THF. The reactions with aqueous catechol, rather than THF-water mixtures, were performed to assess the possible role that compounds found in natural environments, such a tannin-like phenols, might have on the chemistry. These experiments indicated that birnessite mediated debromination of BDE-209 might occur in natural settings.

The evolution and current status of sustainable production education (SPE) in the United States is reviewed, both as a discrete entity and as an intersection of multiple disciplines. This paper (a) examines the current array of compatible and conflicting theories that guide the alternative approaches to SPE, (b) reviews the wide array of applications to which such theories and associated methodologies have been applied, and (c) presents a case study of the emerging interdisciplinary approach to SPE at Purdue University in West Lafayette, Indiana, USA, and its network of national and international collaborators.

3,3′-Dichlorobenzidine (DCB) and its degradation products, 3-chlorobenzidine (MCB) and benzidine, are of environmental concern due to their toxic and carcinogenic nature. Laboratory experiments have been conducted to elucidate the biodegradation behavior of DCB in Lake Macatawa (Holland, Michigan) sediment–water systems at 4, 24, and 30 °C incubation temperatures. Sediment samples varied in pH (6.45–7.41), total organic carbon (OC) content (1.4–17.1), and particle size distribution (silty-clay to sandy). Biodegradation of DCB was observed in non-autoclaved samples that were incubated at 4, 24, and 30 °C for approximately 12 months. The dechlorination rate as a function of OC content was essentially found constant at 4 °C and 24 °C, but demonstrated a roughly linear increase at 30 °C, thereby suggesting that OC content might be correlated to dechlorination rate at 30 °C incubation temperature. The rate as a function of particle size (e.g.

The objective of this work was to test a molecular genetic method for in situ monitoring of aerobic benzene, toluene, and xylene (BTX) biodegrading microorganisms. Catechol 2,3-dioxygenase (C23DO) genes occur in bacteria that biodegrade benzene, toluene, xylenes, phenol, biphenyl, and naphthalene. A competitive quantitative polymerase chain reaction (QC-PCR) technique using a single set of primers specific for an entire subfamily of C23DO genes was recently developed. To determine whether bacteria containing these C23DO genes actually exist in environments contaminated by BTX, aerobic microcosms containing previously uncontaminated soil were amended with different aromatic hydrocarbons and DNA extracts were analyzed by QC-PCR for C23DO genes. Anaerobic microcosms were established to confirm that oxygen was also necessary for the enrichment of C23DO genes. Field testing was done at two sites undergoing monitored natural attenuation. In microcosm experiments naphthalene, m-xylene, and p-xylene strongly enriched for C23DO genes while benzene, toluene, and o-xylene produced only transient, weakly detectable genes. In the field study, C23DO genes were detected in groundwater samples contaminated with either xylenes or naphthalene. The results of this study demonstrated that molecular genetic techniques can provide an accurate and rapid method to detect microorganisms capable of aromatic hydrocarbon biodegradation. Such a technique would be useful for monitoring the effectiveness of aeration technologies and for documenting microbial processes for monitored natural attenuation.

Biotransformation of fluorotelomer (FT) compounds, such as 8:2 FT alcohol (FTOH) is now recognized to be a source of perfluorooctanoic acid (PFOA) as well as other perfluoroalkyl acids. In this study, microbially mediated hydrolysis of FT industrial intermediates 8:2 FT acrylate (8:2 FTAC) and 8:2 FT methacrylate (8:2 FTMAC) was evaluated in aerobic soils for up to 105d. At designated times, triplicate microcosms were sacrificed by sampling the headspace for volatile FTOHs followed by sequential extraction of soil for the parent monomers as well as transient and terminal degradation products. Both FTAC and FTMAC were hydrolyzed at the ester linkage as evidenced by 8:2 FTOH production. 8:2 FTAC and FTMAC degraded rapidly with half-lives ⩽5d and 15d, respectively. Maximum 8:2 FTOH levels were 6-13mol% within 3-6d. Consistent with the known biotransformation pathway of 8:2 FTOH, FT carboxylic acids and perfluoroalkyl carboxylic acids were subsequently generated including up to 10.3mol% of PFOA (105d). A total mass balance (parent plus metabolites) of 50-75mol% was observed on the last sampling day. 7:2 sFTOH, a direct precursor to PFOA, unexpectedly increased throughout the incubation period. The likely, but unconfirmed, concomitant production of acrylic acids was proposed as altering expected degradation patterns. Biotransformation of 8:2 FTAC, 8:2 FTMAC, and previously reported 8:2 FT-stearate for the same soils revealed the effect of the non-fluorinated terminus group linked to the FT chain on the electronic differences that affect microbially-mediated ester cleavage rates.

Although aromatic compounds are most often present in the environment as components of complex mixtures, biodegradation studies commonly focus on the degradation of individual compounds. The present study was performed to investigate the range of aromatic substrates utilized by biphenyl- and naphthalene-degrading environmental isolates and to ascertain the effects of co-occurring substrates during the degradation of mono-aromatic compounds. Bacterial strains were isolated on the basis of their ability to utilize either biphenyl or naphthalene as a sole source of carbon. Growth and transformation assays were conducted on each isolate to determine the range of substrates degraded. One isolate, Pseudomonas putida BP18, was tested for the ability to biodegrade benzene, toluene, ethylbenzene and xylene isomers (BTEX) individually and as components of mixtures. Overall, the results indicate that organisms capable of growth on multi-ring aromatic compounds may be particularly versatile in terms of aromatic hydrocarbon biodegradation. Furthermore, growth and transformation assays performed with strain BP18 suggest that the biodegradation of BTEX and biphenyl by this strain is linked to a catabolic pathway with overlapping specificities. The broad substrate specificity of these environmental isolates has important implications for bioremediation efforts in the field.

Release of 3,3‘-dichlorobenzidine (DCB), an intermediate in dye manufacturing, and its congeners are of environmental concern due to their carcinogenic nature. To elucidate the fate of these compou...

Pentachlorophenol (PCP) use as a general biocide, particularly for treating wood, has led to widespread environmental contamination. Biodegradation has emerged as the main mechanism for PCP degradation in soil and groundwater and a key strategy for remediation. Examining the microbial biodegrading potential for PCP at a contaminated site is crucial in determining its fate. Hundreds of studies have been published on PCP microbial degradation, but few have described the biodegradation of PCP that has been in contact with soils for many years. The bioavailability of “aged” hydrophobic organics is a significant concern. PCP- and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP)-contaminated soil samples from several depths at a former wood treatment site were placed under varying conditions in the laboratory to determine the anaerobic and aerobic potential for biodegradation of chlorophenols at the site. PCP biodegradation occurred in both anaerobic and aerobic soil samples. Rapid aerobic degradation occurred...

The dry anaerobic digestion process is an innovative waste-recycling method to treat high-solidcontent bio-wastes. This can be done without dilution with water by microbial consortia in an oxygenfree environment to recover potential renewable energy and nutrient-rich fertilizer for sustainable solid waste management. It generally takes place at solid concentrations higher than 10% and enables a higher volumetric organic loading rate, minimal material handling, lower energy requirements for heating, limited environmental consequences and energetically effective performance. The long retention time, poor startup performance, incomplete mixing and the accumulation of volatile fatty acids (VFAs) are considered as the main disadvantages for the solid-state fermentation process. In order to develop feasible dry anaerobic digestion processes, it is important to review the optimization techniques and suggest possible areas where improvements could be made. These include reactor configuration, mixing, solid retention time, feedstocks, organic loading rate, inoculation, co-digestion, pretreatment, percolation, additives and environmental conditions within the digester such as temperature, pH, buffering capacity and VFAs concentration.Key words: Solid organic wastes, dry anaerobic digestion process, biogas, optimization.

The wind power industry is growing rapidly. Wind turbines (WTs) are perceived as a low environmental impact energy generation technology. While the service life of a WT is relatively long (20-40 years), at some point a significant number of WTs will reach the end of their service lives. To recover maximum value from these WTs, planning for the end-of-service life of wind turbines (EOSLWTs) is paramount. Historically, environmental life cycle assessments of WTs have often only considered the materials extraction and processing, manufacturing, and use phases, leaving the management of EOSLWTs outside the scope of their attention. Four key EOSLWTs issues that are essential for the continuing development of wind energy technologies are presented: i) The challenges of managing of EOSLWTs given the fast growth rate of the industry and the large number of existing installed WTs; ii) The EOSLWT alternatives such as remanufacturing and recycling to recover functional and material value respectively; iii) The critical activities in the WT reverse supply chain such as recovery methods, logistics of transportation, quality of returns, and quality of reprocessed WTs; and iv) The economic and business issues associated with EOSLWTs. It is expected that the discussion provided will stimulate a dialog among decision makers and raise awareness of economic opportunities and unanticipated challenges in the wind power industry. © 2012 Elsevier Ltd. All rights reserved.

The use of single-wall carbon nanotubes (SWNTs) in manufacturing and biomedical applications is increasing at a rapid rate; however data on the effects of a potential environmental release of the materials remain sparse. In this study, soils with either low or high organic matter contents as well as pure cultures of E. coli are challenged with either raw as-produced SWNTs (AP-SWNTs) or SWNTs functionalized with either polyethyleneglycol (PEG-SWNTs) or m-polyaminobenzene sulfonic acid (PABS-SWNTs). To mimic chronic exposure, the soil systems were challenged weekly for six weeks; microbial activities and community structures for both the prokaryote and eukaryote community were evaluated. Results show that repeated applications of AP-SWNTs can affect microbial community structures and induce minor changes in soil metabolic activity in the low organic matter systems. Toxicity of the three types of SWNTs was also assessed in liquid cultures using a bioluminescent E. coli-O157:H7 strain. Although decreases in light were detected in all treated samples, low light recovery following glucose addition in AP-SWNTs treatment and light absorption property of SWNTs particles suggest that AP-SWNTs suppressed metabolic activity of the E. coli, whereas the two functionalized SWNTs are less toxic. The metals released from the raw forms of SWNTs would not play a role in the effects seen in soil or the pure culture. We suggest that sorption to soil organic matter plays a controlling role in the soil microbiological responses to these nanomaterials.

The performance and microbial community characteristics of a laboratory scale anaerobic baffled reactor (ABR) with four compartments (C1-C4) treating sugar refinery wastewater were investigated. The COD removal was 94.8 % with a CH4 yield of 0.21 L g(-1) CODremoved at total organic loading rate (OLR) of 5.33 kg COD/m(-3) day(-1). Fermentative bacteria were dominant in C1 and C2, while syntrophic acetogens and methanogens were dominant in C3 and C4. Some acid-tolerant methanogens were enriched in acidogenic phase. The present of the acid-tolerant methanogens could improve the efficiency and stability of the ABR as the most of the methanogens are vulnerable to low pH. In addition, high functional redundancy of the fermentative bacteria implicated that the microbial communities in acidogenic phase were stable functionally and allowed the ABR to balance perturbation. It was also found that syntrophic acetogenesis might be a weakness in the ABR as syntrophic acetogens were poor as compared with fermentative bacteria and methanogens.

The fast expansion of the wind power industry has positioned wind turbines (WTs) as a low environmental impact technology with a promising future. Although the useful life of WTs is relatively long, since 2005 a significant number of WTs have reached their end-of use (EOU) phase. The market for WT technology is in the growth phase and recovery of value from these used WTs is an unrealized economic opportunity. Remanufactured WTs will play a key role in supplying the burgeoning demand and unattended markets. This paper examines and discusses the economic and environmental benefits of remanufactured WTs, and how this resource can be effectively utilized.

As the technological benefits of nanotechnology begin to rapidly move from laboratory to large-scale industrial application, release of nanomaterials to the environment is inevitable. Little is known about the fate and effects of nanomaterials in nature. Major environmental receptors of nanomaterials will be soil, sediment, and biosolids from wastewater treatment. Analysis of anaerobic microbial activity and communities provides needed information about the effects of nanoparticles in certain environments. In this study, biosolids from anaerobic wastewater treatment sludge were exposed to fullerene (C60) in order to model an environmentally relevant discharge scenario. Activity was assessed by monitoring production of CO2 and CH4. Changes in community structure were monitored by denaturing gradient gel electrophoresis (DGGE), using primer sets targeting the small subunit rRNA genes of Bacteria, Archaea, and Eukarya. Findings suggest that C60 fullerenes have no significant effect on the anaerobic community over an exposure period of a few months. This conclusion is based on the absence of toxicity indicated by no change in methanogenesis relative to untreated reference samples. DGGE results show no evidence of substantial community shifts due to treatment with C60, in any subset of the microbial community.

The microbial transformation of 8:2 fluorotelomer alcohol (FTOH) to perfluorocarboxylic acids, including the globally detected perfluorooctanoic acid (PFOA), has recently been confirmed to occur in mixed bacteria cultures, activated sludge, and soil. However, little is known to date about the microbes involved in the transformation. In the present study, the effect of three carrier solvents (ethanol, octanol, and 1,4-dioxane), which may serve as carbon sources, on the aerobic degradation rate of 8:2 FTOH and metabolite distribution was evaluated both in a clay loam soil and in two pure soil bacterial cultures. Biodegradation pathways appeared similar regardless of the solvent; however, significant differences in 8:2 FTOH degradation rates were observed: 1,4-dioxane > ethanol > octanol. In the presence of 1,4-dioxane, which is not easily biodegraded, 8:2 FTOH degradation was the fastest With octanol, which is a structural analogue of 8:2 FTOH, the transformation was inhibited, but upon depletion of octanol, 8:2 FTOH was biodegraded. In the pure culture study, two soil bacterial strains, Pseudomonas species OCY4 and OCW4, enriched from soil using octanol as a sole carbon source, also transformed 8:2 FTOH without prior exposure or acclimation to 8:2 FTOH. Increased biomass resulting from octanol metabolism did increase 8:2 FTOH transformation rates; however, 8:2 FTOH could not support bacterial growth, indicating the transformation by pure cultures was via cometabolic processes.

The nascent state of the nanoproduct industry calls for important early assessment of environmental impacts before significant releases have occurred. Clearly, the impact of manufactured nanomaterials on key soil processes must be addressed so that an unbiased discussion concerning the environmental consequences of nanotechnology can take place. In this study, soils were treated with either 1 microg C60 g(-1) soil in aqueous suspension (nC60) or 1000 microg C60 g(-1) soil in granularform, a control containing equivalent tetrahydrofuran residues as generated during nC60 formation process or water and incubated for up to 180 days. Treatment effects on soil respiration, both basal and glucose-induced, were evaluated. The effects on the soil microbial community size was evaluated using total phospholipid derived phosphate. The impact on community structure was evaluated using both fatty acid profiles and following extraction of total genomic DNA, by DGGE after PCR amplification of total genomic DNA using bacterial variable V3 region targeted primers. In addition, treatment affects on soil enzymatic activities for beta-glucosidase, acid-phosphatase, dehydrogenase, and urease were followed. Our observations show that the introduction of fullerene, as either C60 or nC60, has little impact on the structure and function of the soil microbial community and microbial processes.

The photodebromination of decabromodiphenyl ether (BDE-209) adsorbed onto six different solid matrixes was investigated in sunlight and by irradiation with 350 +/- 50 nm lamps (four lamps at 24 W each). After 14 days of lamp irradiation, BDE-209 degraded with a half-life of 36 and 44 days, respectively, on montmorillonite or kaolinite, with much slower degradation occurring when sorbed on organic carbon-rich natural sediment (t1/2 = 150 days). In late summer and fall sunlight (40.5 degrees N, elevation 600 ft), the half-lives of BDE-209 sorbed on montmorillonite and kaolinite were 261 and 408 days, respectively. Under both irradiation schemes, no significant loss of BDE-209 occurred when sorbed to aluminum hydroxide, iron oxide (ferrihydrite), or manganese dioxide (birnessite). Upon exposure to both lamp and solar light and in the presence of montmorillonite and kaolinite, numerous lesser brominated congeners (tri- to nonabromodiphenyl ethers) were produced. Nearly identical product distribution was evident on montmorillonite and kaolinite. Dark control experiments for each mineral showed no disappearance of BDE-209 or appearance of degradation products. These results suggest that photodegradation of BDE-209 on mineral aerosols during long-range atmospheric transport may be an important fate process for BDE-209 in the environment.

This research effort focused on evaluating the toxicity of the saline waste water generated from washing of Indiana Department of Transportation (INDOT) deicing trucks and to study the feasibility of discharging it into wastewater treatment plants. Performance of activated sludge treating wastewater under varying levels of salt concentration was studied by measuring the Chemical Oxygen Demand (COD), activated sludge oxygen uptake rate (OUR) and Turbidity. For the COD tests, wastewater was tested with salt concentrations ranging from 0 mg/L – 1500 mg/L. Within this range there is no impact of salt on COD stabilization, suggesting that the microorganisms are not adversely impacted by salinity in this range. Turbidity tests were conducted for salt concentrations of 0 - 10,000 mg/L. Below a concentration of 3000 mg/ L salt did not have any significant impact on the turbidity. Concentrations above 3000 mg/L aided in flocculation of particles and resulted in faster settling of colloidal solids and reduction in turbidity. Another component of the study was to examine the fate and chemistry of ferric ferro/ferri cyanide, an anti-caking complex that is added to deicing salt. Although, the complex form of cyanide is harmless, in the presence of sunlight it can dissociate to form free cyanide that is highly toxic. Deicing salts collected from INDOT’s West Lafayette and Lafayette Facilities were tested for total and amenable cyanide levels. Lafayette road salt had high levels of cyanide that could lead to violation of pretreatment standards on cyanide, if this salt wash water is discharged to wastewater treatment plant. Respirometry was used for the impact assessment of variable salt concentrations on the biological performance of a low strength activated sludge samples for a POTW using a static liquid – gas flow (GFS) respirometer with salt concentrations varying from 0 – 10% . Generally, positive effect in oxygen uptake rate (OUR) was noticed on low salt concentrations up to 2% and a sharp decrease thereafter. A salt concentration of 6% resulted in a 50% decrease in respiration rate of the tested activated sludge. Further studies should involve the effect of saline shock loads in the specific ammonia uptake rate (SAUR) and specific nitrate uptake rate (SNUR) in addition to the final effluent quality.

The adoption of molecular genetic techniques has greatly improved our ability to characterize microbial populations in situ, leading to more accurate assessments of pollutant biodegradation and the impact of remediation technologies. Initially, biases associated with culturing were avoided by using DNA hybridization techniques with probes containing the catabolic gene of interest. Cross-hybridization at low stringency (46) and exclusion of related but not identical genes at high stringency (15, 30, 56) may produce false-positive and false-negative results with environmental samples. PCR amplification with primers based on conserved regions within the gene of interest, however, will permit amplification despite variability in the overall sequence and detect genotypes not detected by hybridization alone. Molecular methods, particularly in quantitative PCR (Q-PCR), continue to advance rapidly. Our laboratory described a competitive Q-PCR technique to enumerate catechol 2,3-dioxygenase genes as a means to evaluate bioremediation of aromatic hydrocarbons at petroleum-contaminated sites (35). Here we present primer sets targeting additional aromatic catabolic genes and the use of real-time PCR for quantification to extend our ability to enumerate genotypes involved in biodegradation of aromatic pollutants. The two main approaches to Q-PCR are competitive and real-time PCR. In competitive PCR, a comparison of the intensities of the standard and target amplicons allows quantification (42). One limitation of this method is that amplification efficiency of the target and standard are not always equivalent. Furthermore, post-PCR analysis of the products is labor-intensive and not amenable to the large-scale screening of environmental samples. Real-time PCR offers an accurate, sensitive method of quantification without the labor-intensive postamplification analysis and assumptions required by competitive PCR. Detection of product during amplification can be accomplished by several means, including molecular beacons (55), hybridization probes (60), and BODIPY FL-labeled probes and primers (27), but hydrolysis probes and DNA-binding dyes are the most commonly reported methods. The hydrolysis probe (TaqMan) assay takes advantage of the 5′-nuclease ability of DNA polymerase to hydrolyze a labeled probe bound to its target amplicon to produce a signal. The SYBR green assay relies on fluorescence signal produced as the dye binds to double-stranded DNA during the extension step. While the hydrolysis probe provides an additional degree of specificity, identifying an additional highly conserved region for the probe may not always be possible. Furthermore, both the probe and the primers must be from a highly conserved region of the target to avoid biasing quantitation (2). Simpler methods using DNA-staining dyes, such as SYBR green I, have been successful (36, 62), do not require the design of an internal hybridization probe, and thus can be used with any established PCR primers with only minor modifications of the described protocols. This study was conducted to develop multiplex and real-time PCR procedures to quantify aromatic catabolic genes in environmental samples and eventually improve our understanding of biodegradation in the field. The large subunit of aromatic oxygenase genes was chosen as the indicator gene, because it has been implicated in substrate specificity and is one of the rate-limiting steps in aromatic hydrocarbon biodegradation (14) and its DNA sequence is conserved for oxygenases targeting the same substrate. Alignments were constructed from groups of related oxygenase genes, and each primer set was chosen from a conserved region unique to that group of oxygenases. Thus, a single primer set will detect an entire subfamily of related oxygenase genes rather than a species-specific catabolic gene. In all, PCR primer sets which targeted biphenyl dioxygenase, naphthalene dioxygenase, toluene dioxygenase, toluene/xylene monooxygenase, phenol monooxygenase, and ring-hydroxylating toluene monooxygenase genes were identified. Testing and optimization with genetically well-characterized bacterial strains demonstrated the specificity of each primer set. Multiplex PCR protocols were developed to permit simultaneous detection of aromatic oxygenase genes and facilitate rapid screening of environmental samples. Real-time PCR with SYBR green I was used to determine the gene copy number with a quantification limit of 2 × 102 copies of target per reaction mixture. The primer sets and real-time PCR methods presented will be used to assess natural attenuation, investigate the ecology of contaminated sites, and aid in optimization of bioremediation in the field.

Benzene, toluene, xylenes, phenol, naphthalene, and biphenyl are among a group of compounds that have at least one reported pathway for biodegradation involving catechol 2,3-dioxygenase enzymes. Thus, detection of the corresponding catechol 2,3-dioxygenase genes can serve as a basis for identifying and quantifying bacteria that have these catabolic abilities. Primers that can successfully amplify a 238-bp catechol 2,3-dioxygenase gene fragment from eight different bacteria are described. The identities of the amplicons were confirmed by hybridization with a 238-bp catechol 2,3-dioxygenase probe. The detection limit was 10 2 to 10 3 gene copies, which was lowered to 10 0 to 10 1 gene copies by hybridization. Using the dioxygenase-specific primers, an increase in catechol 2,3-dioxygenase genes was detected in petroleum-amended soils. The dioxygenase genes were enumerated by competitive quantitative PCR with a 163-bp competitor that was amplified using the same primers. Target and competitor sequences had identical amplification kinetics. Potential PCR inhibitors that could coextract with DNA, nonamplifying DNA, soil factors (humics), and soil pollutants (toluene) did not impact enumeration. Therefore, this technique can be used to accurately and reproducibly quantify catechol 2,3-dioxygenase genes in complex environments such as petroleum-contaminated soil. Direct, non-cultivation-based molecular techniques for detecting and enumerating microbial pollutant-biodegrading genes in environmental samples are powerful tools for monitoring bioremediation and developing field evidence in support of natural attenuation.

Leaking underground storage tanks are widespread throughout the United States. It is estimated that there are 1.4 million underground gasoline storage tanks in the United States, with as many as 75,000 to 100,000 that may be leaking. In Indiana alone, more than 3,500 of the 15,000 registered underground storage tank facilities have reported leaks. Conventional remediation methods often involve pump-and-treat schemes for contaminated water, and excavation and burial of contaminated soil in hazardous waste landfills. These methods increase the risk of exposure to pollutants for workers and local residents. Furthermore, these methods merely involve the transfer of pollutants from one environmental compartment to another, and are rather costly. Bioremediation is another method available for the restoration of contaminated sites. Advantages of bioremediation include competitive cost, pollutant destruction, and minimal environmental disturbance. By biodegrading organic pollutants on site, exposure to pollutants is minimized and costs are reduced. Bioremediation can potentially be an effective, low-cost, and terminal solution for remediation of sites contaminated with organic pollutants. The goal of bioremediation is to accelerate the biodegradation rates of naturally occurring microorganisms that utilize organic pollutants as a food source. The overall objective of this study was to determine whether bioremediation is a feasible treatment option for contaminated Indiana Department of Transportation (INDOT) soils. All INDOT soils tested had three things in common. First, a thriving heterotrophic microbial population existed. Second, bacteria capable of degrading benzoate (a toluene surrogate) were present in all soils. This study provides some evidence that physical, rather than microbial, parameters control biological processes in soil. Based on these results as a whole, it is concluded that in-situ bioremediation of petroleum hydrocarbons is a treatment option which should have increased utilization.