Evolution of extracellular polymeric substances produced in two submerged membrane bioreactors working at high sludge age

This research paper deals with the evolution of the extracellular polymeric substances (EPS) produced in the mixed liquor of two 25 L bench-scale membrane bioreactors (MBRs), with micro (MF-MBR) and ultrafiltration (UF-MBR) submerged membranes. The conclusion focuses on the relationship between the operation and how EPS respond, demonstrating that significant changes in EPS concentration were commonly observed when abrupt changes in the operational conditions took place. Bound EPS (EPSb) showed moderate positive statistical correlations with sludge age and MLSS for the two MBRs. Soluble EPS (EPSs), on the other hand, showed a moderate negative statistical correlation between EPSs with the two parameters analyzed for MF-MBR and no correlation with the UF-MBR was found. With respect to the composition of EPS, EPSb were mostly made up of proteins (44–46%) whereas in EPSs, the three components (proteins, carbohydrates, and humic substances) appeared in approximately the same proportion. The statistical analysis exhibited strong positive correlations between EPSb and their constituents, however for EPSs, the correlation was strong only with carbohydrates and moderate with humic substances.

Genetically engineered silk and genipin-enhanced fibrin hydrogel for annulus fibrosus repair

INTRODUCTION: Around 80% of people are affected by low back pain at least once in their life, often caused by trauma provoking intervertebral disc (IVD) herniation and/or IVD degeneration. Apart from some promising approaches for nucleus pulposus repair, so far no treatment or repair is available for the outer fibrous tissue, annulus fibrosus (AF). We aimed for sealing and repairing an AF injury in a bovine IVD organ culture model in vitro over 14 days under different loading conditions. For this purpose, a silk fleece composite from Bombyx mori silk was combined with genipin-enhanced fibrin hydrogel [1]. METHODS: Bovine IVDs of 12-17 months old animals were isolated by first removing all surrounding tissue, followed by cutting out the IVDs [2]. Culturing of discs occurred in high glucose Dulbecco's Modified Eagle Medium (HG-DMEM) supplemented with 5% serum as previously described. On the next day, injury was induced using a 2mm biopsy punch (Polymed, Switzerland). The formed cavity was filled with (0.4%) genipin-enhanced human based fibrin hydrogel (35- 55mg/mL human fibrinogen, Baxter, Austria) and sealed with a silk fleece-membrane composite (Spintec Engineering, Germany). Different culture conditions were applied: free swelling, static diurnal load of 0.2MPa for 8h/d and complex loading at 0.2MPa compression combined with ± 2° torsion at 0.2Hz for 8h/d. Complex loading was applied by a custom built 2 degree of freedom bioreactor [3]. After 14 days of culture cell activity was determined with resazurin assay. Additionally, glycosaminoglycan (dimethyl-methylene blue), DNA (Hoechst) and collagen content (hydroxy-proline) were determined. Finally, real-time qPCR of major IVD marker genes was performed. RESULTS: The silk seal closing the injury site could successfully withstand the forces of all three loading conditions with no misplacement over the two weeks’ culture. Nevertheless, disc height of the repaired discs did not significantly differ from the injured group. The disc phenotype could be maintained as demonstrated by biochemical analysis of gene expression, cell activity, DNA-, collagen- and GAG content. The silk itself was evaluated to be highly biocompatible for hMSC, as revealed by cytotoxicity assays. DISCUSSION & CONCLUSIONS: The silk can be considered a highly-elastic and biocompatible material for AF closure and the genipin-enhanced fibrin hydrogel has also good biomechanical properties. However, the cyto-compatibility of genipin seems rather poor and other hydrogels and/or cross-linkers should be looked into. REFERENCES: 1 C.C. Guterl et al. (2014) Characterization of Mechanics and Cytocompatibility of Fibrin Genipin Annulus Fibrosus Sealant with the Addition of Cell Adhesion Molecules, Tissue Eng Part A 2 S.C. Chan, B. Gantenbein-Ritter (2012) Preparation of intact bovine tail intervertebral discs for organ culture, J Vis Exp 3 B Gantenbein et al. (2015) Organ Culture Bioreactors - Platforms to Study Human Intervertebral Disc Degeneration and Regenerative Therapy, Curr Stem Cell Res Ther [epub ahead of print] ACKNOWLEDGEMENTS: This project is supported by the Gebert Rüf Stiftung project # GRS-028/13.

Evaluation of solid waste baling and balefills : volumes I and II.

Item 431-I-7

A rea Sur de Chicago : proyecto Piloto de Notificaci on al P ublico : incluye las a reas de Chicago Heights, South Chicago Heights y Steger.

House Resolution (HR) 1010 adopted June 2004, encourages the Illinois EPA to establish a Right-to-Know Committee and to obtain citizens' input on the most effective and efficient means of providing notice to residents exposed to or potentially exposed to contamination from air, land or water. In keeping with the spirit of the resolution, Illinois EPA is conducting this pilot notification project with the assistance of the Illinois Department of Public Health and the Cook County Department of Public Health. This notice is precautionary, because of the potential for one or more sites to affect the groundwater quality in the area. There are many sites in the area that may have a potential for contaminating groundwater. The current notification has to do with information Illinois EPA has gathered in the course of investigating, monitoring and performing work on the landfill sites discussed below. These are located in the Chicago Heights/South Chicago Heights area, south of 26th Street and west of State Street (see attached map): Chicago Heights Refuse Depot, Triem Landfill and Fitzmar Landfill. A fourth landfill, Lobue, is adjacent to these, although Illinois EPA currently has very little information about that landfill. In 1987, vinyl chloride was detected in South Chicago Heights Well #3 at a level that was more than the Class I Groundwater Standard, which is 2 parts per billion. Investigation and sampling of monitoring wells at the landfill site near Well #3 showed higher concentrations of vinyl chloride (140-240 parts per million) in 1988. South Chicago Heights discontinued the use of Well #3 after this event and later stopped using all its wells and began purchasing water from Chicago Heights in 2000.

A rea Sur de Chicago : un iniciativo de alcanze para pruebas de pozos privados : Incluye las a freas de Chicago Heights, South Chicago Heights y Steger.

Areas of concern: This notification is based on information Illinois EPA has found while investigating, monitoring and working on two landfill sites in the Chicago Heights/South Chicago Heights area. Tests from groundwater and surface water at one landfill site showed levels of vinyl chloride greater than state Class I groundwater standards - the state standards that are designed to protect groundwater for use as drinking water. Vinyl chloride is from a family of chemicals known as volatile organic compounds (VOCs), which are common man-made chemicals found in cleaning solvents, gasoline and oil. These chemicals can travel in groundwater long distances from where they were spilled or dumped.

Final report of the White Goods Task Force to the 88th General Assembly and the Governor of Illinois.

On June 29, 1992, the Illinois General Assembly enacted Public Act 87-858 which placed an impending ban on the landfill disposal of "white goods" and required the Illinois Environmental Protection Agency and the Illinois Department of Energy and Natural Resources to establish a Task Force to develop and propose desired statutory, regulatory, and programmatic changes necessary to effectively implement the provisions of the legislation.

I-RID : Illinois removes illegal dumps /

"12-06."

Industrial Material Exchange Service /

The Industrial Material Exchange Service (IMES) program is a free service designed to provide a mechanism for recycling and reusing unwanted materials. The exchange program maintains and distributes listings of materials both wanted and available provided by our participants. Through IMES, waste generators can be matched with waste users. Any material, either non-hazardous or hazardous that is available from one business yet has potential reuse by another, can be a part of the exchange. IMES functions as an information clearinghouse for industrial by-products, surplus materials, waste and other forms of unwanted industrial materials. The goal of the IMES program is to conserve energy, resources and landfill space by helping find alternatives to disposal of what might be a valuable material.

A Study of Shallow Groundwater Migration through Anthropogenic Fill along a Seawall

This report provides the findings and opinions of a historical document review, hydraulic balance calculation, and proposed additional study for a property that was historically used as a bulk petroleum storage and distribution facility. The property lies along the base, west, of a heavily vegetated bluff with a tidally influenced body of water west-adjacent to the property. The western portion of the property is bounded by a seawall spanning approximately 3,200 linear feet trending north-south. The seawall’s construction details are not known, save for a 225-foot section of driven sheet pile wall located within the northern portion of the property’s seawall. Due to the presence of petroleum hydrocarbons in soil and groundwater at the property, a cleanup action for the property will likely be overseen by the state regulatory agency. The property is currently undergoing remedial investigation in an effort to identify the lateral and vertical extent in which contaminants at the property have come to be located, also known as the “site” as defined by the Model Toxics Control Act (MTCA). The majority of the property bounded within the seawall area has been characterized; however, the shoreline sediments located immediately west-adjacent of the seawall have not been properly delineated. Identifying the bounds of the site to the west within sediment is pivotal for the purposes of the remedial investigation. Since the west-adjacent shoreline is so extensive, conducting a complete sediment sampling event along the entire shoreline would be cost-prohibitive due to analytical costs and logistical issues at the property. Because of the extensive nature of the shoreline, it would greatly benefit the client and project to focus sampling efforts at areas of greater risk for contaminants along the shoreline by identifying potential preferential pathways for contaminants to migrate off of the property and into adjacent shoreline sediments. The review of historical studies of the property yielded some useful information; however much of the findings included within the historical studies were lacking original raw data, therefore limiting the information obtained. The calculated hydraulic balance for the property yielded a relatively large surplus of recharge to groundwater after precipitation events, reinforcing the concept that contaminant have potentially historically, and currently, been migrating into the adjacent shoreline through preferential pathways along the seawall. Due to the limitation within the historical studies for the property as well as the groundwater recharge identified in the hydraulic balance, an additional study was proposed in an effort to provide additional aquifer characteristics along the seawall, and the ability to observe flow propagation at and proximate to the seawall in two-dimensions through time without the need to piece separate studies together. This proposed study includes a single simultaneous tidal study which comprises select monitoring points along the seawall. This report has identified the need for additional data that can be collected through available avenues for the property based upon the client’s desires and project needs. Ultimately, the proposed additional study is suggested based upon its relatively low capital investment, and ability meet the requirements relevant to the specific project needs and scope. Assuming preferential pathways are identified through the additional study proposed within this report, a representative and cost-effective sediment sampling plan can then be put in place in an effort to define the site.

An investigation of contaminant distribution in subsurface marine wood waste at Mill-A South Terminal, Port of Everett, Washington

This project investigates the correlation between contaminants and the wood waste present in marine sediments off the shore of the Port of Everett in the former Weyerhaeuser Mill-A pulp mill site. The investigation includes the results of two field studies, which tested contaminant levels in 22 boreholes as well as several surface samples. The contaminants include heavy metals and wood waste byproducts. These results, along with 14 other bore logs, provide the framework for a three-dimensional site model, interpolating the full extent of the depositional units and organic and inorganic chemicals found at Mill-A. The sediments of interest are divided into five depositional units defined by the percent wood content and type of wood: native material (<5% wood), intermediate (<30% wood), sawdust (<30% wood), woodchips (<30% wood), and poorly sorted sands with silt (SM-SP) (0% wood). The contaminants include arsenic, 2,4-dimethylphenol, and total organic carbon. Three-dimensional modeling software, RockWorks, interpolated the discrete borehole data of sediment and contaminants assuming horizontal continuity between sampling locations. The sediment distribution was calculated within concentration ranges for each contaminant of concern. The lowest detection limits, the screening levels, and the cleanup levels defined these ranges. Total organic carbon served as a proxy to estimate the quantity of wood waste in the sediment. As a known byproduct of wood decomposition, 2,4-dimethylphenol was expected to be more prevalent in the depositional units with more wood waste. Finally, arsenic was a proxy for other contaminants to determine if contaminants at Mill-A are dominant in sediments with high percentages of wood waste. The volumetric distribution established that high levels of total organic carbon are present in the sediment with higher percentages of wood waste. This correlation was stronger in the decomposing sawdust-rich sediment than the woodchip-rich sediment. The 2,4-dimethylphenol concentrations above cleanup standards were dominant in the sawdust-rich, intermediate and native sediments. Concentrations of 2,4-dimethylphenol below cleanup levels characterized the native sediment. The distribution of arsenic showed no statistically significant correlation to wood content in sediment. These results do not support the hypothesis of contaminant-rich wood waste, as many of the high concentrations of contaminants were not in the wood-rich sediments. This suggests that the contaminants are more distributed among all depositional units at Mill-A rather than focused within sediments with a high percent of wood waste. Understanding the distribution of potentially toxic compounds with wood waste is important for restoring the Puget Sound waterways to a more habitable environment. Future studies should include new data to validate these results and to limit the uncertainty of the extent of contaminants. Future studies may also find motive in looking for a correlation between contaminants and grain size based on previous studies linking these characteristics. These investigations will benefit the current cleanup effort as well as future cleanup efforts at similarly contaminated waterways.

Kinetic model for selective cultivation of microfungi in a microscreen process for food processing wastewater treatment and biomass production

The research was aimed at developing a technology to combine the production of useful microfungi with the treatment of wastewater from food processing. A recycle bioreactor equipped with a micro-screen was developed as a wastewater treatment system on a laboratory scale to contain a Rhizopus culture and maintain its dominance under non-aseptic conditions. Competitive growth of bacteria was observed, but this was minimised by manipulation of the solids retention time and the hydraulic retention time. Removal of about 90% of the waste organic material (as BOD) from the wastewater was achieved simultaneously. Since essentially all fungi are retained behind the 100 mum aperture screen, the solids retention time could be controlled by the rate of harvesting. The hydraulic retention time was employed to control the bacterial growth as the bacteria were washed through the screen at a short HRT. A steady state model was developed to determine these two parameters. This model predicts the effluent quality. Experimental work is still needed to determine the growth characteristics of the selected fungal species under optimum conditions (pH and temperature).

Reconsidering the use of photosynthetic bacteria for removal of sulfide from wastewater

The feasibility of using photosynthetic sulfide-oxidizing bacteria to remove sulfide from wastewater in circumstances where axenic cultures are unrealistic has been completely reconsidered on the basis of known ecophysiological data, and the principles of photobioreactor and chemical reactor engineering. This has given rise to the development of two similar treatment concepts relying on biofilms dominated by green sulfur bacteria (GSB) that develop on the exterior of transparent surfaces suspended in the wastewater. The GSB are sustained and selected for by radiant energy in the band 720 - 780 nm, supplied from within the transparent surface. A model of one of these concepts was constructed and with it the reactor concept was proven. The dependence of sulfide-removal rate on bulk sulfide concentration has been ascertained. The maximum net areal sulfide removal rate was 2.23 g m(-2) day(-1) at a bulk sulfide concentration of 16.5 mg L-1 and an incident irradiance of 1.51 W m(-2). The system has a demonstrated capacity to mitigate surges in sulfide load, and appears to use much less radiant power than comparable systems. The efficacy with which this energy was used for sulfide removal was 1.47 g day(-1) W-1. The biofilm was dominated by GSB, and evidence gathered indicated that other types of phototrophs were not present. (C) 2004 Wiley Periodicals, Inc.

Simultaneous saccharification and fermentation of potato starch wastewater to lactic acid by Rhizopus oryzae and Rhizopus arrhizus

The biochemical kinetic of simultaneous saccharification and fermentation (SSF) for lactic acid production by fungal species of Rhizopus arrhizus 36017 and Rhizopus oryzae 2062 was studied with respect to growth pH, temperature and substrate. Both R. arrhizus 36017 and R. oryzae 2062 had a capacity to carry out a single stage SSF process for lactic acid production from potato starch wastewater. The kinetic characteristics, termed as starch hydrolysis, accumulation of reducing sugars, lactic acid production and fungal biomass formation, were affected with variations in pH, temperature, and starch source and concentration. A growth condition with starch concentration approximately 20 g/l at pH 6.0 and 30 degrees C was favourable for both starch saccharification and lactic acid fermentation, resulting in lactic acid yield of 0.85-0.92 g/g associated with 1.5-3.5 g/l fungal biomass produced in 36-48 h fermentation. R. arrhizus 36017 had a higher capacity to produce lactic acid, while R. oryzae 2062 produced more fungal biomass under similar conditions. (c) 2005 Elsevier B.V. All rights reserved.

Ecosystem response to antibiotics entering the aquatic environment

Awareness of antibiotics in wastewaters and aquatic ecosystems is growing as investigations into alternate pollutants increase and analytical techniques for detecting these chemicals improve. The presence of three antibiotics (ciproffoxacin, norfloxacin and cephalexin) was evaluated in both sewage effluent and environmental waters downstream from a sewage discharge. Bacteria cultured from the sewage bioreactor and receiving waters were tested for resistance against six antibiotics (ciprofloxacin, tetracycline, ampicillin, trimethoprim, erythromycin and trimethoprim/sulphamethoxazole) and effects of short term exposure (24h) to antibiotics on bacterial denitrification rates were examined. Antibiotics were detected entering the sewage treatment plant with varying levels of removal during the treatment process. Antibiotics were also detected in effluent entering receiving waters and detectable 500m from the source. Among the bacteria cultured from the sewage bioreactor, resistance was displayed against all six antibiotics tested and bacteria cultured from receiving waters were resistant against two of the antibiotics tested. Rates of denitrification were observed to decrease in response to some antibiotics and not to others, though this was only observed at concentrations exceeding those likely to be found in the environment. Findings from this preliminary research have indicated that antibiotics are entering our aquatic systems and pose a potential threat to ecosystem function and potentially human health. (c) 2004 Elsevier Ltd. All rights reserved.

Challenges for simultaneous nitrification, denitrification, and phosphorus removal in microbial aggregates: mass transfer limitation and nitrous oxide production

The microbial community composition and activity was investigated in aggregates from a lab-scale bioreactor, in which nitrification, denitrification and phosphorus removal occurred simultaneously. The biomass was highly enriched for polyphosphate accumulating organisms facilitating complete removal of phosphorus from the bulk liquid; however, some inorganic nitrogen still remained at the end of the reactor cycle. This was ascribed to incomplete coupling of nitrification and denitrification causing NO3- accumulation. After 2 h of aeration, denitrification was dependent on the activity of nitrifying bacteria facilitating the formation of anoxic zones in the aggregates; hence, denitrification could not occur without simultaneous nitrification towards the end of the reactor cycle. Nitrous oxide was identified as a product of denitrification, when based on stored PHA as carbon source. This observation is of critical importance to the outlook of applying PHA-driven denitrification in activated sludge processes. (c) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.