bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of Endocrine-Disrupting Chemicals in Sewage and Sludge Samples in Toronto, Canada
Authors: Lee Hing-Biu , Peart Thomas E. , Chan Jack , Gris Greg
Published: May 2018

In recent years, many anthropogenic chemicals occurring in the environment have been shown to mimic the action of endogenous hormones. These endocrine-disrupting chemicals (EDCs) can potentially lead to a host of adverse effects on wildlife, such as the feminization of fish, the lack of reproductive success of some species, birth defects, and the development of physical abnormality. In an attempt to establish the levels of contamination by EDCs in municipal sewage and sludge, we have collected samples in the Toronto area and analyzed them for alkylphenols, alkylphenol ethoxylates and carboxylates, 17ß-estradiol and its metabolites, testosterone, bisphenol A, as well as butyltin species. Previously developed methods using solvent extraction, solid-phase extraction, supercritical fluid extraction, GC/MS, and HPLC determination have been used for such samples. Levels of these chemicals varied from <1 ng/L for 17ß-estradiol in the effluent to nearly 900 µg/L for nonylphenol ethoxylates in the influent. Levels of EDCs in sludge also varied widely from >500 µg/g for nonylphenol to <0.1 µg/g for bisphenol A. The screening of many of the above EDCs has become an integral part of an on-going wastewater quality monitoring program in Toronto.
Summary of Case Studies Investigating the Causes of Pulp and Paper Mill Effluent Regulatory Toxicity
Authors: Kovacs Tibor , Gibbons Sharon , O'Connor Brian , Martel Pierre , Paice Michael , Naish Valerie , Voss Ron
Published: May 2018

In Canada, effluents from pulp and paper mills are regulated for toxicity. The regulation requires ≥50% survival of rainbow trout (Oncorhynchus mykiss) exposed to full-strength (i.e., 100%) effluent for 96 h in tests that must be conducted monthly. The regulation also calls for ≥50% survival of Daphnia magna exposed to 100% effluent for 48 h in weekly monitoring tests. Every year, about 10 to 25% of the mills exceed the regulatory limit at least once in tests with either rainbow trout or Daphnia magna. Between 1996 and 2003, we investigated 84 such cases from 32 mills. Of the 84 investigations, 49 involved only trout, 29 involved only Daphnia, and six involved both species. We identified the actual cause of toxicity in 70% of the cases and partially or tentatively identified the toxicant(s) in 17% more. In the cases involving only trout, the most frequent causes of toxicity were related to biotreatment performance (e.g., ammonia). In the cases involving only Daphnia, the most frequent cause of toxicity seemed to be related to polymeric formulations. For those cases involving both trout and Daphnia, the cause of toxicity was traced to more than one compound or to excess concentrations of a specific compound resulting from a spill or biotreatment-related problems.
Treatment of Log Yard Runoff in an Aerobic Trickling Filter
Authors: Woodhouse Christine , Duff Sheldon J.B.
Published: May 2018

Contaminated stormwater runoff from log yards is generated when precipitation comes into contact with wood, woody debris and equipment at outdoor wood sorting, processing and storage facilities. Nine runoff samples collected at a sawmill had biochemical oxygen demand (BOD), chemical oxygen demand (COD), tannins and lignin (T+L), and total suspended solids (TSS) levels ranging from 25 to 745 mg/L, 125 to 4610 mg/L, 10 to 1505 mg/L, and 65 to 2205 mg/L, respectively. Six samples were acutely toxic (EC50 <100%) based on the Microtox assay.

The samples were effectively treated using a laboratory-scale, attached microbial growth reactor. Treatment for 24 hours at 34°C resulted in substantial reductions in BOD (94–100%), COD (86–93%) and T+L (91–97%). Near complete removal of acute toxicity and colour were also observed. Twenty-four-hour treatment at lower temperatures, 24 and 5 C, reduced BOD concentrations by 97 and 76%, COD by 91 and 64%, and T+L by 95 and 67%, respectively.
Application of Activated Sludge Models in Traditionally Operated Treatment Plants—A Software Environment Overview
Authors: Sorour Mohamed Tarek , Bahgat Laila M.F.
Published: May 2018

Activated sludge simulation modelling is considered an accepted tool in engineering practice. However, due to the complexity involved, these models are only extensively used within a limited scientific community. There is a true need to increase the use of these models among average plant operators to make them better understand the interactions of various factors of the process. A user-friendly software environment that enables an ordinary user to access and use these models to simulate a system without the need for either a complete understanding of underlying models or any special programming skills will help promote model applications.

This paper defines the broad architecture of such an environment and identifies other applications that should be integrated into the simulator such as expert systems and database systems. It also discusses the steps necessary to develop a reliable site-independent activated sludge simulator. Finally, the paper points out that to introduce mathematical model simulations to traditionally operated treatment plants, a how-to protocol is needed to adjust routine operating data for model use.
A Review of the Efficiency of Buffer Strips for the Maintenance and Enhancement of Riparian Ecosystems
Authors: Hickey M. Brian C. , Doran Bruce
Published: May 2018

Vegetative buffer strips are being widely promoted as an effective technique to protect rivers and streams from the negative impacts of adjacent land uses including forestry and agriculture. An extensive review of the literature revealed that despite the intuitive appeal of buffer strips, data demonstrating their efficacy is highly variable and most studies demonstrating significant nutrient removal in buffer zones come from studies undertaken in riparian buffers greater than 30 m wide. These buffers are much wider than what land managers can typically expect farmers to remove from active production in order to protect water quality. Research attempting to demonstrate the efficacy of riparian buffers needs to focus on buffer widths that are within the range that landowners are likely to "give up" in the name of water quality protection. Lack of experimental evidence from buffers in the 1- to 10-m width range typically encountered on farms makes it difficult to draw definitive conclusions about the efficacy of riparian buffers in agricultural areas.
A Modelling Analysis of Urban Stormwater Flow Regimes and their Implication for Stream Erosion
Authors: Fan Celia , Li James
Published: May 2018

Stream erosion is a major issue in stormwater management. The objectives of this research are to investigate by means of computer modelling: (a) the flow-duration characteristics of a receiving stream before and after urbanization; (b) the implication of flow regime changes on stream erosion potential with and without control measures (e.g., extended detention basins and source control); and (c) the maximum degree of urbanization, for which stream erosion may be unavoidable regardless of the stormwater control measures applied. The U.S. EPA Stormwater Management Model was used in the analysis of flowduration characteristics of a small northern Ontario watershed. It was found that flow-duration characteristics of the stream could change significantly after urbanization. Although no stream erosion was modelled in this investigation, the change in flow regimes after urbanization may indicate potential stream bed and/or channel erosion. Extended detention basins with short detention times (24-h) could control flow-duration characteristics at low flow rates better than those with long detention times (48-h). Both extended detention basins and source control measures should be applied in order to bring the flow duration curve after urbanization back to its original position. If the watershed were to be urbanized beyond 40% of imperviousness, it may not be possible to bring the flow duration curve back to its original position in spite of the various source control measures and detention basins used. The optimal location of detention ponds for erosion control depends upon the range of flows, which control the stability of the stream.
Mercury Contamination of Marine Sediments and Blue Mussels (Mytilus edulis) in the Vicinity of a Mercury Cell Chlor-Alkali Plant in Dalhousie, New Brunswick, Canada
Authors: Garron Christine , Gagné François , Ernst William , Julien Gary , Bernier Marc , Caldwell Cathy
Published: May 2018

This report examines mercury concentrations in the marine environment of the Restigouche River, near a mercury cell chloralkali plant operated by Pioneer Chemicals Canada Inc. (PCI) in Dalhousie, New Brunswick. The PCI plant is a known point source of mercury in the area, but the extent of marine contamination in the Baie des Chaleurs as a result of those discharges has not been recently evaluated.

Marine sediments (five transects), mussel tissue (six locations) and effluent samples (four locations) were obtained in the vicinity of the PCI plant and analyzed for total mercury. Mussel tissues were also analyzed for condition index, metallothioneins and zinc in the digestive gland and gonad as well as gonad vitellin-like proteins and digestive gland lipid peroxidation. Results indicated that the area of the Restigouche River around the PCI plant had elevated concentrations of mercury in sediment and mussel tissue compared with local background concentrations. Mercury concentrations in sediments decreased with distance from the chlor-alkali plant. Concentrations in sediments ranged from 0.03 mg/kg at a distance of 4.6 km to 1.96 mg/kg at a distance of 20 m from the shoreline at the plant. Nine sites had mercury concentrations exceeding the CCME Interim Sediment Quality Guideline (0.13 mg/kg), the furthest of which was 1090 m from PCI. Mercury concentrations in water discharges from four of the five observed outfalls ranged from 0.84 to 4.32 µg/L. Mercury concentrations in mussel tissue ranged from 0.02 mg/kg at a distance 4.6 km from the plant to 1.40 mg/kg directly in front of the plant. Condition index and zinc concentrations in mussels close to the plant were correlated with mercury levels; however, some abnormal biomarker results were found at locations far from the plant as well, indicating other sources of contaminants.

Further studies are recommended to define the area of contamination near the PCI plant, as well as to determine the potential impact of other sources of mercury in the area. The environmental risk of the mercury contamination should also be more clearly established.
Modelling Approaches for Subsurface Drainage Water Quality Management
Authors: Rudra Ramesh Pal , Negi Satish C. , Gupta Neelam
Published: May 2018

Contamination of surface waters by agricultural activities is a serious problem. Two different modelling approaches to simulate nutrient and pesticide transport in subsurface drained soils were investigated in this study. First, artificial neural network (ANN) models, a trainable fast back-propagation (FBP) network and a self-organizing radial basis function (RBF) network, were developed for simulation of NO3--N concentration in tile effluent. Second, a hydrologic model, DRAINMOD, was linked with a chemical transport model, GLEAMS, to simulate chemical transport of atrazine through the soil into subsurface drain outflow. The ANN models and linked DRAINMOD-GLEAMS model were calibrated and validated against experimental data collected at the Greenbelt Research Farm of Agriculture Canada during the years 1988, 1989 and from 1991 to 1994. Several statistical parameters were calculated to evaluate model performance. A comparison of results indicated that the RBF neural network model was superior to the FBP model in predicting drain outflow and NO3--N concentration. Results obtained from the linked DRAINMOD-GLEAMS model demonstrate that atrazine simulations were underpredicted in subsurface drain outflows for spring and fall seasons. Both modelling approaches provide a useful tool for management of fertilizer/manure and pesticides transport through soil and crop root zones into surface water.
Simultaneous Nitrification/Denitrification in a Single Reactor using Ciliated Columns Packed with Granular Sulfur
Authors: Hwang Yong-Woo , Kim Chang-Gyun , Choo In-Jun
Published: May 2018

This study was conducted to assess the possibility of simultaneous nitrification and denitrification in an activated sludge using a cilia media packed with granular sulfur in a single reactor. For the granular sulfur column adopted, the total nitrogen removal was up to 67%. This facilitated the simultaneous decomposition of autotrophic and heterotrophic denitrifiers present at a 5:2 ratio. On the other hand, the control incubation test employing glass beads achieved only 18% denitrification. Regardless of the NH4-N loadings, the use of ciliated granular sulfur columns, made denitrification 1.5 times faster than when cilia was not used. The size of the granular sulfur columns directly contributed to the extent of denitrification, which was correlated to the void sphere of anoxic zones through the columns. Dissolved oxygen (DO) concentrations lower than 4.0 mg/L did not influence the level of denitrification. However, when higher than 4.0 mg/L, the DO began to negatively impact the denitrification rate. The study found that the simple installation of a cilia media packed with granular sulfur in an existing activated sludge could simultaneously achieve an efficient nitrification/denitrification in a single reactor.
Variations saisonnières des concentrations en métaux (Cd, Cu, Fe, Mn et Zn) chez l'algue Fucus spiralis du littoral de la ville d'El Jadida (Maroc)
Authors: Kaimoussi Aziz , Mouzdahir Abdelkrim , Saih Abdelkbir
Published: May 2018

Cette étude porte sur l'évaluation des concentrations de certains métaux traces (Cd, Cu, Fe, Mn et Zn) chez l'algue brune Fucus spiralis du littoral de la ville d'El Jadida. Ces concentrations ont été étudiées davril 1998 à mars 1999 dans quatre stations de prélèvement dont trois sont caractérisées comme sites dimportants rejets deaux usées et dactivités industrielles croissantes. Les résultats obtenus montrent que la capacité d'accumulation des métaux traces varie en fonction de site de prélèvement et de la saison. La comparaison de nos données avec celles publiées dans la littérature montre que les algues étudiées présentent en général des valeurs plus faibles que celles provenant d'autres aires géographiques.
A Study of Water Quality in Lower Oum Rabiaa Basin, Morocco: Speciation of Nitrogen and Phosphorus
Authors: Taoufik Mohamed , Dafir Jamal Eddine
Published: May 2018

A two-year survey of the physicochemical parameters and nutrient speciation in a lower Oum Rabiaa basin, characterized by three dams in series (Imfout, Daourat and Sidi Maâchou), was performed from December 1998 to November 2000.

The presence of the three dams in series is responsible for the nitrogen and phosphorus loads in the dams because of the reduction of fluvial contributions to the lower sector. Multivariate statistics were used to identify the principal factors influencing water chemistry in the individual dam systems. The three dams are influenced mainly by nutrient and organic sources. The eutrophication status of the studied systems was evaluated by N/P ratios. Mean N/P ratios at the three dams showed a high likelihood of P-limitation. Highest values were observed primarily during winter and early spring.
Soil and Groundwater Quality under a Cattle Feedlot in Southern Alberta
Authors: Olson Barry M. , Miller Jim J. , Rodvang S. Joan , Yanke L. Jay
Published: May 2018

Environmental concerns related to manure often focus on land application and the negative effects on soil and water quality. However, there is also potential for contamination of soil and water directly from feedlot sites. The objective of this study was to determine if a newly constructed feedlot in southern Alberta would change soil and groundwater quality under the feedlot within the first four years of operation. A cattle feedlot was constructed at the Agriculture and Agri-Food Canada Research Centre in Lethbridge, Alberta, in 1995 and 1996. Sixteen groundwater wells were installed at the feedlot in 1996. Groundwater chemistry and microbiology were monitored from 1996 to 2000, which included a baseline period of 3 months at the start before the feedlot was stocked with cattle. Soil samples (0- to 0.15-m, 0.15- to 0.3-m, and every 0.3-m to 1.5-m depth) were collected in 1996 and 1999. Mean water-table depth ranged from 1.23 to 2.50 m. Some soil chemical properties, PO4-P, NO3-N, NH4-N and K, were only significantly affected in the top 0.15-m layer. Other soil properties, EC, SAR, SO4-S, Mg, Ca and Na, increased significantly to a depth of 0.6 m. Chloride content increased significantly to a depth of 1.5 m. Groundwater analysis indicated that contaminants had leached to the water table. Chloride concentrations, E. coli counts and total coliform counts increased in the wells within the pen area, whereas there was little change in the wells outside the pen area.
Evaluation of Horseradish Peroxidase for the Treatment of Estrogenic Alkylphenols
Authors: Wagner Monika , Nicell James A.
Published: May 2018

The xenoestrogen alkylphenols 4-nonylphenol (3.4 mg/L) and octylphenol (6.0 mg/L) were oxidized by hydrogen peroxide using horseradish peroxidase (HRP) as a biocatalyst. Substrate transformation required about one mole of peroxide per mole of phenolic compound. A high degree of conversion of alkylphenol was achieved within a 3-h reaction time. In the case of 4-nonylphenol, HRP treatment led to complete disappearance of Microtox toxicity. Results of the yeast estrogen screen (YES) assay demonstrated that the reaction products of HRP-catalyzed 4-nonylphenol conversion lacked estrogenic activity. A new approach to the YES assay has been suggested based on observations made during this study.
Étude de l'élimination de Cr(VI) par une boue biologique après épandage
Authors: Iddou Abdelkader , Ouali Mohand Said
Published: May 2018

Plusieurs industries, telles que les tanneries, la métallurgie, de traitement de surface, etc, produisent des quantités significatives de déchets liquides riches en élément chrome sous sa forme de Cr(VI). Cette étude traite de l'élimination de cette espèce chimique très toxique. Les expériences ont été effectuées en « batch » sous agitation et le matériau utilisé est une boue de station d'épuration biologique après épandage. Plusieurs facteurs physico-chimiques jouent un rôle dans l'efficacité de l'élimination de l'espèce étudiée sur le support choisi. En effet, des observations de l'influence qu'ont sur le processus des facteurs tels que la variation de la concentration initiale du Cr(VI), le rapport solide/solution ainsi que l'apport en oxygène au système permettent de suggérer un mécanisme d'élimination. L'étude a montré qu'il est nécessaire que la flore microbienne présente dans le support s'adapte au milieu auquel elle est soumise. Cette adaptation est d'autant plus importante que les espèces responsables de l'élimination du Cr(VI) sont plus efficaces à des concentrations inférieures à 30 mg/L, avec des taux d'élimination de 100% au bout de 48 heures. Une plus grande efficacité du système fermé et une cinétique d'ordre 1 sont mises en évidence

L'utilisation de ce genre de matériau dans le traitement des eaux en général, et des eaux chargées en élément Cr(VI) en particulier, permettrait d'une part la réduction des déchets des stations d'épuration biologique des eaux et d'autre part, l'élimination totale de l'élément toxique Cr(VI) à de faibles concentrations, entraînant ainsi la baisse du coût d'exploitation dans les stations d'épuration de rejets chargés en chrome de certaines industries telle que celle de traitement de surface.
Impact of Feeding Activity of Silver Carp on Plankton Removal from a High-Rate Pond Effluent
Authors: Berday Nadia , Zaoui Driss , Lamrini Abdeljaouad , Abi Mustapha
Published: May 2018

The effect of silver carp (Hypophthalmichthys molitrix Val.) feeding activity on the plankton communities in a high-rate pond technology system (HRPTS) effluent was investigated over a period of 100 days. The experiment was conducted at the experimental wastewater treatment plant of the Agronomic and Veterinary Medicine Institute (AVI) of Rabat, Morocco, using a HRPTS in a fish pond receiving the plant effluent. The effluent was highly dominated by phytoplankton (99.95%).

Silver carp could survive and grow in the fish pond. Production was 37 kg with a very low mortality rate (12%). The high specific intestine weight (7%) and intake rates of biomass and phytoplankton by silver carp (616 g kg-1 of fish day-1 and 1.6 x 1011 cell kg-1 of fish day-1, respectively) demonstrated the importance of the feeding activity of the fish. Zooplankton intake rates were lower (2 x 107 bodies kg-1 of fish day-1). The high intestine index (3 to 4.3 for fish sizes of 14 to 22 cm) and the dominance of phytoplankton in the gut contents (99.95%) confirmed an omnivorous/ phytoplanctivorous diet.

Silver carp were efficient in removing plankton from the HRPTS effluent. The net removal yields of biomass were 285 g m-3 day-1 and 322 g kg-1 of fish day-1, 7 x 1010 algal cells kg-1 of fish day-1 and 8.7 x 107 zooplankton bodies kg-1 of fish day-1, with net removal rates of 47, 64 and 62%, respectively. The total suspended solids concentration decreased from 211 in the inflow to 112 mg L-1 in the fish pond.
Évolution des métaux traces dans les eaux de l'oued Sebou en période humide — Approche par modélisation mathématique
Authors: Es-Sette Btissame , Ajdor Youssef , Zidane Fatiha , Fakhraddine Abdelbassit , Foutlane Ali
Published: May 2018

Cet article présente les résultats d'un modèle de transport des métaux traces développé pour l’étude de la pollution par le chrome et le nickel dans l'oued Sebou. Ce modèle, associé à un modèle hydrodynamique unidimensionnel, est représenté par un schéma conceptuel tenant compte des phénomènes physiques et chimiques dans l'eau et le sédiment, tels que l'adsorptiondésorption, la sédimentation, la remise en suspension, la sédimentation profonde et la diffusion. Ces processus sont traduits en équations mathématiques faisant appel à des schémas numériques minimisant la dispersion numérique. Le but de ce travail est de prévoir le comportement des métaux traces et leur devenir afin de déterminer les zones à risque de pollution métallique et de situer le degré de pollution de l'eau dans les environs des prises d'eau. Les simulations faites par le modèle en période humide montrent que, du point de vue pollution par les métaux traces, le bief compris entre Sidi Harazem et Azib Soltane peut être subdivisé en trois zones : la première, non critique, exempte de pollution métallique, la seconde, moyennement critique, présentant des concentrations relativement faibles en chrome et en nickel et la dernière, critique, où les teneurs en métaux étudiés dépassent la norme admissible pour des eaux potables.
Detailed Endocrine Assessments of Wild Fish in the Northern River Basins, Alberta, in Comparison to EEM Monitored Endpoints
Authors: McMaster Mark E. , Hewitt L. Mark , Tetreault Gerald R. , Janoscik Tamara , Boyko Chad , Peters Lisa , Parrott Joanne L. , Van Der Kraak Glen J. , Portt Cam B. , Kroll Kevin J. , Denslow Nancy D.
Published: May 2018

During the Northern River Basins Study (NRBS), several issues were highlighted regarding the health of resident fish populations. Based on a basin-wide study of gonad morphology and circulating sex steroid levels, there was preliminary evidence of potential endocrine disruption in fish within the basins. The main concern with this was the potential loss of reproductive capability and possible declining populations. The Northern Rivers Ecosystem Initiative was established in response to the NRBS and an endocrine study was conducted to evaluate in more detail reproductive endocrine function of fish within the identified areas. A suite of endocrine endpoints was used and compared to overall fish health assessments using the Environmental Effects Monitoring (EEM) Programs protocol in areas exposed to sewage and pulp and paper mill effluents. As these northern rivers are nutrient-limited, fish responded to effluent addition (increased nutrients) by showing signs of increased growth and development relative to the upstream reference fish. Some signs of altered reproductive function were observed downstream of the one mill site, however additional responses were observed downstream of a municipal sewage treatment plant discharge from the neighbouring community. The reproductive responses were minimal compared to earlier studies at other older pulp and paper facilities. Follow-up studies at the Grande Prairie site documented changes in the fish responses to the effluents in terms of enrichment. The sewage treatment plant had installed tertiary treatment prior to the latest studies and reductions in the release of nutrients may be the cause. It is not known at the present time whether the pronounced eutrophication response that is still present in these fish may mask other endocrine alterations, as these effluents have endocrine-active compounds in them. The results also emphasize the need for EEM-like monitoring downstream of municipal sewage discharges.
Accumulation of Hormonally Active Substances by Wild White Sucker (Catostomus commersoni) Exposed to Effluents Discharged to the Wabigoon River
Authors: Hewitt Mark , Schryer Rick , Pryce Andrea , Belknap Andrew , Firth Barry , Van Der Kraak Glen
Published: May 2018

A study was initiated in the spring of 2001 to determine if hormonally active chemicals are bioavailable to white sucker (Catostomus commersoni) residing in the Wabigoon River, downstream of the bleached kraft pulp mill and municipal sewage outfall located in Dryden, Ontario. Females collected during spawning migrations in May 2001 at a near-field exposure site exhibited increased condition factor, liver size and fecundity relative to those collected from a reference site. Liver samples within each site were pooled, soxhlet extracted and fractionated by gel permeation chromatography and HPLC according to octanol/water partition coefficient (Kow). Fractions were then tested to determine if fish accumulated ligands which bind to the goldfish testicular androgen receptor (AR) and sex steroid binding protein (SSBP). The levels of hormonally active substances were low in males whereas females had accumulated significant amounts of several chemicals capable of binding to the hormone receptors. The levels of ligands detected in pulp mill effluent samples were substantially reduced after secondary treatment. Fractionation of final effluent extracts showed only ligands for the AR in the hydrophobic region (log Kow >5), which corresponded to the activities detected in fish tissues from both sexes. It can be concluded that ligands for fish sex steroid receptors are present in final effluent after treatment at the pulp mill and chemicals with the same Kow are bioavailable to fish under spring freshet conditions. Further work at this site is necessary to determine the contribution of pulp mill and municipal sewage effluents to the physiological performance of fish in the Wabigoon River and to their burden of accumulated compounds.
Caging Small-Bodied Fish as an Alternative Method for Environmental Effects Monitoring (EEM)
Authors: Palace Vince P. , Doebel Cecilia , Baron Chris L. , Evans Robert E. , Wautier Kerry G. , Klaverkamp Jack F. , Werner Jeffrey , Kollar Suzanne
Published: May 2018

The utility of using fish held in cages for investigating the potential effects of industrial and municipal effluents has been demonstrated. These types of exposures are able to control the influence of some confounding factors and also provide a measure of certainty with regard to exposure. However, Canada's current Environmental Effects Monitoring (EEM) Program for metal mines does not accept caged fish as a viable alternative for use in place of wild fish surveys. Concerns appear to be focused on the confounding influences of confinement stress on typical EEM endpoints. Confinement stress may be reduced in smaller-bodied fish relative to larger fish, increasing the relevance of their use for EEM. A standardized technique for deploying small-bodied fish in cages that may be useful for EEM programs is described.
Considerations when Using the Reference Condition Approach for Bioassessment of Freshwater Ecosystems
Authors: Bowman Michelle F. , Somers Keith M.
Published: May 2018

The use of the reference condition approach (RCA) in environmental assessments is becoming more prevalent. Although the RCA was not explicitly described in Green's (1979) book on statistical methods for environmental biologists, we expanded his decision key for selecting an appropriate environmental study design to include this approach. The RCA compares the biological community at a potentially impacted ‘test’ site to communities found in minimally impacted ‘reference’ sites. However, to implement the RCA there are a number of assumptions and decisions that must be made. We compare several common multimetric and multivariate bioassessment methods to illustrate that four key decisions inherent in the RCA framework (i.e., criteria used for reference site selection, for grouping similar reference sites, for comparing test and reference sites, and for evaluating the cause of impacts) can markedly affect test site appraisals. Specific guidelines should be developed to select appropriate reference sites. Based on analyses of real and simulated data, we recommend a minimum of 20, but preferably 30 to 50 reference sites per group, and verification of groupings with more than one classification method. New approaches (e.g., test site analysis) incorporating the strengths of both multimetric and multivariate methods can be used to compare test and reference sites. Additional ecological information, models relating degree of impact to a stressor or habitat gradient, and variance partitioning can also be used to isolate the probable cause of impairment, and are particularly valuable when appropriate reference sites are unavailable.
Performance of White Sucker Populations along the Saint John River Main Stem, New Brunswick, Canada: An Example of Effects-Based Cumulative Effects Assessment
Authors: Doherty Chad A. , Galloway Brendan , Curry R. Allen , Munkittrick Kelly R.
Published: May 2018

White sucker (Catostomus commersoni) are widely distributed in North America and are often used in environmental monitoring. Whole organism characteristics of three white sucker populations determined to be resident (outside of spawning) within small sections of the Saint John River, New Brunswick, were studied in 2001 and 2002. Significant differences in performance characteristics were present among sites. The differences can be interpreted as either improved sucker performance at Florenceville (upstream site), or decreased performance at Woodstock. Without further investigation it is difficult to identify whether the apparent improved performance is a response to nutrient enrichment, or increased mortality associated with the recent prevalence of lesions. Confounding factors are also present. Daily water level fluctuations resulting from an upstream dam discharge may change habitat availability and/or diversity, thereby altering the fish community. Liver sizes in Saint John River white sucker are considerably larger than in fish collected in Ontario, but are not relative to nearby New Brunswick river populations. This has implications for the importance of reference site selection and understanding the natural variability within a species (intra-specific variation) on multiple spatial scales.
Survey for Tributyltin in Water and Sediment in Canada in 1999
Authors: Maguire R. James , Batchelor Suzanne P.
Published: May 2018

A survey of water and sediment from 152 harbours, marinas and shipping channels across Canada was conducted in 1999 to determine the extent of contamination by tributyltin (TBT) prior to the total ban on its antifouling uses being phased in over the period 2003 to 2008, and to assess the effectiveness of the 1989 regulation of antifouling uses of TBT under the Canadian Pest Control Products Act. TBT was found in sediments in this survey much more frequently than in water. The main conclusion was that by 1999 the regulation had been generally effective in reducing TBT contamination in water, but not sediment, in small-craft marinas and harbours. TBT continued to be found in some freshwater and seawater locations frequented by larger vessels, that could have been legally painted at the time with TBT antifouling paints, at concentrations that could cause chronic toxicity to aquatic organisms. TBT was also found in many marine sediments, and some freshwater sediments, at concentrations that could cause chronic toxicity to sensitive benthic organisms. In addition, TBT concentrations in many marine sediments could cause acute toxicity to sensitive benthic organisms. Because of the long persistence of TBT in sediments, it may pose a hazard to benthic organisms in some locations in Canada for many years after the total ban on antifouling uses of TBT.
Effect of Polyphosphate on Removal of Endocrine-Disrupting Chemicals of Nonylphenol and Bisphenol-A by Activated Carbons
Authors: Choi Keun J. , Kim Sang G. , Kim Chang W. , Kim Seung H.
Published: May 2018

This study examined the effect of polyphosphate on removal of endocrine-disrupting chemicals (EDCs) such as nonylphenol and bisphenol-A by activated carbons. It was found that polyphosphate aided in the removal of nonylphenol and bisphenol- A. Polyphosphate reacted with nonylphenol, likely through dipole-dipole interaction, which then improved the nonylphenol removal. Calcium interfered with this reaction by causing competition. It was found that polyphosphate could accumulate on carbon while treating a river. The accumulated polyphosphate then aided nonylphenol removal. The extent of accumulation was dependent on the type of carbon. The accumulation occurred more extensively with the wood-based used carbon than with the coal-based used carbon due to the surface charge of the carbon. The negatively charged wood-based carbon attracted the positively charged calcium-polyphosphate complex more strongly than the uncharged coal-based carbon. The polyphosphate-coated activated carbon was also effective in nonylphenol removal. The effect was different depending on the type of carbon. Polyphosphate readily attached onto the wood-based carbon due to its high affinity for polyphosphate. The attached polyphosphate then improved the nonylphenol removal. However, the coating failed to attach polyphosphate onto the coal-based carbon. The nonylphenol removal performance of the coal-based carbon remained unchanged after the polyphosphate coating.
Numerical Modelling of the Grand River Plume in Lake Erie during Unstratified Period
Authors: He Cheng , Rao Yerubandi R. , Skafel Michael G. , Howell Todd
Published: May 2018

The Grand River is a major contributor of nutrients and dissolved and suspended solids to the eastern basin of Lake Erie. To better understand the impact of the Grand River plume on the surrounding receiving waters, we integrated data analysis and modelling of the Grand River plume transport in the eastern basin of Lake Erie using a high-resolution depth-integrated nonlinear barotropic finite element model. An extended domain of receiving waters with closed boundary was applied in this numerical study due to the lack of observations needed for specifying the open boundary conditions. The size of closed domain was chosen by considering balance between the computing time and stabilizing the hydrodynamic flow. Numerical simulations of the influence of wind on the plume transport in the vicinity of the Grand River mouth were performed. The root mean square error values of alongshore and cross-shore current components were 5 and 2.85 cm s-1, respectively. The transport simulations compare favorably (±20%) with observations of conductivity in the vicinity of the Grand River mouth. This study demonstrates that a two-dimensional numerical model can reasonably predict the river plume transport in a large lake during unstratified periods. Plume movement is primarily controlled by the wind-driven coastal current. Our simulations indicate that the frequent reversals of this current should effectively limit the plume's alongshore extent and may result in a continuous coastal band of turbid water extending alongshore in either direction in the vicinity of the river mouth.
The Effects of Scaling and Model Complexity in Simulating the Transport of Inorganic Micropollutants in a Lowland River Reach
Authors: Lindenschmidt Karl-Erich , Wodrich René , Hesse Cornelia
Published: May 2018

A hypothesis stating that more complex descriptions of processes in models simulate reality better (less error) but with more unreliable predictability (more sensitivity) is tested using a river water quality model. This hypothesis was extended stating that applying the model on a domain of smaller scale requires greater complexity to capture the same accuracy as in large-scale model applications which, however, leads to increased model sensitivity. The sediment and pollutant transport model TOXI, a module in the WASP5 package, was applied to two case studies of different scale: a 90-km course of the 5th order (sensu Strahler 1952) lower Saale river, Germany (large scale), and the lock-and-weir system at Calbe (small scale) situated on the same river course. A sensitivity analysis of several parameters relating to the physical and chemical transport processes of suspended solids, chloride, arsenic, iron and zinc shows that the coefficient, which partitions the total heavy metal mass into its dissolved and sorbed fraction, is a very sensitive parameter. Hence, the complexity of the sorptive process was varied to test the hypotheses.
Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes
Authors: Zhang Zhe , Hall Eric R.
Published: May 2018

Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.
A Comparison of Commercial and Experimental Ultrafiltration Membranes via Surface Property Analysis and Fouling Tests
Authors: Dang Huyen T. , Narbaitz Roberto M. , Matsuura Takeshi , Khulbe Kailash C.
Published: May 2018

Surface modified polyethersulfone (PES) membranes via the addition of different hydrophiLic Surface Modifying Macromolecules (LSMMs) have been developed by Matsuura, Narbaitz and co-workers. This study compares the performance of the best PES-LSMM membrane with nine commercial ultrafiltration membranes manufactured using five different types of base polymers (polyethersulfone, polysulfone, celluloseacetate, polyacrylonitrile and cellulose) in the same range of molecular weight cutoff (MWCO) (from 40 to 120 kDal). All membranes were characterized by using atomic force microscopy, contact angle measurements, solute transport analysis and then evaluated through fouling tests with Ottawa River water (ORW). While PES-LSMM membranes had much lower initial flux than the commercial membranes, they had the highest total organic carbon (TOC) rejection (80%) and the lowest flux reduction (62%). For the commercial membranes, the range of TOC rejections and flux reductions were 62 to 80% and 68 to 80%, respectively. Given their high TOC rejection and relatively high foulant deposition, fouling of the PES-LSMM membranes appears to be controlled by a surface gel.
Use of Iron- and Manganese-Oxidizing Bacteria for the Combined Removal of Iron, Manganese and Arsenic from Contaminated Groundwater
Authors: Katsoyiannis Ioannis A. , Zouboulis Anastasios I.
Published: May 2018

The problem of groundwater contamination with arsenic has been under extensive discussion, especially in recent years, because of its adverse effects on human health and its widespread presence in groundwater throughout the world. Large drinking water plants in developed countries normally find alternative and arsenic-free water resources, or they apply conventional arsenic removal methods, such as coagulation/filtration, activated alumina and ion exchange. Smaller towns, communities and individual users in rural areas often rely on local water resources and the respective removal methods developed mainly for larger water treatment plants are not easily applicable, because of high operational and capital costs, or they are simply too complicated and their use is sometimes limited by the specific water composition. Consequently, small drinking water systems face the difficult challenge in providing a safe and sufficient supply of drinking water at a reasonable cost. Alternative treatment methods have been developed for application in these cases. In the present paper, the simultaneous removal of arsenic during biological iron and manganese oxidation is reviewed. The method relies on the use of indigenous non-pathogenic iron- and manganese-oxidizing bacteria. Dissolved iron and manganese species often coexist with arsenic in groundwater. Therefore, the application of this method could provide consumers with water of high quality, which is practically free of iron, manganese and arsenic, complying with the respective legislative limits. In this paper the biological oxidation of iron and manganese has been reviewed and recent findings regarding the removal of arsenic have been summarized. Arsenic(III or V) can be removed efficiently from a wide range of initial concentrations with practically limited operational cost, apart from the capital costs for the installation of treatment units. As a result, the use of chemical reagents for the oxidation of trivalent arsenic can be avoided, because As(III) was efficiently oxidized to As(V) by these bacteria (acting as catalysts) under similar conditions, which are usually applied for the removal of iron and manganese by biological means.
Removal of Arsenic(III) from Groundwater using Low-Cost Industrial By-products-Blast Furnace Slag
Authors: Kanel Sushil Raj , Choi Heechul , Kim Ju-Yong , Vigneswaran Saravanamuthu , Shim Wang Geun
Published: May 2018

Blast furnace slag (BFS), a steel industrial by-product, was tested for the removal of As(III), which is a highly toxic, mobile and predominant species in anoxic groundwater. Batch adsorption experiments were performed to determine the feasibility of BFS as an adsorbent for removing As(III) from groundwater as As(III) concentration and the pH of water were varied. The maximum As(III) adsorption capacity by BFS was 1.40 mg As(III)/g of BFS at 1 mg/L As(III) initial concentration, at 25°C, which was calculated using the Langmuir isotherm. The homogeneous surface diffusion model (HSDM) was successfully applied to predict the sorptive removal of As(III) onto the BFS. Kinetic studies indicated that the film diffusion as well as surface diffusion of As in the BFS was involved. It was found that the film diffusion coefficient (kf) was 5.27 × 10-5 to 4.06 × 10-6 m/s and surface diffusion coefficient (Ds) was 2.31 × 10-14 to 7.13 × 10-14 m2/s for the initial As(III) concentrations of 0.1 to 100 mg/L. Oxidation of As(III) to As(V) and its adsorption/precipitation onto BFS is involved during the As(III) removal mechanism. It was also found that H4SiO40, PO43-, NO3-, SO42- and HCO3- are potential interferences in the As(III) adsorption reaction. Results suggest that 99.9% As(III) at 1 mg/L can be removed by 10 g/L BFS, which can be used as a permeable reactive barrier (PRB) material to remove As(III) from groundwater. Details of As(III) adsorption and coprecipitation systems and interferences of As(III) molecular interactions were also studied.
Occurrence of Arsenic in Groundwater in the Suburbs of Beijing and its Removal Using an Iron-Cerium Bimetal Oxide Adsorbent
Authors: Dou Xiaomin , Zhang Yu , Yang Min , Pei Yishan , Huang Xia , Takayama Tomoo , Kato Shigeru
Published: May 2018

The occurrence of arsenic (As) in groundwater in fourteen villages in Houshayu Town, Shunyi District, Beijing, China, was investigated, and a column experiment for the removal of As was conducted on-site with a pellet type iron-cerium (Fe-Ce) bimetal oxide adsorbent prepared in lab. The As concentration in the groundwater of twelve villages exceeds the maximum contamination level (10 µg/L) of the World Health Organization, and two of them exceed that of China (50 µg/L). A column experiment at a space velocity of 3 h-1 shows that the Fe-Ce adsorbent could remove As(V) (total As, 71 ± 19.7 µg/L) from groundwater with high efficiency. Around 11,500 bed volumes were gained when As(V) in the effluent exceeds 10 µg/L, giving an accumulated adsorption capacity of 6.0 mg As(V)/g adsorbent. Both batch tests and the column test suggest that humic substances might compete with As(V) for the adsorption sites, which disappeared after the column was continuously operated for more than two weeks. The effluent quality including heavy metals, radioactivity, etc., was confirmed to meet the drinking water standards of WHO and China.
Arsenic(V) Removal by Sulfate Modified Iron Oxide-Coated Sand (SMIOCS) in a Fixed Bed Column
Authors: Vaishya Rakesh Chandra , Gupta Sudhir Kumar
Published: May 2018

A novel granular media developed by the coating of iron, barium and sulfur on quartz sand surface has been demonstrated to be an effective sorbent for removal of arsenic(V) from a 0.01 M NaNO3-spiked distilled water system in laboratory-scale tests. The results of fixed bed studies indicate that arsenic(V) removal is dependent on pH, the size of sorbent and influent arsenic concentrations. The particle size of media has shown significant differences in reactor breakthrough times in similar experimental conditions. The removal of As(V) may be explained using the surface complexation theory. The presence of alkalinity (250–260 mg/L as CaCO3) and hardness (200 mg/L as CaCO3) slightly increases reactor breakthrough time for similar experimental conditions without alkalinity and hardness. Desorption studies using 0.2 M NaOH as elutant resulted in nearly 92% recovery of arsenic(V). A theoretical model based on two parameters has shown good correlation with observed experimental data generated during depth variation studies.