bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of a New Adsorbent for Fluoride Removal from Waters
Authors: Rongshu Wang , Haiming Li , Ping Na , Ying Wang 
Published: March 2019

Abstract
A new adsorbent for fluoride removal is reported in this study. The process and mechanism of removing fluoride are also reported. The adsorbent was characterized as having high selectivity for fluoride, large adsorption capacity, applicability to neutral medium and much better adsorption at high temperature. The floride removal mechanism is a typical chemisorption which is different from the one used for activated alumina. Adsorption rate was considerably faster at the beginning of the adsorption process, followed by a much slower porous diffusion process. Results of field tests showed that the adsorbent was much more suitable for treating high temperature geothermal water with high fluoride content. It also had the advantages of reducing turbidity, decolorizing, dealkalizing, and removing iron from drinking water.
Removal of Oil from Concentrated Wastewater by Attapulgite and Coagulant
Authors: Zunan Qiu , Yi Zhang , Yuqiao Fang 
Published: March 2019

Abstract
The removal of oil from wastewater by adsorption on pulverized attapulgite and coagulation was investigated. It was found that raw clay is better for the removal of floating oil than clay-calcined products. Raw clay, however, was not quite so effective for the removal of emulsified oil. The percentage removal is a function of both the amount of attapulgite added and the initial oil concentration. The relationship between the amount added and the remaining oil concentration has a form similar to the Freundlich model, though equilibrium is not achieved. As for the removal of the emulsified oil, the use of coagulant and attapulgite implies a synergistic enhancement. The adsorption time is very important. A linear relationship is observed between the logarithm of adsorption time and the percentage removal. Over 90% removal of the floating oil is obtained by using 1% attapulgite for 1 h at 30°C and 1 ppm PAM when the initial oil concentration is about 500 mg/L. This is superior to that of bentonite. Over 99% removal of emulsified oil is achieved by using 2.5% attapulgite for 15 min and 800 ppm aluminum sulphate when the initial concentration is 126,000 mg/L. The used clay could be regenerated.
Biodegradation of Lubricating Oils in Aquatic Environments
Authors: Xie Yongming , Bewtra J.K. , Biswas N. , Franklin M. 
Published: March 2019

Abstract
Laboratory studies were conducted on the biodegradation of some selected lubricating oils. A standard method for determining the biodegradability of selected recalcitrant organic compounds was developed. Test results show that the species of bacteria present in the sample is an important factor affecting the biodegradation of selected lubricating oils. Results also indicate that it is difficult to degrade lubricating oils in water by using indigenous microorganisms in natural river or lake water. The study shows that up to 23% removal can be achieved biologically after 67 days of operation.
Water Pollution Control Measures in Taiwan
Authors: Lao Robert G. , Shu Youn Y. 
Published: March 2019

Abstract
Environmental degradation in Taiwan is widespread, serious and steadily increasing. Taiwan’s small land mass has been overburdened with a large number of pollutants and ecological imbalance. The situation is not limited to Taiwan alone; it is also all over South-East Asia. The region comprises nations which are becoming industrialized and facing environmental problems similar to those of Taiwan. In order to fight pollution, Taiwan has initiated a tough battle, combining enforcement, education and incentives, to achieve, maintain and restore environmental quality. In 1988, Taiwan produced 7.6 million cubic meters per day of wastewater, and the corresponding BOD totalled 3,600 metric tons. Twenty-one major rivers are heavily polluted, and harbour and ground water pollution has become a serious problem. Several control programs have been designed, including both short-term and major-source control projects. In the six-year National Development Plan (1991 to 1997), US$10 billion will be spent on these projects out of a total pollution control budget of $40 billion.
Laboratory Prediction of Phosphorus Release from Deciduous Leaves to Urban Runoff
Authors: Culbert Heather , France Robert 
Published: March 2019

Abstract
In urban centres, leaves are customarily gathered and temporarily stored in large roadside piles prior to their transport to disposal sites. To simulate the release of total phosphorus to urban runoff, birch and trembling aspen leaves were leached with distilled water in laboratory flasks. There was no difference in rate of total phosphorus release between oven-dried and non-dried leaves. An empirical equation developed from these data and knowledge of the litterfall rates for southern Canada indicated that leaves yielded from 11 to 45 mg TP m−2 of forested watershed. This amount represents up to 5% of the total export of total phosphorus from urban catchments and has the potential to exacerbate eutrophication of municipal waters if leaf pickup is not promptly enforced.
Modelling Nitrate Output from Agricultural Watersheds Using a Hydrological Model
Authors: Boukchina R. , Lagacé R. , Morin G. 
Published: March 2019

Abstract
A distributed area model called CEQNIT (CEQUEAU-NITRATE) to predict nitrate concentration and load from agricultural watersheds has been developed. The model application requires that the watershed be divided into partial squares. At partial-square scale, the model simulates nitrogen reactions within the soil and nitrate leaching. Nitrogen budget in the CEQNIT model includes the leaching of nitrate, plant uptake, denitrification, mineralization of organic nitrogen, immobilisation, nitrification, input by fertilizer and precipitation. Nitrogen dynamics were simulated as first-order kinetic reactions, and the influence of soil temperature and moisture were included. The model requires input from the CEQUEAU hydrological model that provides temporal and spatial estimation of flow discharge over the watershed. Using two-year data from a small agricultural watershed (78 ha), the model was calibrated with first-year data and tested with the second-year data. Results obtained from this study showed that the model was able to reproduce the seasonal nitrate fluctuations accurately.
Long-Term Copper Toxicity on Scenedesmus quadricauda and Complexing Polypeptides
Authors: Bussières Denis , Côté Raynald , Richard Clément , St-Pierre Édith 
Published: March 2019

Abstract
Long-term copper toxicity has been demonstrated in Scenedesmus quadricauda. Upon continuous exposure to copper ions at 250 μg/L, the algae responded by a sharp increase in the synthesis of complexing polypeptides to chelate Cu. Complexing polypeptides gradually decreased, as observed by six sampling tests over 732 h, resembling to a negative exponential curve. This gradual diminution is considered to be a prime mechanism of acclimation or of adaptation to a heavy metal contaminated environment.
Determination of Lead in Soils Surrounding a Lead-Acid Battery Manufacturer
Authors: Skinner Cameron D. , Salin Eric D. 
Published: March 2019

Abstract
Soil lead levels were determined on and around a former battery manufacturing site. Lead concentrations ranging from 120 ppm to 5.1’ were found. The highest concentrations were found close to the factory site. When it was possible to obtain samples over a continuous depth range, it was found that lead concentration decreased with depth and that it increased above underground foundations.
Pesticide Leaching Associated with Conventional Potato and Corn Production in Atlantic Canada
Authors: Milburn Paul , Leger D.A. , O'Neill H. , Richards J.E. , MacLeod J.A. , MacQuarrie K. 
Published: March 2019

Abstract
We employed field-scale tile drainage systems, private wells in farming areas, and research piezometers installed al field edge to evaluate nonpoint source impacts of four pesticides on groundwater quality. Nitrale-N was known to be teaching at all study sites. Herbicides dinoseb and metribuzin and the fungicide chlorothalonil were common to potato production; the herbicide atrazine was common to com production. Based on chemical properties, chlorothalonil is unlikely to leach, while atrazine, dinoseb and metribuzin are identified as potential leachers. In this study, chlorothalonil leaching was indeed very limited; only 4 of 66 tile drainage samples were positive, and al concentrations close to the detection limit (0.005 µg L−1). Chlorothalonil was not detected in any of the farm wells or research piezometers located in areas of intense potato production. Conversely, atrazine, dinoseb and metribuzin were confirmed as nonpoint source leachers. They were often detected in tile drainage water and have been detected in wells, but at mean annual concentrations less than current maximum acceptable concentrations for drinking water as established by Health and Welfare Canada.
Atrazine in Surface and Subsurface Runoff as Affected by Cultural Practices
Authors: Gaynor J.D. , Tan C.S. , Drury C.F. , van Wesenbeeck I.J. , Welacky T.W. 
Published: March 2019

Abstract
Atrazine (2-chloro-4-ethylamino-6-isopn&gt;pylainino-6-triazine) concentration in surface runoff and tile drainage was monitored from small plots managed with conservation tillage and banded herbicide application in com. Atrazine concentrations were larger in surface runoff than in tile drainage. Surface runoff and tile drainage events soon after herbicide application had the greatest atrazine concentrations. When the entire area was treated with atrazine, the maximum concentration recorded in surface runoff was 700 µg/L from conservation tillage compared to 400 µg/L from conventional tillage. Banded application of the herbicide over the seeded row reduced maximum atrazine concentrations in surface runoff to less than 140 µg/L. Atrazine concentration of tile drainage was reduced from a maximum of 350 µg/L in broadcast preemergence treatments to less than 105 µg/L when atrazine was applied preemergence in a band over the seeded row. Deethylatrazine (2-chloro-4-amino-6-isopropylamino-$-triazine) concentration was 0.6 and 0.7 times that for atrazine in surface runoff and tile drainage, respectively, coincident with its transience as an intermediate metabolite of atrazine. Atrazine and deethylatrazine are unlikely to have a direct affect on aquatic life; however, changes in phytoplankton diversity and amounts could indirectly have an adverse affect. Preemergence application of atrazine in a band over the seeded row will reduce the impact of this herbicide on the water quality of surface waters.
Short Communication – Canadian Water Quality Guidelines as Indicators of Sustainable Agriculture
Authors: Caux Pierre-Yves 
Published: March 2019

Abstract
Environmental Quality Guidelines for environmental sustainability are often lacking in many management or environmental policies. These are clear measures or indicators of the quality of the system. In Canada, national soil, water, tissue and sediment guidelines are developed to protect and sustain specific uses of land and water and provide direct measures of sustainability which can be incorporated into an overall ecosystem management framework. This short communication focusses on the use of pesticide Water Quality Guidelines for agricultural sustainability, especially with regard to surface and ground water contamination. Furthermore, this address introduces the new Canadian protocols for deriving Water Quality Guidelines for Irrigation and for Livestock Watering.
Performance and Upgrading Alternatives for Water Pollution Control Plants Discharging to Severn Sound
Authors: Nutt Stephen G. 
Published: March 2019

Abstract
Discharges from municipal water pollution control plants have been identified as major point source inputs of phosphorus to Severn Sound. For the 2-year period 1989–90, the estimated total phosphorus loading from eight water pollution control plants discharging directly or indirectly to Severn Sound exceeded 6,200 kg/year. A review of options available and the relative costs of reducing total phosphorus loadings from these facilities was conducted. It was found that a 59% reduction could be achieved by process modifications at relatively small capital costs. Further improvements would require major capital investment. Large differences in the cost per kg of phosphorus removed were identified between plants. The cost data suggest that it would be more cost effective to impose more stringent effluent limits at some plants than at others. The most cost-effective strategy depends on the total phosphorus load limit which must be achieved to maintain the desired receiving water quality; however, this strategy may not involve the application of the same effluent limits at all facilities discharging to Severn Sound.
Water Currents and Exchange between Severn Sound and Georgian Bay, Lake Huron, during 1988
Authors: Kohli Balbir 
Published: March 2019

Abstract
Water exchange between Severn Sound and Georgian Bay was estimated by current measurements at 16 locations across the Severn Sound Channel from June to October 1988. An excursion episode model was employed to compute the exchange. The current measurements showed that the mean monthly speeds varied from 3.2 to 17.0 cm/s, while the maximum speed recorded was 95 cm/s. Vertical flows were found to be in the opposite direction at the upper and lower levels, particularly in the middle of the channel. A complex flow regime in the channel prevailed. The modelling showed that 0.31% of Severn Sound volume left the Sound daily towards Georgian Bay, while 0.26% of the volume entered the Sound through all inflows. The mean residence time for the Sound was estimated to be 69 days. In other words, water in the Sound is completely replaced in 69 days.
Zooplankton Seasonal Dynamics and Community Structure in Severn Sound, Lake Huron
Authors: Gemza A.F. 
Published: March 2019

Abstract
The limnetic zooplankton of Severn Sound, a eutrophic embayment, were studied between 1978 and 1989. Forty-one species of zooplankton were identified from samples collected in the sound. Total zooplankton biomass ranged seasonally from a minimum of 3.9 mg/m3 at less eutrophic stations to over 1,625 mg/m3 at the most eutrophic sites. Annual means ranged from 38 to 373 mg/m3. At the most eutrophic sites the zooplankton community was dominated by the cladoceran Bosmina longirostris. Cyclopoid and calanoid copepods increased in dominance as conditions approached mesotrophy. Calanoid copepods were insignificant contributors at the eutrophic sites, averaging less than 3% of the total zooplankton biomass.
Total zooplankton biomass declined with distance from shore and phosphorus point sources as conditions became less eutrophic. Significant empirical relationships (r&gt;0.79) were measured between zooplankton biomass and total phosphorus and phytoplankton biovolume. Densities of several species, Eubosmina coregoni, Daphnia retrocurva and Diacyclops thomasi declined by over 50% during the 11-year period of study and may be related to a shift in fish community structure.
Organochlorine Contaminants in Avian Wildlife of Severn Sound
Authors: Martin Pamela A. , Weseloh D. Vaughn , Bishop Christine A. , Legierse Karin , Braune Birgit , Norstrom Ross J. 
Published: March 2019

Abstract
Organochlorine contaminants were measured in pooled egg samples of colonial waterbirds, red-winged blackbirds and tree swallows breeding in or near Severn Sound, Lake Huron, an area designated by the International Joint Commission as an Area of Concern, during 1991. Breast muscle samples of staging waterfowl were also collected the preceding autumn. PCBs, DDE and mirex were the most prevalent organochlorine contaminants present in eggs (concentration ranges of 0.065 to 5.452, 0.118 to 3.12 and 0.007 to 0.174 mg/kg, respectively), while oxychlordane, cis-chlordane, dieldrin, heptachlor epoxide, trans-nonachlor, cis-nonachlor, OCS, HCB and beta-HCH were also detectable at low levels in some egg samples. Tetra- and pentachlorobenzene, and alpha-and gamma-HCH were not detected in any of the samples. Generally, the following interspecific gradient in contaminant levels in bird eggs was found: herring gulls = Caspian terns &gt; common terns &gt; tree swallows &gt; blackbirds. Concentrations in the eggs of piscivorous birds in Severn Sound were similar or slightly lower than those from other colonies in Georgian Bay and Lake Huron, and considerably lower than those from colonies in Hamilton Harbour, Lake Ontario. Mirex levels in herring gulls and Caspian terns from Severn Sound colonies were an exception in that they were substantially higher than levels from other Lake Huron colonies (0.174 and 0.167 mg.kg-1 for the two species, respectively, versus &lt;0.12 mg.kg-1), although still much lower than those from Lake Ontario (0.50 and 0.719, respectively). It is probable that mirex was accumulated by gulls and terns during winter or migrational stopovers on Lake Ontario. Low contaminant levels in common terns may have been a result of their consumption of a smaller size class of prey fish. Higher contaminant levels in tree swallow eggs in comparison to red-winged blackbird eggs may have been due to the preponderance of aquatic insects in their diets, as opposed to the larger proportion of terrestrial arthropods in blackbird diets. Only PCBs and DDE were detected in the breast muscle of lesser scaup and mallards.
Étude expérimentale de traitement des eaux usées par des lagunes à hydrophytes libres au Niger
Authors: Laouali Garba , Delisle Claude E. , Vincent Gilles , Couillard Denis , Laouali Sani 
Published: March 2019

Abstract
Le traitement des eaux usées au Sahel est soumis à diverses contraintes socio-économiques, reléguant au second plan cette problématique, malgré les risques réels de santé publique. Cette réalité nous amène à opter pour un procédé, reconnu économique, composé d’un lagunage facultatif et de bassins à jacinthes d’eau (Eichhornia crassipes) et à laitues d’eau (Pistia stratiotes). Ces deux hydrophytes libres, d’origine tropicale, ont un potentiel d’épuration élevé. Une station pilote a été expérimentée durant l’année 1993 au Niger. Le procédé s’est révélé efficace et adapté aux conditions locales. Le lagunage assure des enlèvements appréciables sur la matière organique (70-240 kg/ha.d) et constitue ainsi une alternative fiable comme traitement secondaire. Les bassins à plantes agissent principalement comme traitement tertiaire. Les unités de traitement sont adaptées et surtout économiquement viables pour le traitement des eaux usées dans cette région. Pour la gestion de la biomasse végétale des bassins, la floraison est un critère de récolte fiable et facile d’application. L’exploitation de ces unités ne nécessite pas de main-d’oeuvre qualifiée.
Critique of Jar Testing for the Design of Coagulation-Flocculation Systems
Authors: Szpak Joseph P. , Woods Donald R. , Bouchard Kyle 
Published: March 2019

Abstract
The effects of clay type and concentration, jar shape, paddle shape, rapid mix time and flocculation velocity gradient on batch, bench-scale jar tests of turbidity were studied using a fractional factorial design. The two-parameter kinetic model for flocculation of Agraman, Kaufman and Bratby was used. This model provided a good fit of the data when they were log-transformed. The variables that had a statistically significant effect on the kinetics constants for floc agglomeration and breakup were the interaction of clay concentration and flocculation velocity gradient, plus clay type combined with rapid-mix time. The jar shape and the paddle shapes did not have significant effects. The kinetic constants measured in this analysis agreed with those reported previously by Agraman and Kaufman. The work assumes that turbidity is an acceptable measure of the number concentration. The results confirm the usefulness of the kinetic model and emphasize the importance of testing the goodness-of-fit of the model before analyzing the data.
Evaluation and Design of Peat Filter to Attenuate Landfill Leachate
Authors: Warith Mostafa A. 
Published: March 2019

Abstract
This study investigated the suitability of using peat as a filtering medium, capable of long-term attenuation of hazardous chemicals, such as heavy metals and organic compounds, which are usually present in landfill leachate. In addition, this study focused on establishing the necessary parameters required for the design of a peat filter which will offer a pretreatment to the migrating landfill leachate before its release to the environment. The experimental program was designed to establish the suitability of peat as an effective filtering media. It included the determination of adsorption isotherms, migration profiles and breakthrough characteristics of various species. The adsorption isotherms were established using a batch study, while the migration profiles and breakthrough characteristics were determined using continuous flow permeating through peat leaching columns. The leaching column study was carried out to simulate the continuous flow of leachate that would occur in the proposed peat filter. Lead, zinc, calcium, sodium and organic matter measured as BOD were examined. Batch and continuous flow tests demonstrated the effectiveness of peat to attenuate heavy metals and other contaminants.
Use of Semipermeable Membrane Devices for Monitoring Pulp Mill Effluents: a Preliminary Assessment
Authors: Rohr A.C. , Hall E.R. , Hall K.J. 
Published: March 2019

Abstract
The application of semipermeable membrane devices (SPMDs) to the monitoring of pulp mill effluents is described. SPMDs are comprised of triolein, a neutral lipid, enclosed by a low-density polymeric membrane, which together will concentrate hydrophobic aquatic pollutants. SPMDs were exposed under laboratory conditions to aqueous solutions of three model compounds with fish tainting propensity that are often found in kraft mill effluent. The model compounds were sequestered to varying extents by SPMDs during the laboratory exposures. A polar compound (guaiacol) did not appear to be amenable to monitoring by SPMDs. Static and continuous flow exposures to unbleached kraft mill effluent were also carried out, and many compounds were subsequently identified in the dialysates of exposed SPMDs. The uptake of these compounds was affected by the extent of biological treatment applied to the sample, the use of aeration during SPMD exposure, the wastewater concentration, and the exposure time. SPMDs were shown to be effective in sequestering candidate fish tainting compounds, thereby indicating their potential for application to aquatic off-flavour problems such as tainting of eulachon.
Chlorinated Organic Contaminants in Benthic Organisms of the Lower Fraser River, British Columbia
Authors: Richardson John S. , Levings Colin D. 
Published: March 2019

Abstract
Benthic insects, sediments and sculpins were collected from the Fraser River, British Columbia, in winter 1993 to assess concentrations of chlorinated organic contaminants. Concentrations of most chlorinated dioxins/furans and phenolics (phenols, guaiacols and catechols) analyzed were below detection limits. Concentrations of 2,3,7,8-tetrachlorodibenzofuran were 2.5 to 6.5 pg/g wet mass in four different taxonomic groupings of aquatic insects. Other chlorinated dioxins/furans detected were heptachlorodioxins and octachlorodioxin in sediments and detritivorous benthic insects, tetrachlorodibenzofurans (not including 2,3,7,8-TCDF) in insects, and pentachlorodibenzofurans. Some chlorinated phenolics, e.g., 3,4,5-trichloroguaiacol, were found in most taxa. Highest concentrations of phenolics were measured in prickly sculpins (Cottus asper) about an order of magnitude higher than in benthos, but all concentrations were less than 6 ng/g wet mass. Concentrations of the chlorinated organics measured were in the same range as those for juvenile chinook salmon collected at the same sites.