Development of tools to assess and mitigate the impacts of peat harvesting on aquatic ecosystems

Author(s):  
André St-Hilaire ◽  
Sophie Duchesne ◽  
Claude Fortin ◽  
Sabiha Hafdi ◽  
Hermine Bettis ◽  
...  

<p>Peat harvesting in an important industry in northern Europe and in North America. In Canada peat is harvested to be used as a horticulture substrate. The harvesting is generally done by vacuuming the thin dried upper layer of peat found below the acrotelm, after removing the latter and draining the water. Drained water is typically routed to settling basins prior to being released in neighbouring natural water courses. This communication summarizes our research efforts to develop tools to optimize settling pond design and minimize suspended sediment loads and to provide the industry with means to assess the health of aquatic ecosystems that receive the drained water.</p><p>Current settling pond designs are based on simple rules of thumb (e.g. 25 m<sup>3</sup>/ha of harvested peatland). In our study, a hydraulic model was used to test different basin configurations (basins with and without weirs at the outlet, basins in series, basins equipped with a geotextile curtain). It was found that while the trapping efficiency was not significantly improved by adding a second basin compared to a single one, adding a geotextile curtain improved the trapping of coarser sediments. Our results moreover showed that fine sediments deposited during low flow periods, in the downstream end of the basins, could be easily resuspended during and after rainfall events, thus showing the importance of frequent maintenance. There are also some strong indications that wind erosion could be a major source of sediments in the drainage water.</p><p>Different indicators of stream ecosystem health were compared to quantify the impact of peat harvesting on the receiving water bodies. They included 1) using fish abundance and species richness; 2) quantifying sediment deposition and its organic content; 3) determining ionic composition of effluents and receiving waters; and 4) developing a water quality index (WQI) based on multiple physico-chemical measurements (ammonia, conductivity, pH and suspended sediment concentrations). The developed WQI was shown to be the most promising indicator of ecosystem health and allows for a simple classification of water quality downstream of the confluence between the drain outlet and the receiving stream.</p>

Author(s):  
D. J. Ballantine ◽  
A. O. Hughes ◽  
R. J. Davies-Colley

Abstract. Many river water quality monitoring programmes do not measure suspended particulate matter (SPM) mass concentrations despite significant interest in its multiple effects on aquatic ecosystems. Regular monthly sampling usually intercepts rivers in baseflow when suspended sediment mass concentrations and fluxes are relatively low and not of particular interest. New Zealand’s National Rivers Water Quality Network (NRWQN) is probably typical in not measuring SPM mass, although visual clarity and nephelometric turbidity are routinely measured. In order to better characterize SPM in NZ rivers, total suspended sediment (TSS) was temporarily added to the NRWQN. Turbidity, visual clarity and TSS are mutually inter-related over all 77 sites, although with considerable data scatter. However, within individual rivers turbidity and visual clarity are typically fairly closely related to TSS and provide fair to excellent surrogates. Therefore, TSS need not be measured routinely because it can be estimated with sufficient precision for many purposes from visibility or turbidity.


Author(s):  

Methodological approach to the water quality and ecosystem health from the ecological paradigm position has been vindicated. Critical analysis of the currently existing methods of water quality assessment has been performed. It has been shown that biological criteria of the ecosystems’ status diagnostics (in-situ) based on studying of laws of aquatic organisms and communities organization levels variability adequately reflect water quality and ecosystem health. New methodical solutions on hydro/chemical information compression to the unified indicator of the impact doze and vindication of informative biological water quality assessment criteria are depicted. Results of practical testing of the developed methods on a number of water bodies of Russia are presented. The methods are based on revealing of the cause-effect relations that are developed on the basis of doze-effect dependencies between the water quality chemical composition integral indicator and fish physiological status indicators.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 189
Author(s):  
Geovanni Teran-Velasquez ◽  
Björn Helm ◽  
Peter Krebs

The fluvial nitrogen dynamics at locations around weirs are still rarely studied in detail. Eulerian data, often used by conventional river monitoring and modelling approaches, lags the spatial resolution for an unambiguous representation. With the aim to address this knowledge gap, the present study applies a coupled 1D hydrodynamic–water quality model to a 26.9 km stretch of an upland river. Tailored simulations were performed for river sections with water retention and free-flow conditions to quantify the weirs’ influences on nitrogen dynamics. The water quality data were sampled with Eulerian and Lagrangian strategies. Despite the limitations in terms of required spatial discretization and simulation time, refined model calibrations with high spatiotemporal resolution corroborated the high ammonification rates (0.015 d−1) on river sections without weirs and high nitrification rates (0.17 d−1 ammonium to nitrate, 0.78 d−1 nitrate to nitrite) on river sections with weirs. Additionally, using estimations of denitrification based on typical values for riverbed sediment as a reference, we could demonstrate that in our case study, weirs can improve denitrification substantially. The produced backwater lengths can induce a means of additional nitrogen removal of 0.2-ton d−1 (10.9%) during warm and low-flow periods.


2018 ◽  
Vol 19 (1) ◽  
pp. 303-312
Author(s):  
A. Szuster-Janiaczyk ◽  
J. Bylka

Abstract The paper presents a detailed analysis of the quality of water pumped into a network and sampled from 39 monitoring points located on the network. A difference in the quality of water sampled from two different sources was demonstrated, as well as the impact of the mixing of the two waters in the water distribution system (WDS) on tap water quality. A mathematical model was used to identify the zones of water mixing and the areas of unfavourable hydraulic conditions (low flow rates and long retention times).


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3002
Author(s):  
Jakub Mazurkiewicz ◽  
Agata Mazur ◽  
Robert Mazur ◽  
Krzysztof Chmielowski ◽  
Wojciech Czekała ◽  
...  

The article discusses the impact of nutrients from sewage on the state of the sewage receiver. Bioremediation was carried out through the use of effective microorganisms. The potential recovery of valuable mineral and organic substances in the form of fertilizers was also examined. The Słoneczko Reservoir is a bathing area and serves many people in the summertime as a place of water recreation. Water quality deteriorated intensively from 2006 as a result of illegal wastewater discharge and the impact of fecal pollution from bathers. The high concentration of nutrients in the water was the cause of the eutrophication process and blooms of cyanobacteria, which pose a threat to human health in the bathing area. The bathing area was also closed many times by sanitary services as a result of exceeding the number of Escherichia coli and Enterococcus faecalis in the water. At the bottom of the reservoir, there was a layer of sediments with a thickness of 30–70 cm. Thus, the processes of anaerobic decomposition generated odor, causing nuisance in the reservoir area. Water transparency varied from 30 to 50 cm, due to the accumulation of suspensions and biomass of planktonic algae. The reservoir was subjected to microbiological bioremediation in 2017 and 2018 to polluted water treatment and to reduce the organic content of bottom sediments. Already after the first application of biopreparations putrefactive odors and the eutrophication process disappeared at the end of the 2017 summer season. Bioremediation reduced the value of E. coli and E. feacalis to the acceptable level. After the second application in 2018, the organic fraction of the bottom sediments was reduced to a very low level and the water transparency reached the bottom (maximum depth was 2.2 m) throughout the entire bathing area. The effect of the water remediation was maintained until 2019, and the surface water quality remained at a very good level. An important aspect in this case is also the exploitation of bottom sediments, because they are rich in nutrients and organic matter, and therefore it may have some potential as a fertilizer. The recovery of nutrients can be used in plant or pot production. However, they contain compounds that degrade quickly, causing unpleasant odors and threatening the environment. Thus, they should be managed and handled in an environmentally friendly and sustainable way.


2017 ◽  
Vol 7 (3) ◽  
pp. 477-484 ◽  
Author(s):  
K. Ghodeif ◽  
R. Wahaab ◽  
S. Sorour

The present work was conducted to document the problems raised regarding low-flow in the Rosetta branch, Egypt and to develop management options to protect drinking water sources. The water quality was monitored during low-flow periods at four drinking water intakes. Results showed an increase in electric conductivity (EC), ammonium (NH4), nitrite (NO2), phosphate (PO4), and total organic carbon (TOC) during the low-flow period. EC ranges from 454 to 1,062 μS/cm and the mean value is 744. Ammonium ranges from 0.38 to 18.5 mg/L and the mean value is 5.45. NO2, PO4, and TOC have mean values of 0.73, 1.85, and 6.71 mg/L, respectively. Statistical evaluation revealed the association of NH4, EC, and PO4 that are good indicators for the load of wastewater. High ammonium often refers to a bad situation regarding oxygen while high nitrite indicates the first oxidation for wastewater through microbiological processes. The low-flow action has a serious impact on drinking water source. A high content of ammonium has delayed coagulation, enhanced algae growth, and prevented the breakpoint being reached during chlorination processes. Potential management options to deal with water scarcity and low-flow, meanwhile reducing the contaminant load in the source drinking water were proposed.


2019 ◽  
Vol 54 (4) ◽  
pp. 309-325 ◽  
Author(s):  
Liyu Chen ◽  
Patrick M. D'Aoust ◽  
Colin D. Rennie ◽  
Alexandre Poulain ◽  
Frances Pick ◽  
...  

Abstract Stormwater ponds (SWPs) are widely utilized for flood and water quality control. Low-flow rates are common in SWPs, sometimes causing wind-driven currents to become the dominant hydrodynamic force during ice-free periods. Hence, it is essential to understand the influence of the wind-induced flow on stratification and dissolved oxygen (DO) concentrations in shallow SWPs to predict the performance and water quality of these systems. The objective of this study is to evaluate the influence of wind-driven circulation on the spatial distribution of DO in an SWP using a numerical model. A bottom-mounted acoustic Doppler current profiler (ADCP) was utilized to measure small wind-induced currents and to validate a hydrodynamic model, which suggested that a wind-dominated circulation was generated even with the moderate wind speed. Countercurrents opposite in the direction to surface wind-generated flow were also present. The DO model demonstrated that complete mixing can be produced by higher wind speed, leading to fully oxic conditions throughout the water column (7.00 mg/L DO or higher), wherein low DO water at depth was carried to the surface by upwelling circulation and was possibly replenished during the surface transportation. This sheds some light on the impact of wind-induced mixing on the water quality in shallow SWPs.


2019 ◽  
Vol 41 (2) ◽  
pp. 368-368
Author(s):  
Maria Kaleem Maria Kaleem ◽  
Shahid Naseem Shahid Naseem ◽  
Erum Bashir Erum Bashir ◽  
Bushra Shahab and Muhammad Mansha Bushra Shahab and Muhammad Mansha

Major and trace element geochemistry of groundwater of southern Mor Range, Balochistan was made to insight the impact of igneous and sedimentary rock on the composition of groundwater. The median values of ions display Na+andgt; Mg2+ andgt;Ca2+andgt;K+ and HCO3-andgt;SO4-2andgt;Cl-andgt;CO3-2 trend in the distribution of cations and anions respectively. The plots on Piper diagram indicated Ca-Na-Cl-type water (40.84%) as dominant water facies, followed by Ca-Cl-type (18.36%), Ca-Na-HCO3-Cl-type (16.33%), Ca-HCO3-Cl-type (12.24%), Na-Cl is (10.20%). The plots on Gibbs’ diagrams delineate rock weathering combined with evaporation process for regulating the ionic composition. Molar ratio of Ca2++Mg2+ vs. HCO3-+SO42- and Ca2+/Na+ vs. Mg2+/Na+ demonstrated that the groundwater of the study area has genetic association with the igneous rocks of Bela Ophiolite and sedimentary rocks of Ferozabad Group. Strong correlation matrix and PCA diagram also witnessed genetic affiliation with the rocks of the study area. The ionic composition revealed, nearly 50% samples faced process of ion exchange. Estimation of selected trace elements (Fe, Zn, V, Mn, Cu, Pb, Cr, Ni, As and Co) was also done to evaluate the drinking water quality and their possible health implications. Majority of them was found within permissible limits; however, in some of the samples, Fe, V and Pb exceed the WHO specifications.


2005 ◽  
Vol 51 (5) ◽  
pp. 53-59 ◽  
Author(s):  
H.A.J. Senhorst ◽  
J.J.G. Zwolsman

A number of possible relationships between climate change and water quality of Dutch surface waters have been investigated and an indicative quantification of the impact of climate change on water quality has been established. The analysis focused on water quality during periods of low flow and extreme heat, which are assumed to increase in frequency and intensity due to climate change. The results indicate that the impact of climate change on water quality cannot be generalised and should be assessed on a case by case basis. However, the impact on extreme situations (floods and droughts) seems to be largest, whilst water quality under average discharge conditions appears to be relatively unchanged.


2001 ◽  
Vol 1 (4) ◽  
pp. 253-263 ◽  
Author(s):  
I. Baudin ◽  
C. Campos ◽  
J.M. Laîne

At the end of 1997, an innovative membrane-adsorption process was integrated at the Vigneux-sur-Seine water treatment plant in the southeast suburbs of Paris, France. This hybrid process consisted of the application of powdered activated carbon (PAC) upstream of ultrafiltration (UF) membranes and recycled to a floc blanket reactor (FBR) after membrane backwashes (FBR-PAC/UF process). This process was designed to mitigate seasonal episodes of micropollutants (pesticides and taste and odors) and to reduce the content of natural organic matter responsible for disinfectant and disinfection by-products. An intensive monitoring campaign of the plant effluent and ten sites in the distribution system was conducted two years before (1996-1997) and two years after (1998-1999) the start up of the PAC/UF process to characterize the impact of this treatment on the water quality of the distributed water. The objective of this paper is to illustrate the positive impact of the PAC/UF process on the organic and biological water quality of the Vigneux-sur-Seine distribution system. Thus, the combination of coagulation and adsorption in the FBR-PAC/UF process resulted in a TOC concentration lower than 0.7 mg/l, BDOC values lower than the detection limit (<0.2 mg/l) and total trihalomethanes concentrations below 10 μg/l. This reduction in organic content results in a reduction of the chlorine consumption by the water produced, which translates in the maintenance of higher chlorine residuals throughout the distribution system while using the same chlorine doses at the plant (0.3 mg/l).


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