scholarly journals The host mussel Sinanodonta woodiana alleviates negative effects of a small omnivorous fish (Acheilognathus macropterus) on water quality: A mesocosm experiment

2020 ◽  
Vol 39 (4) ◽  
pp. 752-761
Author(s):  
Jinlei Yu ◽  
Manli Xia ◽  
Hu He ◽  
Erik Jeppesen ◽  
Baohua Guan ◽  
...  
Keyword(s):  
Water Quality ◽  
Mesocosm Experiment ◽  
Negative Effects ◽  
Omnivorous Fish ◽  
Sinanodonta Woodiana

DIP quality influenced by process water quality

TAPPI Journal ◽  
2014 ◽  
Vol 13 (9) ◽  
pp. 51-60
Author(s):  
DENNIS VOSS ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL
Keyword(s):  
Water Quality ◽  
Surface Tension ◽  
Ph Value ◽  
Water Hardness ◽  
Process Water ◽  
Test Results ◽  
Negative Effects ◽  
Water Parameters ◽  
Effects Of Ph ◽  
Contamination Levels

The need for deinking mills to reduce their fresh water consumption has resulted in higher loads of various contaminants in the process water. Lower recovered paper quality also leads to higher contamination levels in the mills. This higher load has an influence on achievable target brightness. The objective of the work was to determine and explain the main reasons for relatively poor deinked pulp quality or poor deinking potential based on the influence of recovered paper composition and process water quality. The process water parameters significantly affect the deinking potential of recovered paper. The test results showed the negative effects of increased water hardness. For standard recovered paper mixtures, flotation selectivity is higher with increasing flotation pH-value. Good results were realized for standard recovered paper with low hardness, low surface tension, and high pH-value. The results for recovered paper containing flexo newsprint could be slightly improved with low hardness, low surface tension, and low pH-value. The results of the test program using design of experiments showed interacting effects of pH-value and surface tension on luminosity and flotation selectivity.

Effects of resuspension of eastern oyster Crassostrea virginica biodeposits on phytoplankton community structure

2020 ◽  
Vol 640 ◽  
pp. 79-105
Author(s):  
ET Porter ◽  
E Robins ◽  
S Davis ◽  
R Lacouture ◽  
JC Cornwell
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Crassostrea Virginica ◽  
Skeletonema Costatum ◽  
Eastern Oyster ◽  
Energy Dissipation Rate ◽  
Negative Effects ◽  
Cell Densities ◽  
Sediment Bottom ◽  
Nitrite Nitrate

Anthropogenic disturbances in the Chesapeake Bay (USA) have depleted eastern oyster Crassostrea virginica abundance and altered the estuary’s environment and water quality. Efforts to rehabilitate oyster populations are underway; however, the effect of oyster biodeposits on water quality and plankton community structure are not clear. In July 2017, we used 6 shear turbulence resuspension mesocosms (STURMs) to determine differences in plankton composition with and without the daily addition of oyster biodeposits to a muddy sediment bottom. STURM systems had a volume-weighted root mean square turbulent velocity of 1.08 cm s-1, energy dissipation rate of ~0.08 cm2 s-3, and bottom shear stress of ~0.36-0.51 Pa during mixing-on periods during 4 wk of tidal resuspension. Phytoplankton increased their chlorophyll a content in their cells in response to low light in tanks with biodeposits. The diatom Skeletonema costatum bloomed and had significantly longer chains in tanks without biodeposits. These tanks also had significantly lower concentrations of total suspended solids, zooplankton carbon, and nitrite +nitrate, and higher phytoplankton carbon concentrations. Results suggest that the absence of biodeposit resuspension initiates nitrogen uptake for diatom reproduction, increasing the cell densities of S. costatum. The low abundance of the zooplankton population in non-biodeposit tanks suggests an inability of zooplankton to graze on S. costatum and negative effects of S. costatum on zooplankton. A high abundance of the copepod Acartia tonsa in biodeposit tanks may have reduced S. costatum chain length. Oyster biodeposit addition and resuspension efficiently transferred phytoplankton carbon to zooplankton carbon, thus supporting the food web in the estuary.

scholarly journals Catchment water quality in the year preceding and immediately following restoration of a drained afforested blanket bog

2021 ◽  
Author(s):  
Paul P. J. Gaffney ◽  
Mark H. Hancock ◽  
Mark A. Taggart ◽  
Roxane Andersen
Keyword(s):  
Water Quality ◽  
Nutrient Release ◽  
Pass Rate ◽  
Future Research ◽  
Negative Effects ◽  
Short Term ◽  
Peatland Restoration ◽  
Blanket Bog ◽  
Quality Threshold ◽  
Policy Incentives

AbstractThe restoration of drained afforested peatlands, through drain blocking and tree removal, is increasing in response to peatland restoration targets and policy incentives. In the short term, these intensive restoration operations may affect receiving watercourses and the biota that depend upon them. This study assessed the immediate effect of ‘forest-to-bog’ restoration by measuring stream and river water quality for a 15 month period pre- and post-restoration, in the Flow Country peatlands of northern Scotland. We found that the chemistry of streams draining restoration areas differed from that of control streams following restoration, with phosphate concentrations significantly higher (1.7–6.2 fold, mean 4.4) in restoration streams compared to the pre-restoration period. This led to a decrease in the pass rate (from 100 to 75%) for the target “good” quality threshold (based on EU Water Framework Directive guidelines) in rivers in this immediate post-restoration period, when compared to unaffected river baseline sites (which fell from 100 to 90% post-restoration). While overall increases in turbidity, dissolved organic carbon, iron, potassium and manganese were not significant post-restoration, they exhibited an exaggerated seasonal cycle, peaking in summer months in restoration streams. We attribute these relatively limited, minor short-term impacts to the fact that relatively small percentages of the catchment area (3–23%), in our study catchments were felled, and that drain blocking and silt traps, put in place as part of restoration management, were likely effective in mitigating negative effects. Looking ahead, we suggest that future research should investigate longer term water quality effects and compare different ways of potentially controlling nutrient release.

Impacts of Artisanal and Small-Scale Gold Mining on Water Quality in Mozambique and Zimbabwe

2015 ◽  
pp. 101-119 ◽  
Author(s):  
Never Mujere ◽  
Manuel Isidro
Keyword(s):  
Water Quality ◽  
Gold Mining ◽  
Mineral Exploration ◽  
Economic Benefits ◽  
Small Scale ◽  
Negative Effects ◽  
Mining Operations ◽  
Aquatic Life ◽  
Land Disturbance ◽  
Research Findings

Artisanal and small scale gold mining (ASGM) is an informal economic activity. ASGM is the process of extracting gold ore from the ground in the absence of land rights, mining license, exploration or mining mineral exploration permit or any legitimate document that allows the operation. Its haphazard nature, location close to and dependence on water have negative effects on the physical, chemical and biological composition of water. The socio-economic benefits of small scale mining, which include employment and income generation, are seriously outweighed by devastating environmental costs and impacts. The objective of this chapter is to examine effects of ASGM on water quality in Mozambique and Zimbabwe. Findings show that ASGM causes land disturbance, loss of biodiversity, deforestation and depletion of water resources, increased levels of siltation, turbidity and heavy metal content and the disturbance of aquatic life and its habitats. ASGM also negatively effects the health of people and animals. Based on the research findings, it is important to support and formalize, as much as possible, the mining operations so that it becomes environmentally friendly and sustainable.

scholarly journals Aquatic ecosystems in inland Australia: tourism and recreational significance, ecological impacts and imperatives for management

2012 ◽  
Vol 63 (4) ◽  
pp. 325 ◽  
Author(s):  
Wade L. Hadwen ◽  
Paul I. Boon ◽  
Angela H. Arthington
Keyword(s):  
Water Quality ◽  
Protected Area ◽  
Local Governments ◽  
Climate Change Impacts ◽  
Water Clarity ◽  
Ecological Condition ◽  
Ecological Impacts ◽  
Aquatic Systems ◽  
Negative Effects ◽  
Perceived Impacts

The value of aquatic systems for biodiversity, agriculture, pastoralism and mining is widely recognised, whereas their significance for tourism and recreation is often poorly acknowledged. We surveyed protected-area managers, local governments and tour operators (river and general) to determine how aquatic systems were used in inland Australia for tourism and recreation and the perceived impacts of these uses. Inland waterbodies were reported by all respondent groups to be highly significant foci for visitors. Natural features were rated as more important to visitors than infrastructure by protected-area managers and river-tour operators, whereas all respondent groups identified water clarity, water quality and accessibility to water as important aspects of visitor appeal. Although >75% of respondents nominated visitors as being environmentally aware, visitors were reported to have a range of negative effects on the ecological condition of inland waterbodies, especially on water quality, and to also increase erosion and the loss of fringing vegetation. Managing the recreational use of inland waterbodies will become increasingly important as demand from all sectors intensifies and climate-change impacts become more severe. Management must take into account variations in perceptions by different stakeholder groups and the paradox of inappropriate visitor behaviour despite visitors’ apparent environmental awareness.

Raw water quality weight factors: Vaal basin, South Africa

2012 ◽  
Vol 66 (5) ◽  
pp. 1061-1068 ◽  
Author(s):  
B. Dzwairo ◽  
F. A. O. Otieno ◽  
G. M. Ochieng ◽  
J. J. Bezuidenhout
Keyword(s):  
South Africa ◽  
Water Quality ◽  
Environmental Health ◽  
Health Effects ◽  
Health Effect ◽  
Raw Water ◽  
Negative Effects ◽  
Weighted Sum Method ◽  
Weight Factors ◽  
Pollution Indicator

Weight factors (WFs) were developed for surface raw water pollution indicator variables in Vaal River's Upper and Middle Vaal sub-basins, in South Africa. The overall objective was to formulate a quantifiable ranking system to indicate importance of pollutant variables given their established effects on human and environmental health. Multi-criteria decision analysis (MCDA) was applied to qualitative data that were obtained from South Africa's target water quality ranges as well as from literature which represented expert opinion. The human and environmental health effect choice sets were ranked from 1 to 5 on nine pollutant variable criteria: NH3/NH4+, Cl−, conductivity (EC), dissolved oxygen (DO), pH, F−, NO3−/NO2−, PO43− and SO42−. The weighted-sum method (WSM) then assigned highest and lowest normalised weights (NWs) to F− and Cl−, respectively, for human health effects (εhh) alternative. Highest and lowest NWs were assigned to NH3/NH4ε and EC, respectively, for environmental health effects (εeh) alternative. After aggregating the εhh and εeh WFs, resultant values ranked the variables from highest to lowest as follows: F−>NO3−/NO2−>/NH3/NH4+>DO>pH>SO42−>PO43−>EC>Cl−. The results represented the importance of variables given their established effects on human and environmental health. It was concluded that WFs provided a quantifiable barometer which could signal harmful exposure to elucidate negative effects of using polluted surface raw water in the study area. The values could be incorporated into water quality models like water quality indices. The approach could be used to develop WFs for other sites, taking into account issues like the site's pollution variables of concern as well as using a ranking key constructed from established literature.

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