Long-Term Trends in Acid Neutralizing Capacity under Increasing Acidic Deposition: A Special Example of Eutrophic Taihu Lake, China

2016 ◽  
Vol 50 (23) ◽  
pp. 12660-12668 ◽  
Author(s):  
Tao Yu ◽  
Qiujin Xu ◽  
Chengda He ◽  
Haibing Cong ◽  
Dan Dai ◽  
...  
Keyword(s):  
Taihu Lake ◽  
Acidic Deposition ◽  
Acid Neutralizing Capacity ◽  
Neutralizing Capacity ◽  
Long Term Trends

scholarly journals Long-term trends of water chemistry in mountain streams in Sweden – slow recovery from acidification

2014 ◽  
Vol 11 (1) ◽  
pp. 173-184 ◽  
Author(s):  
H. Borg ◽  
M. Sundbom
Keyword(s):  
Water Chemistry ◽  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
Precipitation Trend ◽  
Run Off ◽  
Neutralizing Capacity ◽  
Recovery From Acidification ◽  
Long Term Trends

Abstract. The water chemistry of streams and precipitation in the province of Jämtland, northern Sweden has been monitored since the 1980s to study long-term trends, occurrence of acid episodes, and effects of liming. The acidity in precipitation increased in the 1970s, followed by a loss of acid neutralizing capacity (ANC) and low pH in the streams. Sulfur deposition began to decrease in the 1980s, until approximately 2000, after which the decrease levelled out. Stream water sulfate concentration followed the precipitation trend but decreased more slowly and since the late 1990s a subtle increase was observed. Sulfate concentrations in the snow typically have been higher than or equal to the stream sulfate levels. However, during the period of rapid deposition decrease and also since 2005 stream sulfate has sometimes exceeded snow sulfate, indicating desorption of stored soil sulfate, possibly because of climate-related changes in run-off routes through the soil profiles, following shorter periods of frost. From 1982 to 2000, total organic carbon (TOC) increased by approximately 0.1 mg L−1 yr−1. The mean trends in sulfate and TOC from approximately 1990 until today were generally opposite. Acidic episodes with pH 4.0 at flow peaks occurred frequently in the unlimed streams, despite relatively well-buffered waters at baseflow. To evaluate the main causes for the loss of ANC during episodes, the changes in major ion concentrations during high flow episodes were evaluated. The most important factors contributing to ANC loss were dilution of base cations (Na+, K+, Ca2+, Mg2+), enrichment of organic anions and enrichment of sulfate. Wetland liming started in 1985 after which the earlier observed extreme peak values of iron, manganese and aluminium, did not reoccur. The studied area is remote from emission sources in Europe, but the critical load of acidity is still exceeded. The long-term recovery observed in the unlimed streams is thus slow, and severe acidic episodes still occur.

The long-term acid neutralizing capacity of steel slag

2000 ◽  
Vol 20 (2-3) ◽  
pp. 217-223 ◽  
Author(s):  
Jinying Yan ◽  
Luis Moreno ◽  
Ivars Neretnieks
Keyword(s):  
Steel Slag ◽  
Acid Neutralizing Capacity ◽  
Neutralizing Capacity

Seasalt Effects on the Acid Neutralizing Capacity of Streamwaters in Southern Norway

1995 ◽  
Vol 26 (4-5) ◽  
pp. 369-388 ◽  
Author(s):  
Espen Lydersen ◽  
Arne Henriksen
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
Neutral Salt ◽  
Exchange Reactions ◽  
Short Term ◽  
Sulphur Compounds ◽  
Neutralizing Capacity ◽  
Southern Norway

Input of neutral salt, primarily NaCl, from sea spray is an important factor for short-term acidification of surface water, primarily in already acidified areas, because Na may substitute for H+ and cationic aluminium by cation-exchange reactions in the soil. By evaluating the variation of non-marine sodium (Na*) separately it is possible to estimate the major effect of seasalt episodes on the neutralizing capacity (ANC) of stream water. At four long-term monitored Norwegian catchments, the Na* in stream water on average explained 28 ± 4% of the monthly variations of ANC in stream water at Birkenes, and 27 ± 3%, 20 ± 2% and 56 ± 5% of the correspondent variations at Storgama, Langtjern and Kaarvatn, during the respective monitoring periods. The remaining variations in acid neutralizing capacity are explained by the difference between non-marine base cations (ΣCa*,Mg*,K*) and non-marine sulphate (SO4*) and NO3. This paper also indicates that seasalt episodes are probably of greater importance for the periodic variations in ANC of stream water than commonly recognized. During the last years, extreme seasalt episodes have occurred in southern Norway, and more frequently at winter-time, which means that seasalt inputs have played a more important role for the short-term variations of ANC in stream water the last years. This tendency is also strengthened by the fact that there has been a significant decline in the input of acidic sulphur compounds and non-marine base cations in stream water during the last 10-15 years. Because the decline in soil-derived base cations in stream water is somewhat lower than the correspondent decline of sulphate, a slowly improving ANC of stream water should be expected on long-term basis. Seasalt episodes of the same magnitude as those present during the last years, will therefore most likely cause less extreme water-chemical conditions in the years to come. Because the seasalt effect seems to be a short-term effect, there is no reason to claim that these effects may cause long-term acidification, a conclusion earlier drawn from several correspondent studies.

Effects of acidic deposition on North American lakes: palaeolimnological evidence from diatoms and chrysophytes

1990 ◽  
Vol 327 (1240) ◽  
pp. 403-412 ◽  
Keyword(s):  
United States ◽  
New England ◽  
Sierra Nevada ◽  
Acidic Deposition ◽  
Land Use Changes ◽  
Acid Neutralizing Capacity ◽  
Calibration Data ◽  
Contributing Factors ◽  
Neutralizing Capacity ◽  
Inferred Ph

Analysis of sediment diatom and chrysophyte assemblages is the best technique currently available for inferring past lake water pH trends. Use of this approach for assessing the ecological effects of acidic deposition is increasing rapidly. As of August 1989, sediment core inferred pH data existed for at least 150 lakes in North America and cores from about 100 more lakes are being analysed. Equations for inferring past pH are based on at least 15-20 calibration data-sets involving about 700 lakes. Palaeolimnological studies indicate that recent acidification has been caused by acidic deposition in the Adirondack Mountains (New York), northern New England, Ontario, Quebec and the Canadian Atlantic provinces. Inferred pH decreases are commonly as much as 0.5-1.0 pH units. With the exception of one lake, no acidification trends were observed in regions currently receiving low deposition of strong acids (e.g. Rocky Mountains and Sierra Nevada in the western United States). Slight or no trends towards decreasing pH were observed in study lakes receiving moderately acidic deposition (upper Mid-west and northern Florida). The amount of inferred acidification (increase in H + concentration) correlates with the amount of S and N loading and the ability of watersheds and lakes to neutralize acid inputs, and is generally consistent with current lake-acidification theory. In most cases, the primary cause of recent acidification (post-1850) is acidic deposition, as opposed to land-use changes or natural processes, though these may be contributing factors. Acid loading has decreased in some regions since 1970 (e.g., northeastern United States). Some lakes have become less acidic in response, but others continue to lose acid neutralizing capacity. Many currently acidic lakes were naturally acidic (pH < 5.5) before the onset of anthropogenic acidification. These lakes are typically small (less than 10 ha) are located at moderately high elevations, have thin or peaty soils, or are located in outwash deposits. Many of these have acidified further recently.

Chemical Response of Lakes Treated with CaCO3 to Reacidification

1989 ◽  
Vol 46 (2) ◽  
pp. 258-267 ◽  
Author(s):  
Charles T. Driscoll ◽  
William A. Ayling ◽  
G. F. Fordham ◽  
Leah M. Oliver
Keyword(s):  
New York ◽  
Acid Neutralizing Capacity ◽  
Neutralizing Capacity ◽  
Water Columns ◽  
Decreasing Ph ◽  
Woods Lake ◽  
Dissolution Efficiency ◽  
Hydrologic Inputs ◽  
Mixed Water

The reacidification of two lakes in the Adirondack region of New York treated by CaCO3 application was evaluated. Base treatment resulted in a very high immediate dissolution efficiency in both lakes (78–82%), increasing acid neutralizing capacity (ANC) to values of 450–550 μeq∙L−1. During the fall following manipulation, completely mixed water columns and elevated hydrologic inputs greatly facilitated reacidification, decreasing pH and diluting Ca2+ concentrations. Cranberry Pond effectively reacidified within 7 mo of treatment, while the ANC of Woods Lake decreased to near 0 μeq∙L−1 15 mo after application. In Cranberry Pond, pH values decreased below 5.5 resulting in transport of elevated concentrations of inorganic Al through the lake. Annual ANC budgets suggest that little CaCO3 penetrated to the sediments, limiting long-term release of ANC from sediment dissolution. Hydrolysis of Al, due to the elevated lake pH, served to consume ANC and there is evidence to indicate limited exchange of water column Ca2+ with sediments shortly after treatment followed by release of this Ca2+ during reacidification. However these processes did not significantly accelerate or attenuate the rate of reacidification. The rate of acidification could largely be explained by the flushing of ANC from the lakes by hydrologic inputs.

scholarly journals Rapid Recent Recovery from Acidic Deposition in Central Ontario Lakes

Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 10 ◽  
Author(s):  
Shaun A. Watmough ◽  
M. Catherine Eimers
Keyword(s):  
Acidic Deposition ◽  
Base Cation ◽  
Acid Neutralizing Capacity ◽  
Chemical Recovery ◽  
Charge Balance ◽  
Limited Effect ◽  
Lake Recovery ◽  
Neutralizing Capacity ◽  
Carbon Concentrations ◽  
S Deposition

In many regions, chemical recovery in lakes from acidic deposition has been generally slower than expected due to a variety of factors, including continued soil acidification, climate-induced sulphate (SO4) loading to lakes and increases in organic acidity. In central Ontario, Canada, atmospheric sulphur (S) deposition decreased by approximately two-thirds between 1982 and 2015, with half of this reduction occurring between 2005 and 2015. Chemical recovery in the seven lakes was limited prior to 2005, with only small increases in pH, Gran alkalinity and charge-balance ANC (acid-neutralizing capacity). This was because lake SO4 concentrations closely followed changes in S deposition, and decreases in base cation concentration closely matched declines in SO4. However, decreases in S deposition and lake SO4 were more pronounced post-2005, and much smaller decreases in lake base cation concentrations relative to SO4 resulted in large and rapid increases in pH, alkalinity and ANC. Dissolved organic carbon concentrations in lakes increased over the study period, but had a limited effect on lake recovery. Clear chemical recovery of these lakes only occurred after 2005, coinciding with a period of dramatic declines in S deposition.

scholarly journals Increasing silicon concentrations in Bohemian Forest lakes

2005 ◽  
Vol 9 (6) ◽  
pp. 699-706 ◽  
Author(s):  
J. Veselý ◽  
V. Majer ◽  
J. Kopácek ◽  
J. Safanda ◽  
S. A. Norton
Keyword(s):  
Surface Waters ◽  
Acidic Deposition ◽  
Sharp Decrease ◽  
Inhibitory Effect ◽  
Bohemian Forest ◽  
Long Term Trends ◽  
Marked Decline ◽  
The Bohemian Forest ◽  
Dissolved Silicon

Abstract. Long-term trends of dissolved silicon (Si) concentrations in five glacial lakes in the Bohemian Forest, Czech Republic, recovering from acidification show higher mobility of Si from the soil to surface waters despite lower atmospheric deposition of acids. Si increased by 0.95 to 1.95 µmol yr-1 (36 to 51%) from 1986-2004 and with increasing pH. A change in soil solution conditions because of a sharp decrease in acidic deposition has led to marked decline in Al mobility and to considerable decreases in dissolved Al, especially Al3+. The increase in Si may be related to: (1) unblocking of the inhibitory effect of dissolved Al on weathering of aluminosilicates, (2) biogenic opal (phytoliths) dissolving faster, and/or (3) lower Si precipitation as secondary aluminosilicates in soil. The change in Al speciation on the dissolution rate of biogenic silica is critical. A lack of change in Si at sites outside central Europe may be explained by small or no decline in mobility of dissolved Al. The effect of a long-term increase in temperature was probably minor.

Sensitivity analysis of a watershed acidification model

1984 ◽  
Vol 305 (1124) ◽  
pp. 441-449 ◽  
Keyword(s):  
Soil Depth ◽  
Field Capacity ◽  
Acid Neutralizing Capacity ◽  
Time Step ◽  
Soil Thickness ◽  
Neutralizing Capacity ◽  
Daily Time Step ◽  
Short And Long Term ◽  
Daily Time

A computer model is developed and calibrated for simulating the movement of water and H ion through a forested watershed. The model is appropriate to a small (1 km 2 ) non-calcareous basin. The model is run on a daily time step with meteorological and pH of precipitation inputs. The model incorporates acid neutralizing capacity (a.n.c.) for various soil horizons. Changes in field capacity on the short and long term (weeks and months) and change in the hydraulic conductivity of the saturated zone on the long term affect basin outflow; a.n.c. and depth of the soil affect the pH of water on the long term. Reasonable changes in snow leaching, canopy enrichment, a.n.c., soil depth and total soil thickness have no effect on pH in the short term.

Long-term records and modelling of acidification, recovery, and liming at Lake Hovvatn, Norway

2005 ◽  
Vol 62 (11) ◽  
pp. 2620-2631 ◽  
Author(s):  
Atle Hindar ◽  
Richard F Wright
Keyword(s):  
Salmo Trutta ◽  
Acid Neutralizing Capacity ◽  
Dramatic Reduction ◽  
Egg Survival ◽  
Neutralizing Capacity ◽  
Brown Trout Salmo Trutta ◽  
Acidification Recovery ◽  
To Come ◽  
Acidification History

Lake Store Hovvatn and the adjacent Lake Lille Hovvatn (Norway) are acidified owing to long-term deposition of S and N. By 1974, pH was 4.46 and acid-neutralizing capacity was –42 µequiv.·L–1. Following a lake SO4 reduction from 92 to 33 µequiv.·L–1, pH had increased to 4.8 and acid-neutralizing capacity had increased to –8 µequiv.·L–1 by 2003. The acidification history is well reconstructed using the dynamic model MAGIC. The model predicts that the lakes will not, however, recover to conditions adequate to support a self-reproducing brown trout (Salmo trutta) population. Lake Store Hovvatn was first limed in 1981 and subsequently annually or biannually until 1999, at which time the entire catchment was limed. Liming increased pH to above target levels of 6.0 and reduced inorganic Al to below 5 µequiv.·L–1 in the main water body. Only after the terrestrial liming in 1999, however, was pH potentially adequate for egg survival in the lake during winter, as pH at shallow depths below the ice stayed above 5.5. The results indicate that even the dramatic reduction in acid deposition in Europe will be insufficient to provide water quality adequate for fish populations; such lakes will require some sort of liming for many decades to come.

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