Predicting Reacidification of Calcite Treated Acid Lakes

1989 ◽  
Vol 46 (2) ◽  
pp. 323-332 ◽  
Author(s):  
Joseph V. DePinto ◽  
Richard D. Scheffe ◽  
William G. Booty ◽  
Thomas C. Young
Keyword(s):  
Water Column ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Dissolved Inorganic Carbon ◽  
Proton Exchange ◽  
Acid Neutralizing Capacity ◽  
Water Proton ◽  
Acid Lakes ◽  
Neutralizing Capacity ◽  
Woods Lake

A mathematical model (acid lake reacidification model, ALaRM) for predicting reacidification times of calcite treated acid lakes has been calibrated and field tested using data from two Lake Acidification Mitigation Project (LAMP)) lakes (Woods Lake and Cranberry Pond, Big Moose, N.Y.) The model is based on dynamic water column and sediment mass balances of acid neutralizing capacity (ANC) and dissolved inorganic carbon (DIC). Inclusion of a sediment submodel that includes sediment–pore water proton exchange, production of DIC through sediment respiration, ANC generation or utilization through redox reactions, long-term dissolution of calcite deposited in the surface sediments during application, and pH adjustment through an equilibrium proton balance, permits the deterministic simulation of sediment response to whole-lake liming and its subsequent effect on water column reacidification. Application of ALaRM to the postliming response of the two lakes demonstrated that reacidification was controlled primarily by hydrologic flushing and secondarily by sediment–water ANC transfer. Cranberry Pond, which has a mean hydraulic retention time of 2 mo, reacidified to near 0 ANC and pH < 5 within 6 mo after treatment. Woods Lake, which has a mean hydraulic retention time of almost 6 mo, still had an ANC > 20 μeq∙L−1 and a pH > 5.6 just prior to its reliming 15 mo after its initial treatment.

Short-Term Changes in the Acid/Base Chemistry of Two Acidic Lakes Following Calcium Carbonate Treatment

1989 ◽  
Vol 46 (2) ◽  
pp. 306-314 ◽  
Author(s):  
G. F. Fordham ◽  
C. T. Driscoll
Keyword(s):  
New York ◽  
Dissolved Inorganic Carbon ◽  
Initial Perturbation ◽  
Acid Neutralizing Capacity ◽  
Short Term ◽  
Acidic Lakes ◽  
Neutralizing Capacity ◽  
Rapid Dissolution ◽  
Additional Release ◽  
Woods Lake

Woods Lake and Cranberry Pond, two chronically acidic lakes located in the Adirondack region of New York, USA, were intensively monitored following CaCO3 treatment in May 1985 to evaluate the mechanisms controlling short-term changes in water column chemistry. Immediately following base application (24 h), both lakes responded like systems closed to atmospheric CO2, because the dissolution of very small CaCO3 particles (median diameter 2 μm) exceeded the rate of atmospheric CO2 intrusion. Rapid dissolution of CaCO3 coupled with very low concentrations of dissolved inorganic carbon (DIC) prior to treatment, resulted in pH increases in the upper mixed waters from 4.9 to 9.4 in Woods Lake and from 4.6 to 9.1 in Cranberry Pond, as waters readily became saturated with CaCO3. pH increases were accompanied by stoichiometric increases in dissolved Ca2+, acid neutralizing capacity (ANC), and DIC. Following this initial perturbation, the upper mixed waters equilibrated with atmospheric CO2 over a 4 wk period, facilitating additional release of dissolved Ca2+ and ANC due to dissolution of suspended CaCO3. The amount of CaCO3 that dissolved during the 4 wk immediately following treatment, calculated from Ca2+ budgets, was very high; 86% in Woods Lake and 79% in Cranberry Pond.

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.

Conception and optimization of a membrane electrode assembly microbial fuel cell (MEA-MFC) for treatment of domestic wastewater

2011 ◽  
Vol 64 (7) ◽  
pp. 1527-1532 ◽  
Author(s):  
O. Lefebvre ◽  
A. Uzabiaga ◽  
Y. J. Shen ◽  
Z. Tan ◽  
Y. P. Cheng ◽  
...  
Keyword(s):  
Retention Time ◽  
Microbial Fuel Cells ◽  
Hydraulic Retention Time ◽  
Construction Materials ◽  
Domestic Wastewater ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Electricity Production ◽  
Membrane Electrode

A membrane electrode assembly (MEA) for microbial fuel cells (MEA-MFC) was developed for continuous electricity production while treating domestic wastewater concurrently. It was optimized via three upgraded versions (noted α, β and γ) in terms of design (current collectors, hydrophilic separator nature) and operating conditions (hydraulic retention time, external resistance, aeration rate, recirculation). An overall rise of power by over 100% from version α to γ shows the importance of factors such as the choice of proper construction materials and prevention of short-circuits. A power of 2.5 mW was generated with a hydraulic retention time of 2.3 h when a Selemion proton exchange membrane was used as a hydrophilic separator in the MEA and 2.8 mW were attained with a reverse osmosis membrane. The MFC also showed a competitive value of internal resistance (≈40–50 Ω) as compared to the literature, especially considering its large volume (3 L). However, the operation of our system in a complete loop where the anolyte was allowed to trickle over the cathode (version γ) resulted in system failure.

The nitrogen removal potential of predenitrification systems in sensitive coastal areas

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Domestic Sewage ◽  
Coastal Areas ◽  
Careful Evaluation ◽  
Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

Evaluation of a tropical single-cell waste stabilization pond system for irrigation

1995 ◽  
Vol 31 (12) ◽  
pp. 267-273 ◽  
Author(s):  
B. S. O. Ceballos ◽  
A. Konig ◽  
B. Lomans ◽  
A. B. Athayde ◽  
H. W. Pearson
Keyword(s):  
Single Cell ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Full Scale ◽  
Waste Stabilization Pond ◽  
North East ◽  
Helminth Eggs ◽  
Waste Stabilization ◽  
Better Than

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.

Evaluation of Hemidesmus indicus root as an antacid by In vitro

2016 ◽  
Vol 5 (04) ◽  
pp. 4524
Author(s):  
Abdullah Shaikh Farooque ◽  
Md. Azharuddin Ismail Atar*
Keyword(s):  
Skin Diseases ◽  
Care Delivery ◽  
Health Care Delivery System ◽  
Acid Neutralizing Capacity ◽  
Standard Drug ◽  
Hemidesmus Indicus ◽  
Neutralizing Capacity ◽  
Loss Of Appetite ◽  
Powdered Drug

Medicinal plants are being widely used, either as single drug or in combination in health care delivery system. Indian Sarsaparilla, Hemidesmus indicus (Family: Asclepiadaceae) is a commonly known Indian Medicinal Plant, which is widely recognized in traditional systems of Medicine. It contains various phytoconstituents belonging to the category glycosides, flavonoids, tannins, sterols and volatile oils. It has been reported as useful in biliousness, blood diseases, dysentery, diarrhea, respiratory disorders, skin diseases, syphilis, fever, leprosy, leucoderma, leucorrhoea, itching, bronchitis, asthma, eye diseases, epileptic fits in children, kidney and urinary disorders, loss of appetite, burning sensation, dyspepsia, nutritional disorders, ulcer and rheumatism. Several studies are being carried towards its activities like analgesic, anti-inflammatory, antiulcer, hepatoprotective, antioxidant and helicobactericidal properties. In our study we have evaluated antacid activity of sariva (Anantmool) by using In-Vitro method, i.e. ANC (Acid Neutralizing Capacity). This evaluation was done by comparing the ANC of sariva macerated & powdered drug with water as blank & standard drug i.e. NaHCO3. Based on this In-Vitro experiment, we can conclude that, the macerated & powdered drug of sariva (Anantmool) evaluated in this study, varied in potency as measured in terms of their ANC. These results having ** i.e. P < 0.01 & Passed the normality test. However, the present study being in-vitro, the effects of antacid may vary In-Vitro; individual variations also contribute to the ultimate effectiveness of as antacid.        

Sign in / Sign up

Export Citation Format

Share Document