Biogeochemical interactions between acidic deposition and a low-elevation spruce–fir stand in Howland, Maine

1991 ◽  
Vol 21 (6) ◽  
pp. 867-875 ◽  
Author(s):  
Gregory B. Lawrence ◽  
Ivan J. Fernandez
Keyword(s):  
Organic Matter ◽  
Dry Deposition ◽  
Acidic Deposition ◽  
Water Flux ◽  
Strong Acid ◽  
Mineral Weathering ◽  
East Central ◽  
Soil Solutions ◽  
Annual Deposition ◽  
Measurement Period

The biogeochemical interactions between acidic deposition and a forest ecosystem were investigated in a low-elevation spruce–fir stand in east-central Maine. A 0.2-ha plot was intensively instrumented for measurement of precipitation, throughfall, and soil solutions. Annual precipitation for 1989 had an average pH of 4.39 and an estimated 424, 191, and 231 mol•ha−1 deposition of H+, SO42−, and NO3−, respectively. Soil water flux was determined from precipitation and evaporation estimates. Ion flux data are presented for the 12-month period of 1989. Approximately 50% of inorganic strong acid acidity in precipitation plus unmeasured dry deposition was neutralized by the canopy for the measurement period reported. Soil and soil solution buffering were largely controlled by organic matter and mineral weathering. Mobilization of inorganic Al was minimal (<3 μM) in both the Oa and Bs horizons. Ratios of Al/Ca2+ were well below values considered to cause inhibition of Ca2+ uptake. Annual deposition of SO42− in throughfall (285 mol•ha−1) approximated output (291 mol•ha−1). Virtually 100% of wet-only NO3− input and 90% of wet-only NH4+ input were retained within the ecosystem.

Cation and anion fluxes in northern hardwood throughfall along an acidic deposition gradient

1993 ◽  
Vol 23 (3) ◽  
pp. 457-467 ◽  
Author(s):  
Hal O. Liechty ◽  
Glenn D. Mroz ◽  
David D. Reed
Keyword(s):  
Dry Deposition ◽  
Acidic Deposition ◽  
Strong Acid ◽  
Northern Hardwood ◽  
Ionic Concentrations ◽  
Anionic Composition ◽  
Canopy Leaching ◽  
Atmospheric Inputs ◽  
Deposition Gradient ◽  
Precipitation Acidity

Ionic concentrations and fluxes were measured for 2 years in five northern hardwood stands along an acidic deposition gradient that extends from northern Minnesota (lowest deposition) to southeastern Michigan (highest deposition). Precipitation fluxes of H+, SO42−, and NO3− were, respectively, 340, 69, and 83% greater at the site with the highest deposition than at the site with the lowest deposition. No significant differences among sites were evident for precipitation fluxes of cations along the gradient. Fluxes of H+, SO42−, NO3−, Ca2+, and Mg2+ in throughfall increased along the gradient and were positively correlated with increased atmospheric inputs of H+, SO42−, and NO3− measured at the sites. Fluxes of SO42− and NO3− in throughfall were greater than precipitation fluxes, indicating dry deposition in excess of any assimilation of these anions from precipitation. Dry deposition inputs of SO42− increased from the northwestern to southeastern sites and were estimated to range from 23 to 49% of precipitation inputs. Precipitation acidity was neutralized by the canopy in all stands, but the amount of H+ retained by the canopy was significantly greater at sites with the greatest precipitation acidity. Throughfall fluxes of Ca2+ and Mg2+ in excess of precipitation fluxes were positively correlated with the canopy retention and deposition of H+ along the gradient. Increased throughfall fluxes of these cations were consistent with hypothesized increases in canopy leaching of cations with increased acidic deposition. Increased canopy leaching of Ca2+ and Mg2+, resulting from elevated acidic deposition, was estimated to represent as much as 6.2 and 12.9% of foliar contents of these cations, respectively. Although HCO3− and organic anions were found to play an important role in maintaining electroneutrality in throughfall along the gradient, strong acid anions increasingly dominated anionic composition of throughfall with increasing acidic deposition.

Effect of dissolved organic matter composition on metal speciation in soil solutions

2015 ◽  
Vol 398 ◽  
pp. 61-69 ◽  
Author(s):  
Zong-Ling Ren ◽  
Marie Tella ◽  
Matthieu N. Bravin ◽  
Rob N.J. Comans ◽  
Jun Dai ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Metal Speciation ◽  
Organic Matter Composition ◽  
Soil Solutions

Functional role of earthworms to control the hydraulic conductivity of constructed wetlands 

2021 ◽  
Author(s):  
Océane Gilibert ◽  
Dan Tam Costa ◽  
Sabine Sauvage ◽  
Didier Orange ◽  
Yvan Capowiez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Hyporheic Zone ◽  
Riparian Zone ◽  
Water Flux ◽  
Sediment Surface ◽  
Deep Soil ◽  
The Impact ◽  
Organic Matter Input

&lt;p&gt;Wetlands are known for their natural service of water quality regulation. The hyporheic zones of the rivers filter and purify the surface water from the stream and infiltrated waters in soil nearby through the riparian zone. This purification service occurs because of a synergy between the substrate and its biodiversity (including plants, bacteria and other invertebrates). Our study deals with constructed wetlands (CW) as a nature-based solution mimicking wetlands water purification process, to purify wastewaters. The REUSE technology of CW is based on the use of specific layers of gravels and sands inside a close concrete structure, planted with specific sub-aquatic plants, where wastewaters or runoff of stormwaters are introduced to be filtered. The technology of Vertical Flow Constructed Wetlands (VFCW) reproduces the water flux observed in the riparian zone with a gravity flow of water. It is composed of reeds planted on a sandy layer (&amp;#216; 0-4 mm) and succession of gravel layers. This substrate can be saturated or unsaturated to reproduce the functioning of the hyporheic zone or the riparian zone respectively. By the time, the substrate is colonized by a community of bacteria producing biofilms which capture the residual organic matter from wastewaters to mineralize them. However, the VFCW substrates tend to clog over time due to the accumulation of organic matter and biofilms. Many studies consider earthworms as one of the solutions to alleviate this clogging, thanks to their burrows recreating macropores and preferential channels which help to improve the dispersion of water into the deep soil. The main goal of this study is to assess the impact of earthworm activities on the hydraulic conductivity of columns composed with the same substrate used in the VFCW. Different densities of earthworms (Eisenia fetida) were introduced (0, 100, 500, 1000 g of earthworms/m&amp;#178;) in these columns to be monitored for 37 days. The hydraulic conductivity was measured every 7 days, aside from day 23 with the addition of 40 g of peat bedding on column surfaces to simulate a high organic matter input. Columns with earthworm density superior to 500 g/m&amp;#178; shows an amelioration of their hydraulic conductivity after 21 days. These densities are also able to restore the hydraulic conductivity of the column in less than 7 days after the setting of clogged condition due to the organic matter input (peat bedding) at the sediment surface. This study showed that the burrowing activity of E. fetida improves the hydraulic flux of a sandy substrate and this impact is dependent on the earthworm density introduced. So, the addition of earthworms in the VFCW could serve as a prevention against clogging.&lt;/p&gt;

Recent updates to the atmospheric aerosol modelling of the ECMWF IFS in support to CAMS

2021 ◽  
Author(s):  
Samuel Remy ◽  
Zak Kipling ◽  
Vincent Huijnen ◽  
Johannes Flemming ◽  
Swen Metzger ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dry Deposition ◽  
Wet Deposition ◽  
Deposition Velocity ◽  
Surface Concentration ◽  
Atmospheric Composition ◽  
Small Scale ◽  
Skill Scores ◽  
Simulated Surface ◽  
The Impact

&lt;p&gt;The Integrated Forecasting System (IFS) of ECMWF is used within the Copernicus Atmosphere Monitoring Service (CAMS) to provide global analyses and forecasts of atmospheric composition, including aerosols as well as reactive trace gases and greenhouse gases.&lt;/p&gt;&lt;p&gt;The aerosol model of the IFS, IFS-AER, is a simple sectional-bulk scheme that forecasts seven species: &amp;#160;dust, sea-salt, black carbon, organic matter, sulfate, and &amp;#160;since July 2019, nitrate and ammonium. &amp;#160;The main developments that have been recently carried out, tested and are now contemplated for implementation in the next operational version (known as cycle 48r1) are presented here.&lt;/p&gt;&lt;p&gt;The dry deposition velocities are computed as a function of roughness length, particle size and surface friction velocity, while wet deposition depends mainly on the precipitation fluxes. The parameterizations of both dry and wet deposition have been upgraded with more recent schemes, which have been shown to improve the simulated deposition fluxes for several aerosol species. The impact of this upgrade on the skill scores of simulated aerosol optical depth (AOD) and surface particulate matter concentrations against a range of observations is very positive.&lt;/p&gt;&lt;p&gt;The simulated surface concentration of nitrate and ammonium are frequently strongly overestimated over Europe and the &amp;#160;United States in the current version of the IFS. Nitrate, ammonium, and their precursors nitric acid and ammonia, were evaluated against a range of ground and remote data and it was found that the recently-implemented gas-particle partitioning scheme is too efficient in producing nitrate and ammonium particles.&lt;/p&gt;&lt;p&gt;A series of small-scale changes, such as adjusting nitrate dry deposition velocity, direct particulate sulphate emission, and limiting nitrate/ammonium production by the concentration of mineral cations, have been implemented and shown to be effective in improving the simulated surface concentration of &amp;#160;nitrate and ammonium.&lt;/p&gt;&lt;p&gt;The representation of secondary organic aerosol (SOA) in the IFS has been overhauled with the introduction of a new SOA species, distinct from primary organic matter, with anthropogenic and biogenic components. The implementation of this new species leads to a significant improvement of the simulated surface concentration of organic carbon. An evaluation of simulated SOA concentrations at the surface against climatological values derived from observations using Positive Matrix Factorisation (PMF) techniques also shows a reasonable agreement.&lt;/p&gt;

scholarly journals Removal of natural organic matter for wetland saline water desalination by coagulation-pervaporation

2019 ◽  
Vol 22 (3) ◽  
pp. 85-92 ◽  
Author(s):  
Aulia Rahma ◽  
Muthia Elma ◽  
Mahmud Mahmud ◽  
Chairul Irawan ◽  
Amalia Enggar Pratiwi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Room Temperature ◽  
Sea Water ◽  
Saline Water ◽  
Water Flux ◽  
Water Desalination ◽  
Salt Rejection ◽  
Coagulation Process ◽  
Other Hand

The high number of natural organic matter contain in wetland water may cause its water has brown color and not consumable. In other hand, intrusion of sea water through wetland aquifer create water become saline, notably on hot season. Coagulation is effective method to applied for removing of natural organic matter. However, it could not be used for salinity removal. Hence combination of coagulation and pervaporation process is attractive method to removing both of natural organic matter and conductivity of wetland saline water. The objective of this works is to investigate optimum coagulant doses for removing organic matter by coagulation process as pretreatment and to analysis performance of coagulation-pervaporation silica-pectin membrane for removing of organic matter and conductivity of wetland saline water. Coagulation process in this work carried out under varied aluminum sulfate dose 10-60 mg.L-1. Silica-pectin membrane was used for pervaporation process at feed temperature ~25 °C (room temperature). Optimum condition of pretreatment coagulation set as alum dose at 30 mg.L-1 with maximum removal efficiency 81,8 % (UV254) and 40 % (conductivity). In other hand, combining of coagulation-pervaporation silica-pectin membrane shows both of UV254 and salt rejection extremely good instead without pretreatment coagulation of 86,8 % and 99,9 % for UV254 and salt rejection respectively. Moreover, water flux of silica-pectin membrane pervaporation with coagulation pretreatment shown higher 17,7 % over water flux of wetland saline water without pretreatment coagulation. Combining of coagulation and pervaporation silica-pectin membrane is effective to removing both of organic matter and salinity of wetland saline water at room temperature.

Removal of Natural Organic Matter by Ultrafiltration: Characterisation, Fouling and Cleaning

1999 ◽  
Vol 40 (9) ◽  
pp. 113-120 ◽  
Author(s):  
A. Maartens ◽  
P. Swart ◽  
E. P. Jacobs
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Pure Water ◽  
Water Flux ◽  
Cleaning Efficiency ◽  
Commercial Sample ◽  
Membrane Selectivity ◽  
Flux Measurements ◽  
Pure Water Flux

Organic matter in natural brown water as well as humic acids from a commercial sample were characterised by ultraviolet-visible light-spectroscopy and used in ultrafiltration studies. During ultrafiltration the pure-water flux and the operational flux were measured continuously to determine the degree of membrane fouling. The natural organic matter and commercial humic acid concentrations of the feed and permeate solutions were determined spectrophotometrically. These variables were used in conjunction with conventional flux measurements, to determine the colour-removal efficiency of ultrafiltration as well as the degree of foulant adsorption onto the membranes. Fouled membranes were cleaned with alkaline chemical agents normally used to extract natural organic matter from soil samples. The cleaning efficiency and the effect of cleaning solutions on the membrane selectivity were studied.

Labile soil organic matter pools under a mixed grass/lucerne pasture and adjacent native bush in Western Australia

Soil Research ◽  
2007 ◽  
Vol 45 (5) ◽  
pp. 333 ◽  
Author(s):  
A. J. Macdonald ◽  
D. V. Murphy ◽  
N. Mahieu ◽  
I. R. P. Fillery
Keyword(s):  
Organic Matter ◽  
Plant Material ◽  
Surface Soil ◽  
Organic C ◽  
Soil Solutions ◽  
Mixed Grass ◽  
N Enrichment ◽  
Organic Matter Fractions ◽  
Cp Mas Nmr ◽  
13C Cp Mas Nmr

Total C and N were measured in whole soils (0–0.15, 0.15–0.35, and 0.35–0.65 m), light organic matter fractions (<1 g/cm3 (LF 1.0) and 1.0–1.7 g/cm3 (LF 1.7)) in surface soils, and in leaf litter collected from a mixed grass/lucerne pasture and adjacent native bush at Moora, Western Australia. The C content of the plant material and light fractions was characterised by 13C cross-polarisation/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) spectroscopy. Water-extractable organic C (WEOC) and N (WEON) were measured in soil, and dissolved organic C (DOC) and N (DON) were measured in soil solutions. In addition, both NO3-N and NH4-N (SMN) were measured in soil solutions and water extracts. Total soil C (0–0.65 m) did not differ significantly between land uses, but there was clear evidence of N enrichment under the pasture system, which contained significantly (P < 0.05) more total N in the surface soil (0–0.15 m) compared with that under native bush. The significantly (P < 0.05) smaller C/N ratios of the surface soil, plant litter, and light fractions (LF 1.0 and 1.7) under the pasture provided further evidence of N enrichment. The 13C CP/MAS NMR spectra for plant material and light fractions did not differ greatly between landuses, but in both cases the O-alkyl : alkyl carbon ratio declined with increasing density. The decomposition and subsequent mineralisation of the relatively N-rich organic matter fractions in the pasture system may have contributed to the significantly (P < 0.05) greater DOC, DON, and SMN concentration measured in soil solutions under pasture compared with those under native bush.

scholarly journals Robust Polymer Nanocomposite Membranes Incorporating Discrete TiO2 Nanotubes for Water Treatment

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1186 ◽  
Author(s):  
Mahdi ◽  
Kumar ◽  
Goswami ◽  
Perdicakis ◽  
Shankar ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Oil Sands ◽  
Tio2 Nanotubes ◽  
Water Flux ◽  
Polymer Nanocomposite ◽  
Nanocomposite Membranes ◽  
Practical Applications ◽  
Modified Polymer ◽  
Pes Membrane

Polyethersulfone (PES) is a polymeric permeable material used in ultrafiltration (UF) membranes due to its high thermomechanical and chemical stability. The hydrophobic nature of PES membranes renders them prone to fouling and restricts the practical applications of PES in the fabrication of water treatment membranes. The present study demonstrates a non-solvent-induced phase separation (NIPS) approach to modifying PES membranes with different concentrations of discrete TiO2 nanotubes (TNTs). Zeta potential and contact angle measurements showed enhanced hydrophilicity and surface negative charge in TNTs/PES nanocomposite membranes compared to unmodified PES membranes. To discern the antifouling and permeation properties of the TNTs/PES membranes, steam assisted gravity drainage (SAGD) wastewater obtained from the Athabasca oil sands of Alberta was used. The TiO2 modified polymer nanocomposite membranes resulted in a higher organic matter rejection and water flux than the unmodified PES membrane. The addition of discrete TNTs at 1 wt% afforded maximum water flux (82 L/m2 h at 40 psi), organic matter rejection (53.9%), and antifouling properties (29% improvement in comparison to pristine PES membrane). An enhancement in fouling resistance of TNTs/PES nanocomposite membranes was observed in flux recovery ratio experiments.

Morphological and physicochemical properties of various tropical soils from east-central Puerto Rico

1969 ◽  
Vol 36 (2) ◽  
pp. 167-178
Author(s):  
M. A. Lugo López ◽  
M. B. Martínez ◽  
A. R. Riera
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Laboratory Data ◽  
High Capacity ◽  
Total Porosity ◽  
Tropical Soils ◽  
Drainage Water ◽  
Low Fertility ◽  
Undisturbed Soil ◽  
East Central

This report presents the results of a preliminary soil reconnaissance in east-central Puerto Rico. It contains soil-profile observations made on several deep pits dug for the purpose. It also includes the results of various infiltration tests conducted in the major soil types of the area. The laboratory data reported include organic matter, pH, nitrogen, and total exchange capacity, and also the following measurements conducted on undisturbed soil cores dug with a Kelley (Utah) soil sampling machine: Permeability, quick drainage, water retained at pF 1.78, maximum saturation, and bulk density. Additional data are presented on water retained at pF 2.7 and pF 4.2, available water, total porosity, and air porosity. The soils of east-central Puerto Rico are rather deep, medium- or heavy-textured, acid, and of medium to low fertility. They are not generally well supplied with organic matter and nitrogen. In many cases they have compact, tight subsoil layers near the surface which considerably reduce the permeability of the profile and induce poor drainage. Laboratory soil-moisture studies confirmed field observations indicating that the majority of the soils of this region have a moderately high capacity to store water available for crop growth.

Dry deposition inferential measurement techniques—II. Seasonal and annual deposition rates of sulfur and nitrate

1991 ◽  
Vol 25 (10) ◽  
pp. 2361-2370 ◽  
Author(s):  
Tilden P. Meyers ◽  
Bruce B. Hicks ◽  
Rayford P. Hosker ◽  
James D. Womack ◽  
Lynne C. Satterfield
Keyword(s):  
Dry Deposition ◽  
Measurement Techniques ◽  
Deposition Rates ◽  
Inferential Measurement ◽  
Annual Deposition
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