scholarly journals Mixing State of Submicrometer Sea Spray Particles Enriched by Insoluble Species in Bubble-Bursting Experiments

2014 ◽  
Vol 31 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Ji Yeon Park ◽  
Sungil Lim ◽  
Kihong Park
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Volume Fraction ◽  
Silica Particles ◽  
Artificial Seawater ◽  
Sea Spray ◽  
Natural Seawater ◽  
Mixing State ◽  
High Concentration ◽  
Dissolved Salts

Abstract Measurements of size distribution, hygroscopicity, and volatility of submicrometer sea spray particles produced by the bubble busting of artificial and natural seawater were conducted to determine their mixing state and volume fractions of hygroscopic and nonhygroscopic species or volatile and nonvolatile species. The particles sprayed from artificial seawater having insoluble silica particles were found to be an external mixture of two groups of particles having hygroscopic growth factors (HGFs) of 1.33 (an internal mixture of nonhygroscopic silica particles and hygroscopic salt species) and 1.68 (a similar mixture having more salt species) when the mass ratio of insoluble particles to dissolved salts was higher than 2. For sea spray particles from natural seawater, the external mixing was not significantly observed because of a high concentration of dissolved salts. The HGFs of sea spray particles (80–140 nm) from natural seawater were in the range of 1.70–1.76, which were lower than from pure artificial seawater (1.87), and the HGFs had no change before and after membrane filtration of seawater, suggesting that the sea spray particles from natural seawater contained a significant amount of nonhygroscopic dissolved organic matter in addition to hygroscopic salt species. The volume fraction of the nonhygroscopic species ranged from 20% to 29%, and the highest value was observed for seawater samples from the site where strong biological activity occurred, suggesting that biological materials played an important role in the formation of nonhygroscopic organic matter. Volatility measurements also identified the existence of volatile organic species in single particles from natural seawater, with the volume fraction of volatile species evaporated at 100°C being 4%–5%.

Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Treated Wastewater ◽  
High Concentration ◽  
Effluent Organic Matter ◽  
Dead End ◽  
Flux Decline ◽  
Uf Membranes ◽  
Stirred Cell ◽  
Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

scholarly journals Study on Analysis and Sedimentation of Alumina Nanoparticles

2019 ◽  
Vol 16 (3) ◽  
pp. 510 ◽  
Author(s):  
Xuehong Zheng ◽  
Yuehan Li ◽  
Ding Chen ◽  
Airong Zheng ◽  
Qikang Que
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Ecological Risk ◽  
Sedimentation Rate ◽  
Aquatic Environment ◽  
Artificial Seawater ◽  
Alumina Nanoparticles ◽  
Natural Seawater ◽  
Ultrasonic Dispersion ◽  
Risk Effects

Dispersion and aggregation behavior of nanoparticles in aquatic environment may be affected by pH, salinity, and dissolved organic matter, which would change its ecological risk. Effects of time, power and temperature on the alumina nanoparticles (nano-Al2O3) ultrasonic dispersion in water were discussed. Al2O3 had a best ultrasonic dispersion for 30 min at 105 W and 30 °C. The concentration of Al2O3 could be measured by ultraviolet (UV) spectrophotometer, and the method was efficient and accurate. Furthermore, the sedimentation rate of Al2O3 was related to pH, salinity, and its concentration in the artificial seawater. When pH was 7.31, approaching the isoelectric point of Al2O3, they aggregated and settled fastest. Settlement coefficient (k) of Al2O3 increased by 3 and 2.7 times while the salinity and its concentration increased. The sedimentation rate was higher in natural seawater than that in artificial seawater. All results indicated that nano-Al2O3 would be removed in aquatic environment.

scholarly journals A Two-Component Parameterization of Marine Ice Nucleating Particles Based on Seawater Biology and Sea Spray Aerosol Measurements in the Mediterranean Sea

2020 ◽  
Author(s):  
Jonathan V. Trueblood ◽  
Alesia Nicosia ◽  
Anja Engel ◽  
Birthe Zäncker ◽  
Matteo Rinaldi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Biological Properties ◽  
Organic Content ◽  
Water Soluble ◽  
Sea Spray ◽  
Surface Microlayer ◽  
Natural Seawater ◽  
Order Of Magnitude ◽  
The Mediterranean

Abstract. Ice nucleating particles (INP) have a large impact on the climate-relevant properties of clouds over the oceans. Studies have shown that sea spray aerosols (SSA), produced upon bursting of bubbles at the ocean surface, can be an important source of marine INP, particularly during periods of enhanced biological productivity. Recent mesocosm experiments using natural seawater spiked with nutrients have revealed that marine INP are derived from two separate classes of organic matter in SSA. Despite this finding, existing parameterizations for marine INP abundance are based solely on single variables such as total organic carbon (TOC) or SSA surface area, which may mask specific trends in the separate classes of INPs. The goal of this paper is to improve the understanding of the connection between ocean biology and marine INP abundance by reporting results from a field study and proposing a new parameterization of marine INP that accounts for the two associated classes of organic matter. The PEACETIME cruise took place from May 10 to June 10, 2017 in the Mediterranean Sea. Throughout the cruise, INP concentrations in the surface microlayer (SML) and in SSA produced using a plunging aquarium apparatus were continuously monitored while surface seawater (SSW) and SML biological properties were measured in parallel. The organic content of artificially generated SSA was also evaluated. A dust wet deposition event that occurred during the cruise increased the INP concentrations measured in the SML by an order of magnitude, in line with increases of iron in the SML and bacterial abundances. Increases of INPs in marine SSA (INPSSA) were not observed before a delay of three days compared to increases in the SML, and are likely a result of a strong influence of bulk SSW INP for the temperatures investigated (T = −18 °C for SSA, T = −16 °C for SSW). Results confirmed that INPSSA are divided into two classes depending on their associated organic matter. Here we find that warm (T ≥ −22 °C) INPSSA concentrations are correlated with water soluble organic matter in the SSA, but also to SSW parameters (POCSSW INPSSW,−16 °C) while cold INPSSA (T 

scholarly journals The organic fraction of bubble-generated, accumulation mode Sea Spray Aerosol (SSA)

2010 ◽  
Vol 10 (6) ◽  
pp. 2867-2877 ◽  
Author(s):  
R. L. Modini ◽  
B. Harris ◽  
Z. D. Ristovski
Keyword(s):  
Volume Fraction ◽  
Biologically Active ◽  
Global Ocean ◽  
Sea Spray ◽  
Natural Seawater ◽  
Hygroscopic Growth ◽  
Organic Fraction ◽  
Accumulation Mode ◽  
Order Of Magnitude ◽  
Sea Spray Aerosol

Abstract. Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater samples for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170–200 °C. The organic volume fraction for 71–77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 s to 24 h) in the bubble generator or SSA particle diameter in the range 38–173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. We stress that our results were obtained using coastal seawater and they can't necessarily be applied on a regional or global ocean scale. Nevertheless, considering the order of magnitude discrepancy between this and previous studies, further research with independent measurement techniques and a variety of different seawaters is required to better quantify how much organic material is present in accumulation mode SSA.

scholarly journals On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity

2011 ◽  
Vol 11 (6) ◽  
pp. 2585-2602 ◽  
Author(s):  
E. Fuentes ◽  
H. Coe ◽  
D. Green ◽  
G. McFiggans
Keyword(s):  
Organic Matter ◽  
Particle Production ◽  
Cloud Condensation Nuclei ◽  
Companion Paper ◽  
Artificial Seawater ◽  
Natural Seawater ◽  
Marine Biota ◽  
Marine Aerosol ◽  
Hygroscopic Growth ◽  
Ccn Activity

Abstract. The effect of nanogel colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator. The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 8–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN) activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics. The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles was found to correlate with the seawater organic concentration, without observing saturation of the particle organic mass fraction even for unrealistically high organic matter concentration in seawater. These findings are indicative that discrepancies on the composition of the primary aerosol between different studies could partly be explained by the difference in the nature and concentration of the organic matter in the source seawater employed. Consistently across the experiments, theoretical analysis based on the Köhler model predicted a reduction in the primary marine aerosol CCN activity upon the incorporation of marine organics into the particle composition. This effect is consequence of the replacement of small inorganic sea salt molecules by large molar mass organic molecules, together with a moderate suppression of the surface tension at the point of activation of 5–0.5%, which leads to a dominance of the reduction in the dissolved solute in the Raoult term.

Removal of natural organic matter - a fresh approach

2002 ◽  
Vol 2 (1) ◽  
pp. 71-79 ◽  
Author(s):  
M. Drikas ◽  
J.Y. Morran ◽  
C. Pelekani ◽  
C. Hepplewhite ◽  
D.B. Bursill
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Distribution Systems ◽  
Adsorptive Capacity ◽  
High Concentration ◽  
Australian Water ◽  
Prime Concern ◽  
Exchange Resins

Natural organic matter (NOM) has been shown to be one of the major parameters that affects water quality and treatment processes. NOM reduces the effectiveness of water treatment by interfering with the flocculation process, makes treatment with activated carbon and membrane filtration less efficient and is a precursor to the formation of disinfectant by-products (DBP). Furthermore, NOM acts as a food source for micro-organisms resulting in bacterial regrowth in distribution systems. These concerns have resulted in the removal of NOM from raw water being of prime concern for water authorities. The elevated levels of NOM in Australian water supplies have resulted in priority being given to research into methods of removing NOM by the Australian Water Quality Centre (AWQC). Early work showed that some types of anion exchange resins were very effective for NOM removal and that while resin column systems were rapidly fouled by waters with high concentration of suspended matter, a stirred system had no such limitation. This lead to the development of a resin with a high adsorptive capacity for NOM by the Commonwealth Scientific & Industrial Research Organisation (CSIRO) in collaboration with the AWQC which will be manufactured under licence by Orica Australia Pty Ltd. This resin then formed the basis for a novel process for NOM removal developed by the AWQC in collaboration with Orica Australia Pty Ltd. Both the MIEX® resin and process have been patented internationally. This paper outlines the process, gives examples of some of the benefits and provides recent results from an operating pilot plant with a capacity 160 kL/day.

scholarly journals The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

2017 ◽  
Vol 114 (27) ◽  
pp. 6978-6983 ◽  
Author(s):  
Xiaofei Wang ◽  
Grant B. Deane ◽  
Kathryn A. Moore ◽  
Olivia S. Ryder ◽  
M. Dale Stokes ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Volume Fraction ◽  
Water Soluble ◽  
Sea Surface ◽  
Sea Spray ◽  
Surface Microlayer ◽  
Mixing State ◽  
Organic Species ◽  
Sea Surface Microlayer ◽  
Sea Spray Aerosol

The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate.

scholarly journals On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity

2010 ◽  
Vol 10 (11) ◽  
pp. 26157-26205
Author(s):  
E. Fuentes ◽  
H. Coe ◽  
D. Green ◽  
G. McFiggans
Keyword(s):  
Organic Matter ◽  
Particle Production ◽  
Companion Paper ◽  
Artificial Seawater ◽  
Natural Seawater ◽  
Marine Biota ◽  
Marine Aerosol ◽  
Hygroscopic Growth ◽  
Aerosol Generator ◽  
Ccn Activity

Abstract. The effect of colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator. The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 5–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN) activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics. The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles increased with increasing seawater organic concentration, with the highest organic enrichment found for the diatomaceous exudate. These findings are indicative that, besides the differences induced by the aerosol generator employed, discrepancies between different studies in the behaviour of the organics-enriched primary seaspray could partly be explained by the difference in the nature and concentration of the organic material in the source seawater employed. Consistently across the experiments, theoretical analysis based on the Köhler model predicted a reduction in the primary seaspray CCN activity upon the incorporation of marine organics into the particle composition. This effect is consequence of the replacement of small inorganic sea salt molecules by large molar mass organic molecules, together with a moderate suppression of the surface tension at the point of activation of 5–0.5%, which leads to a dominance of the reduction in the dissolved solute in the Raoult term.

scholarly journals The organic fraction of bubble-generated, accumulation mode Sea Spray Aerosol (SSA)

2009 ◽  
Vol 9 (5) ◽  
pp. 21399-21424 ◽  
Author(s):  
R. L. Modini ◽  
B. Harris ◽  
Z. D. Ristovski
Keyword(s):  
Volume Fraction ◽  
Particle Diameter ◽  
Biologically Active ◽  
Sea Spray ◽  
Natural Seawater ◽  
Hygroscopic Growth ◽  
Organic Fraction ◽  
Accumulation Mode ◽  
Order Of Magnitude ◽  
Sea Spray Aerosol

Abstract. Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater samples for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170–200°C. The organic volume fraction for 71–77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 s0 to 24 h) in the bubble generator or SSA particle diameter in the range 38–173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. Further studies with a variety of different seawaters are required to better quantify how much organic material is present in accumulation mode SSA.

scholarly journals The Influence of Algal Exudate on the Hygroscopicity of Sea Spray Particles

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
H. Wex ◽  
E. Fuentes ◽  
G. Tsagkogeorgas ◽  
J. Voigtländer ◽  
T. Clauss ◽  
...  
Keyword(s):  
Organic Matter ◽  
Aerosol Particles ◽  
Algal Species ◽  
Artificial Seawater ◽  
Time Range ◽  
Sea Spray ◽  
Marine Aerosol ◽  
Hygroscopic Growth ◽  
Droplet Activation ◽  
Kinetic Effects

We examined the effect of organic matter released by four different algal species on the hygroscopic growth and droplet activation behaviour of laboratory-generated marine aerosol particles. Hygroscopic growth factors and dry diameters for activation were reduced by less than 10%, compared to that of sodium chloride or of artificial seawater that was devoid of marine surfactants. Concentration-dependent nonideal behaviour was observed for the artificial seawater. But within measurement uncertainty, the measured hygroscopic growth and droplet activation behaviour for the samples that contained organic matter were consistent with a hygroscopicity parameter that was constant between the sub- and supersaturated measurement points. Also, the hygroscopic growth measured for hydrated particles after 3 and after 10 seconds was similar, which implies that in this time range no kinetic effects were detected.

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