scholarly journals Experimental study on the effect of salinity change on Fe and Cr removal from estuary water

2019 ◽  
Vol 98 ◽  
pp. 07035
Author(s):  
Ximing Luo ◽  
Hang Lang ◽  
Wenjuan Wang
Keyword(s):  
Zeta Potential ◽  
Surface Sediments ◽  
Removal Rate ◽  
Ferric Hydroxide ◽  
Laboratory Simulation ◽  
Salinity Change ◽  
Ph Change ◽  
Key Factor ◽  
Intertidal Surface ◽  
Cr Removal

Freshwater mental contaminants which in the estuary tend to precipitate into intertidal surface sediments during freshwater-seawater mixing because of heavy water chemical reaction. The impacts of ferric hydroxide on the removal rate of Cr with increasing pH and salinity were conducted by laboratory simulation experiment. The removal rate of Cr by ferric hydroxide decreased with increasing pH from river water to seawater in the estuary; this is because pH changed the Zeta potential of ferric hydroxide. And with increasing salinity, the removal rate of Cr by ferric hydroxide firstly decreased and then increased. On the hand, Na+ entering the sliding surface, which could improve Zeta potential and stability of ferric hydroxide colloid, which leads to the amount of Cr removal by colloid aggregation decreased. On the other hand, there was competitive adsorption between Cland CrO42-/HCrO4-. In this study, Fe was the key factor of heavy metal Cr distribution with pH change.

The Use of Satellite Imagery to Determine the Distribution of Intertidal Surface Sediments of The Wash, England

1993 ◽  
Vol 36 (4) ◽  
pp. 333-344 ◽  
Author(s):  
M.G. Yates ◽  
A.R. Jones ◽  
S. McGrorty ◽  
J.D. Goss-Custard
Keyword(s):  
Satellite Imagery ◽  
Surface Sediments ◽  
Intertidal Surface

scholarly journals Impact of coastal environmental factors on quinolone distribution in intertidal surface sediments of the Bohai Sea and Yellow Sea, China

2018 ◽  
Vol 19 (2) ◽  
pp. 482-491
Author(s):  
Hang Lang ◽  
Liang Chen ◽  
Guohua Hou ◽  
Wenjuan Wang ◽  
Shengzhang Zou ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Yellow Sea ◽  
Surface Sediments ◽  
Oxolinic Acid ◽  
Intertidal Sediment ◽  
Organic Carbon Content ◽  
Intertidal Sediments ◽  
Intertidal Zones ◽  
Sediment Types ◽  
Intertidal Surface

Abstract Freshwater contaminants tend to precipitate into intertidal surface sediments, particularly in the estuary and intertidal zones during freshwater–seawater mixing. Quinolone-type antibiotics are such contaminants, and their concentrations in the intertidal sediments are important indicators for the whole spectrum of antibiotics used in the estuary and adjacent areas. The impacts of sediment types and environmental factors on the distribution of 16 quinolones were probed based on nine Bohai and 42 Yellow Sea intertidal sediment samples. The samples were collected from locations along the coastal areas in China. Quinolones were detected in all samples, while moxifloxacin, ciprofloxacin, and ofloxacin were detected at a frequency >50%. Sediment types, pH, organic carbon content, K, Na and Fe concentrations had little correlation with quinolone distributions in intertidal sediments. However, combined concentrations of Ca + Mg (46.7 g/kg in Bohai and 13.7 g/kg in Yellow Sea samples) appeared to correlate with oxolinic acid detecting frequencies (88.9% and 4.8%, respectively) and concentrations (2.0–10.1 μg/g and up to 3.09 μg/g, respectively). Different detection frequencies of the quinolones could be attributed to the formation of cation bridges between oxolinic acid and Ca + Mg, which results in dominant sorption of oxolinic acid at different locations and sediment matrices.

Iron and Arsenic Cycling in Intertidal Surface Sediments during Wetland Remediation

2011 ◽  
Vol 45 (6) ◽  
pp. 2179-2185 ◽  
Author(s):  
Scott G. Johnston ◽  
Annabelle F. Keene ◽  
Edward D. Burton ◽  
Richard T. Bush ◽  
Leigh A. Sullivan
Keyword(s):  
Surface Sediments ◽  
Intertidal Surface

scholarly journals Cold Plasma Treatment for Efficient Control over Algal Bloom Products in Surface Water

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1513 ◽  
Author(s):  
Hee-Jun Kim ◽  
Gui-Sook Nam ◽  
Jung-Seok Jang ◽  
Chan-Hee Won ◽  
Hyun-Woo Kim
Keyword(s):  
Surface Water ◽  
Cold Plasma ◽  
Algal Bloom ◽  
Removal Rate ◽  
Oxygen Depletion ◽  
Plasma Process ◽  
Ph Change ◽  
Chl A ◽  
Efficient Control ◽  
Kinetics Of

Algal bloom significantly alters the physicochemical properties of water due to drastic pH change, dissolved oxygen depletion/super-saturation, and toxicity, which lead to ecosystem destruction. To prevent this, this study evaluated the reduction performance of algal biomass by applying a non-thermal or cold plasma process. We used chlorophyll-a (chl-a), suspended solids (SS), and turbidity as indicators of the biomass. Results demonstrated that their removal efficiencies were in the ranges 88–98%, 70%–90%, and 53%–91%, respectively. Field emission scanning electron microscopy indicated how the cell wall of microalgae was destroyed by cold plasma. Also, the removal kinetics of cold plasma confirmed the enhanced removal rate constants. The estimated required times for 99% removal were 0.4–1.2 d (chl-a), 1.3–3.4 d (SS), and 1.6–6.2 d (turbidity), respectively. Overall, cold plasma could be a useful option to effectively treat pollution associated with algal bloom in surface water.

scholarly journals The Application of Alginate Coated Iron Hydroxide for the Removal of Cu(II) and Phosphate

2019 ◽  
Vol 9 (18) ◽  
pp. 3835 ◽  
Author(s):  
Hee-Gon Kim ◽  
Feng He ◽  
Byungryul An
Keyword(s):  
Removal Rate ◽  
Iron Hydroxide ◽  
Ph Dependence ◽  
Ferric Hydroxide ◽  
Critical Factor ◽  
Cost Effective ◽  
Phosphate Removal ◽  
Alginate Concentration ◽  
Multiple Materials ◽  
High Concentrations

The removal of both cation and anion contaminants in solution typically requires separate processes or multiple materials, resulting in added complexity and higher operational costs. A cost effective and environmental friendly hybrid adsorbent material has been developed for the removal of Cu(II) and phosphate from the solution. Ferric hydroxide (FHO) was prepared by precipitation methods and then dissolved alginate, a biopolymer, was coated on the surface of the FHO particles to generated FHO-A. In the preparation of FHO-A, the alginate concentration is a critical factor in keeping the FHO-A particles suspended in solution where high concentrations of alginate act as a stabilizer and the FHO-A particles are not settled by gravity. The Cu(II) removal efficiency was wholly dependent on the concentration of alginate via the interaction with the polymer carboxyl groups and was not influenced by the concentration of FHO. Conversely, alginate was not involved in the removal of phosphate and instead, FHO was found to be critical for phosphate removal through electrostatic forces. According to FTIR, the new peaks at 1394 and 1593 cm−1 after coating indicated that the alginate was appended to the surface of the FHO. The shift of peak from 1593 to 1588 cm−1 after Cu(II) adsorption confirms the presence of a Cu-carboxylate interaction. The adsorption of Cu(II) was completed within 5 min, which is very similar to nanoparticle mediated sorption processes. In comparison to Cu(II), the presence of alginate retards the phosphate removal rate. Further, pH dependence was observed in the process, where increasing pH results in increased Cu(II) and decreased phosphate removal rates due to alginate deprotonation and the surface charge effects, respectively. The slowed phosphate sorption rate and shifted peaks in the FTIR spectrum confirmed that the layer of alginate was coated on the FHO particle.

Preparation and its Silica Wafer CMP Performance of Cationic Polyelectrolyte Modified Benzoguanamine Formaldehyde/SiO2 Composite Abrasives Slurry

2011 ◽  
Vol 189-193 ◽  
pp. 4158-4162
Author(s):  
Xue Feng Xu ◽  
Bin Shan Zhao ◽  
Yu Zhi Yang ◽  
Quan Guo ◽  
Wei Peng
Keyword(s):  
Zeta Potential ◽  
Adsorption Capacity ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cationic Polyelectrolyte ◽  
Experimental Results ◽  
Adsorption Characteristics ◽  
Maximum Value ◽  
New Type

In this paper, the adsorption characteristics of cationic polyelectrolyte PDADMAC on BGF particles and Zeta potential of BGF particles have been investigated. A new type of composite abrasive slurry was obtained with cationic polyelectrolyte modified BGF particles and its polishing performance was studied. Experimental results showed that the Zeta potential of the modified BGF particles was changed from negative to positive and the maximum value (+35mv) was obtained when the adsorption saturation was achieved, and the adsorption capacity of SiO2 abrasives on BGF particles was improved significantly as well. The material removal rate was 469nm/min with the modified BGF/ SiO2 composite abrasives slurry containing 5% SiO2 and 3% modified BGF particles, increasing by 47% and 89% than those of the unmodified BGF/SiO2 composite abrasives slurry (319nm/min) and the single silica abrasives slurry (248nm/min), respectively.

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