scholarly journals Effects of the addition of nitrogen and sulfate on CH4 and CO2 emissions, soil, and pore water chemistry in a high marsh of the Min River estuary in southeastern China

2017 ◽  
Vol 579 ◽  
pp. 292-304 ◽  
Author(s):  
Minjie Hu ◽  
Benjamin J. Wilson ◽  
Zhigao Sun ◽  
Peng Ren ◽  
Chuan Tong
Keyword(s):  
Water Chemistry ◽  
Co2 Emissions ◽  
Pore Water ◽  
River Estuary ◽  
High Marsh ◽  
Southeastern China ◽  
Min River ◽  
Pore Water Chemistry ◽  
Min River Estuary

scholarly journals Sustainable Exploitation of Dominant Fishes in the Largest Estuary in Southeastern China

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3390
Author(s):  
Linlong Wang ◽  
Li Lin ◽  
Yuan Li ◽  
Yankuo Xing ◽  
Bin Kang
Keyword(s):  
Habitat Degradation ◽  
River Estuary ◽  
Current Status ◽  
Southeastern China ◽  
Fish Stocks ◽  
Min River ◽  
Coilia Mystus ◽  
Fishery Exploitation ◽  
Min River Estuary ◽  
Sustainable Fishery

Globally, marine fisheries have declined under multiple stresses including overfishing, climate change, and habitat degradation. The Min River Estuary, as the largest estuary in southeastern China, has confronted this situation over recent decades. In this study, the dominant species of fish stocks in the Min River Estuary, including Coilia mystus, Cynoglossus abbreviates, Collichthys lucidus, Amblychaeturichthys hexanema, Polydactylus sextarius, Harpodon nehereus, and Secutor ruconius, were evaluated by the length-based Bayesian biomass estimator method (LBB). Outcomes could be grouped into three categories as healthy, showing the lowest exploitation rate (E: 0.31–0.43) and highest relative biomass (B/Bmsy: 1.30–1.90), including S. ruconius, C. mystus, and H. nehereus; overfished, with a medium E (0.50–0.58) and B/Bmsy (0.68–0.79), including A. hexanema and C. abbreviates; and collapsed, with the highest E (0.89–0.92) and lowest B/Bmsy (0.03–0.21), including C. lucidus and P.sextarius. Corresponding imperative countermeasures such as using larger-sized mesh gears and reducing fishing intensity should be deployed according to the current status of each species for sustainable fishery exploitation and fish conservation.

Importance of site-specific factors for the immobilization of contaminants using biochar and wood-based activated carbon

2021 ◽  
Author(s):  
Sampriti Chaudhuri ◽  
Gabriel Sigmund ◽  
Hary von Rautenkranz ◽  
Thorsten Hueffer ◽  
Thilo Hofmann
Keyword(s):  
Activated Carbon ◽  
Ionic Strength ◽  
Water Chemistry ◽  
Pore Water ◽  
Electrostatic Attraction ◽  
Inorganic Contaminants ◽  
Diverse Range ◽  
Pore Water Chemistry ◽  
Specific Factors ◽  
Carbonaceous Sorbents

<p>The use of environmentally friendly low-cost sorbents such as biochar and wood-based activated carbon as soil amendment has shown promising results in immobilizing organic and inorganic contaminants. They can be suitable soil remediation options at sites with residual contamination, where the contaminated hotspot has been removed. The effectiveness of biochar and activated carbon application is site dependent. Specifically, dissolved organic carbon (DOC), pH, and ionic strength in the pore water are important factors which can influence the extent of contaminant immobilization. Although there has been significant progress in developing alternative carbonaceous sorbents, the efficiency of these materials in a diverse range of soil and pore water conditions remains an open question. To address this knowledge gap, the present study investigates the influence of pore water chemistry on sorption of organic and inorganic contaminants to biochar and wood-based activated carbon. Sorption of selected non-polar, polar and ionizable polycyclic aromatic compounds (PACs) and inorganic Cadmium (Cd) to biochar and a wood-based activated carbon was studied under different pore water chemistry conditions. Batch sorption experiments were conducted using an experimental design approach (Box Behnken Design) with three different levels of DOC, pH, and ionic strength, yielding background solutions mimicking a wide spectrum of pore water chemistries. Sorption K<sub>D</sub> values [L/kg] were calculated from aqueous contaminant concentrations after equilibration. Results were analyzed using a response surface methodology (RSM) approach on Minitab 19 and fitted to a model equation using linear, squared and two-way interactions terms.</p><p>Our results show that the ionizable PAC (phenyl phenol) and Cd were most affected by changes in pore water chemistries. For phenyl phenol, the presence of a phenolic group can cause H-bonding and electrostatic attraction and repulsion, while pH-dependent changes in speciation, precipitation and electrostatic attraction can occur for Cd. Sorption of all PACs negatively correlated with DOC, indicating competition of DOC with PACs for sorption sites. Sorption of non-polar (acenaphthene), polar N substituted (carbazole) and ionizable (phenyl phenol) PACs was hindered under acidic conditions, due to precipitation of DOC. For Cd, higher pH and low DOC levels favored sorption. This can be attributed to a lower Cd solubility in the presence of leached phosphate at higher pH, and a predominance of Cd(OH)<sub>2</sub> in the neutral to alkaline regime. Our findings highlight the importance of considering a combination of site- and contaminant-specific factors when planning to apply carbonaceous sorbents for contaminant immobilization, with pH and DOC generally being more important than ionic strength.</p>

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