scholarly journals Short Term Effects of Salinization on Compound Release from Drained and Restored Coastal Wetlands

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1549 ◽  
Author(s):  
Haojie Liu ◽  
Bernd Lennartz

Over the past two decades, great efforts have been made to restore coastal wetlands through the removal of dikes, but challenges remain because the effects of flooding with saline water on water quality are unknown. We collected soil samples from two adjacent coastal fen peatlands, one drained and diked, the other open to the sea and rewetted, aiming at assessing the mobility and export of various compounds. Microcosm experiments with constant flow-through conditions were conducted to determine the effluent concentrations of dissolved organic carbon (DOC), ammonium ( NH 4 + ), and phosphate ( PO 4 3 − ) during saline–fresh water cycles. Sodium chloride (NaCl) was used to adjust salinity (saline water, NaCl concentration of 0.12 mol L−1; fresh water, NaCl concentration of 0.008 mol L−1) and served as a tracer. A model analysis of the obtained chloride ( Cl − ) and sodium ( Na + ) breakthrough curves indicated that peat soils have a dual porosity structure. Sodium was retarded in peat soils with a retardation factor of 1.4 ± 0.2 due to adsorption. The leaching tests revealed that water salinity has a large impact on DOC, NH 4 + , and PO 4 3 − release. The concentrations of DOC in the effluent decreased with increasing water salinity because the combination of high ionic strength (NaCl concentration of 0.12 mol L−1) and low pH (3.5 to 4.5) caused a solubility reduction. On the contrary, saline water enhanced NH 4 + release through cation exchange processes. The PO 4 3 − concentrations, however, decreased in the effluent with increasing water salinity. Overall, the decommissioning of dikes at coastal wetlands and the flooding of once drained and agriculturally used sites increase the risk that especially nitrogen may be leached at higher rates to the sea.

2014 ◽  
Vol 11 (1) ◽  
pp. 141-146 ◽  
Author(s):  
MA Mojid ◽  
KFI Murad ◽  
SS Tabriz ◽  
GCL Wyseure

Response of wheat (Triticum aestivum L., cv. Shatabdi) to irrigation water of five salinity levels was investigated at the Bangladesh Agricultural University (BAU) farm with a view to search for a possible advantageous salinity level for the crop. The experiment comprised five treatments ? I1: irrigation by fresh water of background salinity 0.385 dS m?1 (control) and I2 ? I5: irrigation by synthetic saline water (prepared by mixing sodium chloride salt with fresh water) of electrical conductivity (EC) 4, 7, 10 and 13 dS m?1 (at 25oC), respectively. Wheat was grown under three irrigations applied at maximum tillering, booting and milking/grain filling stages, and with recommended fertilizer dose. Irrigation water of EC ?10 dS m?1 significantly (p = 0.05) suppressed most growth and yield attributes, and yield of wheat compared to irrigation by fresh water (I1). An attention-grabbing observation was that irrigation by saline water of 4 dS m?1 (I2) contributed positively to the crop attributes. Leaf area index (LAI), spike length, spikelets and grains per spike, 1000-grain weight and above ground dry matter (ADM) of wheat increased by 1.9?3.4, 0.9, 2.6, 7.4, 2.1 and 2.8?6.0%, respectively in I2 compared to the control. The improvement in the LAI and ADM in I2 was significant over I1. Because of the largest spike density, the utmost grain (3.85 t ha?1), straw (5.09 t ha?1) and biomass (8.93 t ha?1) yields of wheat were however obtained under I1. The proposition of the advantageous irrigation water salinity level of 4 dS m?1 thus warrants further investigation DOI: http://dx.doi.org/10.3329/jbau.v11i1.18225 J. Bangladesh Agril. Univ. 11(1): 141-146, 2013


1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.


1991 ◽  
Vol 24 (2) ◽  
pp. 309-314 ◽  
Author(s):  
G. Teutsch ◽  
K. Herbold-Paschke ◽  
D. Tougianidou ◽  
T. Hahn ◽  
K. Botzenhart

In this paper the major processes governing the persistence and underground transport of viruses and bacteria are reviewed in respect to their importance under naturally occurring conditions. In general, the simulation of the governing processes is based on the macroscopic mass-conservation equation with the addition of some filter and/or retardation factor and a decay coefficient, representing the natural “die-off” of the microorganisms. More advanced concepts try to incorporate growth and decay coefficients together with deposition and declogging factors. At present, none of the reported concepts has been seriously validated. Due to the complexity of natural systems and the pathogenic properties of some of the microorganisms, experiments under controlled laboratory conditions are required. A laboratory setup is presented in which a great variety of natural conditions can be simulated. This comprises a set of 1 metre columns and an 8 metre stainless-steel flume with 24 sampling ports. The columns are easily filled and conditioned and therefore used to study the effects of different soil-microorganism combinations under various environmental conditions. In the artificial flume natural underground conditions are simulated using sand and gravel aquifer material from the river Neckar alluvium. A first set of results from the laboratory experiments is presented together with preliminary model simulations. The large variety of observed breakthrough curves and recovery for the bacteria and viruses under investigation demonstrates the great uncertainty encountered in microbiological risk assessment.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 894
Author(s):  
Emad M. Hafez ◽  
Hany S. Osman ◽  
Usama A. Abd El-Razek ◽  
Mohssen Elbagory ◽  
Alaa El-Dein Omara ◽  
...  

The continuity of traditional planting systems in the last few decades has encountered its most significant challenge in the harsh changes in the global climate, leading to frustration in the plant growth and productivity, especially in the arid and semi-arid regions cultivated with moderate or sensitive crops to abiotic stresses. Faba bean, like most legume crops, is considered a moderately sensitive crop to saline soil and/or saline water. In this connection, a field experiment was conducted during the successive winter seasons 2018/2019 and 2019/2020 in a salt-affected soil to explore the combined effects of plant growth-promoting rhizobacteria (PGPR) and potassium (K) silicate on maintaining the soil quality, performance, and productivity of faba bean plants irrigated with either fresh water or saline water. Our findings indicated that the coupled use of PGPR and K silicate under the saline water irrigation treatment had the capability to reduce the levels of exchangeable sodium percentage (ESP) in the soil and to promote the activity of some soil enzymes (urease and dehydrogenase), which recorded nearly non-significant differences compared with fresh water (control) treatment, leading to reinstating the soil quality. Consequently, under salinity stress, the combined application motivated the faba bean vegetative growth, e.g., root length and nodulation, which reinstated the K+/Na+ ions homeostasis, leading to the lessening or equalizing of the activity level of enzymatic antioxidants (CAT, POD, and SOD) compared with the controls of both saline water and fresh water treatments, respectively. Although the irrigation with saline water significantly increased the osmolytes concentration (free amino acids and proline) in faba bean plants compared with fresh water treatment, application of PGPR or K-silicate notably reduced the osmolyte levels below the control treatment, either under stress or non-stress conditions. On the contrary, the concentrations of soluble assimilates (total soluble proteins and total soluble sugars) recorded pronounced increases under tested treatments, which enriched the plant growth, the nutrients (N, P, and K) uptake and translocation to the sink organs, which lastly improved the yield attributes (number of pods plant−1, number of seeds pod−1, 100-seed weight). It was concluded that the combined application of PGPR and K-silicate is considered a profitable strategy that is able to alleviate the harmful impact of salt stress alongside increasing plant growth and productivity.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Fauzul Imron ◽  
Setyo Budi Kurniawan ◽  
Siti Rozaimah Sheikh Abdullah

AbstractLeachate is produced from sanitary landfills containing various pollutants, including heavy metals. This study aimed to determine the resistance of bacteria isolated from non-active sanitary landfill leachate to various heavy metals and the effect of salinity levels on the removal of Hg by the isolated bacterium. Four dominant bacteria from approximately 33 × 1017 colony-forming units per mL identified as Vibrio damsela, Pseudomonas aeruginosa, Pseudomonas stutzeri, and Pseudomonas fluorescens were isolated from non-active sanitary landfill leachate. Heavy metal resistance test was conducted for Hg, Cd, Pb, Mg, Zn, Fe, Mn, and Cu (0–20 mg L− 1). The removal of the most toxic heavy metals by the most resistant bacteria was also determined at different salinity levels, i.e., fresh water (0‰), marginal water (10‰), brackish water (20‰), and saline water (30‰). Results showed that the growth of these bacteria is promoted by Fe, Mn, and Cu, but inhibited by Hg, Cd, Pb, Mg, and Zn. The minimum inhibitory concentration (MIC) of all the bacteria in Fe, Mn, and Cu was > 20 mg L− 1. The MIC of V. damsela was 5 mg L− 1 for Hg and >  20 mg L− 1 for Cd, Pb, Mg, and Zn. For P. aeruginosa, MIC was > 20 mg L− 1 for Cd, Pb, Mg, and Zn and 10 mg L− 1 for Hg. Meanwhile, the MIC of P. stutzeri was > 20 mg L− 1 for Pb, Mg, and Zn and 5 mg L− 1 for Hg and Cd. The MIC of P. fluorescens for Hg, Pb, Mg, and Zn was 5, 5, 15, and 20 mg L− 1, respectively, and that for Cd was > 20 mg L− 1. From the MIC results, Hg is the most toxic heavy metal. In marginal water (10‰), P. aeruginosa FZ-2 removed up to 99.7% Hg compared with that in fresh water (0‰), where it removed only 54% for 72 h. Hence, P. aeruginosa FZ-2 is the most resistant to heavy metals, and saline condition exerts a positive effect on bacteria in removing Hg.


1996 ◽  
Vol 180 (1) ◽  
pp. 87-95 ◽  
Author(s):  
S. E. Benes ◽  
R. Arag��s ◽  
R. B. Austin ◽  
S. R. Grattan
Keyword(s):  

2001 ◽  
Vol 5 (1-2) ◽  
pp. 29-36 ◽  
Author(s):  
Masahiro Maruo ◽  
Eiichiro Nakayama ◽  
Hajime Obata ◽  
Kokichi Kamiyama ◽  
Takashi Kimoto

1999 ◽  
Author(s):  
Yunus Çerçi ◽  
Yunus A. Çengel ◽  
Byard Wood

Abstract A general relation is obtained for the minimum work input requirement for desalination processes using the second-law of thermodynamics. The relation developed can be used to determine the minimum work input for any salinity of the incoming water, and the recovery ratio. It is also shown that there is a lower and an upper limit for the minimum work, corresponding to recovery ratios of 0% and 100%, respectively. The minimum work input per unit mass of fresh water produced is determined for various salinities of incoming water, and the salinities of fresh water produced, and the results are tabulated and plotted. It is shown that the minimum work is a strong function of salinity, and increases with salinity and the recovery ratio. It is also shown that the minimum work input requirement remains fairly constant for recovery ratios of up to about 80%; the minimum work increases drastically at high recovery ratios; and an optimum value of recovery ratio exists to minimize the power consumption of actual desalination plants. But the value of this optimum recovery ratio decreases with increasing salinity of the incoming saline water. The results presented in this paper can be used as a basis to evaluate the performance of actual desalination plants.


2017 ◽  
Vol 18 (2) ◽  
pp. 357-370 ◽  
Author(s):  
H. Rouhi ◽  
N. Kalantari

Abstract Both carbonate (as the oil-gas reservoir) and evaporite rocks (as caprock) coexist in the Masjed Soleyman oil field. The Asmari karstic aquifer is formed within Oligo-Miocene carbonate rocks in the south of the oil reservoir. A mixing between fresh karstic groundwater and oil-field brines is to be expected because of underground migration of the brines toward the aquifer. This process can reduce the groundwater quality by both increasing the water salinity and by adding hydrocarbon and sulfur contaminants into the groundwater. Tembi river contains saline water that can affect groundwater resources. Leaking of these brines into the aquifer was distinguished using total dissolved solids, the relative concentration of major elements, bromide ion (as a trace element), total organic carbon, ion ratios, and mixing curve diagrams. The polluted zone was determined by tracking the hydrochemistry changes across the groundwater flow direction. The volume percentage of different water sources in mixed groundwater was calculated and validated using PHREEQC software. The results revealed that the contribution of the oil-field brine in the groundwater is much lower than the salty river brine, but even this low amount has a considerable impact on water quality by increasing water salinity and adding hydrocarbon and sulfur into the groundwater.


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