A LABORATORY MODEL FOR THE ADSORPTION AND LOSS OF THE SULFATE TRANSPORT IN MULTI POROUS MEDIA OF SOIL

Development of industries and agriculture, salts, especially sulfates, used in many industries, such as fertilizers and pesticides, have become one of the most common problems. In this paper, a laboratory model was established to study the sulfate-contaminated transport process. Four samples of porous media contain the same pollutant, sandy soil, sandy gravel soil, agricultural (organic) soil, and calcareous soil. Where a pollutant is pumped at a concentration of 280 mg/l through a system consisting of a tube of length 4 meters and 8 cm thickness and distributed in the soil Each type is one meter. The results showed that all types of soils, except organic, had leaching or loss of sulfates from the soil and dissolving them with a soil solution. The transfer of pollutants from soil to the solution may reach between 50 to 300 mg/l per meter, while organic soil showed the ability to Absorption up to 100 mg/L per meter. However, it was found that organic soil contains the largest amount of sulfate and was able to adsorption, and it was found that bacterial activity has a role in reducing sulfate in organic soil and thus returning the soil to adsorption after a certain time of saturation process.

Physicochemical Modeling of Barium and Sulfate Transport in Porous Media and Its Application in Seawater-Breakthrough Monitoring

Summary Seawater injection is widely used to improve oil recovery in offshore oil reservoirs. However, injecting seawater into reservoirs can cause many flow-assurance issues, such as scaling and reservoir souring, which are strongly related to the percentage of seawater breakthrough. Thermodynamic models have been developed to evaluate the effects of barite deposition on oil production, but the reservoir stripping effect has not been fully considered. In this study, a new model that incorporates both chemical reaction (barium and sulfate reaction) and physical reactions (ion adsorption/desorption) is developed to investigate the in-situbarite-deposition process. To the best of our knowledge, for the first time, ion adsorption/desorption is integrated by coupling the adsorption/desorption isotherm to the reservoir simulator. The barium and sulfate chemical reaction is modeled by incorporating the solubility product constant into the model. The model accuracy is verified through convergence rate tests and comparison with the coreflood experimental results. The simulation results of both barium and sulfate concentration profiles are greatly improved by integrating the ion adsorption/desorption process. The new physicochemical model is further used to investigate barite deposition under various scenarios. Simulation results indicate that most barite deposits are in the deep reservoir for the areal model. Barite that deposits in the reservoir before seawater breakthrough accounts for 45% of total barite deposition and the barite deposited during the seawater-breakthrough period makes up 54%, while the deposition during the tailing period, where the seawater fraction is larger than 95%, is negligible. For a homogeneous reservoir, the barite-deposition period at the near-wellbore area of the producer is between 30% and 65% of the seawater-breakthrough percentage, and heterogeneity leads to a broader deposition period. For vertical heterogeneous reservoirs, a considerable amount of barite forms in the wellbore, which accounts for 17% of total barite deposition. Based on the accurate simulation of barium and sulfate transport in the reservoir, barium and sulfate concentration profiles can be used to determine the seawater-breakthrough percentage and help optimize production operations that aim to mitigate flow assuranceissues.

Coupled electrokinetic and biological remediation method leads to improved treatment of chlorinated solvents at high sulfate, transport limited sites

The combined biotic and abiotic mechanisms of EK-Bio can result in improved remediation of TCE over traditional bioaugmentation methods.

Plant Sulfate Transporters in the Low Phytic Acid Network: Some Educated Guesses

A few new papers report that mutations in some genes belonging to the group 3 of plant sulfate transporter family result in low phytic acid phenotypes, drawing novel strategies and approaches for engineering the low-phytate trait in cereal grains. Here, we shortly review the current knowledge on phosphorus/sulfur interplay and sulfate transport regulation in plants, to critically discuss some hypotheses that could help in unveiling the physiological links between sulfate transport and phosphorus accumulation in seeds.

Sulfate transport systems in plants: functional diversity and molecular mechanisms underlying regulatory coordination

Sulfate transporters are integral membrane proteins controlling the flux of sulfate (SO42–) entering the cells and subcellular compartments across the membrane lipid bilayers. Sulfate uptake is a dynamic biological process that occurs in multiple cell layers and organs in plants. In vascular plants, sulfate ions are taken up from the soil environment to the outermost cell layers of roots and horizontally transferred to the vascular tissues for further distribution to distant organs. The amount of sulfate ions being metabolized in the cytosol and chloroplast/plastid or temporarily stored in the vacuole depends on expression levels and functionalities of sulfate transporters bound specifically to the plasma membrane, chloroplast/plastid envelopes, and tonoplast membrane. The entire system for sulfate homeostasis, therefore, requires different types of sulfate transporters to be expressed and coordinately regulated in specific organs, cell types, and subcellular compartments. Transcriptional and post-transcriptional regulatory mechanisms control the expression levels and functions of sulfate transporters to optimize sulfate uptake and internal distribution in response to sulfate availability and demands for synthesis of organic sulfur metabolites. This review article provides an overview of sulfate transport systems and discusses their regulatory aspects investigated in the model plant species Arabidopsis thaliana.

Unusual Sulfur Requirements During Laboratory Growth ofLuteibacter

Many terrestrial bacteria are assumed to utilize sulfate transport and metabolism as a means for fulfilling cellular sulfur requirements. As such, many defined minimal media for bacterial growth under laboratory conditions contain sulfate as their sulfur source. Herein, an exception to this assumption is described as sulfate transport capabilities have been lost at least once in a lineage ofLuteibacterassociated with plants and fungi. However, a representative of this lineage (an endohyphal species,Luteibactersp. 9143) can grow in minimal media when sulfur is supplemented with organic (cysteine and methionine) or inorganic (thiosulfate) compounds, and when co-cultured with its fungal host. A related strain ofLuteibacter(UNC366Tsa5.1, isolated from the rhizosphere of Arabidopsis) potentially possesses more limited sulfur acquisition pathways thanLuteibactersp. 9143. These results highlight the surprising sulfur requirements ofLuteibacter, which may be illustrative of close associations between these strains and eukaryotes, as well as a need for caution when inferring auxotrophies in a focal strain based on differential growth in minimal versus rich media.ImportanceSulfate is often used as the sulfur source in minimal media. Here we show that someLuteibacterstrains cannot utilize sulfate as a sulfur source, likely due to loss of genes encoding transport proteins. As sulfur requirements forLuteibactercan be met through co-culture with their fungal partner, this knowledge could provide a means to engineer better symbiotic relationships between bacteria and fungi that may be relevant for agriculture. Because growth in minimal media can be restored by supplementation with either cysteine or methionine, and in some cases only methionine, this result highlights how unexpected growth requirements could masquerade as auxotrophy for certain strains and conditions.