Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoate...Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolysed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethy-lidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).展开更多
Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified...Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.展开更多
Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metab...Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.展开更多
Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline ...Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.展开更多
Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production w...Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.展开更多
Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the ...Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.展开更多
Microplastic has been found in all major waterbodies in the world. Many examples of ingestion of microplastic by marine organisms have been reported. This presence of microplastic in marine organisms gives it the poss...Microplastic has been found in all major waterbodies in the world. Many examples of ingestion of microplastic by marine organisms have been reported. This presence of microplastic in marine organisms gives it the possibility to penetrate the human food chain by increasing the chance of microplastic in seafood targeted for human consumption. Although it is known that parts of the Indian Ocean suffer from significant plastic pollution, much of the systematic research on the microplastic abundance in different regions of the Indian Ocean stems only from the last five years. This manuscript reviews the available literature of 2015-2022 on the presence of microplastics in commercially important fish species in the Indian Ocean. The literature data on microplastic content on beaches, in subtidal sediment, in the sediment from the ocean floor, and in surface water of different regions of the Indian Ocean is reviewed, also.展开更多
NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemosele...NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.展开更多
Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produc...Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.展开更多
Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in w...Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.展开更多
In order to find out whether any toothpastes commercially available in the United Arab Emirates (UAE) carry microplastic content in form of plastic microbeads, the filterable solid contents of 31 toothpastes from UAE ...In order to find out whether any toothpastes commercially available in the United Arab Emirates (UAE) carry microplastic content in form of plastic microbeads, the filterable solid contents of 31 toothpastes from UAE markets and 2 toothpastes imported from Syria were analyzed. FT-IR studies of the solids revealed that the major solid components were hydrated silica and calcium carbonate, where the individual toothpaste product exhibited either one or the other as the dominant constituent. Titrimetric analysis of the alkalinity of the ash of the toothpastes was carried out. The solids, ashed at 600°C were subjected to FT-IR and EDS (energy dispersive X-ray spectroscopic) analysis. The ash of some of the products was shown to have TiO<sub>2</sub> and Ca<sub>3</sub> (PO<sub>4</sub>)<sub>2</sub> as minor components. Mostly organic dyes were used as colorants;however, iron oxide (Fe<sub>2</sub>O<sub>3</sub>) was also found. Importantly, none of the toothpastes carried any solid microplastic particles. Only 3 toothpastes carried microbeads at all, which were made of either silica or microcrystalline cellulose. This finding indicates that toothpastes, at least in the UAE, are no longer a significant source of microplastic in the environment. The results were compared to a toothpaste bought through the internet with a formulation from 2014, which exhibited polythene microplastic at 1.31 ± 0.39 w% of the filterable solid content.展开更多
Microplastic has become a ubiquitous environmental pollutant. Microplastic in the oceans has detrimental effects on aquatic organisms. The presence of microplastic in marine fish heightens the chance of finding microp...Microplastic has become a ubiquitous environmental pollutant. Microplastic in the oceans has detrimental effects on aquatic organisms. The presence of microplastic in marine fish heightens the chance of finding microplastic in seafood targeted for human consumption. The Mediterranean Sea is known to suffer from significant plastic pollution. It is also one of the most thoroughly studied water bodies in regard to microplastic contamination. The manuscript reviews the available literature of 2015-2021 on the presence of microplastic in commercially important fish species in the Mediterranean Sea. The literature data on microplastic content on beaches, in subtidal sediment, in the sediment from the ocean floor and in surface water of different regions of the Mediterranean Sea is reviewed, also.展开更多
The manuscript reviews the available literature of 2015-2022 on the microplastic content in commercially important fish species, molluscs and crustaceans in the Arabian/Persian Gulf. The literature on microplastic con...The manuscript reviews the available literature of 2015-2022 on the microplastic content in commercially important fish species, molluscs and crustaceans in the Arabian/Persian Gulf. The literature on microplastic concentrations on beaches, in subtidal sediment, and in surface water of different regions of the Arabian/Persian Gulf is evaluated, also. Overall, the reported concentration of microplastic in marine organisms in the Gulf has been found to be less than for comparable waters such as the Mediterranean Sea. The highest microplastic concentration within the region of the Gulf has been found on its Northern shore, in Iran, where also most of the microplastic studies within the region stem from.展开更多
文摘Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolysed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethy-lidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).
文摘Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.
文摘Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.
文摘Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.
文摘Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.
文摘Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.
文摘Microplastic has been found in all major waterbodies in the world. Many examples of ingestion of microplastic by marine organisms have been reported. This presence of microplastic in marine organisms gives it the possibility to penetrate the human food chain by increasing the chance of microplastic in seafood targeted for human consumption. Although it is known that parts of the Indian Ocean suffer from significant plastic pollution, much of the systematic research on the microplastic abundance in different regions of the Indian Ocean stems only from the last five years. This manuscript reviews the available literature of 2015-2022 on the presence of microplastics in commercially important fish species in the Indian Ocean. The literature data on microplastic content on beaches, in subtidal sediment, in the sediment from the ocean floor, and in surface water of different regions of the Indian Ocean is reviewed, also.
文摘NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.
文摘Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.
文摘Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.
文摘In order to find out whether any toothpastes commercially available in the United Arab Emirates (UAE) carry microplastic content in form of plastic microbeads, the filterable solid contents of 31 toothpastes from UAE markets and 2 toothpastes imported from Syria were analyzed. FT-IR studies of the solids revealed that the major solid components were hydrated silica and calcium carbonate, where the individual toothpaste product exhibited either one or the other as the dominant constituent. Titrimetric analysis of the alkalinity of the ash of the toothpastes was carried out. The solids, ashed at 600°C were subjected to FT-IR and EDS (energy dispersive X-ray spectroscopic) analysis. The ash of some of the products was shown to have TiO<sub>2</sub> and Ca<sub>3</sub> (PO<sub>4</sub>)<sub>2</sub> as minor components. Mostly organic dyes were used as colorants;however, iron oxide (Fe<sub>2</sub>O<sub>3</sub>) was also found. Importantly, none of the toothpastes carried any solid microplastic particles. Only 3 toothpastes carried microbeads at all, which were made of either silica or microcrystalline cellulose. This finding indicates that toothpastes, at least in the UAE, are no longer a significant source of microplastic in the environment. The results were compared to a toothpaste bought through the internet with a formulation from 2014, which exhibited polythene microplastic at 1.31 ± 0.39 w% of the filterable solid content.
文摘Microplastic has become a ubiquitous environmental pollutant. Microplastic in the oceans has detrimental effects on aquatic organisms. The presence of microplastic in marine fish heightens the chance of finding microplastic in seafood targeted for human consumption. The Mediterranean Sea is known to suffer from significant plastic pollution. It is also one of the most thoroughly studied water bodies in regard to microplastic contamination. The manuscript reviews the available literature of 2015-2021 on the presence of microplastic in commercially important fish species in the Mediterranean Sea. The literature data on microplastic content on beaches, in subtidal sediment, in the sediment from the ocean floor and in surface water of different regions of the Mediterranean Sea is reviewed, also.
文摘The manuscript reviews the available literature of 2015-2022 on the microplastic content in commercially important fish species, molluscs and crustaceans in the Arabian/Persian Gulf. The literature on microplastic concentrations on beaches, in subtidal sediment, and in surface water of different regions of the Arabian/Persian Gulf is evaluated, also. Overall, the reported concentration of microplastic in marine organisms in the Gulf has been found to be less than for comparable waters such as the Mediterranean Sea. The highest microplastic concentration within the region of the Gulf has been found on its Northern shore, in Iran, where also most of the microplastic studies within the region stem from.
