Although ocean crude-oil spill accidents did not frequently happened in the past, it really caused great damage to the ma- rine ecosystem once it happened. Because of the spreading and weathering, crude-oil spill usua...Although ocean crude-oil spill accidents did not frequently happened in the past, it really caused great damage to the ma- rine ecosystem once it happened. Because of the spreading and weathering, crude-oil spill usually covers a large area of water surface and its viscosity is very high, which brings hu- man great trouble to clean it up. Dispersant and in-situ burn- ing were frequently used in the past crude-oil spill accidents, but these two methods suffered from the drawbacks includ- ing being toxic to marine lives, causing air pollution, disabil- ity of recovering the crude oil. Oil skimmers could recovery the oils, but their handling capacities are rather limited. Re- cently, porous hydrophobic and oleophilic materials （PHOM） have been demonstrated as low-cost, efficient and ecofriendly materials for the oil spill cleanup [ 1 ]. Nevertheless, their poor absorption speed to viscous oil spill hinders their practical ap- plication.展开更多
This study determined the adsorption ability of modified sponge gourd fibre in adsorbing crude oil from simulated oil-water mixture. Modification was done on the adsorbent by treating with hot water and sodium hydroxi...This study determined the adsorption ability of modified sponge gourd fibre in adsorbing crude oil from simulated oil-water mixture. Modification was done on the adsorbent by treating with hot water and sodium hydroxide. The dependence of the adsorption process on particle size of the fibre was determined using mesh sizes of 4.75, 2.36, 1.18 and 0.85 mm. The hot water treatment significantly increased the adsorbing ability of the sponge gourd, removing 83.3% of the crude oil from the mixture, alkaline treated sample removed 45.1% and the raw sample removed 22.9%. The result of the SEM images shows that hot water treated sample has more pores on the surface which influenced the better performance. The FTIR results obtained after the adsorption show the successful adsorption of crude oil on to the surface of the sponge gourd due to the presence of functional groups characteristics of groups found in crude oil. An optimum particle size for the sponge gourd was found to exist at the value of 1.18 mm, above and below which the crude oil removed was reduced. The modification of sponge gourd promoted the adsorption capacity for crude oil.展开更多
A controlled laboratory study was conducted to measure the dispersion effectiveness of Corexit 9500 on 23 different crude oils. This study was a part of a larger project initiated by the Bureau of Safety and Environme...A controlled laboratory study was conducted to measure the dispersion effectiveness of Corexit 9500 on 23 different crude oils. This study was a part of a larger project initiated by the Bureau of Safety and Environmental Enforcement (BSEE) testing 20 oils to compare the predictive value of laboratory dispersant effectiveness tests with their larger scale test conducted at Ohmsett, BSEE’s national oil spill response test facility located in Leonardo, NJ. The test used in this study was the Baffled Flask Test (BFT), which is planned for adoption as EPA’s official testing protocol for listing commercial dispersant products on the National Contingency Plan Product Schedule, replacing the current Swirling Flask Test (SFT) [1]. In addition, the results of 3 additional oils, the 2 used in the SFT and BFT as currently written plus another reference oil, are presented. The temperature used for the tests was 15°C, to match the temperature used at Ohmsett. The dispersion effectiveness ranged from 3.4% to 93%. The BFT is a laboratory test with results that are inversely correlated with oil viscosity and therefore has predictive value in the decision to use a dispersant in the event of a spill.展开更多
Concentrations of selected heavy metals, nutrient elements and PAHs in farms and produce (cassava tubers and oil bean seeds) from 4-year-old crude oil impacted areas (Ekore and Uduvwoku) and a non-oil-impacted area (O...Concentrations of selected heavy metals, nutrient elements and PAHs in farms and produce (cassava tubers and oil bean seeds) from 4-year-old crude oil impacted areas (Ekore and Uduvwoku) and a non-oil-impacted area (Okpe), all in Ughelli South Local Government Area, Delta State, Nigeria, were investigated to ascertain degree of risk posed. A random sampling design was chosen with three replications. Results obtained revealed significantly (P < 0.05) elevated (mg·kg<sup>-1</sup>) Cd (0.240, 0.140) and Cr (1.327, 3.122) in cassava samples for Ekore and Uduvwoku respectively in comparison to non-detectable amount for those of non-impacted source and exceeded set WHO limits of 0.1 and 0.05 mg·kg<sup>-1</sup> respectively. Although PAHs were low, oil spill increased available levels by factor of 2.5 and 5 for Ekore and Uduvwoku respectively. Again, Cd and Cr exceeded WHO limit for study impacted soils. Available N, P and K decreased (%) by 56.1, 28.5 and 2.4 for Ekore and 82.9, 39.9 and 45.5 for Uduvwoku Cassava samples. Nutrient profiling in oil bean revealed % reduction in avaliable N, P and K by 33.7, 47.7 and 57.9 and 28.9, 76.3 and 39.8 for Ekore and Uduvwoku samples respectively. For oil bean, Cd and Cr did not differ markedly between polluted samples but exceeded WHO limits. Other studied contaminants fell within limits. In soils, available N, P and K decreased (%) by 39.6, 79.1 and 27.4 for Ekore and 53, 88.1 and 45.5 for Uduvwoku samples. Low pH of 5.3 and 5.7 in Ekore and Uduvwoku respectively may increase the leachability of Cr into groundwater. Biopersistent Cd and Cr were found to biomagnify up the food chain and may impair major processes. Although PAHs were relatively low, their % composition was more of High Molecular Weight that was less readily biodegraded by indigenous microorganisms, and hence can persist in the environment as carcinogens.展开更多
文摘Although ocean crude-oil spill accidents did not frequently happened in the past, it really caused great damage to the ma- rine ecosystem once it happened. Because of the spreading and weathering, crude-oil spill usually covers a large area of water surface and its viscosity is very high, which brings hu- man great trouble to clean it up. Dispersant and in-situ burn- ing were frequently used in the past crude-oil spill accidents, but these two methods suffered from the drawbacks includ- ing being toxic to marine lives, causing air pollution, disabil- ity of recovering the crude oil. Oil skimmers could recovery the oils, but their handling capacities are rather limited. Re- cently, porous hydrophobic and oleophilic materials （PHOM） have been demonstrated as low-cost, efficient and ecofriendly materials for the oil spill cleanup [ 1 ]. Nevertheless, their poor absorption speed to viscous oil spill hinders their practical ap- plication.
文摘This study determined the adsorption ability of modified sponge gourd fibre in adsorbing crude oil from simulated oil-water mixture. Modification was done on the adsorbent by treating with hot water and sodium hydroxide. The dependence of the adsorption process on particle size of the fibre was determined using mesh sizes of 4.75, 2.36, 1.18 and 0.85 mm. The hot water treatment significantly increased the adsorbing ability of the sponge gourd, removing 83.3% of the crude oil from the mixture, alkaline treated sample removed 45.1% and the raw sample removed 22.9%. The result of the SEM images shows that hot water treated sample has more pores on the surface which influenced the better performance. The FTIR results obtained after the adsorption show the successful adsorption of crude oil on to the surface of the sponge gourd due to the presence of functional groups characteristics of groups found in crude oil. An optimum particle size for the sponge gourd was found to exist at the value of 1.18 mm, above and below which the crude oil removed was reduced. The modification of sponge gourd promoted the adsorption capacity for crude oil.
文摘A controlled laboratory study was conducted to measure the dispersion effectiveness of Corexit 9500 on 23 different crude oils. This study was a part of a larger project initiated by the Bureau of Safety and Environmental Enforcement (BSEE) testing 20 oils to compare the predictive value of laboratory dispersant effectiveness tests with their larger scale test conducted at Ohmsett, BSEE’s national oil spill response test facility located in Leonardo, NJ. The test used in this study was the Baffled Flask Test (BFT), which is planned for adoption as EPA’s official testing protocol for listing commercial dispersant products on the National Contingency Plan Product Schedule, replacing the current Swirling Flask Test (SFT) [1]. In addition, the results of 3 additional oils, the 2 used in the SFT and BFT as currently written plus another reference oil, are presented. The temperature used for the tests was 15°C, to match the temperature used at Ohmsett. The dispersion effectiveness ranged from 3.4% to 93%. The BFT is a laboratory test with results that are inversely correlated with oil viscosity and therefore has predictive value in the decision to use a dispersant in the event of a spill.
文摘Concentrations of selected heavy metals, nutrient elements and PAHs in farms and produce (cassava tubers and oil bean seeds) from 4-year-old crude oil impacted areas (Ekore and Uduvwoku) and a non-oil-impacted area (Okpe), all in Ughelli South Local Government Area, Delta State, Nigeria, were investigated to ascertain degree of risk posed. A random sampling design was chosen with three replications. Results obtained revealed significantly (P < 0.05) elevated (mg·kg<sup>-1</sup>) Cd (0.240, 0.140) and Cr (1.327, 3.122) in cassava samples for Ekore and Uduvwoku respectively in comparison to non-detectable amount for those of non-impacted source and exceeded set WHO limits of 0.1 and 0.05 mg·kg<sup>-1</sup> respectively. Although PAHs were low, oil spill increased available levels by factor of 2.5 and 5 for Ekore and Uduvwoku respectively. Again, Cd and Cr exceeded WHO limit for study impacted soils. Available N, P and K decreased (%) by 56.1, 28.5 and 2.4 for Ekore and 82.9, 39.9 and 45.5 for Uduvwoku Cassava samples. Nutrient profiling in oil bean revealed % reduction in avaliable N, P and K by 33.7, 47.7 and 57.9 and 28.9, 76.3 and 39.8 for Ekore and Uduvwoku samples respectively. For oil bean, Cd and Cr did not differ markedly between polluted samples but exceeded WHO limits. Other studied contaminants fell within limits. In soils, available N, P and K decreased (%) by 39.6, 79.1 and 27.4 for Ekore and 53, 88.1 and 45.5 for Uduvwoku samples. Low pH of 5.3 and 5.7 in Ekore and Uduvwoku respectively may increase the leachability of Cr into groundwater. Biopersistent Cd and Cr were found to biomagnify up the food chain and may impair major processes. Although PAHs were relatively low, their % composition was more of High Molecular Weight that was less readily biodegraded by indigenous microorganisms, and hence can persist in the environment as carcinogens.
