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11.
《Process Safety and Environmental Protection》2014,92(6):509-514
Produced water is the largest wastestream of oil and gas exploration but its chemical composition hinders its beneficial use. Effective treatment and reuse of produced water can mitigate scarcity of fresh water, especially in arid areas. Presence of inorganic compounds such as boron in produced water renders its beneficial use difficult. In this study, boron removal from produced water was investigated. Synthetic wastewater was prepared simulating the range of boron concentrations in produced water. Four operating parameters pH (3–11), charge loading (1200–3600 Ah/m3), contact time (15–90 min) and concentration (10–30 mg/L) were selected and their optimum conditions investigated. The obtained optimum conditions were applied to treat real produced water. Residual boron concentration of 0.3 mg/L was obtained from initial boron concentration of 15 mg/L in real produced water at optimum conditions of pH 7, charge loading 2400 Ah/m3 and contact time 90 min. Boron adsorption could be represented by Langmuir and Freundlich isotherm models. Electrocoagulation can be used for the effective removal of boron from produced water. 相似文献
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Hailan Wang Baoyu Gao Li an Hou Ho Kyong Shon Qinyan Yue Zhining Wang 《Frontiers of Environmental Science & Engineering》2021,15(6):135
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Ochoa-González R Cuesta AF Córdoba P Díaz-Somoano M Font O López-Antón MA Querol X Martínez-Tarazona MR Giménez A 《Journal of environmental management》2011,92(10):2586-2589
A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study was to evaluate the partitioning of boron in a (co-)combustion power plant, special attention was paid to the analytical procedure for boron determination. A sample preparation procedure was optimised for coal and combustion by-products to overcome some specific shortcomings of the currently used acid digestion methods. In addition boron mass balances and removal efficiencies in ESP and FGD devices were calculated. Mass balance closures between 83 and 149% were obtained. During coal combustion, 95% of the incoming boron was collected in the fly ashes. The use of petroleum coke as co-combustible produced a decrease in the removal efficiency of the ESP (87%). Nevertheless, more than 90% of the remaining gaseous boron was eliminated via the FGD in the wastewater discharged from the scrubber, thereby causing environmental problems. 相似文献
15.
采服硫酸亚铁还原 ,硼泥絮凝沉降的方法处理电镀废水中的铬 (Ⅵ ) .控制还原时的PH为 3 .5~ 5.5,铬 (Ⅵ ) :硫酸亚铁 :硼泥 =1 :2 0 :1 4 0 (重量比 ) ,铬 (Ⅵ ) ,的去除率达 99%以上 .对于铬 (Ⅵ )浓度小于 1 0 0 0mg/L的废水 ,经一次处理 ,就可以达到国家的排放标准 . 相似文献
16.
Removal of boron by electrocoagulation 总被引:2,自引:0,他引:2
Nihal?Bekta?Email author Salim??ncel Hilal?Y.?Akbulut Anatholy?Dimoglo 《Environmental Chemistry Letters》2004,2(2):51-54
Boron compounds are used in many manufacturing products and may be introduced into the environment in the form of hazardous materials. Here the feasibility of removal of boron from aqueous solutions by electrocoagulation was investigated. The process was examined under various factors in order to assess optimal operating conditions. The results showed that electrocoagulation for boron removal depends on current density, initial concentration and time. Under a current density of 30 mA/cm2 the percentage of boron removal from aqueous solutions is in the range of 92–96%. 相似文献
17.
通过对硼在我国34个省(自治区)、市的40种主要土类中的含量研究,提出硼在土壤环境中的分布规律,并对影响其分布特征的因素进行了探讨. 相似文献
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Effects on Environment and Agriculture of Geothermal Wastewater and Boron Pollution in Great Menderes Basin 总被引:1,自引:0,他引:1
Koç C 《Environmental monitoring and assessment》2007,125(1-3):377-388
Boron toxicity is an important disorder that can be limit plant growth on soils of arid and semi arid environments through
the world. High concentrations of Boron may occur naturally in the soil or in groundwater, or be added to the soil from mining,
fertilizers, or irrigation water. Off all the potential resources, irrigation water is the most important contributor to high
levels of soil boron, boron is often found in high concentrations in association with saline soil and saline well water. Although
of considerable agronomic importance, our understanding of Boron toxicity is rather fragment and limited. In this study, Boron
content of Great Menderes River and Basin was researched. Great Menderes Basin is one of the consequence basins having agricultural
potential, aspect of water and soil resources in Turkey. Great Menderes River, water resource of the basin was to be polluted
by geothermal wastewater and thermal springs including Boron element. Great Menderes Basin has abundant geothermal water resources
which contain high amounts of Boron and these ground water are brought to surface and used for various purposes such as power
generation, heating or thermal spring and than discharged to Great Menderes River. In order to prevent Boron pollution and
hence unproductively in soils, it is necessary not to discharged water with Boron to irrigation water. According to results,
it was obtained that Boron content of River was as high in particular Upper Basin where there was a ground thermal water reservoir.
Boron has been accumulated more than plant requirement in this area irrigated by this water. Boron content of River was relatively
low in rainy months and irrigation season while it was high in dry season. Boron concentration in the River was to decrease
from upstream to downstream. If it is no taken measure presently, about 130,000 ha irrigation areas which was constructed
irrigation scheme in the Great Menderes basin will expose the Boron pollution and salinity. Even though Boron concentration
of river water is under 0.5 ppm limit value, Boron element will store in basin soils, decrease in crop yields, and occur problematic
soils in basin. 相似文献
20.
Background, aim and scope Glass wools are man-made vitreous fibres, which consist principally of sodium, calcium and magnesium silicates, but may contain
smaller amounts of other elements, including boron. The boron contents originate from the use of borates in the glass melting
process as a glass former and a flux agent. During the production and application of glass wool insulation products, workers
may legally be exposed to glass fibre up to the occupational limit value, commonly of 1 fibre/cm3. However, in practice, the fibre exposure will be at least ten times lower. Boron is a non-metallic element widely distributed
in nature, where it occurs as boric acid, borates and borosilicates. Humans are mainly exposed to boron via vegetarian food
and drinking water, mineral supplements and various consumer products. Boron is an essential element for plant growth, but
the essentiality for humans is not proven, although intakes of trace amounts of the element seem to be useful for bone health
and proper brain function; higher concentrations of boron, however, may be toxic. In relation to the European Union legislation
on dangerous substances, an EU Expert Group has recommended classifying boric acid and borates with risk phrases for reproductive
toxicity. The aim of this paper is to assess whether the new EU hazard classification of boron compounds should imply that
glass wool products used for building insulation in the future should be labelled, “may impair fertility and cause harm to
the unborn child”, because of the low boron content.
Materials and methods Boron intakes are estimated in a worst-case occupational situation with human exposure to glass wool fibres at the occupational
limit of 1 fibre/cm3 by calculation of the mass of the amount of fibres inhaled during an 8-h work day. Fibres are supposed to be cylinders of
glass with a length of 30 μm, an average diameter of 1.5–2 μm and containing either 1.5% or 3.5% boron. As a worst-case scenario,
the density of the fibres is set to 2,700 kg/m3. The inhalation rate of the individuals at moderate work load was set to 2 m3/h. A worst-case scenario also corresponds to 100% retention and to 100% solubility of the retained fibres in the lungs.
Results With the normal boron content of 1.5% in glass wool fibres for building insulation, the extra daily occupational boron intake/uptake
will be 0.03–0.06 mg B for 5 days a week. For more uncommon glass wool with maximum boron content of 3.5%, the worst-case
daily boron intake/uptake will be 0.08–0.16 mg B. The main boron exposure in the general population is from vegetarian food,
and the average daily dietary intake with food is estimated to 1.2–1.5 mg B/day. In addition, significant intakes may come
with drinking water, especially from mineral water. In some instances, exposure from mineral supplements, cosmetics and other
consumer products may be significant. For example, individuals taking mineral supplements, e.g. for bodybuilding, may have
an additional intake to that of 1–10 mg/day. During the years, various organisations have recommended safe intake values for
boron. Recently, the Scientific Panel on Dietetic Products, Nutrition and Allergies of the European Food Safety Authority
(EFSA) has established the ‘Tolerable Upper Intake Level’ (UL) for the intake of boron (boric acid and borates) at 0.16 mg
B/kg body weight per day or about 10 mg B/day for an adult.
Discussion The calculated, worst-case exposure scenario during an 8-h work day will result in an extra daily boron intake that only corresponds
to about 10% of the average daily adult boron intakes through food and drinks of about 1.5 mg. The inter-individual variations
in boron intakes from foods, water and supplements will be much greater than an eventual, very worst-case, additional intake
of boron from inhalation of glass wool fibres. In addition, the combined intakes are far lower than the ‘Tolerable Upper Intake
Level’ of 10 mg B/day for a person weighing 60 kg, as recommended by the European Food Safety Agency. The potential boron
intake from inhalation of glass wool fibres is also much lower than boron intakes by workers in the boron industry, who at
the present occupational limit value will be exposed to 50 mg of boron 5 days a week, or 100 times more than the worst case
for glass wool fibres. Furthermore, in practice, exposure levels will mostly be ten to 100 times lower than the occupational
limit used here as a worst case.
Conclusions The estimated boron intake from inhalation of glass wool fibres in occupational settings will be insignificant and without
any health risks, even in the case of non-compliance with the occupational limit value. Any proposal requiring hazard labels
on commercial glass wool products for building insulation, because of the boron content, is not supported by the present scientific knowledge.
Recommendations and perspectives The European Commission should ensure that the new EU hazard classification of boron compounds is not applied to commercial
glass wool products for building insulation having a low content of boron. 相似文献