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911.
本法根据NH+4与水杨酸在次氯酸钠和亚硝基铁氰化钠的作用下形成一种有色配合物的反应,最大吸收波长为700nm,体系中NH+4-N浓度在0~14μg/ml范围内符合朗伯—比耳定律,测得摩尔吸光系数ε=11×104。本法灵敏、准确、重现性好,测试误差小于3%,回收率为96~10231%。 相似文献
912.
Three accidents occurred in east China's Jiangsu Province in March and April 2019. These accidents sounded the safety alarm for the management of industrial hazardous waste in the “heavy industry” era. This paper explored the internal causes of these accidents through the current situation of the generation, disposal and comprehensive utilization of industrial hazardous waste in China. The results of the analysis showed that the enterprises management systems of hazardous waste had serious problems at the current stage, leading to many potential risks. The chief problem resided in the fact that these systems failed to take full account of safety and environmental protection. Finally, suggestions for improvement were proposed concerning the above problems. 相似文献
913.
914.
The polluter-pays principle has been widely implemented in OECD countries and credited for bring about a significant reduction in pollutant discharge. However, it has had only limited implementation in developing countries. The consequences of not implementing it in developing countries, to the extent they are documented, are limited to estimating the economic damages of environmental degradation. Yet there are several other but seldom documented negative consequences of the failure to implement the polluter-pays principle. These consequences are documented in the case of Pakistan. They include limited construction of effluent treatment plants, heavy dependence on the government and international donors for funding the only two operational common effluent treatment plants, significant operational issues at the two common effluent treatment plants, missed opportunities to build cost-effective common effluent treatment plants and minimal environmental improvements from isolated investments in individual effluent treatment plants in addition to the already documented significant level of environmental degradation due to uncontrolled pollutant discharge. 相似文献
915.
Christina A. Holcroft Author Vitae Laura Punnett Author Vitae 《Journal of Safety Research》2009,40(4):247-3552
Problem
The reported injury rate for wood product manufacturing in Maine, 1987-2004, was almost twice the state-wide average for all jobs. Method: A case-control study was conducted in wood processing plants to determine preventable risk factors for injury. A total of 157 cases with injuries reported to workers' compensation and 251 controls were interviewed. Results: In multivariable analyses, variables associated with injury risk were high physical workload, machine-paced work or inability to take a break, lack of training, absence of a lockout/tagout program, low seniority, and male gender. Different subsets of these variables were significant when acute incidents and overexertions were analyzed separately and when all injuries were stratified by industry sub-sector. Impact on industry: Generalizability may be limited somewhat by non-representative participation of workplaces and individuals. Nevertheless, these findings provide evidence that many workplace injuries occurring in wood processing could be prevented by application of ergonomics principles and improved work organization. 相似文献916.
Pavlović J Stopić S Friedrich B Kamberović Z 《Environmental science and pollution research international》2007,14(7):518-522
Goal, Scope and Background This paper is a part of the research work on ‘Integrated treatment of industrial wastes towards prevention of regional water
resources contamination — INTREAT’ the project. It addresses the environmental pollution problems associated with solid and
liquid waste/effluents produced by sulfide ore mining and metallurgical activities in the Copper Mining and Smelting Complex
Bor (RTB-BOR), Serbia. However, since the minimum solubility for the different metals usually found in the polluted water
occurs at different pH values and the hydroxide precipitates are amphoteric in nature, selective removal of mixed metals could
be achieved as the multiple stage precipitation. For this reason, acid mine water had to be treated in multiple stages in
a continuous precipitation system-cascade line reactor.
Materials and Methods All experiments were performed using synthetic metal-bearing effluent with chemical a composition similar to the effluent
from open pit, Copper Mining and Smelting Complex Bor (RTB-BOR). That effluent is characterized by low pH (1.78) due to the
content of sulfuric acid and heavy metals, such as Cu, Fe, Ni, Mn, Zn with concentrations of 76.680, 26.130, 0.113, 11.490,
1.020 mg/dm3, respectively. The cascade line reactor is equipped with the following components: for feeding of effluents, for injection
of the precipitation agent, for pH measurements and control, and for removal of the process gases. The precipitation agent
was 1M NaOH. In each of the three reactors, a changing of pH and temperature was observed. In order to verify efficiency of
heavy metals removal, chemical analyses of samples taken at different pH was done using AES-ICP.
Results Consumption of NaOH in reactors was 370 cm3, 40 cm3 and 80 cm3, respectively. Total time of the experiment was 4 h including feeding of the first reactor. The time necessary to achieve
the defined pH value was 25 min for the first reactor and 13 min for both second and third reactors. Taking into account the
complete process in the cascade line reactor, the difference between maximum and minimum temperature was as low as 6°C. The
quantity of solid residue in reactors respectively was 0.62 g, 2.05 g and 3.91 g. In the case of copper, minimum achieved
concentration was 0.62 mg/dm3 at pH = 10.4. At pH = 4.50 content of iron has rapidly decreased to < 0.1 mg/dm3 and maintained constant at all higher pH values. That means that precipitation has already ended at pH=4.5 and maximum efficiency
of iron removal was 99.53%. The concentration of manganese was minimum at pH value of 11.0. Minimum obtained concentration
of Zn was 2.18 mg/dm3 at a pH value of 11. If pH value is higher than 11, Zn can be re-dissolved. The maximum efficiency of Ni removal reached
76.30% at a pH value of 10.4.
Discussion Obtained results show that efficiency of copper, iron and manganese removal is very satisfactory (higher than 90%). The obtained
efficiency of Zn and Ni removal is lower (72.30% and 76.31%, respectively). The treated effluent met discharge water standard
according to The Council Directive 76/464/EEC on pollution caused by certain dangerous substances into the aquatic environment
of the Community. Maximum changing of temperature during the whole process was 6°C.
Conclusion This technology, which was based on inducing chemical precipitation of heavy metals is viable for selective removal of heavy
metals from metal-bearing effluents in three reactor systems in a cascade line.
Recommendations and Perspectives The worldwide increasing concern for the environment and guidelines regarding effluent discharge make their treatment necessary
for safe discharge in water receivers. In the case where the effluents contain valuable metals, there is also an additional
economic interest to recover these metals and to recycle them as secondary raw materials in different production routes.
ESS-Submission Editor: PhD Hailong Wang, hailong.wang@ensisjv.com 相似文献
917.
This paper assessed the composition of waste water effluent generated by a Petrochemical industry and a treatment system developed to improve the quality of the discharge water. Parameters as pH, COD, TSS chloride and lead ions were analysed and treated comparatively using hydrogen peroxide. At pH 8.0 post treatment analysis showed a COD – 96 mg/l TSS – 48 mg/l Cl – 798.75 mg/l and Pb2+ – 2 mg/l for treatment D where 40 g/l of alum was used on 30% solution of H2O2 compared to systems A-C. Process treatment included activated clay with sodium ion resin which at pH 6.8 had COD – 52 mg/l, TSS – 10 mg/l, Cl – 510 mg/l and Pb2+ – 0.070 mg/l. This system has an overall efficiency of 79.0% TSS, 45.83% COD, 97.5% Pb2+ and 36.1% Cl reduction. Characteristics obtained for the study has a higher efficiency compared with FEPA and WHO standard for similar industrial water treatment. 相似文献
918.
J.J. Follstad Shah Y. Jameel R.M. Smith R.S. Gabor P.D. Brooks S.R. Weintraub 《Journal of the American Water Resources Association》2019,55(3):591-607
We conducted synoptic surveys over three seasons in one year to evaluate the variability in water sources and geochemistry of an urban river with complex water infrastructure in the state of Utah. Using stable isotopes of river water (δ18O and δ2H) within a Bayesian mixing model framework and a separate hydrologic mass balance approach, we quantified both the proportional inputs and magnitude of discharge associated with “natural” (lake, groundwater, and tributary inputs) and “engineered” (effluent and canal inflows) sources. The relative importance of these major contributors to streamflow varied both spatially and seasonally. Spatiotemporal patterns of dissolved oxygen, temperature, pH, calcium, chloride, nitrate, and orthophosphate indicated seasonal shifts in dominant sources of river water played an important role in determining water quality. We show although urban rivers are clearly influenced by novel water sources created by water infrastructure, they continue to reflect the imprint of “natural” water sources, including diffuse groundwater. Resource managers thus may need to account for the quantity of both surface waters and also historically overlooked groundwater inputs to address water quality concerns in urban rivers. 相似文献
919.
J. Kurilova-Palisaitiene T. Mannheim K. Buhse M. Lorenz R. Schmitt 《International Journal of Sustainable Engineering》2017,10(3):185-196
The rise in energy consumption and the associated costs instigate financial concerns among industrial energy consumers. For industrial processes addressing heating and cooling as well as material transformation, a wide range of energy efficiency measures have been developed and successfully implemented. In contrast to that, most robot-based operations such as pick-and-place motions or assembly tasks still use inefficient standard concepts causing high-energy consumption and high-energy costs. Thanks to a rather low payload-to-weight ratio of new robot designs, such as parallel kinematic or hybrid robot manipulators, a high potential for energy savings is expected. This article identifies potentials for energy saving concerning industrial consumers by assessing three different robot concepts. Based on a literature review, two existing designs for robots – the conventional serial robot and the parallel kinematic robot are analysed and compared with respect to the energy utilised during a typical item placement task. Afterwards, the concept of PARAGRIP, a hybrid of the two presented robot designs is introduced and examined based on simulation regarding its energy consumption. The final results demonstrate significantly different energy consumptions between the robot concepts, identifying potential savings of about 40% in a selected industrial application scenario. 相似文献
920.
Raquel Barrena Xavier Font Xavier Gabarrell Antoni Sánchez 《Waste management (New York, N.Y.)》2014,34(7):1109-1116
Stability is one of the most important properties of compost obtained from the organic fraction of municipal solid wastes. This property is essential for the application of compost to land to avoid further field degradation and emissions of odors, among others. In this study, a massive characterization of compost samples from both home producers and industrial facilities is presented. Results are analyzed in terms of chemical and respiration characterizations, the latter representing the stability of the compost. Results are also analyzed in terms of statistical validation. The main conclusion from this work is that home composting, when properly conducted, can achieve excellent levels of stability, whereas industrial compost produced in the studied facilities can also present a high stability, although an important dispersion is found in these composts. The study also highlights the importance of respiration techniques to have a reliable characterization of compost quality, while the chemical characterization does not provide enough information to have a complete picture of a compost sample. 相似文献