63 research outputs found

    Sistemas Integrados de Gestión: Procedimientos Interactivos

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    Los sistemas integrados de gestión (SIG), es decir, la gestión de la calidad, medioambiente, seguridad y salud, y más recientemente la I+D+i y la responsabilidad social corporativa también, son actualmente una herramienta empresarial necesaria para establecer un marco de sostenibilidad, mejora e innovación, y aprendizaje continuos que además contribuyan a la mejora final del posicionamiento de la empresa en el mercado. La implantación a nivel global de estas herramientas en la empresa implica la necesidad de formar profesionales preparados en estas áreas de conocimiento, integrando la docencia de estas materias en los grados actuales. La docencia de estas disciplinas se enfrenta a dificultades como el marco cambiante en el que se desarrollan, tanto a nivel empresarial como político o normativo, el tradicional desarrollo de material didáctico enfocado a organismos certificadores, pero no a alumnos universitarios, o la falta de integración de los materiales formativos existentes entre los diferentes docentes que las imparten. Se hace por tanto necesario el desarrollo de foros de discusión en docencia universitaria de estas materias y de materiales didácticos, innovadores, actualizados y enfocados a alumnos universitarios. El desarrollo de este proyecto de innovación docente está permitiendo el desarrollo de dichos foros de discusión intra- e inter-universitarios y el desarrollo de un material docente innovador y enfocado al ámbito universitario.Departamento de Ingeniería Agrícola y Foresta

    The role of iron on the degradation and mineralization or organic compounds using conventional Fenton and photo-Fenton processes

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    The role of iron on the degradation of different organic compounds, differing in their structure (aliphatic versus aromatic) and iron complex formation capacity, by conventional and photo-Fenton processes was investigated. Results show that these chemical characteristics can affect the degree of treatment in terms of COD and TOC removals. While aromatics exhibited a fast and great reduction in the COD by the conventional Fenton process, aliphatic compounds, apart from acetic acid, required the presence of UV light to enhance treatment results. EDTA and oxalic acid responded very positively to UV irradiation in both COD removal and mineralization, reaching the highest values showed by aromatics; and results depended on the intensity of the UV light applied. Phenol and 4-nitrophenol responded favourably to UV irradiation in terms of mineralization and slightly in COD removal. Reductions in the COD were almost total (95.99%), while only an 80% of reduction in the TOC was achieved, for the best photo-Fenton treatment of oxalic acid, phenol and nitrophenol. 60% COD and 40% TOC removals were achieved correspondingly in the case of EDTA. Acetic acid showed almost no mineralization and low COD removal (≈20%) when treated by a conventional Fenton process; and did not enhanced results when assisting the treatment with UV light. Photo-regeneration of ferrous ion and photo-decarboxylation of iron carboxylates are assessed in the framework of these results

    Removal of 1,4-dioxane from industrial wastewaters: routes of decomposition under different operational conditions to determine the ozone oxidation capacity.

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    This paper denotes the importance of operational parameters for the feasibility of ozone (O3) oxidation for the treatment of wastewaters containing 1,4-dioxane. Results show that O3 process, which has formerly been considered insufficient as a sole treatment for such wastewaters, could be a viable treatment for the degradation of 1,4-dioxane at the adequate operation conditions. The treatment of both synthetic solution of 1,4-dioxane and industrial wastewaters, containing 1,4-dioxane and 2-methyl-1,3-dioxolane (MDO), showed that about 90% of chemical oxygen demand can be removed and almost a total removal of 1,4-dioxane and MDO is reached by O3 at optimal process conditions. Data from on-line Fourier transform infrared spectroscopy provides a good insight to its different decomposition routes that eventually determine the viability of degrading this toxic and hazardous compound from industrial waters. The degradation at pH>9 occurs faster through the formation of ethylene glycol as a primary intermediate; whereas the decomposition in acidic conditions (pH<5.7) consists in the formation and slower degradation of ethylene glycol diformate

    Evaluation of MF and UF as pretreatments prior to RO applied to reclaim waste water for fresh water substituion in a paper mill: A practical experience

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    A pilot plant study has been carried out to compare the effectiveness of different low pressure membrane systems (microfiltration and ultrafiltration) as pretreatments for a reverse osmosis system producing high quality reclaimed water from the effluent of a municipal wastewater treatment plant receiving a high percentage of industrial wastewater. The reclaimed water will be used to substitute fresh water in a paper mill. Although the implemented systems showed several problems derived from the unstable quality of the feed water, they were solid enough to keep a constant permeate quality; i.e. percentages of salt rejection above 99%, efficiencies in the removal of microorganisms to lower values than 1 CFU/100 mL, and final COD results below the detection limit (<5 mg L−1). In short, the quality of the produced reclaimed water was good enough to be used substituting fresh water in a paper mill. An enhanced monitoring of the quality of the water feeding the municipal wastewater treatment plant and an improved corresponding management of the treatments performed in there may be one of the keys to the success of this type of reclamation initiatives. Achieving constant disinfection, an appropriate design of the plants, and a good performance of cleaning operations were very important factors to be considered in order to fight against fouling. Temperature and the soaking time of chemical membrane cleanings were particularly well-optimized for the success of the treatment. Chloramines were compared to free chlorine as disinfection agent achieving satisfactory results

    Influence of Water Quality on the Efficiency of Retention Aids Systems for the Paper Industry

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    It has been reported that about 10-15% of the fresh water intake in a paper mill is used for feeding and diluting retention aids, so significant savings could be achieved by replacing fresh water with process water. Water from different sources and qualitiessfresh water, the outflow from an internal ultrafiltration placed in the machine circuit of a paper mill, and water from a membrane bioreactor used to treat the final effluent of this paper millswere used to prepare a dual retention system consisting of a cationic polyacrylamide and bentonite. While the behavior of bentonite was not significantly affected by the quality of the water used in its preparation, the efficiency of the cationic polyacrylamide was reduced to about 12% when it was prepared with water with high anionic trash content and conductivity as a result of a partial neutralization of the charged groups. The effect of nonionic chemical oxygen demand on the efficiency of the polymer was negligible

    Treatment of a mature landfill leachate: Comparison between homogeneous and heterogeneous photo-fenton with different pretreatments

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    Producción CientíficaThis study focuses on the treatment of a mature landfill leachate by coagulation and photo-Fenton at different conditions. Optimal coagulation is carried out with ferric chloride in acid conditions; and with alum in near-neutral conditions, to minimize the use of sulphuric acid for pH adjustment (1 g/L vs. 7.2 g/L), the generation of sludge and the increase of conductivity in the final effluent. In both cases, a similar chemical oxygen demand (COD) removal is obtained, higher than 65%, which is high enough for a subsequent photo-Fenton treatment. However, the removal of absorbance at 254 nm (UV-254) was significantly higher with ferric chloride (83% vs. 55%), due to the important removal of humic acids at acid pH. The best results for coagulation are 2 g/L ferric chloride at initial pH = 5 and 5 g/L alum at initial pH = 7. After coagulation with ferric chloride, the final pH (2.8) is adequate for a homogeneous photo-Fenton using the remaining dissolved iron (250 mg/L). At these conditions, using a ratio H2O2/COD = 2.125 and 30 min contact time, the biodegradability increased from 0.03 to 0.51. On the other hand, the neutral pH after alum coagulation (6.7) allows the use of zero valent iron (ZVI) heterogeneous photo-Fenton. In this case, a final biodegradability of 0.32 was obtained, after 150 min, using the same H2O2/COD ratio. Both treatments achieved similar results, with a final COD, UV-254 and color removal greater than 90%. However, the economic assessment shows that the approach of ferric chloride + homogeneous photo-Fenton is much cheaper (6.4 €/m3 vs. 28.4 €/m3). Although the discharge limits are not achieved with the proposed combination of treatments, the significant increase of the pre-treated leachate biodegradability allows achieving the discharge limits after a conventional biological treatment such as sequencing batch reactor, which would slightly increase the total treatment cost.Ministerio de Economía, Industria y Competitividad (project CTM2016-77948-R

    The application of advanced oxidation technologies to the treatment of effluents from the pulp and paper industry: a review

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    Producción CientíficaPaper industry is adopting zero liquid effluent technologies to reduce fresh water use and meet environmental regulations, which implies water circuits closure and the progressive accumulation of pollutants that must be removed before water re-use and final wastewater discharge. The traditional water treatment technologies that are used in paper mills (such as dissolve air flotation or biological treatment) are not able to remove recalcitrant contaminants. Therefore, advanced water treatment technologies, such as advanced oxidation processes (AOPs), are being included in industrial wastewater treatment chains aiming to either improve water biodegradability or its final quality. A comprehensive review of the current state of the art regarding the use of AOPs for the treatment of the organic load of effluents from the paper industry is herein addressed considering mature and emerging treatments for a sustainable water use in this sector. Wastewater composition, which is highly dependent of the raw materials being used in the mills, the selected AOP itself, and its combination with other technologies, will determine the viability of the treatment. In general, all AOPs have been reported to achieve good organics removal efficiencies (COD removal >40%; and about an extra 20% if AOPs are combined with biological stages). Particularly, ozonation has been the most extensively reported and successfully implemented AOP at an industrial scale for effluent treatment or reuse within pulp and paper mills; although Fenton processes (photo-Fenton particularly) have actually addressed better oxidative results (COD removal ≈65-75%) at lab scale, but still need further development at large scale.Comunidad Autónoma de Madrid - (Proyecto P-2009/AMB/1480)Ministerio de Ciencia e Innovación - (Proyecto CIT-310000-2008-15

    Drivers and economic aspects for the implementation of advanced wastewater treatment and water reuse in a PVC plant

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    AbstractThis paper shows the economic feasibility of water reuse within a polyvinyl chloride (PVC) plant. A two-step treatment of the current primary effluent consisting of an aerobic membrane bioreactor followed by a double pass reverse osmosis process, validated at pilot scale, was used to estimate the costs of the industrial water treatment plant. The economic feasibility of the treatment and reuse concept remained unclear because the required investment of 2.5M€ was high and the discounted payback time of 5 years was long.The proposed solution is profitable for sites where fresh demineralized water production costs are currently higher than 1.5€/m3 and the required flow of the recycled water exceeds 50m3/h. The water reuse concept allows decoupling the production from fresh water use. In this case, anticipating that a drought would lead to a 3% reduction of the production, the amortization period would be lowered to one year

    Optimization of the Fenton treatment of 1,4-dioxane and on-line FTIR monitoring of the reaction

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    1,4-dioxane is a non-biodegradable, toxic, hazardous, and priority pollutant widely used in the chemical industry as a solvent; as well as it is a resulting by-product of many industrial processes. The optimization of the Fenton treatment of 1,4-dioxane, and the on-line FTIR monitoring of its degradation route, including the assessment of the enhancement of the 6 biodegradability of the solution along treatment are herein addressed. Besides the full removal of 1,4-dioxane, an 80% reduction of the chemical oxygen demand (COD) was achieved at the best tested treatment conditions. Whether the used concentration of H2O2 was expectedly addressed as the reaction factor most influencing the achieved COD removal at the end of the process; the performance of the treatment under acid pH conditions showed to have just a slight influence, thus supporting this process may suitably be performed at neutral pH value. On-line FTIR monitoring of the process novelly provided the degradation route of 1,4-dioxane along its oxidation treatment, as well as a comprehensive optimization of the Fenton process based on the increase of the biodegradability of the solution and the reduction of the consumption of reagents

    Comparison of ultrafiltration and dissolved air flotation efficiencies in industrial units during the papermaking process

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    The efficiency of an ultrafiltration unit has been studied and compared with a dissolved air flotation system to get water with a suited quality to be reused in the process. The study was done at a paper mill producing light weight coated paper and newsprint paper from 100% recovered paper. Efficiency was analysed by removal of turbidity, cationic demand, total and dissolved chemical oxygen demand, hardness, sulphates and microstickies. Moreover, the performance of the ultrafiltration unit and the membranes were studied deeply, analysing its variability during the filtration process. As expected, the ultrafiltration gave higher removal efficiencies than the dissolved air flotation cell in parameters like turbidity, cationic demand, dissolved chemical oxygen demand and microstickies. The greatest difference in performance between the units concerned cationic demand and dissolved chemical oxygen demand. Ultrafiltration was influenced by the operating time, decreasing the removal efficiency of the dissolved fraction by 75% and of the colloidal fraction by 30% after 312 of running. Membrane autopsy, carried out to identify the cause of poor membrane performance, showed that the active layer was degraded due to the effect of suspended solids
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