Application of multi-barrier membrane filtration technologies to reclaim municipal wastewater for industrial use

Producción CientíficaThe significant percentage of the world water consumption devoted to industrial use, along with an increasingly higher environmental concern of society, has awaken the interest of industry on using municipal reclaimed water for replacing fresh water use coming from utilities or natural resources. Depending on the type of industry and the specific application, water must meet certain quality requirements. Therefore, those water quality standards that are required for those most relevant industrial applications wherein the use of reclaimed water has noticeably been reported are herewith reviewed. Although the use of internal water treatments for recycling and reusing their own effluents has recently and widely been reported within many industrial sectors worldwide, the substitution of fresh water by reclaimed municipal wastewater has yet to be extended much. The increasing proportion of municipal wastewater reclamation plants that rely on membrane filtration technologies versus the total number of reclamation facilities that are distributed worldwide is also assessed within this review, including the discussion of their main related drawbacks.Comunidad Autónoma de Madrid - (Proyecto S-0505/AMB-0100)Ministerio de Ciencia e Innovación - (Proyecto CTM2008-06886-C02- 01)Unión Europea - (Project 211534

Drinking Water Problems: Nitrates

8 pp., 7 figuresHigh levels of nitrates in drinking water can be harmful for very young infants and susceptible adults. This publication explains how people are exposed to nitrates, what health effects are caused by them in drinking water and how to remove them

Drinking water nanofiltration with concentrate foam fractionation-A novel approach for removal of per- and polyfluoroalkyl substances (PFAS)

Per-and polyfluoroalkyl substances (PFAS) are recognized as persistent pollutants that have been found in drinking water sources on a global scale. Semi-permeable membrane treatment processes such as reverse osmosis and nanofiltration (NF) have been shown effective at removing PFAS, however, disposal of PFAS laden concentrate is problematic. Without treatment of the concentrate, PFAS is released into the environment. The present work examined a novel PFAS removal scheme for drinking water using NF filtration with treatment of the resulting NF concentrate via foam fractionation (FF) with and without co-surfactants. The NF-pilot removed 98% of PFAS from AFFF contaminated groundwater producing permeate with 1.4 ng L-1 total PFAS. Using FF resulted in EPFAS removal efficiency of 90% from the NF concentrate and with improved removal of 94% with addition of cationic co-surfactant. The resulting foamate composed approximately 2% of the NF feedwater volume and contained greater than 3000 ng L-1 PFAS or 41 times greater than the NF feedwater. Addition of the cationic co-surfactant to the FF process resulted in increased removal efficiency of the shorter chain PFAS, specifically 37% for PFPeA, 9% for PFHxA, and 34% for PFBS thus attaining 59%, 99% and 96% removal efficiency, respectively. PFOA, PFPeS, PFHxS, PFOS each attained 99% FF removal with or without co-surfactant addition

Pore size analysis from retention of neutral solutes through nanofiltration membranes. The contribution of concentration–polarization

Producción CientíficaPore size distribution is one of the most important characteristics of a membrane. This can be obtained from the fitting of pore radius calculated fromretention versus flux measurements for a set of solute solutions. In thiswork a set of non-charged similar molecules is chosen as solutes to minimize other interactions apart of those related to size. The hydrodynamic model will be used to characterize the behavior of the membrane to uncharged solutes, assuming that membrane pores are straight and cylindrical. As is known, the phenomenon of concentration polarization must be taken into account because true retention is not experimentally accessible by concentration measurements. Frequently, the film layer model is applied for the dependence of concentration with experimental conditions; but the application of this model requires prior knowledge of the mass transfer coefficientwhich is evaluated by different dimensionless correlations (Sherwood correlation). Here we show a review of different alternatives in doing it and analyze their consequences when computing the pore size distribution. Experimental data were obtained from dead-end filtration experiments of a set of four ethylene glycol solutions with a nanofiltration membrane. Obtained results show the importance of the mass transfer model in the pore size value obtained.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13

Optimização da instalação de água recuperada e seus consumos

aEstágio realizado na UNICER Cervejas e orientado pelo Eng.º José AleixoTese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 200

Drinking Water Problems: Nitrates

8 pp., 7 figuresHigh levels of nitrates in drinking water can be harmful for very young infants and susceptible adults. This publication explains how people are exposed to nitrates, what health effects are caused by them in drinking water and how to remove them

The evaluation of ozone technology to reduce the concentration of polychlorinated biphenyls (PCBs) in contaminated soil.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.Polychlorinated Biphenyls (PCBs) are hazardous and toxic chemicals to both humans and animals. In the late 1960’s PCBs were discovered to be a harmful pollutant which could cause environmental contamination due to its slow degradation and even trace amounts of PCBs were regarded as toxic to both human and animals. Oil spills are a frequent occurrence at Eskom substations which could contain PCBs. The contaminated sediments which are easily carried away by rain and wind can further contaminate the environment and aquatic bodies. Eskom currently disposes of soil and ballast stones contaminated with PCBs by thermal destruction. This is a costly process as PCBs are regarded as hazardous materials and needs to be safely transported and disposed of at a licensed disposal facility. Based on literature, ozone has been used on a laboratory scale to treat soil contaminated with PCBs with the addition of chemicals such as hexane and acetone which assist in breaking down PCBs. The objective of this study was to evaluate whether ozone without the addition of chemicals could reduce the levels of PCBs present in contaminated soil. In this study, two soil samples and one ballast stone sample were contaminated with 50 ppm, 200 ppm and 600 ppm of PCBs and then exposed to 0.4, 0.5 and 0.6 l/min of ozone for a period of 60 minutes to examine the effects of increasing ozone flow rates on PCB destruction in soil. The results of the experimental tests showed that ozone gas reduced the concentration of PCBs in the soil and ballast stone samples for the different total gas flow rates. The literature study identified that the final products of the ozonation of PCBs are carbon dioxide and water and that any products formed after this process could possibly be degraded by the soil natural microorganisms. Calculations based on the Shin et al. (2004) model proved that ozone was in excess after the ozonation process. The results of the experiments also confirmed this, as the PCB residuals were similar for all three total gas flows, which showed that there was no dependence on the gas flow rates hence, ozone was in excess. The experimental data was then trended with zero, first and second order reaction equations, which showed that the best fit was obtained with the firstorder reaction equation. It is recommended that ozone be used for the treatment of PCB contaminated soil at Eskom substations

Physical and chemical parameter effects of UF pretreatment system

In seawater, plankton and suspended solids causes a problem in operating a seawater pretreatment system. Since such substances are filtered as they pass through pretreatment equipment, the importance of pretreatment emerges. This study used disc filters and UF membranes as the pretreatment equipment. As the processes of filtration and washing were repeated, flow and velocity would change as time passed. So it seems that steady experimental conditions not be achieved. This study conducted a fouling analysis using two flow conditions: constant r.p.m and constant flow rate regarding the conditions of flow in the process of filtration. For the fouling analysis, TMP(Trans Membrane Pressure) and permeability were analysed, and turbidity and SDI(Silt Density Index) value were compared. Each specimen was sampled, measured and compared using a measuring instrument.Abstract 그림목차 표 목차 제 1 장 서 론 1.1 연구배경 1.1.1 역삼투 해수담수화 플랜트 1.1.2 UF 전처리 시스템 1.2 연구목적 제 2 장 디스크 필터와 UF 분리막 2.1 디스크 필터 2.1.1 디스크 필터 여과 공정 2.1.2 오염 및 세정 2.2 UF 분리막 2.2.1 분리막의 분류 2.2.2 막여과 공정 2.2.3 막의 특성 2.2.4 오염 및 세정 2.3 취수설비 제 3 장 실험장치 및 방법 3.1 실험장치 구성 3.1.1 취수부 3.1.2 전처리 시스템 3.2 실험방법 3.2.1 전처리 성능실험 3.2.2 UF막의 운전 3.2.3 Parameter 측정방법 제 4 장 실험결과 및 고찰 4.1 차압과 투수율 및 저항 4.2 탁도와 SDI 4.3 Parameters 제 5 장 결 론 참 고 문

Transformação de melancia com o gene da capa proteica do Zucchini yellow mosaic virus e comparação com a cultivar parental

The objective of this study was to transfer Zucchini yellow mosaic virus coat protein (ZYMV-CP) gene to watermelon cultivar Crimson Sweet (CS) genome, and compare the transgenic T1 and T2 progenies with nontransformed parental cultivar for morphological, pomological, growth and yield characteristics. The ZYMV-CP gene was transferred by Agrobacterium tumefaciens, and the presence of the gene in transgenic T0, T1 and T2 plants was determined by polymerase chain reaction, and the results were confirmed by Southern blot. Two experiments were conducted in two different dates. In both experiments, hypocotyl length of transgenic seedlings was significantly higher than that of nontransgenic parental ones. In the second experiment, the differences between transgenic and nontransgenic individuals were significant concerning fruit rind thickness, flesh firmness, fruit peduncle length, size of pistil scar, fruit strip or flesh color a* values. In conclusion, transferring ZYMV-CP gene to CS genome affected only a few characteristics from 80 traits that have been examined. The changes in rind thickness, flesh firmness and flesh color a* value were favorable while size of pistil scar was undesirable. Together, it may be concluded that transgenic watermelon line having ZYMV-CP gene and parental cultivar CS are very similar.O objetivo deste trabalho foi transferir o gene da capa proteica do Zucchini yellow mosaic virus (ZYMV‑CP)e o gene neomycin phosphotransferase II (NPT II) para o genoma da melancia ‘Crimson Sweet’ (CS), e comparar asprogênies T1 e T2 com a cultivar parental não transformada, quanto às características morfológicas, pomológicas, de crescimento e de produção. O gene ZYMV‑CP foi transferido por meio da transformação com Agrobacterium tumefaciens. A presença do gene nas plantas transgênicas T0, T1 e T2 foi determinada pela reação de polimerase em cadeia, e os resultados foram confirmados pelo “Southern blot”. Dois experimentos foram realizados, um no inverno-primavera e outro no verão-outono. Nos dois experimentos, o comprimento do hipocótilo das plântulas transgênicas foi significativamente maior do que nas plântulas não transgênicas. No segundo experimento, asdiferenças entre as plantas transgênicas e não transgênicas foram significativas quanto à espessura da casca das frutas, firmeza da polpa, comprimento do pedúnculo, tamanho da cicatriz do pistilo, e valores a* da cor das listras ou da polpa. A transferência do gene da capa proteica ZYMV‑CP ao genoma CS afetou apenas algumas características, das 80 avaliadas. As alterações na espessura da casca, firmeza e cor da polpa são favoráveis, enquanto o aumento no tamanho da cicatriz do pistilo é indesejável . A linhagem transgênica de melancia com o gene ZYMV‑CP e a cultivar parental CS são muito similares