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Evaluation Of An On-line Device To Monitor Scale Formation In A Brackish Water Reverse Osmosis Membrane ProcessRoque, Jennifer C 01 January 2012 (has links)
A modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city of Sarasota’s Public Works and Utilities (City) water treatment facilities located in Sarasota, Florida. During the time-frame of this study, the City was in the process of eliminating their sulfuric acid feed from the pretreatment system of their existing 4.5 million gallon per day (MGD) RO membrane process. The City was motivated to eliminate its dependence on sulfuric acid to reduce operating costs as well as reduce operation health and safety risks associated with the use of the acid as a pretreatment chemical. Because the City was concerned with secondary process impacts associated with acid elimination, additional measures were desired in order to protect the full-scale process. This thesis reports on the design, fabrication and installation of a third-stage two membrane element pressure vessel “canary” sentinel monitoring device (Canary), its effectiveness as an online scaling monitor during full-scale acid elimination, and presents the results of the study. The Canary sentinel device was controlled using the normalized specific flux of the two membrane elements fed by a portion of the second stage concentrate of one of the City’s full-scale RO process skids. Although the Canary demonstrated the ability to detect changes in an RO process operation, scaling did not occur under the conditions evaluated in this study. An autopsy of one iv of the Canary elements revealed that no scaling had occurred during the acid elimination process. Therefore, the Canary was found to be useful in its function as a sentinel, even though no scaling was detected by the device after acid elimination at the City’s full-scale plant had been accomplished.
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Zein, Collagen and PVA polymer fibre blends embedded with metal (Mn and Fe) oxide nanoparticles for wastewater treatmentKubheka, Nompumelelo Sharol Mbali 09 1900 (has links)
M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences) Vaal University of Technology. / The polymer and their blended fibres provide good surface and intermolecular chemistry that bring additional functionalities and structural changes that can be adapted for new usages. Natural polymers are known to possess desirable qualities in terms of biocompatibility and biodegradability. The natural polymers are chosen due to their abundance but have difficulties in the preparations hence the addition of a synthetic polymer is vital. An important property of the polymer blended fibres is its miscibility which affects the mechanical properties, the morphology and degradation. Metal oxide nanoparticles embedded into polymer blended fibres enhances the performances of the polymer blended fibre permeability, selectivity, strength, and hydrophilicity. This study reports on the synthesis and characterization of zein, collagen nanofibres, zein/PVA fibre blends, iron oxide, manganese oxide nanoparticles, Fe2O3/zein /PVA and Mn2O3/zein/PVA fibre nanocomposite blends. The zein nanofibres and zein/PVA fibre blends were electrospun using electrospinning technique. Parameters such as the concentration and voltage were investigated. These parameters had an effect on the fibre morphology. The electrospun zein nanofibres and zein/PVA fibre blends were characterized using scanning electron microscopy (SEM), UV-Visible spectroscopy, Photoluminescence (PL), X-ray diffraction (XRD), Fourier transformer infrared (FTIR) spectroscopy and Thermal gravimetric analysis (TGA). The SEM results illustrated that an increase in the concentration of zein nanofibres improved the morphology of the fibres into ribbon like shape and had an effect on the average diameter size. The addition of PVA into zein nanofibres enhanced electrospinnabilty and the mechanical strength of zein was dependent on the presence of PVA. The optical properties, XRD, FTIR and thermal studies confirmed that zein/PVA (80/20) blend weight ratio was miscible and the other blend weight ratios remained immiscible, this was due to stronger interaction of hydrophilic performance of zein and PVA through hydrogen bonding. Therefore, fibre blend weight ratios of zein/PVA (90/10, 80/20, 70/30, 60/40 and 50/50) were successfully fabricated. The optimisation of collagen nanofibres favoured electrospraying instead of electrospinning hence collagen nanofibres could not be fabricated.
Iron oxide nanoparticles was synthesized using hydrothermal method and manganese oxide nanoparticles was synthesized through co-precipitation method. The TEM results revealed well defined shapes of metal oxide nanoparticles illustrating that the increment of temperature had an influence on the crystallinity and particle size of 𝛼-Fe2O3 , 𝛼-MnO2 and 𝛼-Mn2O3 nanoparticles. The XRD confirmed the crystalline pattern of the metal oxide nanoparticles were of rhombohedral 𝛼-Fe2O3 structures (JCPDS 00-033-0664), cryptomelane phase 𝛼-MnO2 (JCPDS No. 29-1020) and orthorhombic crystalline phase of 𝛼-Mn2O3 (JCPDS No. 04-007-088). The metal oxide nanoparticles were thermally stable. Three different concentrations (4.25 wt%, 4.75 wt% and 5.25 wt %) of 𝛼-Fe2O3 and 𝛼- Mn2O3 were embedded onto zein/PVA (80/20) fibre blends and electrospun. The SEM, optical properties, XRD and TGA confirmed that the embedment of metal oxide nanoparticles enhanced the zein/PVA fibre blends performance, mechanical strength and resistance to wear therefore 5.25 wt% of 𝛼-Fe2O3/zein/PVA and 𝛼-Mn2O3/zein/PVA were explored further for the adsorption of chrysoidine G removal from wastewater. The adsorption studies of zein/PVA (80/20), 𝛼-Fe2O3/zein/PVA and 𝛼-Mn2O3/zein/PVA were carried out in a batch system on the effects of contact time, pH, initial concentration and adsorbent dosage. All the nanoadsorbents could rapidly reach adsorption equilibrium within 30 min at room temperature. The maximum removal efficiency of chrysoidine G of zein/PVA, 𝛼-Mn2O3/zein/PVA was higher than 𝛼-Fe2O3/zein/PVA. The dye adsorption equilibrium data were well-fit with Langmuir isotherm rather than Freundlich isotherm. The comparison of kinetic models revealed that the overall adsorption process was described well by pseudo second-order kinetics. The polymeric materials were cost effective hence regeneration studies were implemented for three cycles. These nanoadsorbents are easily available and are expected to be economical.
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Adsorption of Cr(VI) by iron oxide functionalized polyethyleneimine (PEI) coated activated carbon-silica compositesQhubu, Mpho Cynthia 14 December 2020 (has links)
M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Water scarcity due to limited resources and pollution of the little available water by organic and inorganic contaminants remains as one of the critical issues of the 21st century. Several treatment methods have been developed, with some being used successfully at industrial scale but many challenges including secondary sludge generation, high operation costs, high maintenance costs and high energy input were observed. In this study, the adsorption process was explored as an effective means for the removal of Cr(VI) ions from aqueous solution due to its economic feasibility and use of abundantly available adsorbents. Amongst the many available adsorbents, this work focused on exploring functionalized activated carbons (ACs) as adsorbents for Cr(VI) ions due to their favorable adsorption characteristics which involve large surface area, high porosity, and high radiant stability. The iron oxide functionalized polyethyleneimine activated carbon-silica composites were prepared through co-precipitation of Fe(II) and Fe(III) over Macadamia activated carbon to form the AC-Fe3O4 co-shell which was reacted with tetraethylorthosilicate (TEOS) and the polyethyleneimine (PEI). The different adsorbents prepared were labelled AC-Fe3O4, AC-Fe3O4-SiO2 and AC-Fe3O4-SiO2-PEI. The adsorbents were further characterized using elemental analysis (CHNS), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET), transmission electron spectroscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). FTIR displayed successful attachment of Fe3O4 and SiO2 with bands at 404 and 786 cm-1 being assigned to the asymmetric vibration of Fe-O and Si-O-Si while the asymmetric stretch of Si-OH is observed at 1066 cm-1. XRD showed the presence of magnetite particles in the adsorbents confirmed by the JCPDS 00-019-0629. EDS revealed the presence of Fe, Si, and N atoms which can relate to successful incorporation of the desired functional groups. Each of these materials were evaluated for their Cr(VI) ion removal through batch adsorption experiments where one parameter at a time was varied while all others were fixed. The parameters investigated included the effect of pH, contact time, initials Cr(VI) concentration, adsorbent dosage concentration and temperature. The optimum conditions were obtained at pH 3, initial concentration 2.5 mg/L, contact time of 120 min for AC-Fe3O4-SiO2-PEI. The optimization of each parameter was done in order to determine the conditions in which the adsorbents work best in the uptake of Cr(VI). All the three studied adsorbents showed acceptable adsorption performance for the removal of Cr(VI) from aqueous solutions. Adsorption isotherms studied confirmed that the adsorption data in all the three adsorbents fitted well into the Langmuir isotherm, demonstrating a homogeneous monolayer coverage. Regarding the kinetic studies, the adsorption data were best described by the pseudo-second order rate model with R2 values of 0.974, 0.974 and 0.962 for AC-Fe3O4, AC-Fe3O4-SiO2 and AC-Fe3O4-SiO2-PEI, respectively. The adsorption capacity observed from the present study (6.62, 3.92 and 5.48 for AC-Fe3O4, AC-Fe3O4-SiO2 and AC-Fe3O4-SiO2-PEI, respectively) were satisfactory and suitable as compared to those reported in literature. Thermodynamics data of the adsorption processes revealed a feasible spontaneous endothermic adsorption process which also confirmed that the reaction process occurred through chemisorption.
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Synthesis of gelatin-cellulose hydrogel membrane for copper and cobalt removal from synthetic wastewaterLukusa, Tresor Kabeya 04 1900 (has links)
M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / Heavy metal ions are one of the most toxic materials in the environment. Adsorption is the most used process for the removal of heavy metals from wastewater. Much research has been conducted into processes to remove heavy metals using different adsorbents. Various adsorbents have been used to remove heavy metal ions from wastewater especially those that are harmful to mankind. Zeolite, clay, activated carbon and biopolymers are the most common adsorbents used.
In this research, gelatin, and cellulose nanocrystals (CNCs) were used to synthesize a hydrogel membrane to remove Cu(II) and Co(II) metal ions from mining processes wastewater. The synthetic wastewater was prepared in the laboratory to conduct the experiments. Batch experiments were conducted to obtain the optimum conditions for the Cu(II) and Co(II) metal ions. The effect of parameters such as pH, ratio, contact time, and temperature were also determined.
The optimum conditions obtained were 120 min contact time for both metal ions at the temperature of 30oC, pH 5 for copper and pH 7 for cobalt. The high removal of both metals ions was obtained using the ratio 3:1 (75% Gelatin and 25% CNCs) at the temperature of 303K. The maximum adsorption capacity of Cu(II) and Co(II) was 7.6923 mg/g and 10.988 mg/g, respectively. The high percentage removal of Cu(II) and Co(II) metal ions obtained was found to be 70.5% for Cu(II) at pH 5 and 74.5% for Co(II) at pH 7. The experimental data fit well to Pseudo-first-order kinetic and Freundlich isotherm models (KF= 1.89x103 mg/g for copper and 3.7x102 mg/g for cobalt) for both metal ions. The values of energy (E) from D-R model have shown that the adsorption of both metal ions was of physical nature (E<8kJ/mol) then confirmed by the thermodynamic results (ΔH°). The kinetic diffusion models have shown that the experimental data fit well with the film diffusion (R2= 0.977 and 0.989) for both metal ions at pH 5. Negative values of ΔG°obtained for both metal ions indicate that the adsorption process was spontaneous. The positive values of ΔH° obtained showed a physical adsorption process and also indicate that the adsorption process of both metal ions was endothermic. The positive values of ΔS° indicate an increase in randomness at the solid/solution interface during adsorption.
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Determining the efficiency of selected vegetated biofilters in reducing nutrients from urban stormwater in the city of Ekurhuleni, South AfricaBvumbi, Mulalo Justice 11 1900 (has links)
M. Tech. (Department of Civil Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / Over time, the quality standard of stormwater in the City of Ekurhuleni (CoE) has deteriorated due to industrial, commercial, residential and farming activities. Stormwater quality directly impacts the treatment chain of potable water, and therefore, it should be kept in check at all stages. Innovations in the biofiltration process can provide useful, practical solutions to overcome crucial stormwater pollution problems. In 2013, the CoE developed stormwater design guidelines and standards to be implemented for the design of stormwater management, which include the principles of Water Sensitive Urban Design (WSUD) and Sustainable Urban Drainage Systems (SuDS) in particular. The CoE stormwater design guidelines and standards do not provide details on how the city plans to implement SuDS treatment trains to reduce stormwater pollution experienced by the city. This study aimed to verify the efficiency and effectiveness of vegetated biofilters on the stormwater treatment using CoE – Olifantsfontain's natural stormwater and to determine the most suitable vegetation to be used in the region. The CoE experimental case study was conducted to assess the efficiency of selected vegetated biofilters in lowering the concentration of orthophosphate (PO4-3), ammonium (NH4+), and nitrate (NO3-) from Tembisa/Olifantsfontain stormwater.
In the experimental setup, six selected plant species were planted into 30 vegetated biofilter columns, namely: Agapanthus praecox (Dryland plant), Carpobrotus edulis (Dryland plant), Stenotaphrum secundatum (Dryland plant), Zantedeschia aethiopica (Wetland plant), Typha capensis (Wetland plant) and Phragmites australis (Wetland plant). The six species were grouped according to general habitats, i.e. three wetland and three dryland plants. Wetland plants were planted into fifteen vegetated biofilters, and dryland plants were also planted on another fifteen vegetated biofilters. The biofilters contained layers of sandy loam soil, coarse and and gravel sand. Each biofilter had a designated inlet and outlet section fitted with a gate valve to control retention time. The raw stormwater consisting of natural nutrient pollutants was applied to each vegetated biofilter through the inlet section. The samples were collected from the inlet and outlet of the six grouped vegetated biofilters during the month of June. All six plant species reduced outflow concentrations of PO4-3 and NH4+ by an average of 99% and 98%, respectively. The results also show that all plant species excluding Phragmites australis were able to reduce NO3- with outflow concentrations being reduced by an average of 58%.
From the results obtained, it may be concluded that all the six plant species may be suitable variants to be applied as biofilter material for the purposes of treating urban stormwater in the CoE. The reason is that the determined removal efficiencies for bio-retention fall within 50% – 60% for PO4-3, and 40% - 50% for NH4+ and NO3- respectively. The results also show that if the plant species were applied for SuDs in the CoE, there could be a great improvement in the urban stormwater quality with the consequent improvement in both surface and groundwater quality of the receiving water bodies in the area. Regardless of the nutrient removal by selected plant species, the inclusion of vegetation in a field setting would slow flow rates and thus encourage infiltration into the soil, improve water quality, and support urban biodiversity. In the CoE, all the selected species could be used in the SuDS treatment trains targeting PO4-3, NH4+ and/or NO3-. The case study results provide a informed records for the CoE in the future/intended application SuDs in the upgrade/rehabilitation of its stormwater system.
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The fabrication of ClNCNTs/Fe3O4 nanoparticles for the removal of Pb2+ ions in aqueous solutionSebake, Morongwa Sowela Mary-Jane 13 December 2021 (has links)
M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Removal of wastewater pollutants is urgent as they are continuously defiling the limited
freshwater resources, affecting the ecosystem, aquatic and terrestrial life. Carbon nanotubes-based adsorbent materials are effective for removal of wastewater pollutants owing to their large specific surface area. Surface modification of carbon nanotubes (CNTs) can mediate specific pollutant adsorption and increase CNTs colloidal stability and chemical reactivity. Heavy metal pollution of wastewater is one of the major threats, as this metals can be toxic to humans when present at certain concentrations in drinking water. This study report the synthesis of chlorine functionalized and nitrogen doped carbon nanotubes (ClNCNTs) loaded with iron oxide nanoparticles and their use as adsorbents for Pb2+ ions in aqueous solutions. Carbon nanomaterials that are functionalized with chlorine and doped with nitrogen were successfully synthesized. This was done through pyrolysis of a mixture of dichlorobenzene and acetonitrile (in a 1:1 volume ratio) over 10% Fe-Co/CaCO3 bi-metallic catalyst via chemical vapour deposition (CVD) method. Addition of chlorine and nitrogen to the CNTs was to enable defect and disorder creation on the surface of the nanotubes which is envisaged to create nucleation sites on the their surface for better adhesion of the iron oxide nanoparticles. Different loadings of magnetite (Fe3O4) nanoparticles on the surface of the ClNCNTs was achieved using a co-precipitation method. The synthesized materials were charaterized by Raman spectroscopy, Transmission electron microscopy (TEM), Powder X-ray diffraction
(PXRD) spectroscopy, Thermal gravimetric analysis (TGA), Brunauer Emmett and Teller
(BET) and X-ray photoelectron spectroscopy (XPS). Highly defected CNTs, some with hollow and others with bamboo-compartments due to nitrogen inclusion were obtained.
The effect of metal salt concentration in wt.% (10, 20, 30 and 53 wt.%) was investigated. The increase in wt.% loading has resulted in an increase in surface area, and a decrease in thermal stability as a result of defected Fe3O4/ClNCNTs. In addition, agglomeration was observed at 30 and 53 wt.% loading, due to large amount of iron present. The identity of the Fe3O4 nanoparticles was confirmed by PXRD and XPS with two iron peaks deconvoluted at 725.6 eV and 721 eV respectively. The percentage loading of the Fe3O4 nanoparticles at the surface of the ClNCNTs was affirmed by TGA analysis, where the residual mass obtained from TGA were closely related to the mass percentages added. Different nitrogen environments namely, the quatenary, pyridinic, pyrollic and nitrogen oxides were also observed, whilst chlorine could not be deconvoluted because it was present in very limited amount probably it was masked by the iron oxide nanoparticle. Thus, a 20 wt.% Fe3O4/ClNCNTs was chosen as an optimum, due to uniform distribution of spherical nanopaticles observed along the radial length of ClNCNTs that had an average size of 10 ± 4.5 nm. The synthesized ClNCNTs and a nanocomposite made
from a 20 wt.% Fe3O4/ClNCNTs were applied in the removal of Pb2+ ions from aqueous
solution. The results obtained showed that a nanocomposite made from a 20 wt.%
Fe3O4/ClNCNTs had a better adsorption capacity of 17.0 mg/g as compared with 14.8 mg/g for ClNCNTs.
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Adsorption studies of toxic metal ions (Co(II), Ni(II), Cu(II), Cr(VI) and Pb(II)) and methylene blue using black cumin (Nigella sativa L.) seedsThabede, P. M. January 2021 (has links)
PhD (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / High levels of pollutants in water are found to have poisonous effects on human health. Due to increasing awareness about the environment and strict environmental regulations, wastewater treatment has become a very important aspect of research. Thus, this makes the adsorption of pollutants an urgent matter. The aim of this research was to investigate the adsorption capacity of black cumin seeds in the removal of cobalt-Co(II), nickel-Ni(II), copper-(II), chromium-Cr(VI), lead-Pb(II), and methylene blue (MB) dye from aqueous solution. In this research work the black cumin seeds were reacted with sodium hydroxide (NaOH), hydrochloric acid (HCl), phosphoric acid (H3PO4), potassium permanganate (KMnO4) and sulfuric acid (H2SO4). Thereafter it was carbonized at 200 and 300 °C and functionalized with magnetite-sucrose nanoparticles and further carbonized at 600 °C to improve the adsorption capacity of the materials towards different pollutants.
The seeds were characterized by scanning electron microscopy (SEM), thermogravimetric analyser (TGA), X-ray diffractometer (XRD), Brunauer, Emmett and Teller (BET) and Fourier transformed infrared (FTIR) spectroscopy. The SEM images showed that the surface morphology of the treated adsorbents was more porous and had cavities more than the starting material. The TGA profile showed a major weight loss between 198-487 °C which was due to disintegration of cellulose, lignin and hemicellulose. The XRD spectra of adsorbents showed broad peaks at 2θ value of 21° associated crystalline lignocellulose content. FTIR results showed that the adsorbents had functional groups such as hydroxyl (-OH), carboxyl (-COOH), amide (-NH) and carbonyl (-C=O). The BET surface area of pristine black cumin seeds was 2.7 m2/g and increased after treatment with KMnO4 and H3PO4 to 10.1 and 9.3 m2/g respectively. The surface area of the carbon black cumin seeds was 11.67 m2/g whilst the activation of carbon from black cumin seeds with 10 and 20% H2SO4 gave the surface area of 20.14 and 21.54 m2/g respectively. The seeds activated with 20% H2SO4 showed larger pore width of 7.13 nm compared to 6.81 and 3.78 nm after treatment with 10% H2SO4 and carbon black cumin seeds respectively. The results show that there is an increase in surface area and pore size for both 10 and 20% H2SO4 in comparison with carbon black cumin seeds.
The adsorption of Co(II), Ni(II), Cu(II), Cr(VI) and Pb(II) and MB in the solution was investigated by studying the effect of initial concentration, contact time, temperature and pH. The batch adsorption experiments were conducted using different ion solution concentrations of 20, 40, 60, 80 and 100 mg/L, contact time was determined at intervals of 1, 5, 10, 15, 20, 30, 60, 90 and 120 min, while temperature was studied at 298, 303, 313, 333 and 353 K. On the other hand, the effect of pH on all solutions was studied at pH 1, 3,5,7 and 9. The results showed that the acid treated black cumin seeds (AT-BCS) and base treated black cumin seeds (BT-BCS) were successfully used for quaternary adsorption study of Cu(II), Co(II), Pb(II) and Ni(II) ions from aqueous solution. The results for the adsorbents indicated that the BT-BCS adsorbed more metals than AT-BCS and the UT-BCS. The maximum capacity for BT-BCS was 190.7 mg/g for Cu(II) whilst AT-BCS and UT-BCS showed capacities of 180.1 and 135 mg/g respectively for Pb(II).
The uptake of Cr(VI) and Cd(II) ions onto pristine black seeds (PBS), KMnO4 black seeds
(KMBS) and H3PO4 black seeds (H3BS) treated adsorbents showed that the trend for Cr(VI) ions was KMBS>H3BS>PBS with capacities of 16.12, 15.98 and 10.15 mg/g respectively. Meanwhile the adsorption of Cd(II) ions showed maximum capacities of 19.15, 19.09 and 16.80 mg/g for KMBS, H3BS and PBS respectively. Carbon from black cumin (CBC) seeds was modified with 10 % and 20 % sulfuric acid (H2SO4) then carbonized at 200 °C to obtain the activated adsorbents of ACBC-10 and ACBC-20. The new adsorbents were used for the adsorption of Cd(II) and methylene blue (MB). The adsorbents maximum trend for Cd(II) was ACBC-10>ACBC-20>CBC meanwhile the trend for methylene blue (MB) dye was ACBC-20>ACBC-10>CBC. The overall capacities showed that the prepared materials adsorbed more MB dye (16.42 mg/g) than Cd(II) ions (13.65 mg/g). The preparation of carbon from black cumin seeds (BCC) and activation with 10 and 20 % sulfuric acid (H2SO4) at 300 °C to obtain new adsorbents namely (BCAC-10) and (BCAC-20) respectively was used for the adsorption of Pb(II) ions and MB dye from aqueous solution. The maximum adsorption of Pb(II) ions was 17.19, 17.71 and 17.98 mg/g onto BCC, BCAC-10 and BCAC-20 respectively. Whilst for MB dye it was 11.63, 12.71 and 16.85 mg/g onto BCC, BCAC-10 and BCAC-20 respectively. The utilization of pristine Nigella Sativa (PNS) and magnetite-sucrose functionalized Nigella Sativa (FNS) seeds as the adsorbents for the uptake of Cr(VI) and Pb(II) ions from synthetic wastewater revealed that the maximum adsorption capacities for Cr(VI) were 15.6 and 13.0 mg/g onto PNS and FNS composites respectively at pH 1. On the hand, the maximum sorption capacities for Pb(II) ions were 39.7 and 37.9 mg/g onto PNS and FNS respectively at pH 5.
The sorption study of Cr(VI), Cd(II) ions and MB dye by pristine Nigella Sativa (PNS) seeds, defatted and carbonized Nigella Sativa seeds from aqueous solution was investigated. The PNS seeds were treated using acetone (then named ANS) and N,N dimethylformamide (named DNS). The defatted ANS and DNS adsorbents were carbonized at 600 °C and named CANS and CDNS. The results of pristine, defatted and carbonized seeds maximum capacities were compared with each other and found that CANS had highest adsorption capacity of 99.82 mg/g for MB, 96.89 mg/g for Cd(II) and 87.44 mg/g for Cr(VI) followed by CDNS with 93.90, 73.91 and 65.38 mg/g for MB, Cd(II) and Cr(VI) respectively. ANS capacities were 58.44, 45.28 and 48.96 mg/g whilst DNS capacities were 48.19, 32.69 and 34.65 mg/g for MB, Cd and Cr(VI) respectively. PNS had the lowest sorption capacities at 43.88, 36.01 and 19.84 mg/g for MB, Cd and Cr(VI) respectively. Therefore, this makes black cumin seeds a promising material for use in wastewater treatment to mitigate metal ions and dye pollution.
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Biomedical Applications Employing Microfabricated Silicon Nanoporous MembranesSmith, Ross Andrew 22 July 2010 (has links)
No description available.
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Reducering av antibiotikarester i akvatiskamiljöer : Alternativa behandlingsmetoder och vattenreningsteknikerEriksson, Karin, Lindströn, Moa January 2022 (has links)
Antibiotikaresistens är en av de största globala utmaningarna i sjukvården och om den mängdantibiotika som används idag fortsätter att användas i framtiden riskerar det att kosta 10 miljonermänniskor om livet varje år från år 2050. Antibiotikarester i akvatiska miljöer ökar risken förspridning av antibiotikaresistenta bakterier. Vissa antibiotikum är även toxiska för vattenlevandeorganismer. Dagens vattenreningsverk är inte utformade att rena vatten från antibiotikaresteroch därför följer resterna med vattnet ut i recipienten. För att lösa det här problemet behövervattenreningsverk utvecklas med nya reningsmetoder för att kunna rena antibiotika och vårdenmåste minska användandet i sjukvården. De kopplade globala målen kopplade till detta problemär mål 3 “God hälsa och välbefinnande”, 6 “rent vatten och sanitet”, 11 “hållbara städer ochsamhällen”, 14 “hav och marina resurser” (Globala målen, 2021a; Globala målen, 2021b;Globala målen, 2021c; Globala målen, 2021d). Arbetet undersöker potentiella lösningar förutveckling av vattenreningsverk och alternativa behandlingsmetoder för att minska användandetav antibiotika inom sjukvården. För att göra detta har intervjuer med respondenter på Gävlesjukhus och Duvbackens reningsverk genomförts för att hitta brister i dagens teknik.Förbättringsförslagen är baserade på vetenskapliga artiklar och myndigheters hemsidor. I EUfinns det inga krav gällande att producenterna av läkemedel ska granska den verkligamiljöpåverkan läkemedlet har efter att det har godkänts för försäljning. Antibiotikaläkemedel ärbiologiskt aktiva föreningar vilka, även i små mängder, kan påverka det akvatiska ekosystemetnegativt. Penicillin är det vanligaste använda antibiotikan i Gävles sluten- och primärvård.Slutenvården utgör den största gruppen av antibiotikaanvändare men beaktas bör att det är okänthuruvida dessa användare tidigare kommer från primärvården. Det är också okänt hur stor andelav inköpta läkemedel som faktiskt använts. De reningstekniker bäst lämpade att använda påvattenreningsverk för att rena antibiotikarester varierar och beror bland annat på klimat,resurser och vilken typ av antibiotika som finns i avloppsvattnet. Ozonering är positivt eftersomdet är effektivt mot antibiotikasubstanser med brett spektrum. Det ger heller inte någonpåverkan på slam från vattenreningsverket eftersom ozonet löses upp och blir till syre efterreningen. Ozonering är ofta mest effektiv i kombination med andra reningstekniker vilket kallasför hybridprocesser. Adsorption är effektivt för rening av antibiotikarester och den vanligametoden kolbaserad adsorption är effektiv vid rening av tetracyklinrester. Metoden är effektiveftersom det tar upp mycket av resterna samt att energikostnaden är låg. Sandfilter är en brametod för att rena bort antibiotikaresistenta bakterier och dessutom renar filtrets adsorptionockså rester av tetracyklin. Genom att införa en reningsteknik kombinerad med aktivt kol ochozonering för att rena antibiotikarester från avloppsvattnet samt att använda vakuumassisteradsårbehandling kan användandet av antibiotika minska. / Antibiotic resistance is one of the biggest global challenges in modern day healthcare and ifcontinued use of antibiotics in the same amount as today, it will kill 10 million people every yeararound 2050. Antibiotic residues in aquatic environments increase the risk of spreading ofspreading antibiotic resistant bacteria. Some antibiotics are also toxic to aquatic organisms.Because the wastewater plants are not designed to purify the water from antibiotics the residuescontinue with the water to the recipient. To solve the problem the wastewater plants needs toupgrade with new technology and the healthcare industry reduces the amount prescribedantibiotics. The UN global goals connected to this issue is goal 3 “Good health and well-being”,6 “clean water and sanitary”, 11 “sustainable cities and communities” and 14 “life below water”(Global goals). This study explores potential developments in the wastewater plants andalternatives for antibiotics in healthcare by interviewing respondents at the hospital in Gävle andthe wastewater plant Duvbacken to find the deficiencies of today. Included suggestions are basedon scientific articles and Swedish agencies. There is no requirement for the medicalmanufacturers within the EU to examine the environmental impact of medicines after they havebeen approved for sale. Antibiotic drugs are biologically active compounds which, even in smallamounts, can adversely affect the aquatic ecosystem. Penicillin is the most widely used antibioticin Gävle's inpatient and outpatient care. Outpatient care constitutes the largest group ofantibiotic users, but it should be taken into account that people from this group may havepreviously belonged to inpatient care. It is also unknown how much of each purchased drug thatis used. The treatment techniques that are best suited to use at water treatment plants to purifyantibiotic residues vary and depend on the climate, resources and the type of antibiotics found inthe wastewater. Ozonation is positive as it is effective for broad spectrum antibiotics. It also hasno effect on sludge from the water treatment plant because the ozone dissolves and becomesoxygen after the treatment. Ozonation is often most effective when combined with otherpurification techniques which is called hybrid processes. Adsorption is effective for thepurification of antibiotic residues and the usual method of carbon-based adsorption is effective inthe purification of tetracycline residues. The method is effective because it absorbs much of theresidues at a low energy cost. Sand filter is an effective method to clean away antibiotic-resistantbacteria and in addition, the adsorption of the filter also cleans residues of tetracycline. Byintroducing a purification technique combined with activated carbon and ozonation to purify thewastewater in wastewater plants and to use vacuum assisted wound treatment, the use ofantibiotics can be reduced.
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VATTENKVALITET I HEMODIALYS: UTVECKLING OCH UTVÄRDERING AV ETT ÖVERVAKNINGSPROGRAM / Development and evaluation of a surveillance program for water quality in hemodialysisBredberg, Fredrik January 2024 (has links)
Dialysis is a crucial aspect of healthcare, involving the replacement of kidney functions with a hemodialysis machine. A critical component of this process is ensuring the water used is free from bacteria and other byproducts. To ensure water quality, two key measurements need to be considered: disinfection efficiency (𝐴0) and water conductivity. To simplify the process of checking water quality, a program has been developed in an earlier thesis, to monitor and display 𝐴0 and conductivity in a graphical format, and to send warnings if these measurements exceed specified thresholds, the data is acquired directly from the sensors on the machine. Additionally, the program generates reports detailing these warnings. A new type of water purification system has been installed, requiring an update to the software to handle the new data format, which is available on a web page provided by the creator. This thesis focused on further developing the program to support an additional water purification system. A script in C# was written to automatically download log files daily at a predetermined time. The log files were then processed to remove unnecessary data, thereby reducing their size, 𝐴0 and conductivity values were plotted over a time series. Warnings for values exceeding or falling below thresholds were documented in a text file, and these warnings were emailed to relevant personnel. The updated program successfully displays 𝐴0 and conductivity in a graph, providing a quick overview of water quality. Additionally, the system sends both weekly and daily warning emails when a significant number of warnings accumulate throughout the week. While the program has been successfully developed and demonstrates the intended functionality, further improvements are needed for larger-scale deployment within Region Västerbotten. Enhancements such as more efficient plotting tools capable of handling large data volumes and a more user-friendly interface are necessary for broader usability. / Dialys är en viktig del av sjukvården och innebär att ersätta njurarnas funktion med en hemodialysmaskin. En kritisk komponent i denna process är att säkerställa att vattnet som används är fritt från bakterier och andra biprodukter. För att säkerställa vattenkvaliteten behöver två viktiga mätningar beaktas: desinfektionseffektivitet (𝐴0) och vattnets ledningsförmåga (konduktivitet). För att förenkla processen att kontrollera vattenkvaliteten har ett program utvecklats i ett tidigare examensarbete, som övervakar och visar 𝐴0 och ledningsförmåga i ett grafiskt format samt skickar varningar om dessa mätningar överstiger specificerade gränsvärden. Programmet genererar också rapporter som detaljerar dessa varningar. Denna uppsats fokuserade på att vidareutveckla programmet för att stödja en ytterligare vattenrenare. Ett skript i C# skrevs för att automatiskt ladda ner loggfiler dagligen vid en förutbestämd tidpunkt. Loggfilerna bearbetades sedan för att ta bort onödiga data och därmed minska deras storlek. 𝐴0 och ledningsförmåga värden plottades över en tidsserie. Varningar för värden som överskrider eller faller under gränsvärdena dokumenterades i en textfil och dessa varningar mejlades till relevant personal. Det förbättrade programmet visar framgångsrikt 𝐴0 och konduktivitet i en graf och ger en snabb översikt av vattenkvalitén. Systemet skickar också veckovisa samt dagliga varningsmejl om ett tillräckligt antal varningar ackumuleras under veckan. Programmet har utvecklats framgångsrikt och uppvisar den avsedda funktionaliteten, men ytterligare förbättringar krävs för storskalig användning inom region Västerbotten. Förbättringar som effektivare verktyg för att plotta grafen, som kan hantera stora datamängder och ett mer användarvänligt gränssnitt är nödvändiga för bredare användbarhet.
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