The removal of anionic surfactant from commercial laundry wastewater with reverse osmosis membrane

Thesis (MEng (Chemical Engineering))--Cape Peninsula University of Technology, 2020Fresh, clean water has always been critical for the world's social development. The current water scarcity will only worsen unless measures are put in place to either reduce water usage or clean and reuse greywater. In areas with limited water resources, affordable technologies can be used to treat greywater and increase the water supply. Greywater sources that can be reused include domestic, hospital and industrial laundry wastewater. These wastewaters contain different chemicals such as organic and inorganic constituents, which make it difficult to treat. Microfiltration and ultrafiltration are examples of physical filtration processes that can reduce turbidity and pathogens sufficiently, but struggle to remove organics. Therefore, implementing an additional step such as reverse osmosis (RO) could be the solution in the removal of harmful chemicals in greywater. Unfortunately, the salts that are removed from the water, precipitate on the membrane surface, thus, decreasing the overall process efficiency, due to fouling and scaling. Scaling causes decline in permeation flux, degeneration of membranes, production loss and higher operating costs. This occurrence of fouling cannot be completely isolated; however, it can be minimised. There are two approaches for dealing with the fouling effect, namely, minimization and remediation. Remediation focuses more on frequent chemical cleaning. By using suitable pre-treatment measurements upstream of RO, scale formation can be minimised. In this study, the use of a commercial antiscalant was examined in the treatment of laundry wastewater influent. The removal of anionic surfactants and COD’s from this effluent with a low-pressure, extra low energy, reverse osmosis membrane for reuse application was investigated. The effect of different laundry detergent feed concentrations on operational parameters such as the membrane salt rejection and permeate flow rate (flux) was also analysed. The effect of different antiscalant concentrations to minimise scaling was also evaluated. Membrane fouling and remediation was evaluated by selected membrane surface characteristics. Model laundry wastewater was treated using a bench-scale reverse osmosis unit. The effects of laundry detergent concentration and antiscalant dosage on the permeate flow rate (flux) and rejection characteristics of the membrane were examined. Removal efficiencies for surfactant and COD concentration were analysed as an indication of membrane performance. A detailed examination of membrane fouling was done by investigating membrane surface characteristics using Scanning Electron Microscopy (SEM); Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Energy Dispersive X-Ray Spectroscopy (EDX), before and after antiscalant addition. Design Expert 11 was used to generate a predictive model to describe the behaviour of permeate flux decline over time. ATR-FTIR revealed all the characteristic peaks on a virgin extra low energy (XLE) polyamide thin film composite membrane, in its clean state. It was observed that more foulant is deposited onto the surface of membranes with lower or no antiscalant dosage compared to the higher antiscalant dosed membranes. A morphological change of the membranes was observed using SEM analysis. The hindered attachment of scalant on the surface of the membranes resulted in a much lower rate of flux decline when compared to membranes with no antiscalant addition. EDX revealed that the amount of carbon decreased with an increase in laundry detergent amount (concentration). This could be due to the carbonyl group present in the PA layer being masked by the foulant layer. The flux decline could be associated with the fouling phenomenon caused by the accumulation of anionic surfactant molecules on the membrane surface, where the build-up of a concentration polarisation layer and/ the or the entrapment in the polyamide layer. Surfactant rejection exceeded 99.8% in almost all the experimental runs over a range of varied feed concentrations. An average COD removal throughout was 91-96%. It must be noted that the COD removal during the Percentage removal (COD and average EC) of the membranes are all significantly high, between 96-98% removal for average EC and between 91-96% removal for COD, however it was observed that membranes with membranes with no anti-scalant addition performed slightly better than membranes with anti-scalant dosing. It was observed that the predictive model successfully described the permeate flux decline of laundry wastewater using an RO membrane within the design space of the model. It can be confirmed that the membrane performance investigated using model laundry wastewater could be improved when using commercial antiscalant

Translational Research Design: Collaborating with Stakeholders for Program Evaluation

In this article, the authors examine researcher collaboration with stakeholders in the context of a translational research approach used to evaluate an elementary school program. The authors share their experiences as evaluators of this particular program to demonstrate how collaboration with stakeholders evolved when a translational research approach was applied to program evaluation. Beginning with a review of literature regarding stakeholder participation in evaluation and other qualitative research, the article reflects on a method for conceptualizing participant involvement and collaboration within the translational framework. The relationship between researchers and stakeholders is articulated according to this method. We interpose these descriptions with their alignment to Petronio’s (2002, 2007) five types of practical validity for translational research. The paper ends with a consideration of what was learned throughout the evaluation process, including both successes and challenges, by means of the translational model

Anomaly Detection in Paleoclimate Records using Permutation Entropy

Permutation entropy techniques can be useful in identifying anomalies in paleoclimate data records, including noise, outliers, and post-processing issues. We demonstrate this using weighted and unweighted permutation entropy of water-isotope records in a deep polar ice core. In one region of these isotope records, our previous calculations revealed an abrupt change in the complexity of the traces: specifically, in the amount of new information that appeared at every time step. We conjectured that this effect was due to noise introduced by an older laboratory instrument. In this paper, we validate that conjecture by re-analyzing a section of the ice core using a more-advanced version of the laboratory instrument. The anomalous noise levels are absent from the permutation entropy traces of the new data. In other sections of the core, we show that permutation entropy techniques can be used to identify anomalies in the raw data that are not associated with climatic or glaciological processes, but rather effects occurring during field work, laboratory analysis, or data post-processing. These examples make it clear that permutation entropy is a useful forensic tool for identifying sections of data that require targeted re-analysis---and can even be useful in guiding that analysis.Comment: 15 pages, 7 figure

The Near-Infrared Broad Emission Line Region of Active Galactic Nuclei -- I. The Observations

We present high quality (high signal-to-noise ratio and moderate spectral resolution) near-infrared (near-IR) spectroscopic observations of 23 well-known broad-emission line active galactic nuclei (AGN). Additionally, we obtained simultaneous (within two months) optical spectroscopy of similar quality. The near-IR broad emission line spectrum of AGN is dominated by permitted transitions of hydrogen, helium, oxygen, and calcium, and by the rich spectrum of singly-ionized iron. In this paper we present the spectra, line identifications and measurements, and address briefly some of the important issues regarding the physics of AGN broad emission line regions. In particular, we investigate the excitation mechanism of neutral oxygen and confront for the first time theoretical predictions of the near-IR iron emission spectrum with observations.Comment: 45 pages, 17 figures, accepted by ApJ

Resilabificación incompleta y acoplamiento gestual ambisilábico en español

In the generative literature, the pattern of coronal fricative lenition found in the traditional Chinato Spanish dialect is commonly cited as a phonological argument that the resyllabification of word-final prevocalic consonants is complete, in the sense that onsets derived by resyllabification are structurally identical to canonical (word-level) onsets. However, recent acoustic studies of Northern-Central Peninsular Spanish have problematized the completeness of resyllabification with experimental evidence that /s̺/ is shorter and more voiced as a derived onset than as a canonical onset. Using a split-gesture, competitive, coupled oscillator model of the syllable in Articulatory Phonology, which divides consonants into a separate constriction and release gesture, we propose a novel representation of ambisyllabicity that predicts the phonetic behavior of derived onset /s̺/ in Northern-Central Peninsular Spanish. We then show that ambisyllabic coupling permits a simpler phonological analysis of coronal fricative lenition in Chinato Spanish as compared to alternative accounts. Our analysis makes typological predictions that are confirmed by patterns from other contemporary Spanish varieties. Lastly, we examine the consequences of ambisyllabicity for the analysis of Spanish rhotic consonants, which have also been argued to support complete resyllabification. We offer an analysis of rhotics that is entirely compatible with an ambisyllabic representation of incomplete resyllabification.En la literatura generativa, el debilitamiento de fricativas coronales en el dialecto chinato del español peninsular se cita comúnmente como un argumento fonológico a favor de la resilabificación completa de consonantes prevocálicas finales de palabra, o sea que los arranques derivados por resilabificación son idénticos estructuralmente a los arranques canónicos a nivel de palabra. Sin embargo, algunos estudios acústicos recientes han problematizado la resilabificación completa en el español peninsular centro-norteño al presentar evidencia experimental de que la /s̺/ es más corta y sonorizada como arranque derivado que como arranque canónico. Utilizamos un modelo de acoplamiento competitivo desde la Fonología Articulatoria, el cual divide a las consonantes en un gesto de constricción y de soltura, para proponer una nueva representación de la ambisilabicidad que predice el comportamiento fonético de la /s̺/ como arranque derivado en el español peninsular centro-norteño. Luego, demostramos que el acoplamiento ambisilábico permite analizar mejor el debilitamiento de fricativas coronales en el español chinato, en comparación con otras explicaciones alternativas. Confirmamos las predicciones tipológicas de nuestro análisis para otras variedades contemporáneas del español. Por último, examinamos las consecuencias de la ambisilabicidad para el análisis de las consonantes róticas del español, también citadas como otro argumento a favor de la resilabificación completa. Ofrecemos un análisis de las róticas que es totalmente compatible con una representación ambisilábica de la resilabificación incompleta

Involving citizens in priority setting for public health research: Implementation in infection research

Background Public sources fund the majority of UK infection research, but citizens currently have no formal role in resource allocation. To explore the feasibility and willingness of citizens to engage in strategic decision making, we developed and tested a practical tool to capture public priorities for research. Method A scenario including six infection themes for funding was developed to assess citizen priorities for research funding. This was tested over two days at a university public festival. Votes were cast anonymously along with rationale for selection. The scenario was then implemented during a three-hour focus group exploring views on engagement in strategic decisions and in-depth evaluation of the tool. Results 188/491(38%) prioritized funding research into drug-resistant infections followed by emerging infections(18%). Results were similar between both days. Focus groups contained a total of 20 citizens with an equal gender split, range of ethnicities and ages ranging from 18 to >70 years. The tool was perceived as clear with participants able to make informed comparisons. Rationale for funding choices provided by voters and focus group participants are grouped into three major themes: (i) Information processing; (ii) Knowledge of the problem; (iii) Responsibility; and a unique theme within the focus groups (iv) The potential role of citizens in decision making. Divergent perceptions of relevance and confidence of “non-experts” as decision makers were expressed. Conclusion Voting scenarios can be used to collect, en-masse, citizens' choices and rationale for research priorities. Ensuring adequate levels of citizen information and confidence is important to allow deployment in other formats

Silica in a Mars analog environment: Ka'u Desert, Kilauea Volcano, Hawaii

Airborne Visible/Near-Infrared Imaging Spectrometer (AVIRIS) data acquired over the Ka'u Desert are atmospherically corrected to ground reflectance and used to identify the mineralogic components of relatively young basaltic materials, including 250–700 and 200–400 year old lava flows, 1971 and 1974 flows, ash deposits, and solfatara incrustations. To provide context, a geologic surface units map is constructed, verified with field observations, and supported by laboratory analyses. AVIRIS spectral end-members are identified in the visible (0.4 to 1.2 μm) and short wave infrared (2.0 to 2.5 μm) wavelength ranges. Nearly all the spectral variability is controlled by the presence of ferrous and ferric iron in such minerals as pyroxene, olivine, hematite, goethite, and poorly crystalline iron oxides or glass. A broad, nearly ubiquitous absorption feature centered at 2.25 μm is attributed to opaline (amorphous, hydrated) silica and is found to correlate spatially with mapped geologic surface units. Laboratory analyses show the silica to be consistently present as a deposited phase, including incrustations downwind from solfatara vents, cementing agent for ash duricrusts, and thin coatings on the youngest lava flow surfaces. A second, Ti-rich upper coating on young flows also influences spectral behavior. This study demonstrates that secondary silica is mobile in the Ka'u Desert on a variety of time scales and spatial domains. The investigation from remote, field, and laboratory perspectives also mimics exploration of Mars using orbital and landed missions, with important implications for spectral characterization of coated basalts and formation of opaline silica in arid, acidic alteration environments

Genetic analysis of root length, root volume and fruit weight of peanut Arachis hypogaea L.

Crop Scienc

Infilling and sedimentation mechanisms at intermittently open-closed coastal lagoons

Ocean entrances to coastal lagoons are a complex, sensitive and important component of the coastal environment. They provide estuarine water exchange between inland waterways and the open ocean, and are increasingly the focus of urban development. Coastal lagoons that are only intermittently connected to the ocean are particularly sensitive since during periods of closure water quality issues are exacerbated, along with the increased risk of flooding. Mechanical clearance was undertaken in 2006 at the ocean entrance to Narrabeen Lagoon, Sydney, Australia, which intermittently opens and closes with the ingress of marine sand into the entrance restricting water exchange between the estuary and the ocean. This `instantaneous reset' of the system provided a unique opportunity to monitor and quantify generic inlet sedimentation processes and mechanisms. An intensive data collection campaign was undertaken for two years following the clearance including video image data, hydrodynamic measurements and detailed morphological surveys of the lagoon entrance system. This data set was used to quantify the sediment ingress flux and pathways within the accreting flood-tide delta of the lagoon entrance. It was found that ingress of sand into the system proceeds via a rapid landward infilling process with the location of the divergence point of the flood tidal current, available accommodation space within the entrance system and the influence of storm events being the key factors in the evolving morphodynamics of this type of coastal lagoon system. Classic inlet stability criteria were applied at the study site and it was found that the uncertainties in the determination of key parameters coupled with issues arising from compatibility of spatial and temporal scales preclude their use at this type of system. An alternative criterion is proposed which is an index of the tendency of an inlet toward instability and closure that is based on the evolution of the principle tidal constituent. Potential impacts of climate change to intermittently open-closed coastal lagoons were investigated using a simple 1D numerical model. Results suggest that the opening duration can be anticipated to decrease, with sea level rise (rather than storm frequency/magnitude and longshore sediment supply) being the principle driver

Avian Resistance to Campylobacter jejuni Colonization Is Associated with an Intestinal Immunogene Expression Signature Identified by mRNA Sequencing

peer-reviewedThis research was funded by the The Irish Department of Agriculture and Food’s Food Institutional Research Measure (http://www.agriculture.gov.ie/ research/foodinstitutionalresearchmeasurefirm) – Grant No: 06_RDD_486.Campylobacter jejuni is the most common cause of human bacterial gastroenteritis and is associated with several post-infectious manifestations, including onset of the autoimmune neuropathy Guillain-Barré syndrome, causing significant morbidity and mortality. Poorly-cooked chicken meat is the most frequent source of infection as C. jejuni colonizes the avian intestine in a commensal relationship. However, not all chickens are equally colonized and resistance seems to be genetically determined. We hypothesize that differences in immune response may contribute to variation in colonization levels between susceptible and resistant birds. Using high-throughput sequencing in an avian infection model, we investigate gene expression associated with resistance or susceptibility to colonization of the gastrointestinal tract with C. jejuni and find that gut related immune mechanisms are critical for regulating colonization. Amongst a single population of 300 4-week old chickens, there was clear segregation in levels of C. jejuni colonization 48 hours post-exposure. RNAseq analysis of caecal tissue from 14 C. jejuni-susceptible and 14 C. jejuni-resistant birds generated over 363 million short mRNA sequences which were investigated to identify 219 differentially expressed genes. Significantly higher expression of genes involved in the innate immune response, cytokine signaling, B cell and T cell activation and immunoglobulin production, as well as the renin-angiotensin system was observed in resistant birds, suggesting an early active immune response to C. jejuni. Lower expression of these genes in colonized birds suggests suppression or inhibition of a clearing immune response thus facilitating commensal colonization and generating vectors for zoonotic transmission. This study describes biological processes regulating C. jejuni colonization of the avian intestine and gives insight into the differential immune mechanisms incited in response to commensal bacteria in general within vertebrate populations. The results reported here illustrate how an exaggerated immune response may be elicited in a subset of the population, which alters host-microbe interactions and inhibits the commensal state, therefore having wider relevance with regard to inflammatory and autoimmune disease