Removal of micropollutants from grey water : combining biological and physical/chemical processes

Grey water consists of the discharges from kitchen sinks, showers, baths, washing machines and hand basins. The amount of grey water produced per person in The Netherlands is about 90 Ld-1, accounting for up to 75 % of the wastewater volume produced by households, and over 90 % if vacuum toilets are installed. Grey water is relatively low in pollution and therefore, after appropriate treatment, has great potential for reuse in non-potable applications such as infiltration, irrigation, toilet flushing, laundry water, etc. The goal of this thesis was to develop a treatment concept for grey water to exploit its reuse potential. A special focus of this thesis was set on the study of organic micropollutants from personal care and household chemicals. Grey water (from 32 houses in Sneek, The Netherlands) contains, on average, 724-150 mgL-1 of chemical oxygen demand (COD), 27-12 mgL-1 of total nitrogen, 7.2-4.2 mgL-1 of phosphorus and 41-12 mgL-1 of anionic surfactants. The high biodegradability of grey water (70-5 %) indicated the possibility of recovering COD as methane. Biological treatment of grey water was conducted in three systems, aerobic, anaerobic and combined anaerobic + aerobic, at a total hydraulic retention time (HRT) of 12-13 hours at 32 °C. Aerobic treatment in a sequencing batch reactor resulted in COD removal of 90 %, which was significantly higher than 51 % removal by anaerobic treatment in an upflow anaerobic sludge blanket (UASB) reactor. Grey water treatment in a combined anaerobic + aerobic system resulted in a COD removal efficiency of 89 %. The application of a UASB reactor for the pre-treatment of grey water yielded a small amount of energy. Therefore, the aerobic system was preferred for grey water treatment. Bioflocculation of grey water in a high loaded membrane bioreactor was tested as alternative to aerobic treatment. The concentrated grey water of this process can potentially increase the methane yield by 73 % within ‘new sanitation' concepts. Eighteen compounds of personal care products and household chemicals (UV- filters, fragrances, preservatives, biocides, surfactants) were measured in grey water at low gL-1 levels. During biological treatment most of these compounds were partially removed. In general, the treatment in the aerobic system lead to the highest removal efficiencies of these compounds, where biodegradation and adsorption to sludge were the most likely removal mechanisms. However, the UV-filters PBSA and EHMC and the fragrance tonalide were poorly removed in the tested biological systems. Although reuse standards for these compounds do not exist, the post-reatment of aerobically treated effluent was recommended prior to reuse. Adsorption on activated carbon and ozonation were proven effective as post-treatment options for grey water

Classical Perturbation Method for the Solution of a Model of Diffusion and Reaction

In this paper, we employ perturbation method (PM) to solve nonlinear problems. As case study PM is employed to obtain approximate solutions for the nonlinear differential equation that models the diffusion and reaction in porous catalysts. We find that the square residual error (S.R.E) of our solutions is in the range and this requires only the third order approximation of PM, which shows the effectiveness of the method

Quantitative image analysis of polyhydroxyalkanoates inclusions from microbial mixed cultures under different SBR operation strategies

Polyhydroxyalkanoates (PHAs) produced from mixed microbial cultures (MMC), regarded as potential substitutes of petrochemical plastics, can be found as intracellular granules in various microorganisms under limited nutrient conditions and excess of carbon source. PHA is traditionally quantified by laborious and time-consuming chromatography analysis, and a simpler and faster method to assess PHA contents from MMC, such as quantitative image analysis (QIA), is of great interest. The main purpose of the present work was to upgrade a previously developed QIA methodology (Mesquita et al., 2013a, 2015) for MMC intracellular PHA contents quantification, increase the studied intracellular PHA concentration range and extend to different sequencing batch reactor (SBR) operation strategies. Therefore, the operation of a new aerobic dynamic feeding (ADF) SBR allowed further extending the studied operating conditions, dataset, and range of the MMC intracellular PHA contents from the previously reported anaerobic/aerobic cycle SBR. Nile Blue A (NBA) staining was employed for epifluorescence microscope visualization and image acquisition, further fed to a custom developed QIA. Data from each of the feast and famine cycles of both SBR were individually processed using chemometrics analysis, obtaining the correspondent partial least squares (PLS) models. The PHA concentrations determined from PLS models were further plotted against the results obtained in the standard chromatographic method. For both SBR the predicted ability was higher at the end of the feast stage than for the famine stage. Indeed, an independent feast and famine QIA data treatment was found to be fundamental to obtain the best prediction abilities. Furthermore, a promising overall correlation (R2 of 0.83) could be found combining the overall QIA data regarding the PHA prediction up to a concentration of 1785.1 mgL-1 (37.3 wt%). Thus, the results confirm that the presented QIA methodology can be seen as promising for estimating higher intracellular PHA concentrations for a larger reactors operation systems and further extending the prediction range of previous studies.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE01-0145-FEDER-000004) funded by European Regional Development Fundunder the scope ofNorte2020 - ProgramaOperacional Regional do Norte.The authors also acknowledge the financial support to Cristiano S. Leal (PTDC/EBB-EBI/103147/2008, FCOMP-01-0124-FEDER009704) and Daniela P. Mesquita through the FCT postdoctoral grant (SFRH/BPD/82558/2011).info:eu-repo/semantics/publishedVersio

Hydrodynamic slip can align thin nanoplatelets in shear flow

The large-scale processing of nanomaterials such as graphene and MoS2 relies on understanding the flow behaviour of nanometrically-thin platelets suspended in liquids. Here we show, by combining non-equilibrium molecular dynamics and continuum simulations, that rigid nanoplatelets can attain a stable orientation for sufficiently strong flows. Such a stable orientation is in contradiction with the rotational motion predicted by classical colloidal hydrodynamics. This surprising effect is due to hydrodynamic slip at the liquid-solid interface and occurs when the slip length is larger than the platelet thickness; a slip length of a few nanometers may be sufficient to observe alignment. The predictions we developed by examining pure and surface-modified graphene is applicable to different solvent/2D material combinations. The emergence of a fixed orientation in a direction nearly parallel to the flow implies a slip-dependent change in several macroscopic transport properties, with potential impact on applications ranging from functional inks to nanocomposites.Energy Technolog

Quantitative Analysis of Single Nucleotide Polymorphisms within Copy Number Variation

BACKGROUND: Single nucleotide polymorphisms (SNPs) have been used extensively in genetics and epidemiology studies. Traditionally, SNPs that did not pass the Hardy-Weinberg equilibrium (HWE) test were excluded from these analyses. Many investigators have addressed possible causes for departure from HWE, including genotyping errors, population admixture and segmental duplication. Recent large-scale surveys have revealed abundant structural variations in the human genome, including copy number variations (CNVs). This suggests that a significant number of SNPs must be within these regions, which may cause deviation from HWE. RESULTS: We performed a Bayesian analysis on the potential effect of copy number variation, segmental duplication and genotyping errors on the behavior of SNPs. Our results suggest that copy number variation is a major factor of HWE violation for SNPs with a small minor allele frequency, when the sample size is large and the genotyping error rate is 0~1%. CONCLUSIONS: Our study provides the posterior probability that a SNP falls in a CNV or a segmental duplication, given the observed allele frequency of the SNP, sample size and the significance level of HWE testing

HPM Approximations for Trajectories: From a Golf Ball Path to Mercury’s Orbit

In this work, we propose the approximated analytical solutions for two highly nonlinear problems using the homotopy perturbation method (HPM). We obtained approximations for a golf ball trajectory model and a Mercury orbit’s model. In addition, to enlarge the domain of convergence of the first case study, we apply the Laplace-Padé resummation method to the HPM series solution. For both case studies, we were able to obtain approximations in good agreement with numerical methods, depicting the basic nature of the trajectories of the phenomena

Application of HPM to Solve Unsteady Squeezing Flow of a Second-Grade Fluid between Circular Plates

In this article, Homotopy Perturbation Method (HPM) is used to provide two approximate solutions to the nonlinear differential equation that describes the behaviour for the unsteady squeezing flow of a second grade fluid between circular plates. Comparing results between approximate and numerical solutions shows that our results are capable to provide an accurate solution and are extremely efficient

COLEC10 is mutated in 3MC patients and regulates early craniofacial development

3MC syndrome is an autosomal recessive heterogeneous disorder with features linked to developmental abnormalities. The main features include facial dysmorphism, craniosynostosis and cleft lip/palate; skeletal structures derived from cranial neural crest cells (cNCC). We previously reported that lectin complement pathway genes COLEC11 and MASP1/3 are mutated in 3MC syndrome patients. Here we define a new gene, COLEC10, also mutated in 3MC families and present novel mutations in COLEC11 and MASP1/3 genes in a further five families. The protein products of COLEC11 and COLEC10, CL-K1 and CL-L1 respectively, form heteromeric complexes. We show COLEC10 is expressed in the base membrane of the palate during murine embryo development. We demonstrate how mutations in COLEC10 (c.25C>T; p.Arg9Ter, c.226delA; p.Gly77Glufs*66 and c.528C>G p.Cys176Trp) impair the expression and/or secretion of CL-L1 highlighting their pathogenicity. Together, these findings provide further evidence linking the lectin complement pathway and complement factors COLEC11 and COLEC10 to morphogenesis of craniofacial structures and 3MC etiology.New life Fundation for Disabled Childre