THM and HAA formation from NOM in raw and treated surface waters

The disinfection by-product (DBP) formation potential (FP) of natural organic matter (NOM) in surface water sources has been studied with reference to the key water quality determinants (WQDs) of UV absorption (UV254), colour, and dissolved organic carbon (DOC) concentration. The data set used encompassed raw and treated water sampled over a 30-month period from 30 water treatment works (WTWs) across Scotland, all employing conventional clarification. Both trihalomethane (THM) and haloacetic acid (HAA) FPs were considered. In addition to the standard bulk WQDs, the DOC content was fractionated and analysed for the hydrophobic (HPO) and hydrophilic (HPI) fractions. Results were quantified in terms of the yield (dDBPFP/dWQD) and the linear regression coefficient R2 of the yield trend. The NOM in the raw waters was found to comprise 30–84% (average 66%) of the more reactive HPO material, with this proportion falling to 18–63% (average 50%) in the treated water. Results suggested UV254 to be as good an indicator of DBPFP as DOC or HPO for the raw waters, with R2 values ranging from 0.79 to 0.82 for THMs and from 0.71 to 0.73 for HAAs for these three determinants. For treated waters the corresponding values were significantly lower at 0.52–0.67 and 0.46–0.47 respectively, reflecting the lower HPO concentration and thus UV254 absorption and commensurately reduced precision due to the limit of detection of the analytical instrument. It is concluded that fractionation offers little benefit in attempting to discern or predict chlorinated carbonaceous DBP yield for the waters across the geographical region studied. UV254 offered an adequate estimate of DBPFP based on a mean yield of ∼2600 and ∼2800 μg per cm−1 absorbance for THMFP for the raw and treated waters respectively and ∼3800 and2900 μg cm−1 for HAAFP, albeit with reduced precision for the treated waters

Pilot-scale spiral wound membrane assessment for THM precursor rejection from upland waters

The outcomes of a pilot-scale study of the rejection of trihalomethanes (THMs) precursors by commercial ultrafiltration/nanofiltration (UF/NF) spiral-wound membrane elements are presented based on a single surface water source in Scotland. The study revealed the expected trend of increased flux and permeability with increasing pore size for the UF membranes; the NF membranes provided similar fluxes despite the lower nominal pore size. The dissolved organic carbon (DOC) passage decreased with decreasing molecular weight cut-off, with a less than one-third the passage recorded for the NF membranes than for the UF ones. The yield (weight % total THMs per DOC) varied between 2.5% and 8% across all membranes tested, in reasonable agreement with the literature, with the aromatic polyamide membrane providing both the lowest yield and lowest DOC passage. The proportion of the hydrophobic (HPO) fraction removed was found to increase with decreasing membrane selectivity (increasing pore size), and THM generation correlated closely (R2 = 0.98) with the permeate HPO fractional concentration

Robust natural organic matter removal from Scottish water sources of variable DOC content.

Natural organic matter (NOM) is found ubiquitously in raw water and is known to react with the chlorine used in water treatment to produce disinfection by-products (DBPs), some of which are potentially harmful to human health due to their links with cancers. Trihalomethanes (THMs) and haloacetic (HAAs) acids are the two types of carbonaceous DBPs widely regulated. The THMs and HAAs are widely regarded as being good indicators of the presence of the more than 500 other DBPs that have been found in treated drinking water. At large and medium sites in Scotland, the coagulation- flocculation process has long been the main control barrier for removal of the precursors for DBPs. At small sites, ultra and nano filtration membrane filtration processes have been considered a good solution due to their small footprint requirement and large volume of water output. In addition, granular activated carbon (GAC) filtration has long been employed for removal of organic matter. However, increases in the organic content of raw waters, stricter regulatory requirements and concerns over coagulant cost and availability have driven the reconsideration of how NOM laden water sources in Scotland are treated. This thesis investigated the approaches required to increase the robustness of drinking water supply to mitigate against these factors. A stronger correlation was found between commonly measured water quality parameters and DBPs in raw water sources compared to treated water, which was as a result of the lower hydrophobic content of the latter. However, the DBP removal as a function of DOC reduction was calculated and revealed coagulation using ferric sulfate in the pH 4-5-5-5 range as the most feasible solution at large and medium sites. The use of GAC media with high pore uniformity would be appropriate at large or medium sited where up to 50% DOC reduction would be sufficient to control DBPs. At small sites, the tighter pore size membranes showed improved THM precursor removal, whilst most of these maintained a throughput of within 90% of the current membranes.Engineering and Physical Sciences (EPSRC)STREAM EngD Programm

FAILNOMORE project - D1-2 - Background document

FAILNOMORE – the background document (Deliverable D1-2) is an internal work document collecting the contributions from the following FAILNOMORE project partners on current state of knowledge in the field of design for mitigating progressive collapse (see I.2.1 for project details): University of Liège, University of Coimbra, Imperial College London, University of Stuttgart, University of Trento, Politehnica University of Timisoara, and ArcelorMittal Belval & Differdange S.A. The involved partners contributed to the Sections of the present document corresponding to their field of expertise; accordingly, the content of each Section has not been necessarily agreed by all the contributors of the present document. The derivation of commonly agreed design guidelines based on the information collected in the present document will come in a later stage (activities developed within WP 2 – see Section I.2.2 for more details). The use of this document is not public and is strictly limited to the execution of the FAILNOMORE project inside the partnership.FAILNOMORE - Mitigation of the risk of progressive collapse in steel and composite building frames under exceptional event

FAILNOMORE project - D2-1: Derivation of practice-oriented design guidelines

The present deliverable reflects the outcome of the activities conducted in the framework of Task 2.1 of WP 2 of the FAILNOMORE project. The objective of this specific task was to derive practice-oriented design approaches from the information collected in Deliverable 1-2, i.e. the background document. Within the present document, these practice-oriented design approaches are reported in two parts: - Part 1 (from Section 1 to Section 4) entitled “Find my way” which groups the design recommendations to help the designer in the identification of the approaches to be considered in the context of a design for robustness and; - Part 2 (Sections 5 and 6) entitled “Tool box” which provides the designer with the required information to apply the different design approaches addressed in Part 1. In the next step of the FAILNOMORE project, the applicability of the proposed design approaches will be illustrated through the worked examples (Task 2-2). Then, the dissemination materials made of a design manual (including the design recommendations and the worked examples) and of PowerPoint presentations will be prepared (Task 2-3) taking into account of the outcomes from Tasks 2.1 and 2.2

RECOMENDAÇÕES PARA DIMENSIONAMENTO CONTRA O COLAPSO PROGRESSIVO EM ESTRUTURAS METÁLICAS E MISTAS AÇO-BETÃO

FAILNOMOR

ZALECENIA PROJEKTOWE ZAPOBIEGAJĄCE WYSTĄPIENIU KATASTROFY POSTĘPUJĄCEJ BUDYNKÓW STALOWYCH I STALOWO-BETONOWYCH

FAILNOMOR

RECOMENDACIONES DE PROYECTO FRENTE AL COLAPSO PROGRESIVO EN EDIFICIOS DE ACERO Y DE ACERO-HORMIGÓN

FAILNOMOR