Face à la nécessité de trouver des alternatives aux ressources d’origine fossile et de limiter les impacts environnementaux de l’activité humaine, un important effort de recherche est actuellement en cours pour favoriser et accroître l’utilisation de produits issus de ressources renouvelables, comme les fibres végétales, dans la conception de pièces industrielles. Toutefois, de nombreux verrous scientifiques et technologiques restent encore à lever avant de pouvoir valoriser de façon fiable et durable ces fibres dans un contexte technique exigeant tel que celui du secteur l’automobile. Ainsi, l’amélioration de la qualité de l’interface fibres végétales / matrice polymère est un enjeu de taille car elle constitue une condition permettant de satisfaire les performances mécaniques requises telles que la rigidité, la résistance ou la tenue au choc. Dans ce contexte, l’objectif de la thèse a été le développement de fibres courtes de chanvre à propriétés de surface maitrisées et ciblées. Des solutions de fonctionnalisation de surface applicables par des procédés industrialisables ont été développées dans le but d’incorporer ces fibres dans une matrice polypropylène (PP). Les fibres de chanvre ont ainsi été traitées selon différentes stratégies de fonctionnalisation incluant l’utilisant du polypropylène greffé anhydride maléique (PP-g-MA), d’organosilanes, d’un acide aminé, d’isocyanates et d’un polyuréthane. Deux procédés de traitement à faible impact environnemental ont été comparés : le sprayage direct des fibres par les molécules de fonctionnalisation et l’incorporation de ces molécules par extrusion réactive. Les traitements en extrusion réactive se sont montrés plus efficaces que ceux réalisés par sprayage dans le cas du PP-g-MA. Trois voies de fonctionnalisation se sont avérées pertinentes au regard des propriétés mécaniques visées  : i) l’utilisation de PP-g-MA seul en extrusion réactive ; ii) la fonctionnalisation par sprayage d’un aminosilane ou d’un acide aminé couplée à l’incorporation du PP-g-MA en extrusion réactive. S’appuyant sur le développement de moyens expérimentaux et d’analyses spécifiques, l’étude du comportement au choc des biocomposites a montré que les composites renforcés fibres de chanvre permettent d’absorber d’avantage d’énergie que les composites PP / verre (à taux volumique de renfort identique) pour une longueur de fissuration similaire. Une modélisation par éléments finis du comportement au choc des composites étudiés est également proposée. / Due to the necessity to find alternatives to fossil resources and to reduce the environmental impacts of human activity, a major research effort is currently ongoing in order to develop and increase the use of biobased products from renewable resources, such as natural fibers, in the design of industrial parts. However, many scientific and technological hurdles have yet to be removed so as to promote these products before we can reliably and durably use these fibers in a demanding technical context as in automotive sector. Thus, improving the quality of the interface between natural fibers and polymer matrix is a major challenge, since it constitutes a condition for satisfying the required mechanical performances, such as stiffness, tensile or impact strengths. In this context, the thesis objective was to develop short hemp fibers with controlled and targeted surface properties. Surface-functionalization solutions have been developed, to be used by industrial processes, with the aim of incorporating these fibers in a polypropylene (PP) matrix. Therefore, hemp fibers have been treated according to various functionalization strategies including the use of grafted polypropylene maleic anhydride (PP-g-MA), organosilanes, an amino acid, isocyanates and a polyurethane. Two treatments processes, with low environmental impact, were compared: the direct spraying of functionalization molecules on fibers and reactive extrusion incorporation of these molecules. Reactive extrusion treatments were more efficient than those performed by spraying in the case of PP-g-MA. Three functionalization lanes have been found to be relevant regarding the mechanical properties targeted: i) using PP-g-MA alone in reactive extrusion; ii) spraying-functionalization of an aminosilane or of an amino acid coupled with the incorporation of PP-g-MA into the reactive extrusion. Based on the development of experimental means and specific analyzes, the study of the impact behavior of biocomposites has shown that hemp fiber reinforced composites allow to absorb more energy than PP / glass composites (at identical reinforcing volume rate) for a similar crack length. Also, a finite element modeling of the impact behavior of the studied composites is propounded.

<p>Benzofenoni&nbsp; i&nbsp; kofein&nbsp; su&nbsp; sveprisutni,&nbsp; kako&nbsp; u&nbsp; otpadnim,&nbsp; tako&nbsp; i&nbsp; u<br />povr&scaron;inskim vodama, u koncentracijama od nekoliko ng/l do mg/l. Koriste se<br />u proizvodnji kozmetičkih preparata, kao&nbsp; pojačivači mirisa i ukusa, fiksatori<br />u&nbsp; parfemima,&nbsp; aditivi&nbsp; u&nbsp; plastici,&nbsp; sredstvima&nbsp; za&nbsp; či&scaron;ćenje,&nbsp; u&nbsp; proizvodnji<br />pesticida.&nbsp; Benzofenoni&nbsp; su&nbsp; UV&nbsp; filteri&nbsp; pa&nbsp; se&nbsp; često&nbsp; koriste&nbsp; u&nbsp; proizvodnji<br />sunčanih&nbsp; naočara,&nbsp; kao&nbsp; i&nbsp; u&nbsp; proizvodnji&nbsp; sapuna&nbsp; i&nbsp; parfema,&nbsp; sprečavajući&nbsp; UV<br />zrake&nbsp; da&nbsp; o&scaron;tete&nbsp; miris&nbsp; ili&nbsp; boju&nbsp; proizvoda.&nbsp; BP-3&nbsp; se&nbsp; najče&scaron;će&nbsp; koristi&nbsp; u<br />kozmetičkoj&nbsp; industriji&nbsp; kao&nbsp; UV&nbsp; filter&nbsp; u&nbsp; kremama&nbsp; za&nbsp; sunčanje,&nbsp; losionima&nbsp; za<br />telo,&nbsp; &scaron;amponima,&nbsp; bojama&nbsp; i&nbsp; sprejevima&nbsp; za&nbsp; kosu.&nbsp; Kofein&nbsp; se&nbsp; primenjuje&nbsp; u<br />proizvodnji&nbsp; prehrambenih&nbsp; proizvoda,&nbsp; lekova&nbsp; i&nbsp; kozmetičkih&nbsp; preparata.<br />Značajno&nbsp; se&nbsp; razlikuju&nbsp; po&nbsp; hidrofilnosti&nbsp; (benzofenon&nbsp; log&nbsp; Kow&nbsp; 3,18;<br />benzofenon-3&nbsp; log&nbsp; Kow&nbsp; 3,79;&nbsp; kofein&nbsp; log&nbsp; Kow&nbsp; -0,07).&nbsp; Usled&nbsp; nedostatka<br />podataka o sadržaju odabranih predstavnika benzofenona (benzofenon (BP) i<br />benzofenon-3(BP-3)) i kofeina (CF)&nbsp; u različitim tipovima vode&nbsp; (pre svega u<br />lokalnim&nbsp; otpadnim&nbsp; vodama&nbsp; i&nbsp; rečnoj&nbsp; vodi)&nbsp; i&nbsp; njihovom&nbsp; pona&scaron;anju&nbsp; u<br />tretmanima&nbsp; voda,&nbsp; izvr&scaron;ena&nbsp; su&nbsp; ispitivanja&nbsp; u&nbsp; efluentu&nbsp; tipičnog&nbsp; postrojenja&nbsp; za<br />preradu&nbsp; otpadnih&nbsp; voda&nbsp; i&nbsp; rečnoj&nbsp; vodi&nbsp; Dunava.&nbsp; Utvrđeno&nbsp; je&nbsp; da&nbsp; su&nbsp; sve&nbsp; tri<br />komponente&nbsp; prisutne&nbsp; u&nbsp; efluentu&nbsp; WWTP&nbsp; (BP&nbsp; od&nbsp; 0,112&nbsp; &micro;g/l&nbsp; do&nbsp; 0,146&nbsp; &micro;g/l;<br />BP-3 od 0,00718 &micro;g/l do 0,42 &micro;g/l; CF od 0,2 &micro;g/l do 12 &micro;g/l) i u Dunavu<br />(maksimalno detektovana koncentracija je za BP 0,95 &micro;g/l, za BP-3 0,62 &micro;g/l<br />i&nbsp; za&nbsp; CF&nbsp; 0,7&nbsp; &micro;g/l).&nbsp; Pored&nbsp; ispitivanja&nbsp; sadržaja&nbsp; ovih&nbsp; jedinjenja&nbsp; ispitana&nbsp; je<br />efikasnost nekonvencionalnih procesa u obradi efluenta WWTP&nbsp; (adsorpcija,<br />koagulacije,&nbsp; PAC/CoA,&nbsp; PAC/UF)&nbsp; i&nbsp; konvencionalnih&nbsp; (adsorpcija,<br />koagulacija)&nbsp; i&nbsp; nekonvencionalnih procesa (PAC/CoA, PAC/UF, CoA/UF)&nbsp; u<br />obradi&nbsp; rečne&nbsp; vode.&nbsp; Pored&nbsp; toga&nbsp; ispitani&nbsp; su&nbsp; efekti&nbsp; prirodnih&nbsp; procesa<br />preči&scaron;ćavanja u rečnoj vodi.<br />Nekonvencionalni&nbsp; procesi&nbsp; za&nbsp; preči&scaron;ćavanje&nbsp; otpadnih&nbsp; voda&nbsp; su&nbsp; ispitani&nbsp; pri<br />početnoj&nbsp; koncentraciji&nbsp; supstanci&nbsp; od&nbsp; 0,96&nbsp; &micro;g/l&nbsp; do&nbsp; 2&nbsp; &micro;g/l.&nbsp; Adsorpcija&nbsp; naaktivnom&nbsp; uglju&nbsp; u&nbsp; prahu&nbsp; se&nbsp; pokazala&nbsp; efikasnom&nbsp; (benzofenoni&nbsp; se&nbsp; uklanjaju<br />&gt;84%&nbsp; -&nbsp; &gt;94% u zavisnosti od doze uglja, a kofein je moguće ukloniti i do<br />84%).&nbsp; Koagulacija&nbsp; dozama&nbsp; prirodnog&nbsp; koagulanta&nbsp; od&nbsp; 0,0375&nbsp; ml/l&nbsp; i<br />komercijalnog koagulanta&nbsp; FeCl₃od 4 mg Fe ³⁺ /l se&nbsp; pokazala&nbsp; neefikasnom za<br />sve&nbsp; supstance&nbsp; (&lt;20%).&nbsp; Hibridni&nbsp; PAC/CoA&nbsp; koji&nbsp; je&nbsp; ispitivan&nbsp; sa&nbsp; različitim<br />dozama&nbsp; aktivnog&nbsp; uglja&nbsp; u&nbsp; prahu&nbsp; (5&nbsp; i&nbsp; 20&nbsp; mg/l),&nbsp; prirodnim&nbsp; koagulantom<br />(0,0375 ml/l)&nbsp; ili&nbsp; komercijalnim&nbsp; koagulantom&nbsp; (4 mg Fe ³⁺ /l),&nbsp; pokazao&nbsp; se&nbsp; kao<br />efikasan za uklanjanje BP, BP-3 i CF sa većom dozom&nbsp; uglja A od 20 mg/l (&gt;88%).&nbsp; Hibridni membranski proces&nbsp; PAC/UF je pokazao&nbsp; visoku efikasnost za uklanjanje BP-3 (&gt;68%) i CF (&gt;99,95%) sa dozom uglja od 20 mg/l. Ispitivanjem&nbsp; biodegradacije&nbsp; BP,&nbsp; BP-3&nbsp; i&nbsp; CF&nbsp; primenom&nbsp; laboratorijskog&nbsp; test filtra, postignuta je efikasnost uklanjanja pri koncentraciji od 20 &micro;g/l od&nbsp; 90% do&nbsp; 99%&nbsp; i&nbsp; pokazano&nbsp; da&nbsp; su&nbsp; supstance&nbsp; biodegradabilne.&nbsp; Testovi&nbsp; toksičnosti pokazali&nbsp; su&nbsp; značajno&nbsp; smanjenje&nbsp; ukupne&nbsp; toksičnosti&nbsp; sme&scaron;a&nbsp; tokom laboratorijskog&nbsp; testa,&nbsp; a&nbsp; rezidualna&nbsp; toksičnost&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; <em>D.&nbsp; magna</em>&nbsp; može biti&nbsp; posledica&nbsp; nedetektovanih&nbsp; transformacionih&nbsp; produkata.&nbsp; Transportom supstanci kroz sediment Dunava&nbsp; uočeno je da&nbsp; sediment predstavlja efikasnu barijeru&nbsp; za&nbsp; oba&nbsp; testirana&nbsp; benzofenona,&nbsp; dok&nbsp; CF&nbsp; lako&nbsp; prolazi&nbsp; usled&nbsp; svoje mobilnosti (log Kow -0,07). Eksperimentima fotodegradacije potvrđeno je da degradacija benzofenona UV zračanjem&nbsp; zavisi od prisustva&nbsp; anjona (HCO₃ -, Cl i SO₄^2-)&nbsp; i DOC&nbsp; u vodenom matriksu. Iako primenjeno UV zračenje nije bilo&nbsp; realno&nbsp; za&nbsp; dezinfekciju&nbsp; u&nbsp; tretmanima&nbsp; voda,&nbsp; rezultati&nbsp; su&nbsp; pokazali značaj detaljnije&nbsp; procene&nbsp; kvaliteta&nbsp; vode&nbsp; u&nbsp; slučajevima&nbsp; kada&nbsp; se&nbsp; UV&nbsp; zračenje primenjuje.Za uklanjanje odabranih supstanci iz rečne vode ispitani su&nbsp; konvencionalni procesi&nbsp; (zasebno&nbsp; adsorpcija&nbsp; na&nbsp; aktivnom&nbsp; uglju&nbsp; u&nbsp; prahu&nbsp; i&nbsp; koagulacija komercijalnim&nbsp; koagulantom,&nbsp; BOPAC &reg; )&nbsp; i&nbsp; hibridni&nbsp; ili&nbsp; nekonvencionalni<br />procesi&nbsp; adsorpcije/koagulacije&nbsp; (PAC/CoA),&nbsp; adsorpcije/ultrafiltracije (PAC/UF) kao i koagulacije/ultrafiltracije (CoA/UF). Tokom ispitivanja PAC/CoA sa ugljem B (2 mg/l) i BOPAC &reg; (2 mg Al ³⁺ /l) u određenim&nbsp; procesnim&nbsp; kombinacijama,&nbsp; (tokom&nbsp; sukcesivnog&nbsp; dodavanja&nbsp; prvo uglja&nbsp; B,&nbsp; a&nbsp; zatim&nbsp; koagulanta)&nbsp; uočene&nbsp; su&nbsp; specifičnosti&nbsp; za&nbsp; BP,&nbsp; efikasnost uklanjanja BP je iznosila 92%. U slučaju doziranja prvo koagulanta, a zatim uglja&nbsp; B&nbsp; i&nbsp; tokom&nbsp; simultanog&nbsp; doziranja&nbsp; koagulanta&nbsp; i&nbsp; uglja&nbsp; B,&nbsp; efikasnosti&nbsp; su iznosile&nbsp; 23&nbsp; i&nbsp; 20%,&nbsp; redom.&nbsp; To&nbsp; je&nbsp; verovatno&nbsp; posledica&nbsp; kompeticije&nbsp; iliblokiranja pora&nbsp; uglja&nbsp; POM iz rečne vode.&nbsp; BP-3 se efikasno uklanjao tokom svih procesnih kombinacija sa ugljem B (87-93%), dok je za CF efikasnost<br />uklanjanja iznosila&nbsp; od 0-12%.&nbsp; Hibridni procesi su se pokazali efikasniji pri<br />primeni uglja C. U slučaju BP efikasnost je iznosila 81-90% i za CF 17-27% ,dok&nbsp; je&nbsp; za&nbsp; BP-3&nbsp; efikasnost&nbsp; iznosila&nbsp; od&nbsp; 71%&nbsp; do&nbsp; 96%.&nbsp; Hibridni&nbsp; membranski procesi&nbsp; PAC/UF&nbsp; i&nbsp; CoA/UF&nbsp; u&nbsp; obradi&nbsp; rečne&nbsp; vode&nbsp; efikasni&nbsp; su&nbsp; u&nbsp; uklanjanju supstanci&nbsp; sa&nbsp; visokim&nbsp; log&nbsp; Kow.&nbsp; Benzofenoni&nbsp; su&nbsp; u&nbsp; hibridnim&nbsp; membranskim procesima&nbsp; uklonjeni&nbsp; od&nbsp; 69%-96% iz rečne&nbsp; vode, dok su za kofein utvrđeni promenljivi rezultati i potreba za daljim istraživanjima.</p> / <p>Benzophenones and caffeine are ubiquitous&nbsp; in wastewaters&nbsp; and in surface&nbsp; waters,&nbsp; in&nbsp; concentrations&nbsp; that&nbsp; vary&nbsp; from&nbsp; ng/L&nbsp; to&nbsp; mg/L. Benzophenones&nbsp; are&nbsp; used&nbsp; as:&nbsp; smell&nbsp; and&nbsp; flavor&nbsp; enhancers,&nbsp; perfume&nbsp; fixers, plastic additives, cleaning agents, as well as in the pesticide manufacturing processes.&nbsp; Their&nbsp; UV-resistant&nbsp; properties,&nbsp; makes&nbsp; benzophenones&nbsp; a&nbsp; suitable packaging component&nbsp; &ndash;&nbsp; to&nbsp; prevent UV light from damaging the odor or the color of the product. Similarly, benzophenone-3 is most commonly used in the&nbsp; cosmetics&nbsp; industry;&nbsp; as&nbsp; a&nbsp; UV&nbsp; filter&nbsp; agent&nbsp; in&nbsp; sunscreens,&nbsp; body&nbsp; lotions, shampoos, paints and hair sprays.&nbsp; On the other hand, caffeine is prevalent in food-,&nbsp; pharmaceutical-&nbsp; and&nbsp; cosmetics-manufacturing.&nbsp; However, benzophenones&nbsp; and&nbsp; caffeine&nbsp; have&nbsp; significantly&nbsp; different&nbsp; log&nbsp; Kow&nbsp; values. Log Kow values for benzophenone and benzophenone-3 are 3.18 and 3.79,respectively, while for caffeine log Kow is&nbsp; -0.07.&nbsp; Due to the lack of data on the&nbsp; content&nbsp; of&nbsp; selected&nbsp; benzophenones,&nbsp; (benzophenone&nbsp; (BP)&nbsp; and benzophenone-3&nbsp; (BP-3))&nbsp; and&nbsp; caffeine&nbsp; (CF)&nbsp; in&nbsp; different&nbsp; types&nbsp; of&nbsp; water (primarily in local wastewater and&nbsp; river water) and their behavior in water treatments, tests were&nbsp; carried out: a) in the effluent of a typical wastewater treatment&nbsp; plant (WWTP);&nbsp; b) and&nbsp; in&nbsp; the river Danube.&nbsp; In case of the WWTP effluent, the presence of all three compounds was detected in the following ranges: 0.112 &mu;g/L to 0.146 &mu;g/L for BP, 0.00718 &mu;g/L to 0.42 &mu;g/L for BP-3,&nbsp; and&nbsp; 0.2&nbsp; &mu;g/L&nbsp; to&nbsp; 12&nbsp; &mu;g/L&nbsp; for&nbsp; CF.&nbsp; With&nbsp; respect&nbsp; to&nbsp; the&nbsp; Danube&nbsp; river,&nbsp; the highest&nbsp; detected&nbsp; concentration&nbsp; for&nbsp; BP&nbsp; was&nbsp; 0.95 &mu;g/L,&nbsp; for&nbsp; BP-3&nbsp; was 0.62 &mu;g/L,&nbsp; while&nbsp; CF&nbsp; in&nbsp; Danube&nbsp; river&nbsp; sample&nbsp; was&nbsp; measured&nbsp; in&nbsp; only&nbsp; one sample, resulting in a concentration of 0.7 &mu;g/L. In addition, this&nbsp; work has investigated&nbsp; the&nbsp; efficacy&nbsp; of&nbsp; several&nbsp; treatment&nbsp; processes:&nbsp; unconventional processes&nbsp; in&nbsp; the&nbsp; WWTP&nbsp; effluent&nbsp; treatment&nbsp; (adsorption,&nbsp; coagulation, PAC/CoA, PAC/UF);&nbsp; as well as the&nbsp; conventional (adsorption, coagulation) and&nbsp; unconventional&nbsp; processes&nbsp; (PAC/CoA,&nbsp; PAC/UF,&nbsp; CoA/UF)&nbsp; in&nbsp; the treatment&nbsp; of&nbsp; river&nbsp; waters.&nbsp; Furthermore,&nbsp; the&nbsp; effects&nbsp; of&nbsp; natural&nbsp; purification processes&nbsp; in&nbsp; river&nbsp; water&nbsp; had&nbsp; also&nbsp; been&nbsp; examined&nbsp; within&nbsp; the&nbsp; scope&nbsp; of&nbsp; this research.Unconventional&nbsp; wastewater&nbsp; treatment&nbsp; processes&nbsp; were&nbsp; investigated&nbsp; at&nbsp; initial concentrations&nbsp; of&nbsp; selected substances&nbsp; that ranged&nbsp; from 0.96 &mu;g/L to 2 &mu;g/L. Adsorption&nbsp; on&nbsp; powder&nbsp; activated&nbsp; carbon&nbsp; was&nbsp; effective&nbsp; for&nbsp; removal&nbsp; of benzophenones&nbsp; (&gt; 84%&nbsp; -&gt; 94%)&nbsp; and caffeine&nbsp; (84%),&nbsp; depending on the&nbsp; dose of PAC A. Coagulation with doses of&nbsp; natural coagulant of 0.0375 mL/L&nbsp; and commercial&nbsp; coagulant&nbsp; FeCl 3 of&nbsp; 4&nbsp; mg&nbsp; Fe 3+ /L&nbsp; was&nbsp; ineffective&nbsp; for&nbsp; all substances&nbsp; (&lt;20%).&nbsp; Hybrid&nbsp; PAC/CoA&nbsp; process,&nbsp; investigated&nbsp; with&nbsp; different doses&nbsp; of&nbsp; PAC&nbsp; A&nbsp; (5&nbsp; and&nbsp; 20&nbsp; mg/L),&nbsp; natural&nbsp; coagulant&nbsp; (0.0375&nbsp; mL/L)&nbsp; or commercial coagulant (4 mg Fe 3+ /L), proved to be effective for&nbsp; the removal of BP, BP-3 and CF at a higher PAC A dose of 20 mg/L (&gt; 88%). The hybrid membrane process PAC/UF proved to be highly effective in the&nbsp; removal of BP-3 (&gt; 68%) and CF (&gt; 99.95%) with&nbsp; 20 mg/L&nbsp; of&nbsp; PAC A.&nbsp; Biodegradation of BP, BP-3 and CF had been confirmed in Danube river water sample using a&nbsp; laboratory&nbsp; test&nbsp; filter&nbsp; filled&nbsp; with&nbsp; inert&nbsp; material.&nbsp; The&nbsp; removal&nbsp; efficacy&nbsp; was 90-99%&nbsp; at&nbsp; a&nbsp; concentration&nbsp; of&nbsp; 20&nbsp; &mu;g/L.&nbsp; Toxicity&nbsp; tests&nbsp; showed&nbsp; significant reduction in total toxicity of the mixture during the&nbsp; course of the&nbsp; laboratory test,&nbsp; whereas&nbsp; the&nbsp; residual&nbsp; toxicity&nbsp; in&nbsp; relation&nbsp; to&nbsp; D.&nbsp; magna&nbsp; may&nbsp; be&nbsp; due&nbsp; to undetected transformation products. Transportation of the substances through the&nbsp; Danube&nbsp; sediment,&nbsp; indicated that sediment&nbsp; acts as&nbsp; an&nbsp; effective barrier for both tested benzophenones, while&nbsp; this is not&nbsp; the&nbsp; case with&nbsp; CF.&nbsp; Its mobility (log Kow&nbsp; -0.07) allows CF to pass through the sediment.&nbsp; Photodegradation experiments have confirmed that&nbsp; BP&nbsp; degradation&nbsp; occurs due to&nbsp; the presence of&nbsp; anions&nbsp; (HCO 3-, Cl&nbsp; 2-) and DOC in the aqueous matrix. Although the applied UV radiation was&nbsp; not a realistic representation of disinfection in conventional water treatments, the results showed the importance of a more detailed&nbsp; assessment&nbsp; of&nbsp; the&nbsp; water&nbsp; quality&nbsp; in&nbsp; cases&nbsp; where&nbsp; UV&nbsp; radiation&nbsp; is applied.&nbsp; Herien&nbsp; investigated&nbsp; are&nbsp; also&nbsp; conventional&nbsp; processes&nbsp; (separately adsorption on PAC,&nbsp; and coagulation&nbsp; with commercial coagulant -&nbsp; BOPAC &reg; ) and hybrid or unconventional&nbsp; adsorption/coagulation&nbsp; processes (PAC/CoA), adsorption/ultrafiltration (PAC/UF) and coagulation/ultrafiltration (CoA/UF) for the&nbsp; removal of the selected substances from river water.The efficiency of BP&nbsp; removal&nbsp; via&nbsp; PAC/CoA&nbsp; with&nbsp; PAC&nbsp; B&nbsp; (2&nbsp; mg/L)&nbsp; and&nbsp; BOPAC &reg; (2 mg Al 3+ /L)&nbsp; observed&nbsp; specificity&nbsp; of&nbsp; removal&nbsp; of&nbsp; BP&nbsp; in&nbsp; certain&nbsp; process combinations, such as successive addition of first PAC B and then coagulant. The efficacy of such BP removal was 92%. In case of the initial coagulant dosing, then PAC B, and in the case of simultaneous dosage of coagulant anPAC&nbsp; B,&nbsp; efficacy&nbsp; were:&nbsp; 23%&nbsp; and&nbsp; 20%,&nbsp; respectively.&nbsp; Such&nbsp; outcome&nbsp; is probably&nbsp; a&nbsp; result&nbsp; of&nbsp; the&nbsp; competition/blocking&nbsp; of&nbsp; natural&nbsp; organic&nbsp; matter&nbsp; in river&nbsp; water.&nbsp; BP-3&nbsp; was&nbsp; efficiently&nbsp; removed&nbsp; during&nbsp; all&nbsp; process&nbsp; combinations with&nbsp; PAC&nbsp; B&nbsp; (87-93%),&nbsp; while&nbsp; the&nbsp; efficiency&nbsp; of&nbsp; CF&nbsp; ranged&nbsp; from&nbsp; 0-12%.&nbsp; In general, hybrid process proved to be more efficient in case of PAC C. For BP and&nbsp; CF,&nbsp; the&nbsp; efficacy&nbsp; of&nbsp; removal&nbsp; amounted&nbsp; to&nbsp; 81-90%&nbsp; and&nbsp; 17-27%, respectively, wheareas the efficiency of BP-3 removal was found to be in the range&nbsp; of&nbsp; 71-96%.&nbsp; For&nbsp; the&nbsp; treatment&nbsp; of&nbsp; river&nbsp; water,&nbsp; hybrid&nbsp; membrane processes PAC/UF and&nbsp; CoA/UF are effective in the removal of&nbsp; substances with&nbsp; high&nbsp; log&nbsp; Kow.&nbsp; Benzophenones&nbsp; were&nbsp; removed&nbsp; from&nbsp; hybrid&nbsp; membrane processes&nbsp; by&nbsp; 69%-96% from river water, while caffeine was found to have less consistent results and requires further research.</p>

<p>Fluoride has been detected in groundwater in many places throughout the world and its concentration is often higher than the WHO standard of 1.5 mg/L. Too much fluoride can cause teeth and skeletal issues in the body and inhibit local economic growth. Fluoride concentration in the local groundwater in the Rajasthan region of India is above 5 mg/L and poses significant health risks to local people. Electrocoagulation and electrodialysis have been used for fluoride removal but information on their application for cost-effective removal of fluoride in groundwater is still limited. The aim of this study was to develop and evaluate cost-effective defluoridation systems to remove fluoride from 5 mg/L to below 1 mg/L in the groundwater. Multiple electrocoagulation reactors were fabricated with an aluminum anode and copper/steel cathode. Fluoride concentrations decreased from 5 mg/L to below 1 mg/L within 2 hours of electrocoagulation under an applied potential of 8 V. Under a lower applied potential of 5 V, fluoride concentration was reduced to below 1 mg/L after 6 hours 30 minutes and further reduced to 0.191 mg/L after 9 hours 30 minutes. Our results showed that higher voltage led to higher removal efficiency at a cost of higher energy consumption. The results showed that aluminum alloy used as the anode released impurities into the water during electrocoagulation and could affect fluoride removal efficiency. In addition, synthesized groundwater with different hardness levels was prepared to simulate water quality in the groundwater in the Rajasthan region of India. The results showed that high hardness inhibited fluoride removal efficiency. An electrodialysis reactor was tested as well on the removal performance of anions, including fluoride and chloride. Fluoride concentration after one hour of electrodialysis did not decrease below 1 mg/L but showed a promising trend for effective fluoride removal. However, cation permeable membrane and anion permeable membrane are relatively expensive and could affect the overall cost-effectiveness of fluoride removal with electrodialysis. These results showed that both electrocoagulation and electrodialysis were effective in removing fluoride from groundwater. Their long-term performance and overall cost-effectiveness need further investigation.  </p>

The overuse and misuse of antibiotics to treat bacterial infections, the release of unmetabolized residuals into the sewer system, and the incomplete removal antibiotic residues by wastewater treatment plants (WWTPs) pose a severe threat to human health. The accumulation of antibiotic residue induces selective pressure on the bacterial population, resulting in the spread of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) in water. This study investigated the degradation of different types of ARGs in water matrices using a wide variety of treatment technologies. Real wastewater samples were collected from a WWTP in urban Philadelphia and the presence of single and multidrug-resistant bacteria and resistance genes were investigated using molecular-based techniques. Subsequently, an analytical method was developed and validated for the detection and quantification of the ARGs against a range of antibiotics, such as tetracycline (TCN), ciprofloxacin (CIP), and levofloxacin (LVX). Finally, to remove the ARGs from water matrices, different conventional and advanced oxidation processes were applied. At the very onset, conventional treatment processes such as chlorine treatment was used to inactivate the E.coli resistant strains. It was observed that chlorination can potentially deactivate the ARBs by applying a lower dose and contact time. However, the effectiveness of chlorine treatment in removing all types of ARGs from water matrices was limited. For instance, no significant degradation of extracellular ARGs (e-ARGs) was observed in DI water during chlorine treatment. Subsequently, a peracetic acid (PAA) based treatment process was used to degrade the genomic and plasmid-encoded ARGs from the water matrices. Similar to chlorine treatment, no significant changes were observed in the degradation of extracellular ARGs (e-ARGs) in DI and WW. Then, the degradation kinetics of ARGs across different types (gyrAR, tetAR, qnrSR) and forms (chromosomal, plasmids) were evaluated using the Ultraviolet (UV) disinfection process. Compared to chlorination and PAA, UV treatment showed better removal efficiencies for the degradation of different types of e-ARGs in DI water. The degradation profile of e-ARGs showed 1-4 log reductions at a UV fluence of 900 mj/cm2. The i-ARGs showed similar degradation rates as compared to e-ARGs in phosphate buffer saline (PBS) at the same UV dosage. On the other hand, the regrowth potential of ARBs at low UV dosage (60–180 mJ/cm2) showed the evidence of damage repairment after several hours of exposure to light (photoreactivation) and dark conditions, making it susceptible again to the resistance spread. To resolve this issue, process parameters were optimized, and no regrowth of the ARBs were found from the higher fluence from 300 to 600 mJ/ cm2. Later, UV/ H2O2 based AOP was applied to evaluate the degradation and deactivation of the same resistant genes. The addition of H2O2 during the UV treatment produces strongly reactive •OH radicals during the treatment and showed considerable improvements in e-ARGs degradation (1.2-5 logs) compared to UV treatment alone. However, this AOP showed minimal contribution to i-ARG degradation (1-2.4 logs), possibly due to the scavenging of •OH radicals by the cellular components in PBS. In contrast to PBS, the wastewater matrix moderately enhanced the gene degradation during the treatment. In terms of plasmid degradation, the conformational differences of the supercoiled structures showed 1.2-2.8 times slower degradation rates than chromosomal ARGs. In addition, the degradation kinetics of the free residual ARGs (f-ARGs) were assessed during the treatment to reduce the AMR dissemination risk from the treated sample. This study also examined the potential of ozone (O3) based oxidation process to degrade and deactivate the extracellular and intracellular ARGs, and MGE (plasmid, intl-1) from E.coli ARBs. The degradation kinetics of the ARGs across different sizes (118-454 bps) and types were evaluated in different water matrices (DI water, PBS, and WW), and showed a significantly higher removal for chromosomal, and plasmid encoded ARGs than other treatment technologies. For the e-ARGs in DI water, 3.8-5.2 logs removal was observed at ozone dosage of 2.0 × 10-2 M.s. i-ARGs in PBS and wastewater showed nearly similar degradation (3.8-5 logs) during O3, indicating the elimination of i-ARGs was not dependent on the cellular components and effluent organic matter. Moreover, an analysis of environmental DNA (eDNA) from wastewater was conducted to examine the degradation of DNA and ARGs for different storage periods and temperatures (-20°C, 0°C, 4°C, 22±0.87°C). Result indicated that water samples kept at -20°C and 0°C showed the best performance in preventing the DNA concentration and gene degradation over time. Additionally, the effectiveness of different preservatives (Longmire buffers: LB1 and LB2, benzalkonium chloride at 0.1%, 0.01%) were investigated in preserving the DNA integrity and the gene degradation at an ambient temperature. It was found that the Longmire buffer (LB1) exhibited lowest gene degradation during the three-week storage period. In summary, this research provided a comprehensive assessment on the degradation of e-ARGs, i-ARGs, and free ARGs from water using different treatment technologies (i.e., UV, UV/H2O2, O3, PAA, chlorine). Additionally, this study suggested valuable information on optimizing the process parameters of the selected methods and developed a comparative assessment of removing the ARGs from the water matrix (DI/PBS, WW). The estimation of Electrical Energy per Order (EEO, kWh/m3) during UV and ozone treatments provided a comparison of the energy consumption for ARGs degradation in the water. Overall, the findings of this study can be useful for evaluating different types and forms (chromosomal, plasmid) of ARG degradation from water matrices and can help to reduce the risk of AMR dissemination in the environment. / Civil Engineering

Radon dissolved in drinking-water can be transferred into the indoor air and is one of the main transfer pathways for radon. At water purification plants, large quantities of water are treated and there is a risk that radon degasses from the water and enters into the indoor air. Hence, there is a risk for elevated radon levels in the indoor air at these facilities. This study aims to investigate the general impact of water treatment processes on the radon concentration in water and its transfer into the indoor air. Moreover, the risk that radon exposure exceeds the regulatory limits at workplaces was investigated. In total, the results from 39 Swedish water purification plants are included in the study. The methodology includes long-term air measurements with alpha track detectors, and short-term air measurements with AlphaGUARDs. In addition, water samples were collected in order to analyze the radon concentration in the untreated and treated water. The results show that several plants experience elevated radon levels in the indoor air and in some cases the exposure could be problematic. Several connections were investigated without finding apparent connections for those cases. For example, the relation between radon concentration in the water and radon level in the indoor air was investigated and the connection between the volume of water treated and the radon level in the indoor air. Calculations with transfer coefficients indicate that the transfer of radon into the indoor air is relatively small. However, there can also be contribution from other radon transfer pathways, such as soil and buildings, which may have an impact on the radon levels in the indoor air.

Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard. / Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium. / In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.

<div> Here, the quartz crystal microbalance with dissipation monitoring (QCM-D) is employed to explore the interaction of the various free oxidant species with condensed PA model membranes in order to improve our understanding of how the interaction with these species affects rates of membrane chlorination and alter membrane structure. Molecular-scale mass uptake and changes in the dissipative nature of the of the model membranes as measured by the QCM is correlated to performance changes in interfacially polymerized PA reverse osmosis (RO) membranes. Leveraging newly gained insights from these measured interactions, new strategies are explored to improve flux and chlorine resistance using novel membrane structure and chemistry.<br></div>

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology, 2016 / Natural organic matter if not removed from water used for electricity generation has dire consequences that affect the long term plant health. The main problem is that organic matter at higher temperature and pressure disintegrate into smaller organic acids and carbon dioxide. This causes the cycle water and steam to be acidic and this can result in corrosion of the plant. The raw water from the Komati (Arnot power station) and Usutu (Kriel power station) scheme were analysed to determine the organic profile and seasonal variation. There was a noticeable variation in the quality of the water with an increase in DOC during rainy season. The water was found to be containing hydrophobic as well as hydrophilic molecules that could be quantified with a liquid chromatography organic detector (LC-OCD). Current water treatment processes employed at the two stations, Arnot and Kriel, has demonstrated the capability of removing organics to just over 50 percent at the pre-treatment section. The water treatment plant includes demineralisation plant that was able to produce water that met Eskom’s target specifications of less than 250 ppb DOC values. Qualitative and quantitative analysis of the steam-condensate water was done by use of an ion chromatography method. The determined organic anions were found to be acetates, formats and lactates.

Neste trabalho, a partir da aplicação da teoria de controle ótimo, são estabelecidos sistemas de controle aplicáveis a três importantes sistemas aeróbios de tratamento de esgotos - filtros biológicos, processos de lodos ativados e os processos combinados formados a partir da combinação dos filtros biológicos e lodos ativados. Para a definição dos sistemas de controle são necessários modelos dinâmicos que descrevam o comportamento dos diferentes sistemas de tratamento. Da literatura são obtidos os modelos dinâmicos destinados à descrição do comportamento do processo de lodos ativados; para o filtro biológico, é proposto um modelo combinando à equação de balanço do reator e o modelo de ordem variável, este último destinado ao cálculo do fluxo de substrato para o interior de biofilmes profundos. Os resultados demonstram que, independentemente do sistema de tratamento considerado, os sistemas de controle reduzem substancialmente os tempos de acomodação e os desvios apresentados pelas variáveis de estado em relação as suas condições de equilíbrio. Por fim, função da inviabilidade de monitoramento de todas as variáveis de estado utilizadas para caracterizar os sistemas de tratamento, são propostos, a partir de modelos simplificados, controladores que incorporam a observação de estados. Também neste caso, os controladores estabelecidos permitem melhorar significativamente o desempenho dos sistemas de tratamento de esgotos analisados. / This paper constructs automatic control systems by means of optimal control theory for three different combinations of wastewater treatment units, namely, trickling filter, activated sludge process and a combined process. The dynamic model for the activated sludge process available in literature and a model proposed for the trickling filter were used in the construction of control systems. It is shown that the controls obtained in this study substantially reduce the durations necessary for the reestablishment of the equilibrium conditions in terms of state variables and the attenuation of oscillations around these conditions. Controls including observers for the state variables were devised on the basis of simplified models for the process in order to deal with the difficulties involved in monitoring all the state variables. These control systems were also found to be quite effective in improving the performance of the wastewater treatment plants considered in this paper.

Alguns dos chamados processos oxidativos avançados (POA) foram aplicados após um processo biológico anaeróbio no tratamento de efluentes do processo industrial de branqueamento da polpa celulósica, visando a aumentar a biodegradabilidade desses efluentes e remover compostos tóxicos, de modo a permitir que um posterior tratamento biológico possa ser mais eficiente e atender às regulamentações ambientais. Para que esse objetivo fosse alcançado, as seguintes etapas de tratamento foram realizadas: processo biológico realizado em reator anaeróbio horizontal de leito fixo (RAHLF), visando à redução inicial da carga orgânica do efluente, seguido de aplicação de um dos POA: 'O IND.3', 'O IND.3'/'H IND.2'O IND.2', 'O IND.3'/UV, UV, 'H IND.2'O IND.2', 'H IND.2'O IND.2'/UV e 'O IND.3'/'H IND.2'O IND.2'/UV, visando a aumentar a biodegradabilidade dos compostos recalcitrantes encontrados no efluente do primeiro tratamento biológico e diminuir a toxicidade. No tratamento biológico, a biomassa anaeróbia se adaptou facilmente à água residuária. Dessa forma, o reator atingiu a estabilidade e apresentou eficiências de remoção de DQO e AOX adequadas para esta etapa da pesquisa (média de 50%), satisfazendo o objetivo de promover uma redução inicial da matéria orgânica de fácil degradação presente nessa água residuária. Com relação aos POA, foi concluído que todos os processos testados provocaram modificações na biodegradabilidade do efluente do RAHLF. O processo 'O IND.3'/UV, realizado em meio neutro, foi considerado o mais eficiente, provocando um aumento de biodegradabilidade de 160%, após 45 minutos de oxidação com uma concentração de ozônio de 1155 mg/L. Através da análise de AOX, observaram-se também degradações médias dos compostos organoclorados maiores que 95% para todos os processos testados. Os resultados gerais mostram a importância e a vantagem de se utilizar um POA como complemento de um tratamento biológico para efluentes de baixa biodegradabilidade, provocada pela presença de compostos recalcitrantes e tóxicos. / Some advanced oxidation processes (AOP) were applied after an anaerobic process for the treatment of bleaching effluents from a kraft pulp mill, aiming the increase of the effluent biodegradability and the removal of toxic compounds, in a way that a further biological treatment could be more efficient to attain the environmental regulations. A horizontal anaerobic imobilizaded sludge reactor (HAIS) was used as the anaerobic treatment in order to reduce the effluent initial organic load. The AOP used were 'O IND.3', 'O IND.3'/'H IND.2'O IND.2', 'O IND.3'/UV, UV, 'H IND.2'O IND.2', 'H IND.2'O IND.2'/UV and 'O IND.3'/'H IND.2'O IND.2'/UV. These AOP were not applied only to promote a further degradation of the remaining COD from the HAIS reactor, but in order to increase the effluent biodegradability and eliminate AOX or other toxic compounds from this effluent. In this way, the AOP would provide an effluent with characteristics to be easily treated by a further and final biological process. In the biological process, the anaerobic biomass was fast adapted to the wastewater. The HAIS reactor reached the stability and had efficiency in COD and AOX removals of approximately 50%, satisfying the aim of promoting an initial reduction in the easy-to-degrade organic matter presented in the bleaching effluents. All the tested AOP promoted modifications in de HAIS effluent biodegradability. The 'O IND.3'/UV at pH 8 was the more efficient process, achieving an increase of 160% on the biodegradability of the HAIS effluent after 45 minutes of oxidation and an ozone concentration of 1155 mg/L. By the AOX analyses, it was observed average degradations of the organochlorine compounds higher than 95% for all the AOP tested. The general results show the importance and the advantage of using an AOP as a complement of a biological treatment process for the degradation of effluents with low biodegradability, due to the presence of recalcitrant and toxic compounds.