Performance of Italian zeolitic tuffs and pozzolana in 2-chlorophenol removal from contaminated groundwater. Lab-scale experience

The physical and chemical properties of zeolites and the availability of localized deposits of naturally occurring zeolitized tuffs and pozzolana, make them desirable for and applicable to the remediation of contaminated groundwater. This paper documents the results of a laboratory study to test the capacity of native Italian zeolites to remove 2-chlorophenol (2-CP) from water. Italian zeolitic tuff and pozzolana were characterized in terms of their chemical and structural properties and of their adsorption capacities. Moreover, the experimental activity investigated their adsorption behaviour: time and pH dependence of the adsorption process was evaluated. The results of the time-dependence adsorption study under a constantly stirred condition showed that the adsorption increases with a longer contact time for all samples; the highest adsorption occurred at pH=8 divided by 8.5. Due to the good removal efficiencies obtained, a column test simulating the condition of an in situ permeable reactive barrier was carried out, in order to estimate the removal kinetics and the long-term behaviour. The removal efficiencies reached values higher than 90%, even if some long-term performance worsening occurred, due to the progressive exhaustion of the adsorption sites. These experiments demonstrate the capacity of naturally occurring zeolites to remove 2-CP from water and the opportunity to make economic use of these native deposits for in situ groundwater remediation

Fate of selected drugs in the wastewater treatment plants (WWTPs) for domestic sewage

The wide diffusion of Emerging Organic Micropollutants (EOMs) in the environment is receiving increasing attention due to their potential toxicological effects on living organisms. So far, the Wastewater Treatment Plants (WWTPs) have not been designed with the purpose to remove these contaminants; therefore, they can represent the major source of release into the environment both through the effluent and the wasted sludge. The fate of EOMs in the WWTPs is still not completely known; further investigations are therefore needed to assess if it is possible to exploit the existing treatment units to reduce EOM concentrations or which processes must be implemented to this purpose. Among the wide class of EOMs, the present study focused on the following drugs of abuse: amphetamine (AM), methamphetamine (MET), 11-nor-Δ9-THC-9carboxy (THC-COOH) and benzoylecgonine (BEG). Presence and removal efficiency of these drugs in the activated sludge tank of a WWTP for domestic sewage was investigated through analyses at both full-scale and laboratory scale. Determinations conducted in the full-scale WWTP highlighted that, among the searched drugs, AM was found to be the most abundant in the influent and effluent of the biological oxidation tank, while 11-nor-Δ9-THC-9carboxy was present at the lowest concentration. Some removal took place in the units prior to the oxidation tank, although the main reduction was observed to occur in the biological oxidation reactor. All the drugs showed a wide variability of the measured concentrations during the week and the day. Taking into account results from both full-scale observations and batch tests, removals in the biological reactor were found within the following ranges: 33–84% for AM, 33–97% for MET, 33–57% for BEG and 29–83% for THC-COOH. These removals were due to a combination of adsorption and biodegradation mainly, while volatilization did not play a significant role. Other processes, e.g. hydrolysis, were likely to occur. © 2017 Springer-Verlag Berlin Heidelber

Magnetic core nanoparticles coated by titania and alumina for water and wastewater remediation from metal contaminants

Nanomaterials have been widely used for remediation of contaminated streams. However, using nanomaterials within water and wastewater might be dangerous since fate and health impact of nanoparticles is still unknown. Therefore, it is mandatory to avoid contamination by removing all the nanoparticles from the treated stream. This can be performed by immobilizing the nanoparticles on supports, although this approach leads to lower efficiency values. Another possibility is to use suspended nanoparticles: in this case, efficiency of the treatment process is enhanced. If nanomaterials have a magnetic core-shell, then suspended nanoparticles can be removed in a safe and easy was by using magnetic traps. In the present study, new nanomaterials based on magnetic core-shell structure were developed: the magnetic core guarantees a complete removal from the treated water and wastewater streams, whereas the shell (coating) is functionalized to eliminate specific classes of pollutants. A first experimental step allowed to produce the magnetic nanoparticles and perform a coating with SiO2 in order to electrically isolate the core from the ambient and to avoid degradation. This procedure is well established and the production of SiO2 coated magnetic nanoparticles are nowadays a validated procedure by using a spinning disk reactor.In a successive step, the silica shell magnetic cores were coated by titania and/or activated alumina particles with the aim of removing metals by adsorption. In the present study, the arsenic adsorption capacity of silica shell magnetic cores nanoparticles coated by titania and/or activated was investigated through kinetic experiments. All the tested adsorbents performed very well showing very rapid rates of the adsorption process. Among them, the best performing media were found to be those with titania coating. The best fitting kinetic model was found to be the pseudo-second order one for all of the adsorbents

Editorial for special issue “Supergene evolution of polymetallic deposits, including non-laterite fe and mn ores”

This Special Issue of Minerals published 3 years after the issues on non-sulphide ore deposits [...

Os contornos da mediação intercultural na educação contemporânea: delineamentos e projeções

O processo da globalização, aliado ao uso das novas tecnologias de informação e comunicação, permeia o presente embate cultural, pois viabiliza não só o contacto pessoal mas também virtual entre inúmeras pessoas de diferentes proveniências, numa proporção inimaginável há algumas décadas. O conceito de mediação intercultural tem sido elaborado no contexto da comunicação em relação com os processos oriundos dos fenómenos de mobilidade transnacional. Estas questões têm tido um impacto assinalável nos debates académicos contemporâneos, particularmente no contexto educacional, que tem vindo progressivamente a dar uma maior importância à mediação. Em 2018, o Conselho da Europa publica um volume de acompanhamento ao Quadro Europeu Comum de Referência para as línguas (QECR), publicado em 2001, que apresenta um quadro de descritores que incidem na mediação em relação com o ensino/aprendizagem de línguas. Face a este cenário, o presente artigo faz uma breve análise crítica do documento, acentuando o papel da mediação intercultural da perspetiva da educação para a paz, apresentando alguns vetores desses documentos reguladores (Conselho da Europa, 2001, 2018) e enfatizando a nova dimensão da mediação intercultural prevista neste último em relação intrínseca com a aprendizagem de línguas. A mediação adquire, assim, relevância para professores e formadores que desejam obter melhores resultados em seus encontros comunicativos em contextos plurilingues e pluriculturais, especialmente quando há elementos interculturais envolvidos. Acreditamos que a cultura de não-violência ou cultura de paz e, principalmente, uma educação para cidadania global intercultural, sejam questões inerentes à formação de professores de línguas, de modo a que estes possam melhor gerir o processo comunicativo e orientar ações de cidadania global. No final interrogamo-nos em que medida é que o objetivo principal deste novo documento do Conselho da Europa dedicado à mediação poderá ser alcançado, sem que se considerem alguns aspetos veiculados quer pelas teorias da comunicação, quer pelas teorias da mediaçãoinfo:eu-repo/semantics/acceptedVersio

Study of the performance of disinfection with sodium hypochlorite on a full-scale sewage treatment plant

A full-scale sewage treatment plant was investigated to assess the performance of the disinfection stage. Sodium hypochlorite was used as a disinfectant agent and the process efficiency was evaluated by E.coli removal. The research took place over a period of two years in order to evaluate the effect of retention time (t) and residual chlorine (Cr) under different seasonal conditions. The effectiveness of E.coli removal with sodium hypochlorite proved to be strictly dependent on the factor CR t (product of residual chlorine with the contact time). The regression line of the experimental points was, on the whole, well comparable with the model proposed by Collins, especially in the field of CRt lower than 30 mg L-1 min

Remediation of Lead-Contaminated Water by Virgin Coniferous Wood Biochar Adsorbent. Batch and Column Application

In this paper, RE-CHAR® biochar, produced by a wood biomass pyrolysis process, which is usually applied as a soil fertilizer, was investigated for a novel use, that was as adsorbent for remediating a lead-contaminated solution. Firstly, a deep physical and chemical characterization of RE-CHAR® biochar was carried out. Then, the adsorption capacity of lead from 50 to 100 mg/L solutions was determined under batch and continuous flow conditions. Kinetics of the batch adsorption process were very rapid and complete removal was achieved within 4-h contact time at both Pb concentrations, using a biochar dosage of 5 g/L. These data were best fitted by the pseudo-second-order model, with the rate constant and the equilibrium capacity equal to ks = 0.0091 g/min and qe = 9.9957 mg/g at 50 mg/L Pb and ks = 0.0128 g/min and qe = 20.1462 mg/g at 100 mg/L Pb, respectively. The Langmuir isotherm model best fitted the equilibrium data at both Pb concentrations, with the Langmuir constant and maximum adsorption capacity equal to b = 11.5804 L/mg and qmax = 4.6116 mg/g at 50 mg/L Pb and b = 2.8933 L/mg and qmax = 9.5895 mg/g at 100 mg/L Pb. Continuous flow column tests showed that adding biochar to the soil of the adsorbent bed significantly extended the breakthrough and exhaustion times, with respect to the column filled with soil only. The Thomas model best fitted the experimental data of the breakthrough curves, with the constant kTH = 5.28 × 10−5 mL/min/mg and the maximum adsorption capacity q0 = 334.57 mg/g which was comparable to the values reported for commercial adsorbents. Based on these results, it can be assessed that RE-CHAR® biochar can be used as an effective adsorbent for lead removal from water solutions even at high concentrations

Do trágico à clínica do possível no cuidado de usuários de drogas

The article describes an intervention research conducted in a city of southern Brazil with users of alcohol and other drugs considered "nonadherent" to the treatment offered in psychosocial care network in the region. Sustaining an inclusive approach and anti-prohibitionist, the study identify the paths taken by drug users in the territory in order to identify "nodes" of the network (rituals, strategies, services, affections). This can indicate a possible Care Clinic based on affection and bond. It is discussed the polarization of the political debate about drugs. It was made a bet on Harm Reduction as a guideline care from the per - spective of overcoming the resentment commonly impregnated in the practices and discourses from the area. Among the results was possible to identify the collective production of a rap music in the middle of the investigative process, this "gives another tone" to the experiences and positions of the patients, pointing to the creation of new existential territories as an alternative to public policies committed with health promotion.O artigo relata uma pesquisa-intervenção realizada em município do sul do Brasil com usuários de álcool e outras drogas tidos como “não aderentes” aos tratamentos ofertados na rede de atenção psicossocial da região. Sustentando uma abordagem inclusiva e anti-proibicionista, o estudo cartografou caminhos tecidos pelos usuários de drogas no território, a fim de identificar quais “nós” da rede (rituais, estratégias, serviços, afetos) apontam uma Clínica do Possível pautada no cuidado e no vínculo. Problematiza a polarização do debate das políticas sobre drogas, apostando na Redução de Danos como diretriz de um cuidado na perspectiva da superação dos ressentimentos comumente impregnados às práticas e discursos dessa área. Entre os resultados, a experimentação de uma produção coletiva que emerge na criação de um rap em meio ao processo investigativo, “dá um outro tom” às vivências e posições dos usuários, apontando à criação de novos territórios existenciais como alternativa às políticas públicas compromissadas com a produção de saúde

Biohydrogen production from food waste: Influence of the inoculum-to-substrate ratio

In this study, the influence of the inoculum-to-substrate ratio (ISR) on dark fermentative hydrogen production from food waste (FW) was evaluated. ISR values ranging from 0.05 to 0.25 g VSinoculum/g VSsubstrate were investigated by performing batch tests at T = 39 °C and pH = 6.5, the latter being the optimal value identified based on a previous study. The ISR was found to affect the fermentation process, clearly showing that an adequate ISR is essential in order to optimise the process kinetics and the H2 yield. An ISR of 0.14 proved to optimum, leading to a maximum H2 yield of 88.8 L H2/kg VSFW and a maximum production rate of 10.8 L H2/kg VSFW∙h. The analysis of the fermentation products indicated that the observed highest H2 production mostly derived from the typical acetate/butyrate-type fermentation

Meiosis progression and donor age affect expression profile of DNA repair genes in bovine oocytes

Several genetic and physiological factors increase the risk of DNA damage in mammalian oocytes. Two critical events are meiosis progression, from maturation to fertilization, due to the extensive chromatin remodelling during genome decondensation and aging which is associated to a progressive oxidative stress. In this work, we studied the transcriptional patterns of three genes, RAD51, APEX-1 and MLH1, involved in DNA repair mechanisms. The analyses were performed by Real-Time quantitative PCR (RT-qPCR) in immature and in vitro matured oocytes collected from 17 ± 3 mo old heifers and 94 ± 20 mo old cows. Batches of 30-50 oocytes for each group (three replicates) were collected from ovarian follicles of slaughtered animals. The oocytes were freed from cumulus cells at the time of follicle removal, or after IVM carried out in M199 supplemented with 10% foetal calf serum, 10 IU LH /ml, 0.1 IU FSH /ml and 1 µg 17β-oestradiol/ml. Total RNA was extracted by Trizol method. The expression of bovine GAPDH gene was used as internal standard, while primers for bovine RAD51, APEX-1 and MLH1 genes were designed from DNA sequences retrieved from GeneBank. Results obtained indicate a clear up-regulation of RAD51, APEX-1 and MLH1 genes after IVM ranging between 2- and 4-fold compared to GV oocytes. However, only RAD51 showed a significant transcript increase between the immature oocytes collected from young and old individuals. This finding candidates RAD51 as gene marker for discriminating bovine immature oocytes in relation to the donor age