Intensification of supercritical water oxidation (ScWO) by ion exchange with zeolite for the reuse of landfill leachates.

The disposal of solid residues in sanitary landfills results in the formation of a complex, variable, and recalcitrant wastewater, known as leachates. Supercritical water oxidation (ScWO) can be applied to treat leachates although most studies are based on removing the most relevant contaminants, such as organic matter and ammonia. Therefore, comprehensive analysis of this process is essential for large-scale applications. In this study, we investigated a system composed of ScWO and ion exchange using zeolite (ScWO/zeolite) for the reuse possibilities of treated leachates based on different regulations for municipal wastewater reuse. This system was applied to both raw leachate (RL) and leachate treated via conventional processes at the studied landfill (PL). The continuous ScWO reactor operated under a pressure of 23 MPa at 600 °C without the addition of oxidants. A commercial zeolite (clinoptilolite) in a fixed-bed glass column was used for ion exchange. The intensified system significantly improved the characteristics of RL by removing 89% of COD and 99% of NH3-N. Moreover, the contaminant concentrations of PL were within the limits for discharge and reuse, except arsenic and molybdenum contents. The unexpected high concentrations of arsenic in RL and PL necessitated the requirement of further investigation of the complex and toxic characteristics of leachates. Nevertheless, the intensified process was conducted without the addition of oxidants or auxiliary substances and resulted in a less expensive and more environmentally -friendly process that can be applied for the treatment of leachates with similar characteristics.

Evaluation of hospital laundry effluents treated by advanced oxidation processes and their cytotoxic effects on Allium cepa L.

Hospital laundries are responsible for a significant part of the amount of wastewater that is generated in hospitals. Hospital laundry wastewater represents a complex mixture of chemicals that arouse concerns about possible environmental risks. The objective of the present study was to evaluate the cytotoxicity of different laundry effluents from the Regional University Hospital of Maringá, Paraná, Brazil, on Allium cepa L. meristematic root cells. The effluents were characterised as rinsing, wetting, prewashing, washing, softening, wastewater (the effluent generated at the end of the washing process), the wastewater that was treated by physicochemical (PC) processes and the wastewater that was treated by advanced oxidation processes (PC + UV, PC + H2O2 and PC + UV/H2O2). The mitotic indexes were calculated by scoring 5000 cells per group and the statistical analyses were performed by one-way ANOVA, followed by Tukey's post-test (α = 0.05). Results showed that the rinsing, wetting, prewashing and wastewater laundry effluents were cytotoxic at 24 h of exposure, significantly reducing the mitotic index. Despite the slight cytotoxicity of the PC + UV/H2O2 treatment, physicochemical and advanced oxidation processes efficiently reduced the critical parameters of wastewater, such as the biochemical and chemical oxygen demands, to tolerable levels of effluent discharge. It is essential to perform constant monitoring of these effluents in order to reduce the possible occurrence of environmental impacts.

Adsorption of naturals hormones estrone, 17ß-estradiol, and estriol by rice husk: monocomponent and multicomponent kinetics and equilibrium.

In the present study, the use of the rice husk biomass as an alternative biosorbent for treating the estrone, 17 ß-estradiol, and estriol hormones in monocomponent and multicomponent systems was investigated. The high-performance liquid chromatography technique (HPLC-UV) was applied in order to quantify the hormones, validating this method according to ANVISA and INMETRO. The biosorbent presented functional groups typical of cellulose, hemicellulose, lignin, and proteins, with an amorphous, fibrous, and porous surface. The best performance was obtained with a neutral pH and at room temperature (25[Formula: see text]C). The equilibrium times in batch systems were 60 min for the estrone, and 120 min for 17 ßestradiol and estriol. The monocomponent kinetics of adsorption of estrone and estriol were adequately described by the pseudo-first-order model, whereas for the 17 ß estradiol both pseudo-first-order and pseudo-second-order models well described the experimental data. For the multicomponent system, the kinetics of adsorption was appropriately represented by the pseudo-first-order model, demonstrating that the number of active sites was the limiting factor of the process. The monocomponent adsorption isotherms were adequately fitted by the Langmuir model, reaching adsorption capacities of 2.698, 1.649, and 0.979 mg g-1 for the estrone, 17 ßestradiol, and estriol hormones, respectively. The ternary isotherm models did not represent the experimental data, indicating that there was no competition among the hormones. The reactions presented favourable and spontaneous characteristics. The rice husk biomass showed a great potential as an adsorbent when treating effluents contaminated with hormones.

Intensification of supercritical water oxidation (ScWO) process for landfill leachate treatment through ion exchange with zeolite.

Over the past few years, supercritical water oxidation (ScWO) has shown great potential for application to landfill leachate treatment, providing substantial organic matter degradation in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC). However, the conversion of ammonia, which is present at high concentrations in leachates, is the rate-limiting step during ScWO and usually requires large amounts of oxidants, the addition of catalysts, or severe operating conditions. Aiming at proposing a treatment system that effectively removes both organic matter and ammonia from leachate, this paper evaluates the intensification of the ScWO process through ion exchange with zeolite. Thus, ScWO was operated under a pressure of 23 MPa at 600 and 700 °C, without the addition of oxidants. The zeolite (clinoptilolite) was used without any modification inside a glass column. The ScWO (600 °C)/zeolite system removed 90% ammoniacal nitrogen (NH3-N), 100% nitrite (NO2-N), 98% nitrate (NO3-N), color, and turbidity, 81% TOC, and 74% COD, suggesting that this system is a promising alternative for leachate treatment. However, the final NH3-N and COD values were slightly above the limits (20 and 200 mg L-1, respectively) stipulated by the Brazilian environmental legislation. These results suggest that further improvements are still required for the application of the intensified ScWO to be feasible. Notably, ammonium-saturated clinoptilolite is amenable for regeneration or can be applied to soil as a slow-release fertilizer.

Identification of organic compounds in landfill leachate treated by advanced oxidation processes.

Landfill leachates are considered to be complex effluents of a variable composition containing many biorecalcitrant and highly toxic compounds. Considering the shortage of studies concerning the treatment of landfill leachates using ozone, as well as its combination with catalysts, the aim of this paper was to identify the organic compounds in this effluent treated with advanced oxidation processes (AOPs) of ozonation (O3), and heterogeneous catalytic ozonation with TiO2 (O3/TiO2) and with ZnO (O3/ZnO). In addition, this study sought to assess the efficiency of the removal of the organic matter present in the leachate. For the pre- and post-AOPs, the leachate was characterized through physicochemical parameters and identification of organic compounds using gas chromatography coupled to the mass spectrometry (GC-MS). The three processes studied (O3, O3/TiO2, and O3/ZnO) presented color removal, turbidity, BOD above 95%, and lower COD removals (19%, 24%, and 33%, respectively). All AOPs studied promoted a similar reduction of organic compounds from leachate, some of which with toxic and carcinogenic potential, such as p-cresol, bisphenol A, atrazine, and hexazinone. In addition, upon the removal of organic matter and organic compounds, the heterogeneous catalytic ozonation processes proved more efficient than the process carried out only with ozone.

Alternative adsorbents applied to the removal of natural hormones from pig farming effluents and characterization of the biofertilizer.

Pig farming has a very strong economic importance in Brazil. The residues from this activity are applied to the soil because of their excellent characteristics as biofertilizers. The present study aimed at studying the estrone, 17ß-estradiol, and estriol natural hormones, emerging contaminants present in this type of residue that are not mentioned in the current legislation. The characterization of the pig farming effluent presented high concentrations of hormones (mg L-1). The objective was to apply the biosorbents to the removal of the hormones in batch systems directly in the manure heaps without affecting the potential of the effluent as a fertilizer. It was verified that the adsorption of hormones using the rice husk biomass in natura and soybean hull in natura, abundant alternative adsorbents, presented a good capacity of removal of hormones. The presence of the organic materials (rice husk and soybean hull) caused few alterations in the biofertilizer characteristics, demonstrating that these adsorbents present a potential of application in batch treatment systems, with possible applications related to pig farming effluents containing natural hormones.

Combined processes of ozonation and supercritical water oxidation for landfill leachate degradation.

Leachate is a highly variable, heterogeneous and recalcitrant wastewater generated in landfills which may contain high concentrations of many organic and inorganic compounds, hampering the application of a single technique in its treatment. Therefore, this paper assessed leachate degradation through supercritical water oxidation (ScWO) as well as combined processes of ozonation and supercritical water oxidation (O3/ScWO and ScWO/O3), a yet innovative combination. Ozonation was carried out at different reaction times (30-120 min). ScWO was developed at 600 °C, 23 MPa, and spatial time (τ) from 29 to 52 s. A combination of ozonation (30 min) and supercritical water oxidation process (O3-30'/ScWO) was the most efficient technique for the degradation of the leachate assessed. These conditions enabled to remove high values of apparent and true color (92% and 97%, respectively), biochemical oxygen demand (BOD5,20) (95%), chemical oxygen demand (COD) (92%), total organic carbon (TOC) (79%), nitrite (78%), nitrate (84%), total (96%), dissolved (96%) and suspended (94%) solids. In addition, the combined process presented significant decrease in electric conductivity (EC) (68%) and less leachate turbidity removal (43%). Except for ammonia and nitrite, all parameters of the leachate treated by O3-30'/ScWO met the specifications of Brazilian legislation (CONAMA Resolutions No. 357/2005 and No. 430/2011) for the disposal of wastewater in water bodies. Besides, both processes are considered to be clean technologies. This shows the great possibility of applying the O3/ScWO combination to landfills leachates.

Treatment of hospital laundry wastewater by UV/H2O2 process.

Hospitals consume a large volume of water to carry out their activities and, hence, generate a large volume of effluent that is commonly discharged into the local sewage system without any treatment. Among the various sectors of healthcare facilities, the laundry is responsible for the majority of water consumption and generates a highly complex effluent. Although several advanced oxidation processes (AOPs) are currently under investigation on the degradation of a variety of contaminants, few of them are based on real wastewater samples. In this paper, the UV/H2O2 AOP was evaluated on the treatment of a hospital laundry wastewater, after the application of a physicochemical pretreatment composed of coagulation-flocculation and anthracite filtration. For the UV/H2O2 process, a photoreactor equipped with a low-pressure UV-C lamp was used and the effects of initial pH and [H2O2]/chemical oxygen demand (COD) ratio on COD removal were investigated through a randomized factorial block design that considered the batches of effluent as blocks. The results indicated that the initial pH had no significant effect on the COD removal, and the process was favored by the increase in [H2O2]/COD ratio. Color and turbidity were satisfactorily reduced after the application of the physicochemical pretreatment, and COD was completely removed by the UV/H2O2 process under suitable conditions. The results of this study show that the UV/H2O2 AOP is a promising candidate for hospital laundry wastewater treatment and should be explored to enable wastewater reuse in the washing process.

Caracterização de blocos cerâmicos acústicos produzidos com incorporação de lodo de lavanderia têxtil / Characterization of acoustic ceramic blocks produced with incorporating textile laundry sludge

Características físicas (absorção de água), mecânicas (resistência à compressão), de toxicidade e de superfície (microscopia eletrônica de varredura) foram avaliadas em blocos cerâmicos acústicos, fabricados por meio do processo de solidificação/estabilização (S/E), a partir da incorporação de lodo proveniente de estação de tratamento de efluentes têxteis. Os blocos cerâmicos acústicos foram produzidos com incorporação de 5, 10, 15, 20, 25, 30 e 35% de lodo têxtil na massa de argila, bem como o bloco controle. Os resultados indicaram a porcentagem de 20% de lodo como o limite para fornecer material com características de acordo com os padrões estabelecidos pela legislação brasileira. O processo de S/E foi eficiente no aproveitamento/tratamento do lodo têxtil, uma vez que permitiu a imobilização dos poluentes na massa de argila, os quais não foram lixiviados, tampouco solubilizados.

Physical characteristics (water absorption), mechanical (compression length), of toxicity and surface (scanning electron microscopy) were evaluated in acoustic ceramic blocks, manufactured by the process of solidification/stabilization (S/S) from the incorporation of sludge from a textile wastewater treatment plant. Acoustic ceramic blocks were produced by incorporating of 5, 10, 15, 20, 25, 30 and 35% of textile sludge in the clay mass/material as well as the control block. The results indicated the percentage of 20% of sludge, as the limit to provide materials with good characteristics of accordance with the standards established by Brazilian law. The S/S process was efficient in the recovery/treatment of the textile sludge, as it allowed the immobilization of pollutants in the clay mass/material, which have not been leached, neither solubilized.

Effects of coconut granular activated carbon pretreatment on membrane filtration in a gravitational driven process to improve drinking water quality.

This study evaluates the performance of a polymeric microfiltration membrane, as well as its combination with a coconut granular activated carbon (GAC) pretreatment, in a gravitational filtration module, to improve the quality of water destined to human consumption. The proposed membrane and adsorbent were thoroughly characterized using instrumental techniques, such as contact angle, Brunauer-Emmett-Teller) and Fourier transform infrared spectroscopy analyses. The applied processes (membrane and GAC + membrane) were evaluated regarding permeate flux, fouling percentage, pH and removal of Escherichia coli, colour, turbidity and free chlorine. The obtained results for filtrations with and without GAC pretreatment were similar in terms of water quality. GAC pretreatment ensured higher chlorine removals, as well as higher initial permeate fluxes. This system, applying GAC as a pretreatment and a gravitational driven membrane filtration, could be considered as an alternative point-of-use treatment for water destined for human consumption.

Sulfate removal from waste chemicals by precipitation.

Chemical oxidation using Fenton's reagent has proven to be a viable alternative to the oxidative destruction of organic pollutants in mixed waste chemicals, but the sulfate concentration in the treated liquor was still above the acceptable limits for effluent discharge. In this paper, the feasibility of sulfate removal from complex laboratory wastewaters using barium and calcium precipitation was investigated. The process was applied to different wastewater cases (two composite samples generated in different periods) in order to study the effect of the wastewater composition on the sulfate precipitation. The experiments were performed with raw and oxidized wastewater samples, and carried out according to the following steps: (1) evaluate the pH effect upon sulfate precipitation on raw wastewaters at pH range of 2-8; (2) conduct sulfate precipitation experiments on raw and oxidized wastewaters; and (3) characterize the precipitate yielded. At a concentration of 80 g L(-1), barium precipitation achieved a sulfate removal up to 61.4% while calcium precipitation provided over 99% sulfate removal in raw and oxidized wastewaters and for both samples. Calcium precipitation was chosen to be performed after Fenton's oxidation; hence this process configuration favors the production of higher quality precipitates. The results showed that, when dried at 105 degrees C, the precipitate is composed of hemidrate and anhydrous calcium sulfate ( approximately 99.8%) and trace metals ( approximately 0.2%: Fe, Cr, Mn, Co, Ag, Mg, K, Na), what makes it suitable for reuse in innumerous processes.

Characterization of solids originating from the Fenton's process.

Fenton's process has proven to be a viable alternative for the oxidation of organic pollutants in mixed waste chemicals, with a high efficiency in the removal of heavy metals from the effluent as a side effect. However, a solid residue loaded with metals is obtained as a by-product. In this paper, the solids originating from the Fenton's oxidation of mixed waste chemicals from an academic laboratory were studied. The process was applied to different wastewater cases (two composite samples generated in different periods) in order to study the effect of their characteristics on the residues composition. Residues were evaluated and classified according to their leaching properties. In addition, a most comprehensive assessment of metal mobility in the residues was obtained by chemical speciation. The Fenton's residues were classified as hazardous according to Brazilian waste regulations. The application of the sequential dissolution procedure indicated that the metals in the Fenton's residues are mainly constituted of amorphous material (over 80%). Furthermore, the reactive fractions of the residues (exchangeable and amorphous iron oxide fractions) retain most of remaining metals. Therefore, the Fenton's residues present great potential for environmental contamination, and require an administration system and control of their final disposal.

Influence of the temperature, volume and type of solution in the mercury vaporization of dental amalgam residue.

One of the qualitative methods for the identification of mercury vapor is what it occurs as a way of chemical reaction between palladium chloride and metallic mercury. Palladium chloride ribbons with yellowish coloration put in contact with the vaporized mercury of dental amalgam residue, liberates palladium and forms mercury chloride in your surface, and starts to have black coloration; this form identify the presence of the mercury vapor in the system. This work studies the influence of temperature, volume and type of barrier-solution in the vaporization of mercury during the period of storage of dental amalgam residues, aiming to establish the best conditions for storage of these residues. It was found that for all tested solutions, the longest storage times without any occurrence of mercury vaporization were obtained in the lowest temperatures tested and the largest solution volumes of barrier-solution. The radiographic effluent presented bigger efficacy in the reduction of the volatilization, increasing the period when the residue was stored, however the analysis of this solution after the vaporization test showed the presence of organic mercury. These results show that water is the most efficient barrier against the vaporization of mercury, since it did not result in organic mercury formation in the effluent solution from the storage process.

Conhecimento e utilização de serviço de atenção básica em saúde por famílias em município da região sul do Brasil / Knowledge and utilization of basic health service by families in a southern municipality of Brazil / Conocimiento y utilización del servicio de atención básica en salud por familias en municipio de la región sur de Brasil

Este estudo foi realizado para verificar se famílias residentes na região leste de um município do Estado do Paraná conhecem e utilizam os serviços da Unidade Básica de Saúde (UBS) de sua área de abrangência. Foram entrevistadas 385 famílias selecionadas a partir do Sistema de Informação da Atenção Básica (SIAB). O instrumento previamente testado, com questões fechadas, foi aplicado em fevereiro e março de 2004 por alunos de graduação de enfermagem e estatística, devidamente capacitados. Das famílias entrevistadas 78% não possuíam nenhum tipo de plano ou seguro saúde e 95,3% conhecia algum serviço oferecido pela UBS. A consulta médica foi citada por 91,7%, seguida pela coleta de exames laboratoriais, citados por 68,8% e a distribuição de medicamentos por 38,5% das famílias. Chamou atenção o pouco conhecimento sobre atendimento dentário referido por apenas 22,9% famílias. Os serviços da UBS eram utilizados por 90% das famílias, pela proximidade (53,9%) ou por falta de opção (40,3%). A equipe de saúde deve aprimorar suas atividades e a estrutura do serviço, avaliar a oferta e a humanização do atendimento. Além da utilização e do conhecimento dos serviços de saúde, este estudo mostra aspectos da metodologia de pesquisa como o inquérito populacional.

This investigation was made to verify the knowledge and use of basic health services (BHS) by families resident in the East side of a municipality of Paraná State. Three hundred and eighty five families, selected from the Basic Health Service System were interviewed. The instrument, with closed questions, previously tested, was applied by trained Nursing and Statistics undergraduate students, in February and March 2004. From the families 78% had any kind of private health care plan, and 95.3% knew some activities offered by the BHS. The medical visits were mentioned by 91.7%, followed by the laboratory tests activities mentioned by 68.8% and drug distribution mentioned by 38.5% of families. It was observed that only 22.9% of families had some knowledge about dental care services. The BHS were used by 90% of families and the reasons for the use were the proximity to their home (53.9%) or because they had no other option of health assistance (40.3%). The health team has to evaluate the services offered, to improve and humanize the health assistance, also to care about the good appearance of the BHS physical area. Beyond families' knowledge and the BHS utilization profile, this study had also showed some main aspects of research methods for population surveys.

Este estudio se ha realizado para verificar si las familias residentes en la región este de un municipio del Estado de Paraná conocen y utilizan los servicios de la Unidad Básica de Salud (UBS) de su área de alcance. Se entrevistó a 385 familias seleccionadas a partir del Sistema de Información de Atención Básica (SIAB). El instrumento previamente experimentado, con cuestiones cerradas, se aplicó en febrero y marzo de 2004 por alumnos del curso de graduación de Enfermería y Estadística, debidamente capacitados. De las familias entrevistadas, un 78% no estaba filiado a ningún plan de salud, privado o público, un 95,3 % conocía algún servicio ofrecido por la UBS. La consulta médica fue citada por un 91,7%, seguida por la tomada de muestras de exámenes de laboratorio, citados por un 68,8% y la distribución de medicamentos por 38,5% de las familias. Ha llamado la atención el escaso conocimiento sobre la atención odontológica, referida apenas por un 22,9% de las familias. Los servicios de la UBS son utilizados por 90% de las familias, por la proximidad (53,9%) o por falta de opción (40,3%). El equipo de salud debe mejorar su desempeño, así como la estructura del servicio, evaluar la propuesta de humanización en la atención. Además de la utilización y del conocimiento de los servicios de salud, este estudio muestra aspectos e la metodología de investigación, como la encuesta pública.

Ultrafiltração como processo de tratamento para o reúso de efluentes de laticínios / Ultrafiltration as treatment process for reuse of dairy effluent

O trabalho objetivou testar duas membranas de ultrafiltração com diferentes tamanhos de poros (uma membrana espiral de polieterssulfona e corte de 5-8 kDa e uma membrana tubular de PVDF com corte de 30-80 kDa) para a recuperação de nutrientes do efluente de laticínios, procurando avaliar o comportamento de fluxo e a remoção de parâmetros de controle de poluição. Os resultados demonstraram uma remoção de DQO próxima de 75 por cento, separando, no entanto, proteínas na faixa de 97 por cento e gorduras na faixa de 91 por cento a 93 por cento. Os fluxos apresentados foram de 18 kg m-2 h-1 para a membrana espiral e 50 kg m-2 h-1 para a membrana tubular. O processo demonstrou que estudos posteriores poderiam tornar possível o reuso destes dois nutrientes em subprodutos lácteos.

The work aimed to test two different pore size ultrafiltration membranes (a spiral wound PES membrane, cut off 5-8 kDa; and another, a tubular PVDF membrane, cut off 30-80 kDa) to nutrients recovery from dairy effluents, looking up to evaluate the flux behavior and the pollution control parameters removal. The results have shown that COD removal is nearby 75 percent; however, proteins separation is near 97 percent and fats removal is in a range 91 percent - 93 percent. The fluxes were 18 kg m-1 h-1 for spiral wound membrane and 50 kg m-2 h-1 for tubular membrane. The process has shown latter studies could became possible the both nutrients reuse on dairy products.

Optimization of Fenton's oxidation of chemical laboratory wastewaters using the response surface methodology.

Establishing a treatment process for practical and economic disposal of laboratory wastewaters has become an urgent environmental concern of the Department of Chemical Engineering of the Universidade Estadual de Maringá (State University of Maringá), Brazil. Fenton and related reactions are potentially useful oxidation processes for destroying toxic organic compounds in water. In these reactions, hydrogen peroxide is combined with ferrous or ferric iron in the presence or absence of light to generate hydroxyl radicals (.OH). The feasibility of Fenton's reagent to treat waste chemicals from an academic research laboratory was investigated in this study. A response surface methodology was applied to optimize the Fenton oxidation process conditions using chemical oxygen demand (COD) removal as the target parameter to optimize, and the reagent concentrations, as related to the initial concentration of organic matter in the effluent, and pH as the control factors to be optimized. Maximal COD removal (92.3%) was achieved when wastewater samples were treated at pH 4 in the presence of hydrogen peroxide and iron in the ratios [COD]:[H2O2]=1:9 and [H2O2]:[Fe2+]=4.5:1. Under these conditions, it was possible to obtain simultaneously maximal COD removal and minimal chemical sludge after treatment, which is a residue that needs further processing.

Screening of filamentous fungi for the decolorization of a commercial reactive dye.

The aim of this work is to verify the ability of 19 isolates of 13 different fungal species to decolorize the reactive dye blue-BF-R. The isolates of Pleurotus pulmonarius, P. ostreatus, P. ëous, P. citrinopileatus, Lentinus edodes, Phanerochaete chrysosporium, Schizophyllum commune, Agaricus blazei, Ganoderma sp. and four isolates obtained from textile effluent were evaluated in minimum liquid medium. In addition, seven of them were also evaluated on solid medium, and both media were both added 0.5 g dye/l. All isolates evaluated on solid medium decolorized the dye. The isolates Phanerochaete chrysosporium CCB478 and Lentinus edodes CCB047 were the ones that presented the fastest and slowest growth, respectively. Despite the isolate of the textile effluent had grown on solid medium, it did not decolorize the dye. All the isolates of the genus Pleurotus, except the isolate Pleurotus ëous CCB440, decolorized the dye in liquid medium. They presented decolorization percentage ranging from 39% to 51%. The absorbance ratio (Abs590/Abs455) of the culture medium inoculated with these isolates decreased throughout the experiment indicating the fungal dye degradation. The others presented decolorization percent below 8%. The isolates of Pleurotus, except the isolate Pleurotus ëous CCB440, were able to decolorize and to degrade the commercial reactive dye blue-BF-R. The results indicate their potential to be used in the treatment of effluents containing this dye.