Abstract Due to the need to achieve the principles of sustainable development and to understand the processes of formation of phytocenoses in areas that were adversely affected by the industrial impact, this study assessed the condition of the Grachevsky uranium mine (Kazakhstan), which underwent conservation procedures about 25 years ago. The purpose is to determine the level of water quality and phytocenosis of the shores of the reservoir accumulating natural effluents from reclaimed dumps and anthropogenic sites of a uranium mine, as well as quality indicators and toxicology. The assessment included a qualitative research method (analysis of documents) to determine agro-climatic conditions and empirical methods of collecting information. The authors studied the intensity of ionizing radiation of the gamma background of the water surface of the reservoir (and sections of the shoreline and territories adjacent to the reservoir), and hydrochemical parameters of the waters of the reservoir, and performed a description of the botanical diversity. The vegetation cover of the sections of the reservoir shore is at different stages of syngenesis and is represented by pioneer groupings, group thicket communities, and diffuse communities. Favorable ecological conditions for the settlement and development of plants develop within the shores of the reservoir. The intensity levels of ionizing radiation do not exceed the maximum permissible levels and practically do not affect the formation of phytocenoses. An anthropogenically modified dry meadow with the participation of plants typical of the steppe zone has been formed on the floodplain terrace. Concerning the indicators of quality and toxicology of this reservoir, the water can be used for household and drinking purposes under the condition of prior water treatment. It can be concluded that a high level of natural purification of the reservoir waters occurred within twenty years after the reclamation of the uranium mine. impact Kazakhstan, Kazakhstan , (Kazakhstan) 2 ago analysis documents agroclimatic agro climatic information reservoir) diversity groupings communities terrace treatment (Kazakhstan

Resumo Devido à necessidade de alcançar os princípios do desenvolvimento sustentável e de compreender os processos de formação de fitocenoses em áreas que foram negativamente afetadas pelo impacto industrial, este estudo avaliou o estado da mina de urânio de Grachevsky (Cazaquistão), que foi submetida a procedimentos de conservação há cerca de 25 anos. O objetivo é determinar o nível de qualidade da água e fitocenose das margens do reservatório que acumula efluentes naturais provenientes de depósitos recuperados e sítios antrópicos de uma mina de urânio, bem como indicadores de qualidade e toxicologia. A avaliação incluiu um método de investigação qualitativa (análise de documentos) para determinar as condições agroclimáticas e métodos empíricos de coleta de informação. Os autores estudaram a intensidade da radiação ionizante do fundo gama da superfície da água do reservatório (e seções da linha de costa e territórios adjacentes ao reservatório), bem como os parâmetros hidroquímicos das águas do reservatório, e fizeram uma descrição da diversidade botânica. A cobertura vegetal da seções da margem do reservatório encontra-se em diferentes estádios de singênese e é representada por agrupamentos pioneiros, comunidades de arbustos agrupados e comunidades difusas. Nas margens do resevatório desenvolvem-se condições ecológicas favoráveis à fixação e desenvolvimento das plantas. Os níveis de intensidade da radiação ionizante não ultrapassam os níveis máximos admissíveis e praticamente não afetam a formação de fitocenoses. No terraço da planície de inundação formou-se um prado seco modificado antropogenicamente com a participação de plantas típicas da zona de estepe. Em relação aos indicadores de qualidade e toxicologia deste reservatório, a água pode ser utilizada para fins domésticos e de consumo, desde que seja objeto de um tratamento prévio. Pode concluir-se que ocorreu um elevado nível de purificação natural das águas do reservatório nos vinte anos seguintes à recuperação da mina de urânio. industrial Cazaquistão, Cazaquistão , (Cazaquistão) 2 análise documentos informação reservatório) botânica encontrase encontra se pioneiros difusas desenvolvemse desenvolvem formouse formou estepe consumo prévio concluirse concluir (Cazaquistão

As deel van die strewe na volhoubare ontwikkeling, kan lewende muurstelsels biofiliese waarde en ekosisteemdienste verskaf. Ten spyte van hul voordele en potensiaal om globale uitdagings krisisse aan te spreek, beperk hul ekonomiese haalbaarheid, veerkragtigheid, instandhouding en volhoubaarheid hul toepassing en gebruik. Hierdie artikel gee 'n oorsig van 'n pragmatiese studie wat die faktore wat lewende mure se prestasie as groen infrastruktuur (GI) belemmer, evalueer het, en die werkverrigting van buitemuurse modulëre lewende mure as GI ontleed het. Die doel is om 'n stel kriteria te ontwikkel om die mees geskikte LWS vir groen infrastruktuur te bepaal. Datavaslegging het 'n gemengde metode-metodologie behels. Plaaslike kundiges het deur middel van vraelyste insig gegee in plaaslike lewende mure-tipologieë. Die ses maande-lange eksperimentele studie het twee geselekteerde LWSs van 4m² elk in omvang op die Universiteit van Pretoria se Future Africa-kampus in Pretoria, in Suid-Afrika se Gauteng-provinsie, behels. Veranderlikes het minimum en maksimum daaglikse temperature, relatiewe humiditeit, neerslag, grondtemperatuur, waterinhoud en elektriese geleidingsvermoë, blaarbiomassa-opbrengs en plantstres ingesluit. Die navorser het vars en droë biomassa-opbrengste gemonitor met 'n gekalibreerde laboratorium skaal as die primêre prestasie-aanwyser. Plantstres, die sekondêre prestasie-aanwyser, is deur chlorofilfluoressensie-analise gemeet. Data is statisties ontleed. Die bevindinge lê die grondslag vir die verbetering van lewende mure as GI wat kan bydra tot meer volhoubare stede. Dit word bereik deur tegniese kenmerke vir lewende mure te definieer om hul werkverrigting as GI te verbeter. Die resultate bevoordeel plaaslik vervaardigde, lae-tegnologie, buitemuurse modulêre lewende mure met beperkte, robuuste, liggewig, herwonne komponente wat ongekompliseerde samestelling behels. Stelsels moet lae-tegnologie besproeiing behels. Die lewende muur-posisie moet die plantgewasse se ligvereistes en besoedeling in ag neem. Potte moet beperkte sonblootstelling kry, en 'n grondvolume van 3 liters en 'n minimum diepte van 200mm hê.

Living wall systems (LWSs) can provide biophilic value and ecosystem services as part of the quest for sustainable development. Despite their benefits and potential to mitigate global challenges such as cooling, air purification, sound absorption, and human well-being, their economic feasibility, resilience, maintenance, and sustainability impact on their application and use. This article gives an overview of a pragmatic study which synthesised the factors hampering LWSs' performance as green infrastructure (GI) and analysed the performance of outdoor modular LWSs as GI. The study aims to establish criteria for selecting the most suitable LWSs as green infrastructure. Data capturing involved a mixed-method methodology. Local experts provided insight into local LWS typologies through questionnaires, which were analysed qualitatively. The six-month experimental study involved two selected LWSs of 4m² each in extent on the University of Pretoria's Future Africa campus in Pretoria, in South Africa's Gauteng province. Variables included minimum and maximum daily temperatures, relative humidity, precipitation, soil temperature, water content and electrical conductivity, leaf biomass yield, and plant stress. The researcher monitored fresh and dry biomass yields with a calibrated laboratory balance as the primary performance indicator. Plant stress, the secondary performance indicator, was measured by chlorophyll fluorescence analysis. Experimental data were statistically analysed. The findings lay the groundwork for improving LWSs as GI, which can contribute to more sustainable cities. This is achieved by defining LWSs' technical characteristics to enhance their performance as GI. The results favour locally produced, low-technology, outdoor modular LWSs with limited, robust, lightweight, recycled components entailing uncomplicated assembly. Systems must involve low-technology irrigation. The LWS position should consider the plant crops' light requirements and pollution. Pots should receive limited sun exposure and have a soil volume of 3 litres and a minimum depth of 200mm.

Abstract: Wastewater treatment systems based on floating aquatic plants represent an interesting option, whose development, design, and operation have been based on empirical procedures, mainly because sufficient data has not been generated to create general design and maintenance models. Floating macrophytes have proven to be efficient in bioremediation of wastewater containing organic matter and toxic substances that are harmful to the environment. The need to find a solution to this growing situation of contamination and the possibility of reusing wastewater has motivated this study, whose objective was to study the purifying capacity of Pistia stratiotes L. in wastewater treatment in order to establish the potential use of this species. The physicochemical parameters were analyzed following the standardized analytical techniques published by the Standard Methods for the Examination of Water and Wastewater APHA-AWWA-WPC. Regarding the results obtained from the tested parameters, a removal below 50% was observed: BOD5 (30.7%), COD (40.8%), Total Suspended Solids - TSS (42%), pH it varied between 5.4 and 6.2, the dissolved Oxygen was increasing, taking values from 4.78 mgO2/L to 12.09 mgO2/L. Taking into account the statistical results of the t test values, it was concluded that there was no significant removal of the physicochemical and microbiological parameters analyzed in the different concentrations used (5, 25, 50, 75 and 100) %, this could be influenced by the low temperatures of the season and the short term of exposure of the plant with the residual water.

Resumen: Los sistemas de tratamiento de aguas residuales a base de plantas acuáticas flotantes representan una opción interesante, cuyo desarrollo, diseño y operación se ha basado en procedimientos empíricos debido principalmente a que no se han generado los datos suficientes que permitan crear modelos generales de diseño y mantenimiento. Las macrófitas flotantes han demostrado ser eficientes en la biorremediación de aguas residuales con contenidos de materia orgánica y sustancias tóxicas perjudiciales para el medio ambiente. La necesidad de encontrar alguna solución a esta situación creciente de contaminación y la posibilidad de reutilizar las aguas residuales ha motivado a realizar este estudio, cuyo objetivo fue estudiar la capacidad depuradora de la Pistia stratiotes L. en el tratamiento de aguas residuales a fin de establecer el uso potencial de esta especie. Los parámetros fisicoquímicos fueron analizados siguiendo las técnicas analíticas estandarizadas publicadas por el Standard Methods for the Examination of Water and Wastewater APHA-AWWA-WPC. Con respecto a resultados obtenidos de los parámetros ensayados se observó una remoción por debajo del 50%, la DBO5 (30,7 %), la DQO (40,8%), los Sólidos Suspendidos Totales - SST (42%), el pH varió entre 5,4 y 6,2, el Oxígeno disuelto fue en aumento tomando valores de 4,78 mgO2/L a 12,09 mgO2/L. Teniendo en cuenta los resultados estadísticos de los valores del tes t, se concluyó que no hubo remoción significativa de los parámetros fisicoquímicos y microbiológico analizados en las distintas concentraciones utilizadas (5, 25, 50, 75 y100) %, esto pudo estar influenciada por las bajas temperaturas de la estación y el corto plazo de exposición de la planta con el agua residual.

Abstract Pterocarpus santalinoides is used in Nigerian ethnomedicine to treat diabetes mellitus. This study aimed to establish the antidiabetic property of the plant, and isolate and characterize its active principle. Dried and pulverized leaves (500 g) of P. santalinoides were extracted with 1.8 L of 80 % hydromethanol by cold maceration. The dried extract (10 g) was partitioned into n-hexane, ethyl acetate (EtOAc), n-butanol, and water. Antidiabetic activitiy-guided isolation by column chromatographic separation of the EtOAc soluble and purification of the sub-fractions by repeated preparative thin layer chromatography (pTLC) yielded a C-glycosyl flavonoid, identified as isovitexin. The chemical structure was elucidated based on high-resolution mass spectroscopy, 1D, and 2D nuclear magnetic resonance spectroscopic analyses. Alloxan-induced diabetic rat model was adopted for antidiabetic screening. The extract of P. santalinoides (100-200 mg/kg), fraction F4 (50 mg/kg), sub-fraction F4.3 (10 mg/kg), and the semi-purified compound F4.3.2 (5 mg/kg) significantly (p<0.05) reduced the fasting blood glucose of alloxan-induced diabetic rats, causing 48.4, 69.4, 57.7 and 64.5 % antidiabetic activity respectively, compared with > 68 % recorded in glibenclamide (2 mg/kg) control. These results reveal that isovitexin is the antidiabetic principle in P. santalinoides. mellitus plant 500 g P 18 1 8 1. maceration 10 (1 nhexane, nhexane n hexane, hexane n-hexane EtOAc, , (EtOAc) nbutanol, nbutanol butanol, butanol n-butanol water activitiyguided activitiy guided subfractions sub fractions pTLC (pTLC Cglycosyl C glycosyl flavonoid highresolution high resolution spectroscopy 1D D analyses Alloxaninduced Alloxan induced screening 100200 100 200 (100-20 mg/kg, mgkg mg/kg mg kg F 50 subfraction F43 3 F4. semipurified semi purified F432 2 F4.3. 5 ( p<0.05 p005 p 0 05 (p<0.05 alloxaninduced alloxan rats 484 48 4 48.4 694 69 69.4 577 57 7 57. 645 64 64. respectively 6 control (EtOAc 10020 20 (100-2 p<0.0 p00 (p<0.0 48. 69. 1002 (100- p<0. p0 (p<0. (100 p<0 (p<0 p< (p< (p

Abstract The sweet-tasting protein, brazzein, has potential as a low-calorie sugar substitute owing to its high sweetness, stability, and water solubility. In this study, the synthetic brazzein gene was expressed in the tobacco plant, Nicotiana tabacum. Three types of expression cassettes containing the brazzein gene were constructed to examine the expression and purification efficiency of the brazzein: pBI-BZ1 containing a signal sequence and His-tag, pBI-BZ2 containing a signal sequence, and pBI-BZ3 containing only the brazzein gene. Brazzein expression confirmed by ELISA was purified using ammonium sulfate precipitation, heat treatment, and CM-sepharose chromatography. The purity and conformational state of the brazzein were confirmed using SDS-PAGE, HPLC, and circular dichroism. The identity of the brazzein was confirmed by N-terminal amino acid analysis, ESI-MS/MS, and sweetness analysis. We successfully generated brazzein overexpression tobacco plants, suggesting that this method could be used as a brazzein production platform to provide an alternative to currently produced sweeteners.

Abstract Quality of groundwater is threatened due to pollution by industrial, domestic and agricultural waste. A large number of populations are residing in rural areas which are unable to afford high cost water purifiers due to their low income as well as limited awareness. However, limited availability of fresh water has become a critical issue in developing countries. Around 1.2 billion population is deprived of affordable and safe water for their domestic need. Additionally, chemical coagulants which are nowadays being used for water purification pose severe and numerous health hazards to human. Thus utilization of easily accessible natural coagulant for water purification might offer a sustainable, practical and cost effective solution to the current alarming situation in developing countries. Several experimental findings have shown strong efficiency of Moringa oleifera plant extracts obtained from different solvents in the improvement of water quality parameters including physicochemical (such as pH, hardness, turbidity, metallic impurities, total dissolved solid) and biological (E.coli count) parameter. We have also highlighted the limitations and advantages of chemical coagulation in water purification. Altogether, this review summarizes one such miracle tree which has shown significant potential as a natural coagulant and its associated underlying mechanism in water purification process. industrial waste awareness However countries 12 1 2 1. need Additionally human sustainable pH hardness turbidity impurities solid E.coli Ecoli E coli count parameter Altogether process

Abstract The present work reports the implementation of the Hazard Analysis Critical Control Point (HACCP) methodology to analyze the water purification system of a pharmaceutical site, in order to assure the system quality and prevent failures. As a matter of fact, the use of HACCP for development and implementation of Quality Risk Management (QRM) is not usual in pharmaceutical plants and it is applied here to improve the performance of the water purification system of a polymerization pilot plant used to manufacture pharmaceutical grade polymer microparticles. Critical Control Points (CCP) were determined with the aid of a decision tree and questions were made to characterize whether identified hazards constitute actual CCPs and should be monitored. When deviations were detected, corrective actions were performed and action plans were used for following-up and implementation of corrective actions. Finally, microbiological and physicochemical parameters were analyzed and the obtained results were regarded as appropriate. Therefore, it is shown that HACCP constitutes an effective tool for identification of hazards, establishment of corrective actions and monitoring of the critical control points that impact the process and the quality of the final pharmaceutical product most significantly.

Abstract Drinking water flavor is influenced by some dissolved substances like Na., K., Fe3+, Cu2+, Ca2+, Mg2+, HCO.., NO.., Cl., SO.2- and CaCO3. This research was conducted in the Public Metropolitan Water and Sanitation Company or EPMAPS (for its acronym in Spanish) which is in charge of water purification and distribution in Quito. It was taken samples from six different treatment plants during five weeks and the following analysis were made: Sensory analysis executed by a panel of trained judges, who evaluated the acceptance ratio (FRA Test (Flavor Rating Assessment)) and the satisfaction ratio (Hedonic Test), physiochemical parameters determination and dissolved minerals concentration. Later the minerals concentration was correlated with the water’s flavor through a multiple factor analysis with main components analysis. As a result of this correlation, it was evidenced that the dissolved mineral concentration directly influences on the tap water flavor and determined statistically that the best sensory analysis is the Hedonic Test. Only the water from the treatment plant number 2 (PT2) obtained a lower sensorial valuation, whose flavor was described as lightly salted, which is related to its concentration of Ca2., Mg2., Na., K., HCO.., CaCO. y Cl..

Resumen El sabor del agua potable está influenciado por sustancias disueltas como: Na., K., Fe3+, Cu2+, Ca2+, Mg2+,HCO.., NO.., Cl., SO.2- y CaCO.. El presente estudio se llevó a cabo en la Empresa Pública Metropolitana de Agua Potable y Saneamiento (Epmaps), encargada de potabilizar y distribuir el agua en Quito. Se tomaron muestras de agua en seis plantas de tratamiento durante cinco semanas y se realizaron los siguientes análisis: evaluación sensorial con un panel de jueces entrenados, que determinaron el grado de aceptación (Prueba FRA (Flavor Rating Assessment)) y el grado de satisfacción (Prueba hedónica), determinación de parámetros fisicoquímicos y de la concentración de minerales disueltos. Posteriormente, se correlacionó la concentración de minerales y el sabor, mediante análisis factorial múltiple con análisis de componentes principales. Se demostró que la concentración de minerales disueltos influye directamente en el sabor del agua potable y que, estadísticamente, el mejor método sensorial es la prueba hedónica. Todas las muestras cumplieron la norma ecuatoriana y únicamente el agua de la planta de tratamiento 2 (PT2) obtuvo menor valoración sensorial. Su sabor fue descrito como ligeramente salado, lo que se relaciona con sus concentraciones de Ca2+, Mg2+, Na., K., HCO.., CaCO. y Cl..

ABSTRACT The construction of artificial wetlands for the water treatment from water bodies such as the “Rumiyacu” River, has the purpose of reducing organic and inorganic pollutants from lotic ecosystems through primary processes, such as sedimentation, enzymatic degradation, absorption and volatilization of compounds. For this, in this bioremediation process, plant species (grasses) of the area were used, such as: Echynochloa polystachya, Pennisetum purpureum, Panicum máximum, and Arvenses sp. The water flow (0.58 m3/s) was determined by the float method, and using composite sampling (aliquots) the wetlands were designed. The statistical test of analysis of variances was applied to determine the species with the highest removal of pollutants such as: nickel, iron, chemical oxygen demand, biochemical oxygen demand, total coliforms and total oil hydrocarbons. As a whole, the removal of contaminating loads represents 44.53%, depending on the different efficiencies of each species in each parameter. Therefore, the tributaries of the river should be monitored and environmentally evaluated.

RESUMEN La construcción de humedales artificiales para el tratamiento de aguas provenientes de cuerpos hídricos como el Río Rumiyacu, tiene como propósito disminuir la cantidad de contaminantes orgánicos e inorgánicos de ecosistemas lóticos mediante procesos primarios, tales como la sedimentación, degradación enzimática, absorción y volatilización de compuestos. En este proceso de biorremediación se emplearon especies vegetales (gramíneas) de la zona como: Echynochloa polystachya, Pennisetum purpureum, Panicum máximum, y Arvenses sp. Se determinó el caudal hídrico (0,58 m3/s) por el método del flotador, y mediante un muestreo compuesto (alícuotas) se diseñaron los humedales. Se aplicó la prueba estadística de análisis de varianzas (ANOVA) para determinar las especies de mayor remoción de contaminantes como: níquel, hierro, demanda química de oxígeno, demanda bioquímica de oxígeno, coliformes totales e hidrocarburos totales de petróleo. En su conjunto, la remoción de cargas contaminantes representa el 44,53%, en dependencia de las diferentes eficiencias de cada especie en cada parámetro, por lo que, se recomienda monitorear y evaluar ambientalmente a los tributarios del río.

ABSTRACT A model that represents the behavior of a critical system or process, such as the drinking water treatment process, is vital for the evaluation of new procedures or their optimization without affecting the real system or risking the population, avoiding economic losses. Due to the complexity in the dynamics of drinking water treatment plants, the use of Coloured Petri Nets is recommended to model the behavior of the variables involved in the process. In this context, this work presents a structured procedure that allows to obtain a model considering a dynamic driven by the occurrence of discrete events and that allows the generation of useful information that can later be used to verify the effectiveness and efficiency of new operating strategies. To evaluate this proposal, a model of the drinking water treatment process of Puerto Mallarino located in Cali, Colombia was developed. Modeling, both the stages of the purification process, and the approximate behavior of the variables involved under the assumption that the changes obey only to the intensity of the raining season.

RESUMEN El disponer de un modelo que represente el comportamiento de un sistema o proceso crítico, como lo es el proceso de una planta de purificación de agua, resulta de vital importancia a la hora de evaluar nuevos procedimientos u optimizarlos sin afectar el sistema real o poner en riesgo a la población, evitando así pérdidas económicas. Debido a la complejidad en la dinámica de las plantas de purificación de agua, se recomienda el uso de redes de Petri coloreadas para modelar el comportamiento de las variables involucradas en el proceso. En este contexto, este trabajo presenta un procedimiento estructurado que permite obtener un modelo considerando una dinámica dirigida por la ocurrencia de eventos discretos y que permite la generación de información útil que posteriormente puede ser utilizada para verificar la efectividad y eficiencia de nuevas estrategias de operación de una planta de tratamiento de agua potable. Para evaluar esta propuesta, se desarrolló un modelo de la planta de tratamiento de agua potable de Puerto Mallarino ubicada en Cali, Colombia. Modelando, tanto las etapas del proceso de purificación, como, el comportamiento aproximado de las variables involucradas bajo el supuesto que los cambios obedeces únicamente a los cambios en la intensidad de las estaciones de lluvia.

ABSTRACT Brazil is home to several plant species that exhibit potential for starch extraction. The arrowroot plant stands out owing to its South American origin. Arrowroot starch is especially important for fine confectionery, which is a high-value niche market. Thus, a small producer could benefit from the high prices of arrowroot starch. However, to have consistent production, the extraction should be performed using simple, safe, and inexpensive equipment. Starch extraction involves disintegration of the raw material under water, followed by the separation of fibrous bagasse from the starch–water suspension. This study presents an equipment design based on the concept of appropriate technology that is suitable for small producers to extract starch. A rotating sieve was projected and was evaluated using the ratio of water and starch, which represents the concentration and amount of starch extracted at each point in the equipment. The results highlighted that the sieve length should be longer to increase the separation efficiency. Efficiency of the process depends on the disintegration process because during the separation of bagasse from the starch suspension in water, the large average diameter of the grounded masses required higher water consumption compared with the masses with small average diameter.

Abstract One of the first stages in the purification of surface water is the coagulation and flocculation of suspended solids. The presence of solids alters the physical-chemical properties of water, which can affect color, taste and in many cases generate microbiological contamination. The most commonly used coagulant-flocculant is aluminum sulphate, however, the presence of residual aluminum in water has been associated with health disorders in consumers, since aluminum as a soluble salt becomes bioavailable in the human metabolism. Therefore, the possibility of replacing aluminum sulphate with non-toxic biopolymers such as chitosan is considered. Thus, the water coming from different slopes to the storage tanks of Bellavista treatment plant in the north of Quito city, was analyzed by jar tests. It was found that chitosan in concentrations of 8 ppm causes a 19.7% decrease in turbidity of raw water; at this same concentration, aluminum sulphate generates the opposite effect, producing an increase in turbidity of 19.3%. Due to this behavior, chitosan can become a viable alternative to clarify water for human consumption, in addition to its quality as a natural polymer.

Resumen Una de las primeras etapas en la potabilización del agua superficial es la coagulación floculación de sólidos suspendidos. La presencia de sólidos altera las propiedades físico-químicas del agua, pudiendo afectar su color y sabor, generando, en algunos casos, contaminación microbiológica. El coagulante-floculante más utilizado es el sulfato de aluminio; sin embargo, la presencia de aluminio residual en el agua se ha asociado con trastornos en la salud de los consumidores, ya que el aluminio, como sal soluble, llega a ser biodisponible en el metabolismo humano. Por tanto, se plantea la posibilidad de reemplazar el sulfato de aluminio con biopolímeros no tóxicos como el quitosano. Así, se analizó, mediante pruebas de jarras, el agua que llega de diferentes vertientes a los tanques de almacenamiento de la planta de tratamiento de Bellavista en la ciudad de Quito. Se encontró que el quitosano en concentraciones de 8 ppm ocasiona un 19,7% de disminución en la turbidez del agua cruda; a esta misma concentración, el sulfato de aluminio genera el efecto contrario, produce un incremento de turbidez del 19,3%. Debido a este comportamiento, el quitosano puede convertirse en una alternativa viable para clarificar agua para consumo humano, además de su cualidad como polímero natural.

Resumen En las plantas de extracción de gas natural, el dióxido de carbono (CO2) que viaja en la corriente de gas extraída, se separa y se libera a la atmósfera, acompañado de sulfuro de hidrógeno (H2S), agua e hidrocarburos. El objetivo de esta investigación fue diseñar un proceso de purificación de la corriente de CO2 residual, de tal manera que se evite su emisión a la atmósfera y se pueda utilizar en la industria alimenticia. En la industria alimenticia, el CO2 se puede usar en bebidas carbonatadas y como fluido supercrítico, requiriendo una pureza superior a 99,95% mol. Para ello, se seleccionó como caso de estudio un flujo real de 3454 ton/año de CO2 emitido por una planta de tratamiento de gas localizada en Neiva, Colombia y se simularon varios procesos de purificación usando el software ProMax. La purificación y recuperación de CO2 se evaluó mediante (1) absorción química con metildietanolamina (MDEA), (2) deshidratación con trietilenglicol (TEG) combinada con tamiz molécular, y (3) remoción de compuestos livianos (metano-etano) por el proceso criogénico de Ryan Holmes. La combinación de los tres procesos permitió una recuperación de 99,95% de CO2 con una pureza del 99,99% mol, requiriendo una inversión total de USD 412.323 o 53 USD/tCO2. Este CO2 podría ser comercializado a valores superiores a 5000 USD/tCO2 en la industria alimenticia. Además, la combinación de los procesos (1) y (2) arrojó costos de 37 USD/tCO2, produciendo una pureza de CO2 de 99,85% mol, apto para otras aplicaciones de menor pureza en la industria alimenticia o en el recobro mejorado del petróleo.

Abstract In natural gas plants, the carbon dioxide (CO2) traveling in the extracted stream is separated and released to the atmosphere. This stream also contains hydrogen sulfide (H2S), water and hydrocarbons. The purpose of this investigation was to design a process to purify this CO2 stream, to its further use in the food industry. There, the CO2 can be employed in carbonated drinks and as supercritical fluid; requiring a purity higher than 99.95 mol%. Therefore, a real flow of 3454 ton/year CO2 was selected as case of study, which is emitted in a gas treatment plant located in Neiva, Colombia. This stream was simulated in ProMax and subjected to chemical absorption with methyl diethanolamine (MDEA), to a dehydration with diethylene glycol combined with molecular sieve, to a Ryan-Holmes cryogenic process for removing light components (methane and ethane) and their combinations. The combination of the three processes allowed us for a 99.95% CO2 recovery and a 99.99 mol% CO2 purity, requiring capital expenses (CAPEX) of USD 412.323 or 53 USD/tCO2. This CO2 could be commercialized at sell prices as high as 5000 USD/ tCO2 to the food industry. In addition, the combination of the two first processes delivered a CAPEX of 37 USD/tCO2 with a 99.85 mol% CO2 purity, suitable for other applications requiring less purity in the food industry or improved oil recovery.

Abstract: The most important environmental problem in the cheese industry is the generation of wastewater, due to its volume and the associated pollutant load generated. In order to minimize the environmental impact, it is necessary to purify water coming from the production of cheese. This paper presents the design, construction and start-up of a prototype wastewater treatment plant using the activated sludge method. The design consisted of three stages: characterization of the wastewater treatment plant, study of activated sludge and study of the effect of the organic load on the removal of organic matter. It is a quasi-experimental study based on real data collected from one of the cheese industries in canton Guano, province of Chimborazo, using spot sampling on the wastewater deposit. The prototype is comprised of a homogenizer tank, an aerator tank, and a sedimentation tank. The evaluation of the prototype used different hydraulic retention times of 12, 24, 48 and 72 hours and recirculation of sludge. As a result, a reduction of the Biological Oxygen Demand (BOD) of 21600 mg/L was achieved, reaching a final value of 59 mg/L, with an efficiency of 99.7%. Additionally, a shorter purification time was obtained compared to results presented in related studies.

Resumen: El problema ambiental más importante de la industria quesera es la generación de aguas residuales, tanto por su volumen como por la carga contaminante asociada. Con la finalidad de minimizar el impacto ambiental es necesaria la depuración de las aguas provenientes de la producción de quesos. En este trabajo se presenta el diseño, construcción y puesta en marcha de un prototipo de planta de tratamiento de aguas residuales usando el método de lodos activados. El diseño consistió de tres etapas: caracterización de la planta de tratamiento de aguas residuales, estudio de lodos activados y estudio del efecto de la carga orgánica sobre la remoción de la materia orgánica. Es un estudio cuasi-experimental basado en datos reales recogidos en una de las industrias queseras del cantón Guano, provincia de Chimborazo, usando muestreo puntual sobre el depósito de aguas residuales. El prototipo está conformado de un tanque homogeneizador, un tanque aireador y un tanque sedimentador. La evaluación del prototipo inició empleando varios tiempos de retención hidráulica en 12, 24, 48 y 72 horas y recirculación de lodos. Como resultado se obtuvo una reducción de la Demanda Biológica de Oxigeno (DBO) de 21600 mg/L hasta llegar a un valor de 59 mg/L, con una eficiencia del 99.7%. Adicionalmente se empleó un tiempo menor de depuración en comparación con los resultados que se presentan en trabajos relacionados.

A well-established technology for uranium recovery comprises sulphuric acid leaching, followed by solvent extraction (SX) with tertiary amines such as Alamine 336. The inherent challenge with uranium processing in arid mining regions, such as Namibia and Australia, is that good quality water sources are in short supply. Supplying water through a desalination facility is a costly solution, and the use of high-salinity water, for example, seawater or saline bore water, could provide an alternative option. However, the presence of chlorides above 3 g/L in the pregnant leach solution hinders uranium loading on the conventional tertiary amine solvent extraction organic. In this paper, the opportunity to utilize high-salinity water (20 g/L Cl-) as make-up water in the plant is evaluated using two uranium solvent-extraction (SX) recovery options: Option 1 employs a large seawater reverse-osmosis treatment plant for the supply of fresh water throughout the process, together with Alamine 336 organic for SX; option 2 uses saline water for the front-end water requirements, with the chloride-tolerant Cyanex 272 organic for purification and a smaller reverse osmosis plant for fresh water supply downstream of SX. The main focus is the selection of materials of construction as well as the capital and operating expenditure differentials for water treatment and front-end unit operations. A high-level techno-financial trade-off study using cost differentials revealed that a flow sheet incorporating a high-salinity water source is an economical option when mild steel rubber-lined platework and super-duplex SAF2507 steel mechanicals are used.