Factors affecting the performance of a solar still and productivity enhancement methods: A review.

Good-quality drinking water is an essential requirement for a healthy and sustainable future. In the current scenario, people living in remote areas of the world are deficient of potable water, especially in developing nations. Desalination technologies available today are energy intensive and aggravate carbon emissions as most energy requirements are fulfilled by using fossil fuels. Solar still is a simple and direct solar desalination device used for water distillation. The major problem associated with a solar still is its low productivity. The main aim of this review paper is to discuss various modifications in a solar still which resulted in productivity enhancement. Different parameters affecting a passive solar still performance and their optimum values for maximum productivity are also thoroughly analysed in this paper. Water depth is an important operating parameter that influences still productivity, and various results showed that maximum productivity is achieved mostly at minimum water depths.

How Can the Desert Beetle and Biowaste Inspire Hybrid Separation Materials for Water Desalination?

Highly effective, hybrid separation materials for water purification were generated following a bioinspired system available in nature. The desert beetle was the inspiration for the generation of separation materials. Using the hydrophobic poly(vinylidene fluoride) (PVDF) membrane as the basis, the membrane was first activated and then furnished with silane-based linkers, and the covalent anchoring of chitosan was successfully accomplished. The obtained surface architecture was a copy of the desert beetle's armor possessing a hydrophobic matrix with hydrophilic domains. The modification was done in the presence or the lack of catalyst (N,N-diisopropylethylamine) that made it possible to tune easily wettability, roughness, and material as well as adhesive features. The membrane morphology and surface chemistry were studied by applying a series of analytical techniques. As a result of chitosan attachment, substantial improvement in transport and separation was reported. Pristine PVDF was characterized by a water flux of 5.28 kg m-2 h-1 and an activation energy of 48.16 kJ mol-1. The water flux and activation energy for a hybrid membrane with chitosan were equal to 15.55 kg m-2 h-1 and 33.98 kJ mol-1, respectively. The hybrid materials possessed enhanced stability and water resistance that were maintained after 10 cycles of membrane distillation tests.

Variations in compositions and antioxidant activities of essential oils from leaves of Luodian Blumea balsamifera from different harvest times in China.

Xanthoxylin was the main compound (content 44.92% of total volatiles) in the leaves of Luodian B. balsamifera, which might be the key cause of failure in collecting essential oil (EO) of the leaves using general hydrodistillation in Clevenger apparatus. A modified hydrodistillation equipped with Clevenger apparatus was designed for isolating EO from the leaves. Six EOs of Luodian B. balsamifera harvested once a month from September to next February were collected successfully. The main components of EOs were δ-elemene, α-cubenene, caryophyllene, caryophyllene epoxide, γ-eudesmol, xanthoxylin, and α-eudesmol. The EOs of Luodian B. balsamifera collected from October to December had higher antioxidant activities (ACs). Combining the principal component analysis of chemical components with the results of ACs and the yields of six EOs, the leaves of Luodian B. balsamifera were suitable to be harvested in November and December to obtain EO with high quality.

Identification by NMR of key compounds present in beer distillates and residual phases after dealcoholization by vacuum distillation.

BACKGROUND: Nowadays, low alcohol and non-alcohol beer intake has increased due to expanding concerns about healthy diets. However, there are still appreciable differences between non-alcoholic beer and conventional beer, particularly regarding flavor. Vacuum distillation is commonly used to remove ethanol from the beer in industrial processes and it is used here. RESULTS: The presence of n-propanol, isobutanol, 3-methylbutanol, 2-methylbutanol, 2-phenylethanol, ethyl acetate, isoamyl acetate, and acetaldehyde, which are key compounds responsible for aroma and flavor of beer, have been analyzed using nuclear magnetic resonance (NMR) spectroscopy in commercial beers and also in the corresponding distillates and residual phases after dealcoholization. CONCLUSION: The compounds present in each phase were identified by monodimensional and bidimensional NMR spectra. The compounds that are completely removed or that remain in the residue of the conventional beers studied are described in detail. The presence of these compounds in dealcoholized beer would be beneficial in keeping the aroma and flavor in dealcoholized beer. © 2020 Society of Chemical Industry.

A pilot study of spiral-wound air gap membrane distillation process and its energy efficiency analysis.

Brine disposal is a major drawback for seawater desalination. Membrane distillation (MD) is an emerging technology to treat a high saline water including brine disposal instead of reverse osmosis, multi-stage flash and multi-effect distillation. This study investigated a pilot scale of a spiral-wound air gap MD (AGMD) module and evaluated its efficiency. A pilot-scale AGMD module with design production capacity of 10 m3/d was operated. Experiments with varying flow velocity showed increasing trend of water vapor flux as flow velocity increases. The temperature is one of the significant points in maximizing water permeate vapor flux in MD. Increasing temperature from 65 °C to 75 °C in evaporator channel has increased flux from 0.59 to 1.15 L/m2/h. Under various conditions, specific thermal energy consumption (STEC) and gained output ratio (GOR) was used to analyze energy efficiency. The pilot plant showed high GOR value in spite of a limited heating and cooling source available at the site. The highest GOR achieved was 3.54 with STEC of 182.78 kWh/m3. This study provides an overview of operation experience and its data analysis related to temperature, concentration, flow rate and energy supply.

Avaliação do crescimento de micro-organismos fotossintetizantes em fotobiorreator tubular empregando nutrientes provenientes da vinhaça tratada / Evaluation of the growth of photosynthetic microorganisms in tubular photobioreactor using nutrients from treated vinasse

vinhaça é resultante da produção de álcool, após a fermentação do mosto e destilação do vinho. É um resíduo rico em nutrientes, principalmente matéria orgânica, nitrogênio, fósforo e potássio. Para ser despejado em rios e lagos, esse efluente deve passar por tratamentos para remoção desses nutrientes, pois o excesso desses elementos nos corpos hídricos poderia levar a grandes problemas ambientais, de modo que tem sido utilizado em fertirrigação. Microorganismos fotossintetizantes absorvem nutrientes inorgânicos, podendo absorver nutrientes de águas residuais. Se for removida a parte orgânica da vinhaça, a fração inorgânica ou com baixa carga orgânica pode ser a base ou o próprio meio de cultivo destes micro-organismos, que absorvem gás carbônico e sua biomassa é de interesse industrial. Neste contexto, foi estudado o cultivo de Monoraphidium contortum e Synechocystis salina, oriundos de água de mangue, em frascos de Erlenmeyer e em fotobiorreatores tubulares por processo descontínuo, empregando a vinhaça proveniente do tratamento aeróbio (biológico), acoplada a processos físico-químicos, com diferentes diluições. As características físico-químicas das vinhaças tratadas foram avaliadas. Além disso, foram comparados os crescimentos celulares nas diferentes condições experimentais adotadas para o crescimento da microalga M. contortum e da cianobactéria S. salina na vinhaça tratada com e sem diluição. Em cultivos em frascos de Erlenmeyer, em meio proveniente de tratamento biológico, o crescimento celular não diferiu do cultivo em meio padrão, com diluições de 5 e 2 vezes da vinhaça tratada para M. contortum e S. salina, respectivamente. Em fotobiorreator tubular, independente do tratamento ser apenas biológico ou também com carvão ativado, as concentrações celulares máximas (Xm) de M. contortum e S. salina foram da ordem de 1,86x107 células mL-1 e 7,90x106 células mL-1, respectivamente, valores esses menores que os obtidos em meio padrão, com valores de Xm de 2,69x107 células mL-1 e 1,27x106 células mL-1 para M. contortum e S. salina, respectivamente. Em fotobiorreatores tubulares, os teores de mínimos de lipídios de M. contortum e S. salina foram de 33,4 % e 11,0 %, respectivamente. Adicionalmente, os teores mínimos de proteínas da microalga foram de 15,1 % e da cianobactéria foi de 23,2 %

The vinasse is the result of the production of alcohol after the fermentation of the mash and the distillation of the wine. It is a waste rich in nutrients, mainly organic matter, nitrogen, phosphorus and potassium. To be discharged into rivers and lakes, this effluent must be treated in order to remove nutrients, because the excess of these elements in water bodies can lead to major environmental problems, so that it has been used in fertigation. Photosynthetic microorganisms absorb inorganic nutrients and they can absorb nutrients from wastewater. If the organic fraction of vinasse is removed, the inorganic or low organic fraction may be the basis or a medium of cultivation of these microorganisms, which absorb carbon dioxide and its biomass is of industrial interest. In this context, Monoraphidium contortum and Synechocystis salina from mangrove water were cultivated in Erlenmeyer flasks and in tubular photobioreactors by batch process using vinasse from aerobic biological treatment, coupled to physicochemical treatments with different dilutions. The physicochemical characteristics of the treated vinasse were evaluated. In addition, cell growth was compared under different experimental conditions adopted for growth of microalgae M. contortum and cyanobacteria S. salina in vinasse treated with and without dilution. In Erlenmeyer flask cultivations, in medium from the biological treatment, the cell growth was not different of that one in standard medium cultivation, with dilutions of 5 and 2 times the vinasse treated for M. contortum and S. salina, respectively. In the tubular photobioreactor, irrespective if the treatment is only biological or also is carried out treatment with activated charcoal, they were obtained maximum cell concentrations (Xm) of M. contortum and S. salina of 1.86x107 cells mL-1 and 7.90x106 cells. mL-1 , respectively, lower than the standard, whose Xm values were 2.69x107 cells mL-1 and 1.27x106 cells mL-1 for M. contortum and S. salina, respectively. In tubular photobioreactors, the minimum lipid contents of M. contortum and S. salina were 33.4 % and 11.0 %, respectively. In addition, the minimum protein content of microalgae was 15.1 % and cyanobacterium was 23.2 %

Combined Osmotic and Membrane Distillation for Concentration of Anthocyanin from Muscadine Pomace.

Bioactive anthocyanins from aqueous extracts of muscadine grape pomace were concentrated using osmotic distillation (OD) and direct contact membrane distillation (DCMD) using polypropylene (PP) and poly(ethylene chlorotrifluoroethylene) (ECTFE) membranes. The driving force for OD is created by using a high concentration brine solution while the driving force for DCMD is generated by elevating the feed temperature relative to the permeate temperature. The brine concentration used was 4 M. The lowest fluxes were obtained for OD. Given the temperature sensitive nature of anthocyanins, the maximum temperature difference during DCMD was limited to 30 °C. The feed temperature was 40 °C and the permeate at 10 °C. Consequently, the maximum flux during DCMD was also limited. A combination of OD and DCMD was found to give the highest fluxes. High-performance liquid chromatography (HPLC) and HPLC-electrospray mass spectrometry were used to identify and quantify anthocyanins, cyanidin-3,5-O-diglucoside, delphinidin-3,5-O-diglucoside, petunidin-3,5-O-diglucoside, peonidin-3,5-O-diglucoside, and malvidin-3,5-O-diglucoside. The results obtained here suggest that, though water fluxes for DI water feed streams for PP and ECTFE membrane were similar, the fluxes obtained for the two membranes when using muscadine pomace extracts were different. Concentration factors of close to 3 was obtained for anthocyanins. Membranes also showed slightly different performance in the concentration process. Membrane surfaces were analyzed using scanning electron microscopy and Fourier-transformed infrared spectroscopy. The results suggest that adsorption of these anthocyanins on the membrane surface lead to performance differences. In an actual operation, selection of an appropriate membrane and regeneration of the membrane will be important for optimized performance. PRACTICAL APPLICATIONS: Anthocyanins are valuable therapeutic compounds, which are found in the solid residue left following fruit juice pressing. However, recovery and concentration of these therapeutic compounds remains challenging due to their stability. Here, a novel membrane-based unit operation has been investigated in order to concentrate the anthocyanins that have been extracted into aqueous solutions. The unit operation investigated here use mild processing conditions. Insights into the factors that need to be considered when optimizing of the unit operation for commercialization are discussed.

Influence of dye class on the comparison of direct contact and vacuum membrane distillation applied to remediation of dyeing wastewater.

This work investigated the influence of dye class on permeate flux and color rejection by comparing direct contact membrane distillation (DCMD) and vacuum membrane distillation (VMD) applied to remediation of dyeing wastewater. The same operating system at the feed side was used and the driving force of each configuration was determined. Reactive and disperse dye solutions were considered, and a commercial membrane was employed. Final color rejection > 90.79% was obtained, and water was recovered at the permeate side (final normalized permeate flux up to 38.92 kg m-2day-1kPa-1). VMD showed higher normalized permeate flux when compared to DCMD. However, the performance according to dye class depended on MD configuration. Reactive dye resulted in higher permeate flux than the disperse dye solution in DCMD. Contrarily, disperse dye solution showed higher permeate flux in VMD. The formation of a concentration boundary layer at the permeate membrane interface was suggested with disperse dye solution in DCMD, decreasing thus the driving force. In VMD, the boundary effect is negligible with disperse dye solution. This result implies that the VMD performance in the textile industry may depend more on driving force rather than the dye class of the dyeing bath.

Multifunctional microchip-based distillation apparatus II - Aerated distillation for sulfur dioxide detection.

A multifunctional microchip-based distillation apparatus is presented for the distilled of sulfur dioxide (SO2) in food products. The microchip is fabricated on poly(methyl methacrylate) (PMMA) substrates, and comprises a sample zone, a buffer zone, a serpentine distillation column, and a collection zone. In the process, the sample is introduced into the sample zone and is heated under carefully controlled temperature and time conditions. The resulting SO2 and water vapor are carried by nitrogen (N2) gas to the distillation column, where the SO2 is separated from the water vapor via the condensing effects of a continuous cold water flow. Finally, the SO2 is transported to the collection zone, where it is collected with hydrogen peroxide (H2O2) and its concentration determined using an alkali-based titration and paper-based detection method. A distillation efficiency of 90.5% is obtained under the optimal distillation conditions at concentrations of 20-4000 ppm. Moreover, a linear correlation (R2 = 0.9997) is observed between the experimental measurements of the SO2 concentration and the known concentration. The validity of the presented microchip-based distillation apparatus is further investigated by distilling the SO2 concentrations of 25 commodity samples. The detection results show that the deviation does not exceed 5.4% compared with the traditional official method.

Simultaneous saccharification and fermentation of native rye, wheat and triticale starch.

BACKGROUND: The increasing global demand for starchy raw material requires new methods for obtaining ethanol from a range of plants using environmentally friendly methods. Granular starch-hydrolyzing enzymes (GSHE) can effectively support the development of the distillery industry. RESULTS: The aim of this study was to evaluate the effectiveness of simultaneous saccharification and fermentation of native rye, wheat or triticale starch. Mashes were prepared using methods that limit water and energy consumption (pre-hydrolysis at 35 °C for 30 min). The results show that the degree of starch saccharification depended on the raw material. However, the highest yields of ethanol were obtained with 100 kg of triticale mashes (38.9 ± 1.4 L absolute alcohol) as compared to rye and wheat mashes. The concentration of dry matter (between 250 and 280 g L-1 ) in the mashes was not associated with a decrease in ethanol yield and improved efficiency in the case of wheat and triticale. CONCLUSION: Simultaneous saccharification and fermentation offers a low-cost and environmentally friendly alternative to existing procedures for industrial ethanol production, which may be of particular interest to raw-spirit producers, as well as to the food and fermentation industry at large. © 2019 Society of Chemical Industry.

Surface Modification of PVDF Membranes for Treating Produced Waters by Direct Contact Membrane Distillation.

Direct contact membrane distillation (DCMD) has been conducted to treat hydraulic fracturing-produced water using polyvinylidenedifluoride (PVDF) membranes. Tailoring the surface properties of the membrane is critical in order to reduce the rate of adsorption of dissolved organic species as well as mineral salts. The PVDF membranes have been modified by grafting zwitterion and polyionic liquid-based polymer chains. In addition, surface oxidation of the PVDF membrane has been conducted using KMnO4 and NaOH. Surface modification conditions were chosen in order to minimize the decrease in contact angle. Thus, the membranes remain hydrophobic, essential for suppression of wetting. DCMD was conducted using the base PVDF membrane as well as modified membranes. In addition, DCMD was conducted on the base membrane using produced water (PW) that was pretreated by electrocoagulation to remove dissolved organic compounds. After DCMD all membranes were analyzed by scanning electron microscopy imaging as well as Energy-Dispersive X-Ray spectroscopy. Surface modification led to a greater volume of PW being treated by the membrane prior to drastic flux decline. The results indicate that tailoring the surface properties of the membrane enhances fouling resistance and could reduce pretreatment requirements.

Essential oil composition in natural population of Lippia origanoides (Verbenaceae) during dry and rainy seasons / Composición de los aceites esenciales en poblaciones naturales de Lippia origanoides (Verbenaceae) durante las estaciones seca y lluviosa

Abstract Lippia origanoides Kunth. is a medicinal shrub native to some countries in South America, Central America and the Caribbean. This study aims to investigate the chemical composition of the essential oil and the genetic diversity of a natural population of Lippia origanoides in two seasons. Leaf samples were collected from 30 individuals in the dry and rainy seasons. The essential oil was extracted into a Clevenger apparatus and analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The relative quantification of thymol and carvacrol was performed by gas chromatography coupled to a flame ionization detector (GC-FID). Multivariate analysis was used to evaluate the genetic divergence between plants. Carvacrol was the major compound found in most plants for both seasons. In the rainy season, plant 15 presented thymol as the major compound, and plants 16, 27, 28 and 29 presented camphor as the major compound. In the dry season, thymol remained the main compound of plant 15 and camphor remained the main compound of plants 16, 28 and 29; however, plant 27 presented carvacrol as the main compound in this season. After carvacrol, the compounds with the highest content were γ-terpinene, p-cymene and methyl-ether-thymol. Of the 30 plants studied, only five differed in their chemical composition, showing some degree of stability in relation to the dry and rainy seasons. There was no variation in the main compounds between the two seasons, but there was chemical diversity among the main compounds. Tocher grouping revealed five distinct groups, with group 1 including most of the plants in both dry and rainy seasons, indicating that the time of year evaluated did not significantly interfere with the essential oil composition of most plants.(AU)

Resumen Lippia origanoides Kunth. es un arbusto medicinal nativo de algunos países de Centro y Sur América y el Caribe. El objetivo de este estudio fue investigar la composición química de los aceites esenciales y la diversidad genética de una población natural de L. origanoides en dos estaciones. El aceite esencial se extrajo en un equipo de Clevenger y se analizó por cromatografía de gases acoplado a espectrometría de masas (CG-EM). La cuantificación relativa de timol y carvacrol se realizó por cromatografía de gases acoplado a un detector de ionización de llamas (CG-DIL). Se utilizó un análisis multivariado para evaluar la divergencia genética entre plantas. El carvacrol fue el compuesto principal encontrado en la mayoría de las plantas para ambas estaciones. En la estación lluviosa, la planta 15 presentó timol como el compuesto principal y las plantas 16, 27, 28 y 29 presentaron alcanfor como el compuesto principal. En la estación seca, el timol se mantuvo como el principal compuesto en la planta 15, de igual manera el alcanfor se mantuvo como el principal en las plantas 16, 28 y 29. Sin embargo, la planta 27 presentó carvacrol como el principal compuesto en esta estación. Después del carvacrol, los compuestos con el mayor contenido fueron γ-terpineno, p-cimeno and metil-eter-timol. De las 30 plantas estudiadas, solo cinco difirieron en su composición química, mostrando algún grado de estabilidad en relación a la estación seca y lluviosa. No hubo variación en los compuestos principales entre las dos estaciones, pero hubo diversidad química entre los compuestos principales. El agrupamiento de Tocher mostró cinco grupos distintos, con el grupo 1 incluyendo la mayoría de las plantas en ambas estaciones, lo cual indica que el periodo del año evaluado no interfiere significativamente con la composición de aceites esenciales en la mayoría de plantas.(AU)

Essential oils as natural additives to prevent oxidation reactions in meat and meat products: A review.

Oxidation reactions during manufacturing, distribution, and storage of meat and meat products result in undesirable physicochemical changes and aromas, which leads to detrimental effects on the product quality. This could be translated into the consumer dissatisfaction and economic loss. One of the most common practices to overcome this issue is the incorporation of synthetic antioxidants. However, the increasing health-consciousness of consumers and their preference for natural additives leads to the search of natural alternatives to synthetic antioxidants. A number of essential oils have strong antioxidant properties and are explored as potential alternatives to chemical antioxidants in the meat industry. These compounds are classified as Generally Recognized as Safe (GRAS), and their application single or combined with other essential oils, ingredients or preservation technologies have beneficial effects on meat products. Their activity depends on several parameters including their concentrations, their possible synergistic effects, and the extraction method used to obtain them. Although steam distillation is the most common industrial technique for essential oils extraction, novel technologies have been emerged to address the drawbacks of the traditional extraction method and to obtain high-quality essential oils. This paper provides an overview of the application of essential oils as potential substitutes for synthetic antioxidants in the meat industry, exploring their mechanism of action against oxidation reactions, and the effect of extraction methods on their effectiveness.

Preparation and Application of Standardized Typical Volatile Components Fraction from Turmeric (Curcuma longa L.) by Supercritical Fluid Extraction and Step Molecular Distillation.

A green and reliable method using supercritical fluid extraction (SFE) and molecular distillation (MD) was optimized for the separation and purification of standardized typical volatile components fraction (STVCF) from turmeric to solve the shortage of reference compounds in quality control (QC) of volatile components. A high quality essential oil with 76.0% typical components of turmeric was extracted by SFE. A sequential distillation strategy was performed by MD. The total recovery and purity of prepared STVCF were 97.3% and 90.3%, respectively. Additionally, a strategy, i.e., STVCF-based qualification and quantitative evaluation of major bioactive analytes by multiple calibrated components, was proposed to easily and effectively control the quality of turmeric. Compared with the individual calibration curve method, the STVCF-based quantification method was demonstrated to be credible and was effectively adapted for solving the shortage of reference volatile compounds and improving the QC of typical volatile components in turmeric, especially its functional products.

Application of membrane distillation for the treatment of anaerobic membrane bioreactor effluent: An especial attention to the operating conditions.

This study was carried out by applying the direct contact membrane distillation (DCMD) into the treatment of effluent from anaerobic membrane bioreactor. The treatment efficiency of DCMD was highly emphasized, which was expected to be improved through the optimization of operating conditions. Three operating conditions, including temperature difference, cross-flow velocity and membrane pore size, were considered. The relative flux (the ratio of actual flux to initial flux) increased from 0.50 to 0.98 as the operating conditions changed and that was enhanced by the increment of temperature difference and cross-flow velocity. Regarding the wastewater treatment efficiency, except for ammonia nitrogen, the interception ratio was greater than 90.0%, which even reached 99.0% for CODCr, protein and polysaccharide by optimizing operating conditions. In addition, the interception ratio of PO43--P almost reached 100.0% under any operating condition. Further study about membrane fouling was carried out, and the crystallization fouling was found to be the main fouling type.

Wetting phenomena in membrane distillation: Mechanisms, reversal, and prevention.

Membrane distillation (MD) is a rapidly emerging water treatment technology; however, membrane pore wetting is a primary barrier to widespread industrial use of MD. The primary causes of membrane wetting are exceedance of liquid entry pressure and membrane fouling. Developments in membrane design and the use of pretreatment have provided significant advancement toward wetting prevention in membrane distillation, but further progress is needed. In this study, a broad review is carried out on wetting incidence in membrane distillation processes. Based on this perspective, the study describes the wetting mechanisms, wetting causes, and wetting detection methods, as well as hydrophobicity measurements of MD membranes. This review discusses current understanding and areas for future investigation on the influence of operating conditions, MD configuration, and membrane non-wettability characteristics on wetting phenomena. Additionally, the review highlights mathematical wetting models and several approaches to wetting control, such as membrane fabrication and modification, as well as techniques for membrane restoration in MD. The literature shows that inorganic scaling and organic fouling are the main causes of membrane wetting. The regeneration of wetting MD membranes is found to be challenging and the obtained results are usually not favorable. Several pretreatment processes are found to inhibit membrane wetting by removing the wetting agents from the feed solution. Various advanced membrane designs are considered to bring membrane surface non-wettability to the states of superhydrophobicity and superomniphobicity; however, these methods commonly demand complex fabrication processes or high-specialized equipment. Recharging air in the feed to maintain protective air layers on the membrane surface has proven to be very effective to prevent wetting, but such techniques are immature and in need of significant research on design, optimization, and pilot-scale studies.

Anaerobic treatment of blended sugar industry and ethanol distillery wastewater through biphasic high rate reactor.

This study aimed to investigate the physicochemical properties of sugar industry and ethanol distillery wastewater and the treatment of the blended wastewater through a two-stage anaerobic reactor. For this treatment, different initial chemical oxygen demand (COD) concentrations (5-20 g/L) and hydraulic retention times (HRTs) (2-10 days) were applied. The sugar industry effluent characteristics obtained in terms of organic matter (mg/L) were as follows: 5 days biochemical oxygen demand (BOD5): 654.5-1,968; COD: 1,100-2,148.9; total solids (TS): 2,467-4,012 mg/L; and pH: 6.93-8.43. The ethanol distillery spent wash strengths obtained were: BOD5: 27,600-42,921 mg/L; COD: 126,000-167,534 mg/L; TS: 140,160-170,000 mg/L; and pH: 3.9-4.2. Maximum COD removal of 65% was obtained at optimum condition (initial COD concentration of 10 g/L and HRT of 10 days), and maximum color removal of 79% was recorded under similar treatment conditions. Hence, the performance of the two-stage anaerobic reactor for simultaneous removal of COD and color from high-strength blended wastewater is promising for scaling up in order to mitigate environmental problems of untreated effluent discharge.

A strategy to reduce inflammation and anemia treatment's related costs in dialysis patients.

This is a post-hoc analysis evaluating erythropoiesis stimulating agents' (ESA) related costs while using an additional ultrafilter (Estorclean PLUS) to produce ultrapure dialysis water located within the fluid pathway after the treatment with reverse osmosis and before the dialysis machine. Twenty-nine patients (19 treated with epoetin alfa and 10 with darboepoetin alfa) were included in the analysis. We showed to gain savings of 210 € per patient (35 € per patient each month) with epoetin alfa during the experimental period of 6 months, compared to the control period and of 545 € per patient (90 € per patient each month) with darboepoetin alfa. Estorclean PLUS had a cost of 600 € (25 € per month per each patient) and was used for 6 months. Intravenous iron therapy with sodium ferrigluconate had a cost of 0,545 €/62,5 mg. In conclusion, during the experimental period with the use of Estorclean, we obtained global savings of 11 € per patient per month with epoetin alfa and 30 € per patient per month with darboepoetin alfa to treat anemia in dialysis patients.

Sensory quality of milk fat with low cholesterol content fractioned by molecular distillation.

BACKGROUND: Anhydrous milk fat (AMF) is a valuable ingredient in several industries, but its cholesterol content is a disadvantage because it is associated with several diseases. The objective of this study was to remove the largest possible amount of cholesterol from AMF by molecular distillation and to analyze the sensory properties of the obtained product. AMF was subjected to various molecular distillation arrangements. RESULTS: The first set of experiments involved molecular distillations performed over a range of evaporation temperatures. Then, according to the outcome of the first set of experiments, a second set of experiments was carried out in order to study the effect of the feeding flow rate. Finally, the number of distillation stages was modified. CONCLUSION: The best results were obtained in a three-stage arrangement, in which ∼60% of cholesterol was removed with a 30.48% distillate yield. The sensory properties of this distillation cut were also the most similar to those of the untreated milk fat. © 2018 Society of Chemical Industry.

Detailed modeling and simulation of an out-in configuration vacuum membrane distillation process.

In this study, a detailed rigorous theoretical model was developed to predict the transmembrane flux of a shell-and-tube type vacuum membrane distillation (VMD) module for seawater desalination. Two modes of operation are used for performing the VMD, namely lumen-side feed (in-out) configuration and shell-side feed (out-in) configuration. In this study, detailed mathematical formulations are derived for an out-in configuration that is commonly used in seawater desalination applications. Experimental results and model predictions for mean permeate flux are compared and shown to be in good agreement. The results indicate that although the simple VMD model that maintains a constant permeate pressure is easy to use, it is likely to significantly overestimate the mean permeate flux when compared to the detailed model that considers the pressure build-up in the fiber lumen. The pressure build-up of water vapor in the fiber lumen is identified as the crucial factor that significantly affects the VMD performance because it directly reduces the driving force for vapor permeation through the membrane pores. Additionally, its effect is more pronounced at longer fiber lengths and higher permeate fluxes, and this is achieved at higher feed temperatures and velocities and at lower feed salinities. In conclusion, the results of the study are extremely important in module design for the practical applications of VMD processes.