Membrane Water Treatment for Drinking Water Production from an Industrial Effluent Used in the Manufacturing of Food Additives.

An integrated membrane process for treatment of effluents from food additive manufacturing was designed and evaluated on a laboratory scale. The principal focus was water recovery with the possibility of its reuse as potable water. The industrial effluent presented high content of dyes and salts. It was red in color and presented brine characteristics. The whole effluent was fed into the integrated process in continuous flow. The steps of the process are as follows: sedimentation (S), adsorption by activated carbon (AC), ion exchange using resins (IEXR), and reverse osmosis (RO) (S-AC-IEXR-RO). The effect of previous operations was evaluated by stress-rupture curves in packaged columns of AC and IEXR, membrane flux, and fouling dominance in RO. Fouling was evaluated by way of the Silt Density Index and membrane resistance examination during effluent treatment. The integrated membrane process provided reclaimed water with sufficiently high standards of quality for reuse as potable water. AC showed a high efficiency for color elimination, reaching its rupture point at 20 h and after 5L of effluent treatment. IEXR showed capacity for salt removal, providing 2.2-2.5 L of effluent treatment, reaching its rupture point at 11-15 h. As a result of these previous operations and operating conditions, the fouling of the RO membrane was alleviated, displaying high flux of water: 20-18 L/h/m2 and maintaining reversible fouling dominance at a feed flow rate of 0.5-0.7 L/h. The characteristics of the reclaimed water showed drinking water standards.

Organochlorine pesticides and polychlorinated biphenyls in high mountain lakes, Mexico.

Pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the El Sol and the La Luna alpine lakes. The lakes are located in central Mexico, in the crater of the Nevado de Toluca volcano. The El Sol and the La Luna lakes are extremely relevant in Mexico and in the world because they are recognized as pristine regions and environmental reservoirs. Samples of atmospheric aerosol, sediment, plankton, and Tubifex tubifex (sludge worm) were collected at three different sample locations for three years (2017, 2018, and 2019) at three different times of year, meaning that the weather conditions at the time of sampling were different. Pollutants were analysed by gas chromatography-mass spectrometry with negative chemical ionisation (GC-MS/NCI). Endosulfan was the most frequent and abundant pollutant, showing the highest peaks of all. Atmospheric aerosol revealed Σ2 = 45 pg/m3, including α and ß, while sediment lakes displayed α, ß and endosulfan sulfate as Σ3 = 1963 pg/g, whereas plankton and Tubifex tubifex showed Σ2 = 576 pg/g and 540 pg/g for α and ß respectively. Results of endosulfan ratios (α/ß) and (α-ß/endosulfan sulfate) suggest that both fresh and old discharges continue to arrive at the lakes. This study shows for the first time the pollution levels of OCP and PCB in high mountain lakes in Mexico. These results that must be considered by policy makers to mitigate their use in the various productive activities of the region.

Extraction and Stabilization of Betalains from Beetroot (Beta vulgaris) Wastes Using Deep Eutectic Solvents.

Deep eutectic solvents (DES) using magnesium chloride hexahydrate [MgCl2·6H2O] and urea [U] proportions (1:1) and (2:1), were prepared for their use as extracting and stabilizer agents for red and violet betalains from beetroot (Beta vulgaris) waste. The synthetized DES [MgCl2·6H2O] [U] showed similar properties to eutectic mixtures, such as, liquid phase, low melting points and conductivity, thermal stability, and variable viscosity. In turn, betalain DES extracts (2:1) exhibited compatibility in the extraction and recovery of betalains from beetroot wastes, showing a betalain content comparable to that of betalain extracts. Betalain stability was determined by degradation tests; the exposure conditions were visible light (12 h), molecular oxygen from atmospheric air and environmental temperature (20-27 °C) for 40 days. The kinetic curves of the betalain degradation of water samples depicted a first-order model, indicating the alteration of a violet colouration of betalains from beetroot waste for 5-7 days. However, betalains from DES extracts were kept under visible light for 150 days, and for 340 days in storage (amber vessels), achieving a stability of 75% in comparison with initial beet extracts.

Water recovery by treatment of food industry wastewater using membrane processes.

This work presents a proposal for the recovery of water through the treatment of food industry wastewater using membrane processes. Three wastewater streams from the different manufacturing steps were identified as possible sources of water recovery: (1) wastewater from the washing of ionic exchange resins and (2) wastewater from the concentration stage of animal proteins (type 1 and 2). The wastewater streams were treated as effluent mixtures; each one with different level of pollution. The principal characteristics of the effluent mixtures were identified as high conductivity and the presence of organic matter. Under these conditions, ultrafiltration and reverse osmosis were carried out for the treatment of wastewater. The ultrafiltration process was tested at an industrial-level plant and the reverse osmosis process was applied at a pilot-plant level. The results showed the feasibility of the proposed treatment for water recovery. The data demonstrates an efficiency greater than 95% in all the quality parameters and therefore, a high quality in the recovered water was obtained by membrane processes. According to the chemical composition of wastewater, the reversible fouling was linked to salts and protein retention, promoting the formation of a cake layer as reversible resistance; whereas, irreversible fouling was minimum during wastewater treatment.

Obtainment and Characterization of Hydrophilic Polysulfone Membranes by N-Vinylimidazole Grafting Induced by Gamma Irradiation.

Polysulfone (PSU) film and N-vinylimidazole (VIM) were used to obtain grafted membranes with high hydrophilic capacity. The grafting process was performed by gamma irradiation under two experiments: (1) different irradiation doses (100-400 kGy) and VIM 50% solution; (2) different concentration of grafted VIM (30-70%) and 300 kGy of irradiation dose. Characteristics of the grafted membranes were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, swelling degree, desalination test, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both experiments indicated that the absorbed dose 300 kGy and the VIM concentration, at 50% v/v, were effective to obtain PSU grafted membranes with 14.3% of grafting yield. Nevertheless, experimental conditions, 400 kGy, VIM 50% and 300 kGy, VIM 60-70% promoted possible membrane degradation and VIM homopolymerization on the membrane surface, which was observed by SEM images; meanwhile, 100-200 kGy and VIM 30-50% produced minimal grafting (2 ± 0.5%). Hydrophilic surface of the grafted PSU membranes by 300 kGy and VIM 50% v/v were corroborated by the water contact angle, swelling degree and desalination test, showing a decrease from 90.7° ± 0.3 (PSU film) to 64.3° ± 0.5; an increment of swelling degree of 25 ± 1%, and a rejection-permeation capacity of 75 ± 2%. In addition, the thermal behavior of grafted PSU membranes registered an increment in the degradation of 20%, due to the presence of VIM. However, the normal temperature of the membrane operation did not affect this result; meanwhile, the glass transition temperature (Tg) of the grafted PSU membrane was found at 185.4 ± 0.5 °C, which indicated an increment of 15 ± 1%.

Encapsulation of Antihypertensive Peptides from Whey Proteins and Their Releasing in Gastrointestinal Conditions.

Antihypertensive peptide fraction from whey protein hydrolysate <3 kDa (measured as angiotensin-converting enzyme (ACE) activity %) was isolated and encapsulated into three composite materials: alginate-collagen, alginate Arabic gum, and alginate-gelatin. The release behavior of peptide fraction from capsules was analyzed according to the encapsulation material efficiency, the characteristics of the capsules, and the released antihypertensive peptides during gastrointestinal digestion. The highest encapsulation efficiency was found in capsules of alginate Arabic gum (95%). In this case, the released peptides incremented their ACE activity (85%) after the digestion process, with respect to the initial ACE activity (74%). Whey antihypertensive fraction revealed five peptide sequences; however, other amino acid sequences were released from digested capsules. Protein databases confirmed some antihypertensive sequences indicating the peptides content from ß-Lg and α-La. Consequently, new peptides could be revealed from whey antihypertensive fraction.

Whey cheese: membrane technology to increase yields.

Sweet cheese whey has been used to obtain whey cheese without the addition of milk. Pre-treated whey was concentrated by nanofiltration (NF) at different concentration ratios (2, 2.5 and 2.8) or by reverse osmosis (RO) (2-3 times). After the concentration, whey was acidified with lactic acid until a final pH of 4.6-4.8, and heated to temperatures between 85 and 90 °C. The coagulated fraction (supernatant) was collected and freely drained over 4 h. The cheese-whey yield and protein, fat, lactose and ash recoveries in the final product were calculated. The membrane pre-concentration step caused an increase in the whey-cheese yield. The final composition of products was compared with traditional cheese-whey manufacture products (without membrane concentration). Final cheese yields found were to be between 5 and 19.6%, which are higher than those achieved using the traditional 'Requesón' process.

Hiperplasia multiepitelial focal: tratamiento comparativo, ácido glicirricínico contra nitrógeno líquido / Focal multiepithelial hyperplasia: comparative treatment, glycyrrhizinic acid versus liquid nitrogen

La hiperplasia multiepitelial focal (HMF), se caracteriza por la aparición de lesiones múltiples en la mucosa de la cavidad bucal en población pediátrica y se asocia con la presencia del virus papiloma humano. Actualmente no existe un tratamiento de elección, el más empleado es el nitrógeno líquido (NL), pero es doloroso e incómodo para el paciente. Es por eso la necesidad de buscar nuevas alternativas de tratamiento, cuidando de ser menos invasivos, como el ácido glicirricínico (AG). Objetivo: Comparar la eficacia del AG contra el NL en la HMF en pacientes entre los 5 a 13 años de edad, en el HIM. Determinar las características clínico-epidemiológicas y los efectos adversos. Material y métodos: Ensayo clínico controlado aleatorizado. Se dividió en dos grupos. Grupo A tratado con la aplicación de AG cuatro veces al día con dos disparos del atomizador por un mes. Un grupo B tratado con NL una vez al mes por tres meses. Resultados: Se estudiaron 20 pacientes en edad pediátrica, 11 masculinos y 9 femeninos; 12 con familiares afectados. La topografía más frecuente fue el labio inferior. El grupo tratado con AG tuvo una eficacia de 63% en comparación con NL que tuvo una eficacia del 81%. Sólo se observaron efectos adversos sistémicos con NL. Se obtuvo una p de 0.075 (7.5%). Conclusiones: Se comprobó la eficacia del AG, a pesar de que fue menor que con NL. Se puede utilizar como un tratamiento coadyuvante para disminuir las lesiones, con mínimos efectos adversos locales.

In pediatric population, focal multiepithelial hyperplasia (FMH) is characterized by the onset of multiple lesions in the mucosa of the mouth; it is associated to the human papillomavirus. Presently, no special treatment is preferred, the most widely used is liquid nitrogen (LN) treatment, nevertheless, this is an uncomfortable and painful treatment for the patient. This would prompt us to look for new, less invasive treatment alternatives such as use of glycyrrhizinic acid (GA). Aim: To compare GA efficiency versus LN in FMH in Mexico Children's Hospital patients (HIM) aged 5 to 13 years. To determine clinical epidemiological characteristics as well as adverse effects. Material and methods: The present was a randomized controlled clinical trial. It was divided into two groups: group A was treated with GA applications, four times a day, two atomizer shots, for one month. Group B was treated with LN once a month for three months. Results: 20 pediatric-age patients were studied, out of which 11 were male and 9 female. 12 patients had relatives afflicted with the disease. Most frequent topography was the lower lip. Efficiency of group treated with GA was 63% when compared to group treated with LN which exhibited 81% efficiency. Systemic diverse effects were only observed with use of LN. 0.075 p was obtained (7.5%). Conclusions: GA efficiency was ascertained although it was lesser than that of LN. GA can be used as an adjuvant treatment in order to decrease lesions, it elicits minimal local adverse effects.