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Two sequential batch reactors (R1 and R2) of aerobic granular sludge (AGS) were inoculated with activated sludge of different origins. The objective was to investigate the granulation and the consistency between the structure of the microbial communities (16S rRNA amplicon sequencing) in each reactor and their metabolic performance (removal of C, N, and P). Both reactors were fed with acetate-based synthetic wastewater, targeting an anaerobic-aerobic cycle reputed to favor the phosphorus- and glycogen-accumulating organisms (PAO and GAO). Stable granulation was achieved in both reactors, where, instead of PAO, the dominant genera were ordinary heterotrophic organisms (OHO) such as Thauera, Paracoccus, and Flavobacterium known for their high capacity of aerobic storage of polyhydroxyalkanoates (PHA). Generally, there was good consistency between the metabolic behavior of each reactor and the bacterial genera detected. Both reactors showed high removals of C and complete nitrification (Nitrosomonas and Nitrospira detected) but a low level of simultaneous nitrification-denitrification (SND) during the aerated phase. The latter causes that nitrates were recycled to the initial phase, in detriment of PAO selection. Meanwhile, the study showed that selecting slow-growing OHOs (with aerobic storage capacity) favors stable granulation, revealing an alternative AGS technology for C and N removal.

Municipal Wastewater Treatment Plants (MWWTPs) have proven to be sources of adverse environmental impacts; however, integrated management can help improve their efficiency. Therefore, this study aims to evaluate the gap between the current management and another based on an international standard applied to WWTPMs, in order to understand their environmental commitment, and to identify the challenges and opportunities they present for the adoption or certification of an environmental management system (EMS) based on ISO 14001. For this purpose, a descriptive cross-sectional study was carried out in two MWWTPs in southern Mexico. In a first step, an automated checklist was designed based on the requirements of the ISO 14001:2015 standard and based on a modified FMEA (Failure Mode and Effects Analysis) calculation method. In a second step, a diagnosis was carried out at the MWWTPs, followed by a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis to determine internal and external factors until a series of challenges and opportunities was identified. The findings indicate that the selected MWWTPs have a wide gap that keeps them away from efficient management. Among the challenges, “limited financial resources” were identified followed by “high turnover of managerial staff”, while the opportunities with the greatest potential for improvement are related to the factors “candidate for investment” and “environmental policy”. The treatment plants show a weak environmental commitment, therefore rigorous action plans should be considered, not only to protect the environment but also the investment, and they should be the main promoters that challenge the private sector.

Municipal wastewater treatment plants (MWWTPs) are considered essential to protect human health and aquatic systems. However, several studies in the scientific field have identified adverse environmental effects in these treatment units that involve challenges in the water industry. Therefore, this work has the following objectives: (1) to understand the global context in which MWWTPs operate and (2) to determine the thematic and geographic trend in scientific research. Through the “Publish or Perish” software, scientific articles indexed in the Scopus and Google Scholar databases during the period 2000 to 2020 were obtained. Specific terms were used: “Municipal Wastewater Treatment Plants”; “Municipal Wastewater Treatment Plants,” so that all terms must be contained in the title of the document. Categorization was defined according to key concepts considered as adverse effects indicated in the literature and that involve common problems in the water industry at the municipal level. As a result, 1844 documents (papers, reviews, books, book chapters, citations, letters, theses, and conference papers) were retrieved and subjected to a process of refinement (discrimination) where only articles, chapters, conference papers, and reviews were considered. Finally, 800 articles were selected for further content analysis, identifying seven categories and 30 subcategories. The category of “Emerging contaminants” was the most relevant within the research topics, and the category with the least available research was “Air quality.” The articles were also analyzed by economic region, identifying Asia with the largest number of studies on various topics. In conclusion, future research should be oriented towards management, energy, and air quality issues, because they are subjects of little research involving process efficiency, energy savings, and impacts on the quality of life.

Blackberry juice (BJ) and Lactobacillus acidophilus (LA) were co-encapsulated by spray drying in three single materials: gum Arabic (GA), maltodextrin (MD) and whey protein concentrate (WPC), as well as in the 50:50 blends of these materials were also considered. After the spray drying, total phenolic compounds (TPC) and total monomeric anthocyanin content (TMAC) was higher when GA-MD blend was used as an encapsulating agent with 98.4 ± 1.0% and 99.0 ± 1.0%, respectively. FTIR analysis indicated that the BJ affected the structure of the wall material, mainly when WPC was incorporated. The viability of LA was significantly higher when WPC was used (93.3 ± 0.9%) in comparison with a single material or a blend of materials. After storage of microcapsules, the best blend of biopolymers to protect TPC and TMAC was GA-MD with values of 67.9 ± 0.6% and 81.8 ± 0.8% respectively, while WPC presented the highest protection in LA cell survival (81.2 ± 0.7%). The degradation dynamics of compounds in microcapsules was described by first-order kinetics, with degradation rates ranging between 0.06 and 0.30 week−1 for bioactives and probiotic bacteria. The overall results showed GA-MD can be considered the most viable formulation to protect bioactives and probiotic bacteria.

Chitosan–starch polymers are reinforced with different keratin materials obtained from chicken feather. Keratin materials are treated with sodium hydroxide; the modified surfaces are rougher in comparison with untreated surfaces, observed by Scanning Electron Microscopy. The results obtained by Differential Scanning Calorimetry show an increase in the endothermic peak related to water evaporation of the films from 92 °C (matrix) up to 102–114 °C (reinforced composites). Glass transition temperature increases from 126 °C in the polymer matrix up to 170–200 °C for the composites. Additionally, the storage modulus in the composites is enhanced up to 1614% for the composites with modified ground quill, 2522% for composites with modified long fiber and 3206% for the composites with modified short fiber. The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73% for chitosan-starch matrix up to 16% for the composites with 5 wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiating chitosan–starch films with sustainable features.

Este trabajo describe el desarrollo e implementacion de un sistema de monitoreo y control de los parametros fisicos involucrados en las etapas de inicio, sostenimiento y apagado de descargas de barrera dielectrica generadas dentro de un reactor de geometria coaxial. En el proceso se empleo el diseno grafico de sistemas ( GSD , graphical system de- sign ) para conjuntar eficientemente una interfaz grafica de usuario ( GUI , graphical user interface ), la tarjeta de adqui- sicion de datos DAQ-6259 con canal de comunicacion USB, una fuente de voltaje conmutado push - pull , controladores de flujo gaseoso y equipo de diagnostico quimico y electronico. El nucleo del enfoque GSD se encuentra en el codigo de programacion G de LabVIEW; de esta manera, se recopilaron datos precisos y en tiempo real de las variables (vgr.: flujo de aire y potencia aplicada), mismos que permitieron realizar un analisis del desempeno de las descargas Durante las pruebas se emplearon diferentes concentraciones de una mezcla de helio contaminada con oxidos de nitrogeno, con la finalidad de cuantificar el porcentaje de degradacion/destruccion de los ultimos. Los resultados indican un valor mayor a 88%. Por seguridad, a la GUI se accede a traves de la intranet institucional, debido a que los compuestos generados pueden representar un riesgo para la salud humana.

A sensory profile of Oaxaca cheese was developed. To represent both industrial and artisanal Oaxaca cheese, 3 types of cheese were manufactured under controlled conditions: 2 with pasteurized milk using a mesophilic lactic acid bacteria culture (Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris) and a thermophilic lactic acid bacteria culture (Streptococcus salivarius ssp. thermophilus), and a third with naturally acidified raw milk. The cheeses were evaluated by a panel of 11 trained judges. Additionally, chemical composition and instrumental color parameters were determined, an instrumental texture profile analysis was performed, and volatile compounds were identified by solid-phase microextraction coupled with gas chromatography/mass spectrometry. The sensory profile developed includes 43 descriptors, of which 13 are discriminant among these 3 cheese types. Descriptors include visual attribute waxy; tactile (manual) attributes moist and oily; orthonasal aroma attributes empyreumatic and cow; basic taste attribute salty; mouth texture attributes chewable, gummy, adherent, fibrous, moist, and fatty; and auditory attribute squeaky. A strong correlation was found between specific sensory data and physicochemical parameters measured by instrumental and chemical methods.

The effect of the interaction polysaccharide–polysaccharide (P–P) and polysaccharide–protein (P–Pr) blends on thermal and mechanical properties in films as biodegradable alternative of materials for food packaging was studied. Essential oils (cloves and cinnamon) emulsified were successfully incorporated into the films and evaluated as antifungal agents. Films were prepared using the film casting method. The morphological analysis showed that P–Pr films display a fractured rough surface without pores or globular formations and P–P films exhibiting continuous phases and absence of cracks. FTIR spectra evidence interactions between polysaccharides and polysaccharides-protein. Initial degradation temperature (T 5 %) decreases in two kinds of films with the addition of antifungal agents. P–Pr films showed higher maximum decomposition temperature (T max) regarding P–P films. The incorporation of carrageenan in films enhances the tensile strength and elongation at break. Higher antifungal activity against Botrytis cinerea and Rhizopus stolonifer was revealed in the films containing cinnamon oil.

The Head Space Solid Phase Microextraction Method (HS-SPME), coupled with Gas Chromatography and Mass Spectrometry (GC-MS) was optimized to quantify Volatile Organic Compounds (VOC’s) in a fresh Oaxaca cheese during its shelf life of 22 days. Optimal extraction conditions were ascertained by means of a multiple linear regression analysis and the generation of a response surface. Conditions to reach the equilibrium of VOC’s at the headspace were established to be 30 minutes of ultrasonic agitation at 50°C. The conditions for extraction were exposure of the fiber at room temperature for 30 minutes. Optimal extraction of volatile compounds released by the Oaxaca cheese allowed identification of 21 volatile compounds: 8 acids, 1 alcohol, 4 aldehydes, 4 ketones, 1 ester, and 3 lactones. Quantification of VOC’s was carried out using the technique of standard addition. The limits of quantification ranged from 0.0033 to 0.0311 ng/μg. Ten compounds were identified with the heaviest concentration and are listed as follows, from heaviest to lightest: propionic acid, acetoin, acetic acid, diacetyl, capric acid, caprylic acid, δ-decalactone, δ-dodecalactone, γ-dodecalactone, butyraldehyde. During storage of the cheese, the most significant changes in the concentration of VOC’s took place between day 1 and day 15. Based on the results obtained, it can be concluded that the optimization of the SPME makes it possible to isolate and quantify VOC’s of fresh cheeses in an efficient and reproducible manner.

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater.

Chicken feathers are composed mainly of avian keratin, a fibrillar protein with a complex structure, and important properties such as durability, hydrophobicity, being chemically unreactive, and depending on the specific function can change its morphological and inner structure. This study takes advantage of these features and for the first time the use of keratin from chicken feathers to modify characteristics on expansive soils is reported. Swelling characteristics of remolded expansive soil specimens were studied through varying the percentage of keratin fiber content using 0.25, 0.50, 1.00 and 3.00 wt%. One-dimensional swell-consolidation tests were conducted on oedometric specimens, specific surface area was determined using methylene blue, and degree of saturation was also analyzed. Finally random distribution and interaction between keratin structures and soil were studied by scanning electron microscopy. The results show that randomly distributed fibers are useful in restraining the swelling tendency of expansive soils. The maximum reduction of pressure (43.99%) due to swelling is achieved by reducing the void ratio, which can be reached with the addition of chicken feather keratin structures to the expansive soil. Finally, the mechanism by which discrete and randomly distributed fibers reduce swelling pressure of expansive soil is explained.

Within the framework of precursor events related to earthquakes, this paper analyzes the possible effect on the aquatic environment of the surrounding energy that accompanies earthquakes, particularly in the area where oceanic and continental plates collide (Cocos Plate and North American Plate, south of Mexico). As a preamble, the types of precursor events, characteristics, and their possible origin are described. A project was designed under the assumption that in areas with high frequency and intensity seismicity there is an electrical and electromagnetic potential promoter which is detectable and assessable indirectly by measuring water conductivity behavior, which also may have atypical variations of data; the outcome of intensive conductivity monitoring in different settings, natural as well as manmade (wellsprings, artesian well and a cistern), are presented herein. The results of the conductivity monitoring for seven months, highlight two patterns in data behavior: one pattern shows the subtle dependence of data behavior on the geographic location of data monitoring instruments, revealing that could have a slight relationship between areas with increased seismic frequency and intensity and the presence of atypical conductivity variations. Another pattern reveals the possible relationship between atypical variations in conductivity and subsequent earthquake events; a total of 241 seismic events were analyzed and 59 of them are provided as evidence related with patterns mentioned.

The cationic dye malachite green (MG) and the anionic dye Remazol yellow (RY) were removed from aqueous solutions using electrocoagulation-adsorption processes. Batch and continuous electrocoagulation procedures were performed and compared. Carbonaceous materials obtained from industrial sewage sludge and commercial activated carbons were used to adsorb dyes from aqueous solutions in column systems with a 96–98% removal efficiency. The continuous electrocoagulation-adsorption system was more efficient for removing dyes than electrocoagulation alone. The thermodynamic parameters suggested the feasibility of the process and indicated that the adsorption was spontaneous and endothermic (ΔS=0.037 and −0.009 for MG and RY, resp.). The ΔG value further indicated that the adsorption process was spontaneous (−6.31 and −10.48; T=303 K). The kinetic electrocoagulation results and fixed-bed adsorption results were adequately described using a first-order model and a Bohart-Adams model, respectively. The adsorption capacities of the batch and column studies differed for each dye, and both adsorbent materials showed a high affinity for the cationic dye. Thus, the results presented in this work indicate that a continuous electrocoagulation-adsorption system can effectively remove this type of pollutant from water. The morphology and elements present in the sludge and adsorbents before and after dye adsorption were characterized using SEM-EDS and FT-IR.

Due to its analgesic properties, diclofenac (DCF) is one of the most commonly used non-steroidal anti-inflammatory drugs (NSAIDs). While residue from this pharmaceutical agent has been found in diverse water bodies in various countries, there is not enough information of its potential toxicity on aquatic organisms, particularly in species which are economically valuable due to their high consumption by humans, such as the common carp Cyprinus carpio. This study aimed to evaluate potential DCF-induced oxidative stress in brain, liver, gill and blood of C. carpio. The median lethal concentration of DCF at 96h (96-h LC50) was determined and used to establish the concentration equivalent to the lowest observed adverse effect level (LOAEL). Carp specimens were exposed to this concentration for different exposure times (12, 24, 48, 72 and 96h) and the following biomarkers were evaluated: lipid peroxidation (LPX) and the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Also, the DCF and 4-hydroxy DCF was determined by LC-MS/MS. Results show a statistically significant LPX increase (P

The sorption of As(III) and As(V) from aqueous solutions onto iron-modified Petroselinum crispum (PCFe) and iron-modified carbonaceous material from the pyrolysis of P. crispum (PCTTFe) was investigated. The modified sorbents were characterized with scanning electron microscopy. The sorbent elemental composition was determined with energy-dispersive X-ray spectroscopy (EDS). The principal functional groups from the sorbents were determined with FT-IR. The specific surfaces and points of zero charge (pzc) of the materials were also determined. As(III) and As(V) sorption onto the modified sorbents were performed in a batch system. After the sorption process, the As content in the liquid and solid phases was determined with atomic absorption and neutron activation analyses, respectively. After the arsenic sorption processes, the desorption of Fe from PCFe and PCTTFe was verified with atomic absorption spectrometry. The morphology of PC changed after iron modification. The specific area and pzc differed significantly between the iron-modified non-pyrolyzed and pyrolyzed P. crispum. The kinetics of the arsenite and arsenate sorption processes were described with a pseudo-second-order model. The Langmuir-Freundlich model provided the isotherms with the best fit. Less than 0.02% of the Fe was desorbed from the PCFe and PCTTFe after the As(III) and As(V) sorption processes.

The adsorption behavior of denim blue from aqueous solutions in column systems, using both carbonaceous material and Fe-zeolitic tuff (Fe-Z), was determined. The breakthrough data obtained for denim blue adsorption were fitted to the empty-bed contact time, Bohart–Adams, Thomas, and Yoon–Nelson models. The parameters such as breakthrough and saturation times, bed volumes, kinetic constants, adsorption capacities, and adsorbent usage rates (AUR) were determined. The results show that the breakthrough time increases proportionally with increasing bed height, but it decreases as the kinetic constant increases. The adsorption capacity for denim blue for carbonaceous material was higher than Fe-Z. AUR was lower for carbonaceous material than Fe-Z. The results indicated that the carbonaceous material from pyrolysis of sewage sludge is a good adsorbent for denim blue removal.

In the present study, the processes of adsorption of denim blue by Fe-zeolitic tuff from aqueous solutions at different pH values were determined. The parameters, Kd(n), Kd(i), Φn, pKa were accurately predicted by applying the linear model to sorption isotherms at different pH values of denim blue. Maximum removal of denim blue was observed at pH values between 3 and 5, where neutral species are the main components of the solution. The results indicate that pH has a pronounced effect on denim blue sorption depending on the conditions of the system.

The effect of varying fat content in Oaxaca cheese, a typical pasta filata, on microstructure was described. Microstructure of cheeses was analysed by scanning electron microscopy (SEM) and light microscopy (LM) in nondehydrated and dehydrated samples. In nondehydrated samples, protein fibres were wide and compact in fat-free cheese, and big serum channels were approximately 100 μm in width. Width of protein fibres and size of channels decreased as fat content increased. Small channels seemed to be occupied only by fat, while in big channels, water and fat were observed. LM both confirmed and supplemented the observations made by SEM, particularly the presence and distribution of fat in channels.

Novel adsorption materials—Fe-Ni nano- structures and C/Fe-Ni composites—with the carbona- ceous material coming from sewage sludge, have been developed and evaluated to remove indigo carmine from aqueous solution. The adsorbents were characterized by transmission and scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and Brunauer- Emmett-Teller analysis. Sorption kinetics and isotherms were determined and the adsorption behaviours ana- lysed. All adsorbents here studied have exhibited good efficiency to remove indigo carmine from aqueous solution. Pseudo-second-order kinetic and Langmuir- Freundlichisothermmodels were successfully appliedto the experimental data. Fe-Ni nanostructures adsorption capacitywas977.18mg/g,followedbyC/Fe-Ni75/25% composite with 654.33 mg/g, and a lowest value, 486.41 mg/g, was obtained for C/Fe-Ni 95/5% compos- ite. It can be suggested that the sorption mechanism of the dye is chemisorption on these heterogeneous novel, cheap and efficient functional materials. All materials provide the highest adsorption capacities in pH between 4 and 10. In addition, three sorption-desorption cycles using 30% H2O2 solution and distilled water were performed; sorption efficiencies of both composites (C/FeNi 75/25% and C/FeNi 95/5%) decreases in each cycle, but this behaviour is not observed for FeNi nanoscale oxides.

The objective of this work was the removal of pollutants of an effluent of municipal wastewater, through physicochemical of coagulation-flocculation, sedimentation, filtration, chemical oxidation treatments and disinfection in a train of treatment in continuous flow at 1.65 mL/s. For the process coagulation-flocculation used a dose of 1mL/L Al2(SO4)3 0.01 M, the filters were packed with silica sand and activated carbon from coconut shell, in the process of chemical oxidation it was applied a concentration of 3 mg/L ozone with a time of contact of 10 to 15 min, the disinfection was realized by means of ultraviolet radiation to a wave length of 253-260 nm. The removal obtained was 98% of color, 94% of turbidity, 93% of COD, 93% of BOD5, 84% of MBAS, 63% of NH3, 98% of total fecal and coliforms.

Indigo carmine removal from aqueous solution has been evaluated using Fe-zeolitic tuff and carbonaceous material from pyrolyzed sewage sludge treated with HCl (CM). The adsorbents were characterized by scanning electron microscopy, BET surface area and X-ray diffraction. Sorption kinetics and isotherms were determined and the adsorption behaviors analyzed. Kinetic pseudo-second order and Langmuir–Freundlich models were successfully applied to the experimental results obtained with the Fe-zeolitic material, while kinetic first order and Langmuir–Freundlich models were applied to the results from the carbonaceous materials. This indicates mechanisms of chemisorption and physic sorption, respectively, on the heterogeneous materials. The results indicate that the carbonaceous material from the pyrolysis of sewage sludge (sorption capacity 92.83 mg/g) is a better adsorbent of indigo carmine than the zeolitic material (sorption capacity 32.83 mg/g).

Actually, there is a growing interest in finding efficient low-cost materials that allow the removal of chemical substances from water in order to decrease the environmental impact. The use of nanoscale systems is a new area of investigation for the elimination of polluting agents from water among other useful applications in science and technology. In this work, removal of indigo blue in water solutions has been evaluated using Fe/Cu nanoparticles and composites of C/Fe–Cu nanoalloy. The first composite was using carbon obtained by pyrolysis of sewage sludge with Fe/Cu nanoparticles (MCL-NP); the second one was made with commercial activated carbon and Fe–Cu nanoparticles (CAC-NP). Synthesis of materials were carried out by the sodium borohydride reduction of FeSO4⋅7H2O and CuSO4⋅5H2O aqueous mixture. Batch adsorption and isotherm experiments were carried out in order to know the behavior of each adsorbent material employed. The experimental data were adjusted to Langmuir, Freundlich, and BET models.