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In this study, three different two-stage hybrid ecological wastewater treatment systems (HEWTS) with combinations of horizontal flow (HF) constructed wetlands (CWs), vertical flow (VF) CWs and stabilization ponds (SP) were evaluated for the removal of Organic-N, NH 4 + , NO 3 − , Total N, Total P, Total Coliforms (TCol) and Escherichia Coli, BOD, COD and TSS. The overall goal of the study was novel in comparison to most other studies in that we sought to evaluate and compare the efficiency of the three HEWTSs for water quality improvements, while minimizing nutrient removal from the wastewater in order to generate high quality reclaimed water for reuse for irrigation of crops. The most effective systems were those systems containing a vertical flow component, either HF-VF or VF-HF. In these two HEWTS, NH 4 + was reduced by 85.5% and 85.0% respectively, while NO 3 − was increased to 91.4 ± 17.6 mg/L and to 82.5 ± 17.2 mg/L, respectively, an artifact of nitrification. At the same time, E. coli was reduced by 99.93% and 99.99%, respectively. While the goal of most wastewater treatment is focused on reducing nutrients, the results here demonstrate that two-stage HEWTSs containing VF components can be used to produce a high quality effluent while retaining inorganic nutrients, thereby conserving this valuable resource for reuse as irrigation water for agriculture in subtropical developing countries where water and fertilizer resources are scarce or expensive.

The amount of total phenols and flavonoids and the antioxidant activity of leaf, stem, and rhizome methanolic extracts from a commonly consumedAnemopsis californicaunder different storage conditions were investigated. Storage conditions were at 50, 25, 4, and −20°C, protected or not from light, during 180 days. The inhibition of the elastase enzyme was also evaluated. The results demonstrated that leaf, stem, and rhizome methanolic extracts ofAnemopsis californicamaintain approximately up to 97 and 95% stability in phenolic content and antioxidant activity, respectively, when stored during 60 days at −20°C in the dark. Additionally, these extracts, principally from leaf and rhizome, showed an elastase inhibitory effect by 75 and 71.8%, respectively. Therefore, this study provides the basis for further research on the anti-inflammatory activity. On the other hand,Anemopsis californicacould comprise a good alternative of use as antioxidant in foods.

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A composite membrane based on polycaprolactone (PCL) and cellulose nanofibers (CNF) with different compositions was prepared using the electro-spinning method, with the objective of developing organic membranes with good mechanical properties to remove contaminants from water. Water is a resource of primary importance for life and human activities. In this sense, cellulose obtained from agave bagasse and polycaprolactone nanofibers was used to prepare membranes that were tested by filtering tap water. The membranes obtained presented a porosity and structure on a nanometric scale. The water quality variables evaluated after filtration with the PCL/CNF membranes showed 100% turbidity removal, 100% conductivity, and heavy metal removal of the order of 75% to 99% for iron and chromium. CNF comprises biowaste derived from tequila production, and it has added value. Electro-spun CNF and PCL membranes can be applied as a "green" and eco-friendly filtration system for water purification.Molecules 2020, 25, 683 2 of 13 about 40% (wet basis) of over 1000 tons of agave grown in Mexico [11]. The availability of such large quantities of agave bagasse [9] poses serious disposal problems, since most of the biomass ends up in clandestine dumps (due to little environmental regulation), causing adverse effects on the fertility of farmland [12], contamination by leachates, and phytosanitary risks due to the inadequate incorporation of this material into the soil [13]. Chemically, agave bagasse is 44.5% cellulose, 25.3% hemicellulose, and 20.1% lignin [7]. Taking advantage of these constituents, there have been many efforts to use agave bagasse for various applications, e.g., the production of biopolymers [14,15], composting [16], animal nutrition [17], generation of biofuels [10,18], reinforcement materials [19], etc. More recently, agave bagasse is being explored for the production of cellulose nanofibers and nanocrystals [7,8,20,21] to further diversify the utilization of this biowaste. On the other hand, electro-spinning of biopolymers has become popular in the manufacture of nanofibers for a variety of added value applications, such as tissue engineering, drug release, sensors, and air and liquid filtration systems [22][23][24][25][26].Our main interest in electro-spinning agave cellulose nanofibers was to produce membranes that can retain suspended particles in water (due to the diameter of the fibers), a membrane with high porosity and good surface area properties. However, the main challenge with the preparation of electro-spun agave cellulose was the poor solubility of cellulose that was to be dispersed into an electro-spinnable liquid [24]. We overcame the poor solubility challenge by dissolving agave cellulose in dimethylformamide (DMF) and blending with polycaprolactone to prepare a composite electro-spun blend, subsequently producing electro-spun nanocellulose and polycaprolactone membranes. The main objective of using a copolymer blend was to improve technical properties, such as contaminant retention capacity, therma...

This work proposes an innovative wastewater treatment system that consists of a constructed subsurface flow wetland planted with ornamental flowers of high market value. In addition to the benefit of the water treatment, this cash crop provides a profitable business by producing commercial flowers that can meet all biological and safety requirements in order to be commercialized. This characteristic of the treatment system makes it very valuable for application in developing countries. Five different species of ornamental plants were studied from September 2004 to January 2005. Several water quality parameters were evaluated at the inlet and outlet of a laboratory-scale system. COD was reduced by more than 75% in all cases; BOD and nitrogen were removed by more than 70%, except in one cell; phosphorus was reduced by more than 66% and the dissolved oxygen increased from 0.175 to 5.8 mg L-1. Total and fecal coliforms were removed in the wetland by more than 99.3%. According to these results, it is feasible to couple ornamental flower production with wastewater treatment. A pilot-scale study is recommended in order to validate the preliminary results under more realistic conditions.