Potential of <i>Epipremnum aureum</i> and <i>Bacopa monnieri</i> (L.) Wettst for Saline Phytoremediation in Artificial Wetlands

The aim of this research was to evaluate the phytoremediative potential of Epipremnum aureum and Bacopa monnieri to improve the chemical properties of irrigation water exposed to the following two saline concentrations: highly saline (EC 2000 μS cm−1) and severely saline (EC 4000 μS cm−1). The artificial wetlands used in this experiment were of the free water surface type, considering a hydraulic retention time of 42 days. The evaluated treatments were configured as follows: T1 (B. monnieri [control, 300 μS cm−1]), T2 (B. monnieri [2000 μS cm−1]), T3 (B. monnieri [4000 μS cm−1]), T4 (E. aureum [control, 300 μS cm−1]), T5 (E. aureum [2000 μS cm−1]), T6 (E. aureum [4000 μS cm−1]), T7 (B. monnieri + E. aureum [control, 300 μS cm−1]), T8 (B. monnieri + E. aureum [2000 μS cm−1]), and T9 (B. monnieri + E. aureum [4000 μS cm−1]). The results showed that the species B. monnieri and E. aureum (both separately and together) showed a good ability to reduce the salinity of the irrigation water. However, B. monnieri showed a greater ability of phytoremediation, to the point of improving its chemical properties and reducing potential damage to the soil to use this water. In the highly saline group, B. monnieri accumulated 7.992 g per experimental unit and achieved to reduce of the pH from 7.96 to 7.75, EC from 2000 μS cm−1 to 670 μS cm−1, SAR from 13.54 to 3.91 and ESP from 20.17 to 5.83, which allowed it to go from (C3-S3) to (C3-S1). In the severely saline group, B. monnieri accumulated 13.494 g per experimental unit and achieved to reduce the pH from 8.14 to 7.91, EC from 4000 μS cm−1 to 1730 μS cm−1, SAR from 27.35 to 8.73, ESP from 40.35 to 13.01, which allowed it to go from (C4-S4) to (C3-S2)

Compost Quality Indexes (CQIs) of Biosolids Using Physicochemical, Biological and Ecophysiological Indicators: C and N Mineralization Dynamics

The increasing production of biosolids (BS) as a result of urban wastewater treatment generates pollution problems in their management and final disposal, and a better management is needed for their disposal. The composting of BS is an alternative process for obtaining a product with potential application as an organic amendment in the recovery of agricultural soils. As a biotechnological contribution, this study analyzed a composting process with BS, bovine manure (BM) and rice husks using four treatments T1 (C/N = 24); T2 (C/N = 34); T3 (C/N = 44); T4 (C/N = 54) for 120 days, in order to develop compost quality indexes (CQIs) through the analysis of 18 physicochemical, biological and ecophysiological indicators. Subsequently, three methodologies&mdash;successfully used on soils&mdash;were implemented for the development of the CQIs called &ldquo;unified&rdquo;, &ldquo;additive&rdquo; and &ldquo;nemoro&rdquo;. The indicators that comprised the CQIs were nitrification index (NI) and synthetic enzymatic index (SEI). The CQIs made it possible to differentiate the quality of the compost according to the treatments applied. The treatments used resulted in composts considered phytonutritious whose average quality value depending on the CQI developed was considered high (CQIw = 0.62), moderate (CQIa = 0.56) and low (CQIn = 0.30). The developed CQIs can be applied to determine the quality of BS composting systems reducing the cost of monitoring

Spectroscopic and Structural Analyses of <i>Opuntia Robusta</i> Mucilage and Its Potential as an Edible Coating

Mucilage extracted from the parenchymatous and chlorenchymatous tissues of Opuntia robusta were obtained using water or ethanol as the extraction solvent. The changes in the different tissues by using different extraction solvents were evaluated via scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) and Raman spectroscopy; in addition, the effect of mucilage coating on the various quality characteristics of tomato (Lycopersicum sculentum) was evaluated. The SEM results showed that the mucilage extracted from the parenchyma had a higher aggregation level that the mucilage extracted from the chlorenchyma. The presence of three characteristic bands of pectic substances in the FT-IR spectra between 1050 and 1120 cm&#8722;1 indicated that the mucilage extracted from the parenchymatous tissue had a higher content of pectic compounds than the mucilage extracted from the chlorenchymatous tissue. It was also observed in the Raman spectra that the level of pectic substances in the mucilage extracted from the parenchymatous was higher than that in the mucilage extracted from the chlorenchymatous tissue. The mucilage extracted from the parenchymatous tissue was more effective as an edible coating than the mucilage extracted from the chlorenchymatous tissue. Tomatoes covered with mucilage showed significantly enhanced firmness and reduced weight loss. The uncoated tomatoes showed higher lycopene content than the coated tomatoes on the 21st day. This study showed that the Opuntia robusta tissue and extraction solvent influence mucilage characteristics and that Opuntia robusta mucilage is a promising edible coating