Search results for " Sustainability"
showing 10 items of 2550 documents
Effect of complexing agents on phosphorus release from chemical-enhanced phosphorus removal sludge during anaerobic fermentation
2020
Phosphorus (P) release from sludge containing phosphate precipitates (FePs or AlPs) as well as the anaerobic performance with the addition of complexing agents (citric, tartaric and EDTA) during ambient anaerobic fermentation process were investigated. Results showed that citrate addition was the most effective method to enhance P release from inorganic phosphate by chelation and promote volatile fatty acids (VFAs) production simultaneously during anaerobic fermentation. Equimolar citrate addition with chemical precipitates was the optimal dosage. Microbial analysis revealed that EDTA has the strongest inhibitory effect on microbial activity and community structure, while citrate was more e…
Study on the effects of several operational variables on the enzymatic batch saccharification of orange solid waste
2017
In this work, batch enzyme-aided extraction and enzymatic saccharification of blade-milled orange waste was studied. The operation variables for this process were thoroughly analysed. It was determined that batch runs with initial pH values of 5.0 and 5.2 controlled during the first hour, 50°C and 300-500r.p.m. agitation resulted in the best yields, with a limited total and partial first-order enzyme deactivation (for cellulases and polygalacturonidase, respectively). Orange peel waste (OPW) at 6.7% w/w dry solid, 0.22 filter paper units (FPU)/g DS and proportional activities of other enzymes led to over 40g/L free monosaccharides and global yields to glucose over 80%. When using 10.1% w/w …
Bioplastic recovery from wastewater: A new protocol for polyhydroxyalkanoates (PHA) extraction from mixed microbial cultures
2019
Abstract A new protocol for polyhydroxyalkanoates (PHA) extraction from mixed microbial cultures (MMCs) is proposed. PHA-accumulating capacity of the MMC was selected in a sequencing batch reactor (SBR) fed with a synthetic effluent emulating a fermented oil mill wastewater (OMW). The highest recovery yield and purity (74 ± 8% and 100 ± 5%, respectively) was obtained when using NH4-Laurate for which operating conditions of the extraction process such as temperature, concentration and contact time were optimized. Best conditions for PHA extraction from MMC turned to be: i) a pre-treatment with NaClO at 85 °C with 1 h of contact time, followed by ii) a treatment with lauric acid in a ratio ac…
Species disparity response to mutagenesis of marine yeasts for the potential production of biodiesel.
2019
Abstract Background Among the third-generation biodiesel feed stock, oleaginous marine yeasts are the least studied microorganisms for such purpose. Results Wild strains yeasts were isolated from various Tunisian marine sources including fish waste (Candida tenuis CtTun15, Debaryomyces hansenii DhTun2015, Trichosporon asahii TaTun15 and Yarrowia lipolytica YlTun15) and seawater (Rhodotorula mucilaginosa RmTun15). Following incubation with ethyl methanesulfonate (EMS: 75 mM) for various periods of time (T15, T30, T45, T60 min), the cell viability of these strains responded differentially according to yeast species. For instance, mutated CtTun15 did not survive after 30 min of EMS treatment; …
Water Status and Yield Response to Deficit Irrigation and Fertilization of Three Olive Oil Cultivars under the Semi-Arid Conditions of Tunisia
2019
Sustainability of olive production is possible by adopting the modern techniques of irrigation and fertilization. In Tunisia, olive trees are usually cultivated in poor soils, under semi-arid conditions characterized by water scarcity. This study investigated the effects of different water supply and fertilization on leaf water status and crop yield of three different olive oil varieties cultivated in central Tunisia, during four experimental seasons (2014&ndash
Effect of Bacterial Inoculum and Fertigation Management on Nursery and Field Production of Lettuce Plants
2020
Plant growth-promoting rhizobacteria have been applied to different vegetable crops but there is still no information on the effect of bacterial biostimulant application under variable nutritional level on lettuce seedlings and their performance after transplanting in the field. This study aimed to evaluate the efficacy of a bacterial biostimulant to enhance growth and quality of lettuce seedlings fertigated with increasing nutrient rates and to assess the efficacy of these treatments on lettuce head production. Lettuce seedlings were inoculated with 1.5 g L&minus
Artificial germination activation of Dialium corbisieri by imitation of ecological process.
2013
11 pages; International audience; Species of the gender Dialium commonly are trees found in Central African rainforests. They produce tasty sugary fruits, feeding numerous frugivores, but are, despite their valuable nutritional value, rarely exploited by humans. A potential reason for this could be the complexity of symbiotic dependence between trees and pollinators, germination activators, and dispersers causing problems in ancestral and contemporary domestication. We investigated Dialium corbisieri reproduction in the Democratic Republic of the Congo, Bandundu Province. Here we give a key for an artificial activation of germination of these trees ecologically adapted to the digestive syst…
Managing the Historical Agricultural Landscape in the Sicilian Anthropocene Context. The Landscape of the Valley of the Temples as a Time Capsule
2021
The debate over whether we are entering the Anthropocene Epoch focuses on the unequal consumption of the Earth system’s resources at the expense of nature’s regenerative abilities. To find a new point of balance with nature, it is useful to look back in time to understand how the so-called “Great Acceleration”—the surge in the consumption of the planet’s resources—hastened the arrival of the Anthropocene. Some particular places—for various reasons—survived the Great Acceleration and, as time capsules, have preserved more or less intact some landscape features that have disappeared elsewhere. How can we enhance these living archives that have come down to us? Through the analysis of the case…
Performance of a membrane-coupled high-rate algal pond for urban wastewater treatment at demonstration scale
2020
[EN] The objective of this study was to evaluate the performance of an outdoor membrane-coupled high-rate algal pond equipped with industrial-scale membranes for treating urban wastewater. Decoupling biomass retention time (BRT) and hydraulic retention time (HRT) by membrane filtration resulted in improved process efficiencies, with higher biomass productivities and nutrient removal rates when operating at low HRTs. At 6 days of BRT, biomass productivity increased from 30 to 66 and to 95 g.m(-3).d(-1) when operating at HRTs of 6, 4 and 2.5 days, respectively. The corresponding nitrogen removal rates were 4, 8 and 11 g N.m(-3).d(-1) and the phosphorous removal rates were 0.5, 1.3 and 1.6 g P…
Effect of ambient temperature variations on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella
2019
[EN] Two outdoor photobioreactors were operated to evaluate the effect of variable ambient temperature on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella. Four experiments were carried out in different seasons, maintaining the temperature-controlled PBR at around 25¿°C (by either heating or cooling), while the temperature in the non-temperature-controlled PBR was allowed to vary with the ambient conditions. Temperatures in the range of 15¿30¿°C had no significant effect on the microalgae cultivation performance. However, when the temperature rose to 30¿35¿°C microalgae viability was significantly reduced. Sudden temperature rises triggered AOB growth in the indig…