This study investigated the biogas production and dewaterability of sewage sludge with alkaline pretreatment at mesophilic and thermophilic temperatures. The total suspended solids (TSS) and volatile suspended solids (VSS) of raw sludges were 21.1 ± 2.3 and 16.2 ± 1.5 g L⁻¹, respectively. Raw sludges were pretreated at uncontrolled, pH 8, pH 10, and pH 12 under mesophilic (Mu, M8, M10, and M12) and thermophilic (Tu, T8, T10, and T12) conditions, respectively. All the pretreatments last 6 days. The pH of pretreated sludges was adjusted to the pH 7.0 prior to inoculating with mesophilic anaerobic digested sludge and undergoing 60 days of anaerobic digestion. The ultimate biogas yield of Mu, M8, M10, M12, Tu, T8, T10, and T12 was 296.8, 384.8, 339.9, 323.1, 376.6, 322.4, 271.5, and 258.1 mL g⁻¹-VSₐddₑd, respectively. Both the pH of alkali treatment and temperature of thermal treatment affect the performance of anaerobic digestion. High hydrolysis pH (pH 10 and pH 12) resulted in high Na⁺ concentration (over 4000 mg L⁻¹), and Na⁺ inhibitory effect reduced the ultimate biogas yield. The normalized capillary suction time (NCST) found in the treatments of M8 and Tu were 11.8 ± 1.1 to 23.4 ± 1.7 and 27.9 ± 5.4 to 111.8 ± 1.7 s g⁻¹-TSS, respectively. The results suggest that both the pH of alkali treatment and temperatures of mild thermal treatment affect the performance of anaerobic digestion and sludge pretreated at pH 8.0 under mesophilic conditions could achieve high biogas yield and adequate dewaterability of digested sludge.

Biodegradation of phenol, o-cresol, and p-cresol was evaluated in continuous flow circulating packed bed bioreactors. Effect of loading rate on the removal rate of phenolic compounds was assessed by varying the influent concentration and flow rate. Regardless of the nature of phenolic compounds at a constant concentration, increase of loading rate caused the removal rate to pass through a maximum and then decline. Influent concentrations of 100 and 300 mg L⁻¹ did not affect the removal rates of phenol and p-cresol, but higher rates were obtained at 500 mg L⁻¹. With o-cresol, increase of influent concentration from 100 to 300 mg L⁻¹ enhanced the removal rate but no further enhancement was observed at 500 mg L⁻¹. The maximum removal rates for phenol, o-cresol, and p-cresol were 67.6–97.8, 38.7–73.8, and 77.2–107.2 mg L⁻¹ h⁻¹ at loading rates of 96.7–171.1, 61.6–163.9, and 87.4–183.9 mg L⁻¹ h⁻¹ (hydraulic residence time 2.9, 1.7–1.8, 1.2–2.8 h), respectively. Toxicity examination of untreated influents singled out phenol as the least toxic compound, while o-cresol and p-cresol showed similar toxicities. Treatment of influent containing 100 mg L⁻¹ of phenolic compound led to the highest decrease in toxicity (> 93%) for all three compounds. With influent concentrations of 300 mg L⁻¹ or higher, the decrease in toxicity of treated effluent was highest for phenol, followed by p-cresol, and then o-cresol. Finally, the observed patterns revealed that the toxicity of treated effluent was affected by the extent of biodegradation, as well as the toxic nature of phenolic compound under treatment.

Even if it is less polluting than other farm sectors, grape growing management has to adopt measures to mitigate greenhouse gas (GHG) emissions and to preserve the quality of grapevine by-products. In viticulture, by land and crop management, GHG emissions can be reduced through adjusting methods of tillage, fertilizing, harvesting, irrigation, vineyard maintenance, electricity, natural gas, and transport until wine marketing, etc. Besides CO₂, nitrous oxide (N₂O) and methane (CH₄), released from fertilizers and waste/wastewater management are produced in vineyards. As the main GHG in vineyards, N₂O can have the same harmful action like large quantities of CO₂. Carbon can be found in grape leaves, shoots, and even in fruit pulp, roots, canes, trunk, or soil organic matter. C sequestration in soil by using less tillage and tractor passing is one of the efficient methods to reduce GHG in vineyards, with the inconvenience that many years are needed for detectable changes. In the last decades, among other methods, cover crops have been used as one of the most efficient way to reduce GHG emissions and increase fertility in vineyards. Even if we analyze many references, there are still limited information on practical methods in reducing emissions of greenhouse gases in viticulture. The aim of the paper is to review the main GHG emissions produced in vineyards and the approached methods for their reduction, in order to maintain the quality of grapes and other by-products.

This study describes the capacity of different sorbents to form stable biofilms under highly hydrocarbon-polluted conditions and the degrading capacity of the microbiota present in the biofilm. With this aim, microcosms were designed in a 1 L beaker with 400 mL of culture medium or polluted wastewater and an amount equivalent of 200 mL of the selected sorbent carrier, made of cork and/or polypropylene meltblown. The culturable bacteria adhered to the sorbent carrier were quantified, and the time course of the hydrocarbon concentration was studied together with the formation of a biofilm on the carrier’s surface. The results revealed a different performance of the carriers in terms of bacterial adhesion, significantly reduction in the hydrocarbon content in water at the end of the assays, and a biofilm tolerance to high hydrocarbon concentration in the polluted water. From these results, it was concluded that the use of a sorbent, hydrophobic cork, or meltblown polypropylene, together with indigenous microbiota, constitutes a promising technology for the treatment of hydrocarbon-polluted water.

Aquatic macrophytes play a key role in nutrient cycling and in the dynamics of aquatic ecosystems. Many species have been evaluated in terms of their potential in phytoremediation processes in environments contaminated by metals. Considering this kind of application, we evaluated the potential for the bioaccumulation and biosorption of mercury by Salvinia biloba as a function of (i) different concentrations of mercury ions in the solution, (ii) the exposure time of live plants and dry biomass to the contaminant, and (iii) different pH’s, besides (iv) analyzing the effects of this metal on morphological and anatomical parameters. Bioaccumulation was evaluated by subjecting live plants to treatments with concentrations of 0.05, 0.1, and 0.2 μg.mL⁻¹ of mercury in the solution and the control (0 μg.mL⁻¹), at intervals of 3 days (0, 3, 6, 9, 12, and 15 days) at pH values of 5.5, 6.0, and 6.5. For biosorption, we used the dry biomass applying the same design, only changing the time intervals (0, 4, 8, 12, and 24 h). The bioaccumulated and biosorbed mercury was determined by atomic absorption spectroscopy. High values of mercury were bioaccumulated and biosorbed, and accordingly, as the concentration of mercury ions increases in the solution, the higher the value accumulated by both living plant and dry biomass. The time of exposure and the different pH values presented variation when associated with different concentrations in the bioaccumulation of mercury. Finally, few symptoms of toxicity in living plants were observed, evidencing the resistance of S. biloba to mercury and its potential use as a phytoremediation in water bodies contaminated by this metal.

The abandoned Aldermac Mine in Québec, Canada, has been a source of acid mine drainage to Lake Arnoux since 1946. Restoration of the site was undertaken in 2008 and completed in 2010. We compared lakewater chemistry and benthic invertebrate communities in the spring of 2010, prior to complete restoration, and in spring 2011, when acid mine drainage was no longer entering the lake. Between these years, lakewater pH increased by about one unit and the concentrations of many trace metals declined substantially. In 2010, benthic taxonomic richness increased significantly with distance from the source of contamination, whereas after restoration, there was no longer a clear trend. Communities in highly contaminated stations tended to be dominated by burrowing taxa such as larvae of Chironomus (Chironomidae) and Oligochaeta, whereas less contaminated stations had taxonomic and functional communities that were more diverse. In the year following recovery, some new taxa appeared (Trichoptera, Odonata, and the Ceratopogonidae Bezzia), whereas the populations of an acid-tolerant Chironomus species declined. However, only larger individuals exhibited a significant response to pH and metal contamination.

Soil salinization is an increasing problem in agricultural soils on a worldwide scale. To assess the effects of salinity on the fate of herbicide lactofen in soil, laboratory degradation experiments were performed using soil with and without additional salinity. Lactofen and two major metabolites desethyl lactofen and acifluorfen were analyzed using HPLC-MS/MS. The degradation of lactofen and metabolites followed first-order kinetics with rate constants ranged from 0.30 to 0.35 day⁻¹ (estimated half-lives from 1.99 to 2.30 days) when additional salinity was not present. Lactofen concentration was greater in the salinized soil than in the control soil. The maximum concentrations of metabolites desethyl lactofen and acifluorfen were increased by 6.9 and 53% in salinized soil compared to control soil, respectively. The degradation of lactofen and metabolites was restrained by the application of salts and residues remained for a longer time in the salinized soil. Inappropriate management of soil and water resources may lead to the increase of salinity, which has the potential to enhance pesticides residues risk in soil.

The contamination of soil with petroleum products is a major environmental problem. Petroleum products are common soil contaminants as a result of human activities, and they are causing substantial changes in the biological (particularly microbiological) processes, chemical composition, structure and physical properties of soil. The main objective of this study was to assess the impact of soil moisture on CO₂ efflux from diesel-contaminated albic podzol soils. Two contamination treatments (3000 and 9000 mg of diesel oil per kg of soil) were prepared for four horizons from two forest study sites with different initial levels of soil water repellency. CO₂ emissions were measured using a portable infrared gas analyser (LCpro+, ADC BioScientific, UK) while the soil samples were drying under laboratory conditions (from saturation to air-dry). The assessment of soil water repellency was performed using the water drop penetration time test. An analysis of variance (ANVOA) was conducted for the CO₂ efflux data. The obtained results show that CO₂ efflux from diesel-contaminated soils is higher than efflux from uncontaminated soils. The initially water-repellent soils were found to have a bigger CO₂ efflux. The non-linear relationship between soil moisture content and CO₂ efflux only existed for the upper soil horizons, while for deeper soil horizons, the efflux is practically independent of soil moisture content. The contamination of soil by diesel leads to increased soil water repellency.

Antibiotics as growth promoters in poultry have been used for long time for improving feed efficiency and performance. Due to their various side-effects such as antibiotic resistance, destruction of beneficial bacteria in the gut, and dysbiosis, it is required to think about some alternatives. Probiotics are one of the options in this regard for improving poultry production. Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” They are available in various forms for use as feed additives. Probiotics as feed additives aid in proper digestion of feed hence make the nutrients available for faster growth. Immunity can also be improved by addition of probiotics to poultry diets. Moreover, probiotics aid in improving meat and egg quality traits. Various infectious diseases of poultry can be countered by use of probiotics in their feed. A proper selection of probiotic strains is required for gaining optimal effects. This review focuses on the mechanisms of action of probiotics and their importance in poultry feed supplementation for enhancing production and safeguarding health of poultry.