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We investigated how a community of microbial decomposers adapted to a reference site responds to a sudden decrease in the water quality. For that, we assessed the activity and diversity of fungi and bacteria on decomposing leaves that were transplanted from a reference (E1) to a polluted site (E2), and results were compared to those from decomposing leaves either at E1 or E2. The two sites had contrasting concentrations of organic and inorganic nutrients and heavy metals in the stream water. At E2, leaf decomposition rates, fungal biomass, and sporulation were reduced, while bacterial biomass was stimulated. Fungal diversity was four times lower at the polluted site. The structure of fungal community on leaves decomposing at E2 significantly differed from that decomposing at E1, as indicated by the principal response curves analysis. Articulospora tetracladia, Anguillospora filiformis, and Lunulospora curvula were dominant species on leaves decomposing at E1 and were the most negatively affected by the transfer to the polluted site. The transfer of leaves colonized at the reference site to the polluted site reduced fungal diversity and sporulation but not fungal biomass and leaf decomposition. Overall, results suggest that the high diversity on leaves from the upstream site might have mitigated the impact of anthropogenic stress on microbial decomposition of leaves transplanted to the polluted site.

Dolomite-based binders are characterised by interesting technical and environmental features. For their synthesis, sources of both CaO and MgO are required. The idea developed in this work is to couple the synthesis of dolomite-based binders, starting from a natural dolomite, through the concept of concentrated solar energy (needed to drive the endothermal dolomite calcination process) in fluidised bed reactors. To this end, a fluidised bed system, where the concentrated solar radiation is mimicked by the use of Xe-lamps (short-arc), has been set up and operated. Natural dolomite (sieved in the 420-590 ?m size range) was calcined at a nominal temperature of 850 °C, and bed temperature profiles during solar-driven calcination were investigated. Then, four binders were prepared by mixing slaked dolomite (obtained from the hydration of solar calcined dolomite) with either blast furnace slag or coal fly ash as supplementary cementitious materials. The binders were hydrated for curing times ranging from 7 to 56 days. X-ray fluorescence, X-ray diffraction and combined differential thermal and thermogravimetric analyses were employed as characterisation techniques both to analyse the chemical composition of starting materials and to investigate the evolution of the hydration in the four systems.

This study highlights how Chinese economic development detrimentally impacted water quality in recent decades and how this has been improved by enormous investment in environmental remediation funded by the Chinese government. To our knowledge, this study is the first to describe the variability of surface water quality in inland waters in China, the affecting drivers behind the changes, and how the government-financed conservation actions have impacted water quality. Water quality was found to be poorest in the North and the Northeast China Plain where there is greater coverage of developed land (cities + cropland), a higher gross domestic product (GDP), and higher population density. There are significant positive relationships between the concentration of the annual mean chemical oxygen demand (COD) and the percentage of developed land use (cities + cropland), GDP, and population density in the individual watersheds (p < 0.001). During the past decade, following Chinese government-financed investments in environmental restoration and reforestation, the water quality of Chinese inland waters has improved markedly, which is particularly evident from the significant and exponentially decreasing GDP-normalized COD and ammonium (NH4+-N) concentrations. It is evident that the increasing GDP in China over the past decade did not occur at the continued expense of its inland water ecosystems. This offers hope for the future, also for other industrializing countries, that with appropriate environmental investments a high GDP can be reached and maintained, while simultaneously preserving inland aquatic ecosystems, particularly through management of sewage discharge.

The influence of compost on the growth of bean plants irrigated with As-contaminated waters and its influence on the mobility of As in the soils and the uptake of As (as NaAs(III)O2) by plant components was studied at various compost application rates (3·10(4) and 6·10(4) kg ha(-1)) and at three As concentrations (1, 2 and 3 mg kg(-1)). The biomass and As and P concentrations of the roots, shoots and beans were determined at harvest time, as well as the chlorophyll content of the leaves and nonspecific and specifically bound As in the soil. The bean plants exposed to As showed typical phytotoxicity symptoms; no plants however died over the study. The biomass of the bean plants increased with the increasing amounts of compost added to the soil, attributed to the phytonutritive capacity of compost. Biomass decreased with increasing As concentrations, however, the reduction in the biomass was significantly lower with the addition of compost, indicating that the As phytotoxicity was alleviated by the compost. For the same As concentration, the As content of the roots, shoots and beans decreased with increasing compost added compared to the Control. This is due to partial immobilization of the As by the organic functional groups on the compost, either directly or through cation bridging. Most of the As adsorbed by the bean plants accumulated in the roots, while a scant allocation of As occurred in the beans. Hence, the addition of compost to soils could be used as an effective means to limit As accumulation in crops from As-contaminated waters.

Abstract Orange Peel Waste (OPW) is a widely produced residue whose management is complicated by its physical and chemical properties. Anaerobic digestion (AD), which is commonly used for the treatment and exploitation of many biodegradable wastes, is inefficient on OPW due to the presence of essential oils (mainly d -Limonene) as well as the low pH, which cause the process to be unstable. Here we explore the effect of alkaline pre-treatment of OPW and of the addition of granular activated carbon (GAC) and Zero Valent Iron (ZVI) in improving AD in two semi-continuous reactors at a laboratory scale. The addition and pre-treatment of ZVI/GAC were shown to help process stability up to a loading of 3 kgVS·m−3·d−1 and to increase methane production even at a sub-optimal pH. The investigation of the bacterial community, by high-throughput sequencing, has also increased our insight on their involvement in AD in the presence of ZVI, including its biotic oxidation. In addition, direct interspecies electron transfer was shown to play a role in the reactor supplemented with ZVI.

AbstractThe potential impacts of future climate scenarios on water balance and flow regime are presented and discussed for a temporary river system in southern Italy. Different climate projections for the future (2030–2059) and the recent conditions (1980–2009) were investigated. A hydrological model (Soil and Water Assessment Tool) was used to simulate water balance at the basin scale and streamflow in a number of river sections under various climate change scenarios, based on different combinations of global and regional models (global circulation models and regional climate models). The impact on water balance components was quantified at the basin and subbasin levels as deviation from the baseline (1980–2009), and the flow regime alteration under changing climate was estimated using a number of hydrological indicators. An increase in mean temperature for all months between 0.5–2.4 °C and a reduction in precipitation (by 4–7%) was predicted for the future. As a consequence, a decline of blue water (7–18%) and total water yield (11–28%) was estimated. Although the river type classification remains unvaried, the flow regime distinctly moves towards drier conditions and the divergence from the current status increases in future scenarios, especially for those reaches classified as I‐D (ie, intermittent‐dry) and E (ephemeral). Hydrological indicators showed a decrease in both high flow and low flow magnitudes for various time durations, an extension of the dry season and an exacerbation of extreme low flow conditions. A reduction of snowfall in the mountainous part of the basin and an increase in potential evapotranspiration was also estimated (4–4.4%). Finally, the paper analyses the implications of the climate change for river ecosystems and for River Basin Management Planning. The defined quantitative estimates of water balance alteration could support the identification of priorities that should be addressed in upcoming years to set water‐saving actions.

Abstract Green analytical chemistry is primarily directed towards minimization of the amount of waste associated with either the sample preparation or analysis. Among different chromatographic methods, liquid chromatography is considered the least green, allowing for various possibilities for greening. Using green solvents such as ethanol or acetone in RP-HPLC, as an alternative to acetonitrile, is recently attracting an attention. Both ethanol and acetone are characterized with low toxicity, with certain drawbacks limiting their regular use in RP-HPLC. Ethanol has low eluotropic strength and causes high backpressures, while acetone shows high UV cut-off, making it unsuitable for UV/Vis detection. To overcome the existing problems, Corona Charged Aerosol Detector was employed for development of RP-HPLC methods for separation of risperidone and its structurally related impurities with either ethanol or acetone as organic modifier. The methods were optimized by experimental design methodology, while optimal conditions for separation were determined using Derringer's desirability function. Detailed assessment of 3D surface plots of Derringer's desirability function enabled selection of 0.6 mL min−1 flow rate and 20% (v/v) organic modifier content as optimal when using ethanol, while in case of acetone mobile phase flow rate was 0.8 mL min−1 and organic modifier content 17% (v/v). Methods were validated and their eco-friendly character was confirmed through Green Analytical Procedure Index (GAPI). Although both methods are ecologically acceptable, the main drawback is reflected in the fact that no recycling or another waste treatment method exist. In the end, acetone was prioritized over ethanol, due to lower health hazard and decreased amount of generated waste.