1,721,059 research outputs found
Water Science and Technology
No full textWater Science and Technology publishes peer-reviewed papers on all aspects of the science and technology of wastewater treatment and water quality management worldwide. This encompasses five broad areas:
Wastewater treatment and transportation processes for stormwater and domestic, industrial and municipal effluents
Sources of pollution including hazardous wastes and source control
Effects and impacts of pollution on rivers, lakes, groundwater and marine waters
Water reuse and aquatic environmental restoration
Policy, strategy, control and management aspects of water qualit
Remote sensing to estimate ET-fluxes and the performance of an irrigation district in southern Italy
No full textReclaimed water to face agricultural water scarcity in the Mediterranean area: An overview using Sustainable Development Goals preliminary data
Full text linkClimate change is exacerbating the existing water scarcity issue in the Mediterranean area, leading to unprecedented pressure on water supply, especially in arid regions. Current changes and future scenarios all indicate significant and increasing water demand during the coming decades. Water demand is further aggravated by the population growth, which consequently increases demand for crops and agricultural products. The use of reclaimed water (RW) seems to be a promising alternative and valuable water resource, particularly for agriculture, which is currently the main user of renewable water resources. In addition to preserving freshwaters, the use of RW for irrigation would represent a source of nutrients, namely nitrogen, phosphorus, and other salts, which are necessary for the physiological growth of crops. For the Mediterranean area, it was possible to investigate on the significance of the RW use through the comparison of different data such as the total amount of generated wastewater, which represents the potential of using RW as an irrigation source, and irrigation water requirement, respectively. The analysis showed that the use of RW could significantly decrease the current pressure on total renewable water resources, and therefore help to face water scarcity and climate change issues. Nevertheless, for the Mediterranean area, there are still limiting elements such as the non-existence of a univocal regulatory framework on the use of RW for irrigation purposes as well as a lack of data on real quantities of wastewater that are safely treated, collected and generated
The Long-Term Effects of Land Use and Climate Changes on the Hydro-Morphology of the Reno River Catchment (Northern Italy)
Full text linkAnthropogenic activities, and in particular land use/land cover (LULC) changes, have a
considerable effect on rivers’ flow rates and their morphologies. A representative example of those changes and resulting impacts on the fluvial environment is the Reno Mountain Basin (RMB), located in Northern Italy. Characterized by forest exploitation and agricultural production until World War II, today the RMB consists predominantly of meadows, forests and uncultivated land, as a result of agricultural land abandonment. This study focuses on the changes of the Reno river’s morphology since the 1950s, with an objective of analyzing the factors that caused and influenced those changes.
The factors considered were LULC changes, the Reno river flow rate and suspended sediment yield, and local climate data (precipitation and temperature). It was concluded that LUCL changes caused some important modifications in the riparian corridor, riverbed size, and river flow rate. A 40–80% reduction in the river bed area was observed, vegetation developed in the riparian buffer strips, and the river channel changed from braided to a single channel. The main causes identified are reductions in the river flow rate and suspended sediment yield (−36% and −38%, respectively), while climate change did not have a significant effect
Diffuse Water Pollution from Agriculture: A Review of Nature-Based Solutions for Nitrogen Removal and Recovery
Full text linkThe implementation of nature-based solutions (NBSs) can be a suitable and sustainable approach to coping with environmental issues related to diffuse water pollution from agriculture. NBSs exploit natural mitigation processes that can promote the removal of different contaminants from agricultural wastewater, and they can also enable the recovery of otherwise lost resources (i.e., nutrients). Among these, nitrogen impacts different ecosystems, resulting in serious environmental and human health issues. Recent research activities have investigated the capability of NBS to remove nitrogen from polluted water. However, the regulating mechanisms for nitrogen removal can be complex, since a wide range of decontamination pathways, such as plant uptake, microbial degradation, substrate adsorption and filtration, precipitation, sedimentation, and volatilization, can be involved. Investigating these processes is beneficial for the enhancement of the performance of NBSs. The present study provides a comprehensive review of factors that can influence nitrogen removal in different types of NBSs, and the possible strategies for nitrogen recovery that have been reported in the literature
Constructed wetlands combined with disinfection systems for removal of urban wastewater contaminants
Full text linkThe removal efficiency of an urban wastewater treatment plant (WWTP) to obtain an effluent suitable for agriculture reuse was evaluated in a one-year period, taking into account the Italian wastewater limits and the recent European proposal for the minimum requirements water quality for agricultural irrigation. The secondary effluent of WWTP was treated by three full-scale horizontal sub-surface flow (H-SSF) constructed wetlands (CWs), working in parallel, planted with different macrophytes species, and combined with a UV device and a lagooning system running in series. The H-SSF CW system effectively reduced physico-chemical pollutants and its efficiency was steady over the investigation period, while, Escherichia coli densities always exceed the Italian limits required for wastewater reuse in agriculture. The UV system significantly reduced the microbiological indicators, eliminating E. coli, in compliance with the Italian regulation, and somatic coliphages, although a variable efficacy against total coliforms and enterococci, especially in winter season, was achieved. Although the lagooning unit provides a high removal of the main microbial groups, it did not reduce physico-chemical parameters. Even if the overall performance target, for the whole treatment chain, met the recent log10 reduction (≥5.0), required by the European Commission, the persistence of enterococci, especially in winter season, poses a matter of concern for public health, for the potential risk to serve as a genetic reservoir of transferable antibiotic-resistance
Advancing IoT-Based Smart Irrigation
Full text linkIntegrated Internet of Things (IoT) platforms are needed for realizing IoT potential in commercial-scale applications. The main challenge is to provide solution flexibility to meet custom application needs. We developed an IoT-based platform for smart irrigation, with a flexible architecture to easily connect IoT and machine learning (ML) components to build application solutions. Our architecture enables multiple and customizable analytical approaches to precision irrigation, making room for the improvement of ML approaches. Impacts on different stakeholders can be anticipated, including IoT professionals, by facilitating system deployment, and farmers, by providing cost reduction and safer crop yields. Examples are given based on pilots in Europe and Brazil
A novel smart fertigation system for irrigation with treated wastewater: Effects on nutrient recovery, crop and soil
Full text linkBoth southern and northern regions of Italy are experiencing reduced precipitation and increased heat waves due
to climate change, negatively affecting agricultural sector. Urban wastewater could be a solution to this problem,
providing a constant source for irrigation and reducing synthetic fertilizer use. This research presents a two-year
field study on using tertiary treated wastewater for processing tomato crop irrigation through an innovative
smart fertigation system, designed to supply the exact doses of NPK nutrients considering those already delivered
to the plants via the irrigation water. With the aim of studying the effects of irrigation with treated wastewater,
three water sources were compared: fresh water added with chemical fertilizer, tertiary treated wastewater
added with chemical fertilizer and tertiary treated wastewater without addition of fertilizer. The proposed
system was efficient and consistent with the design, it saved considerable amounts of fertilizers, handling
nutrient fluctuations in wastewater. Of the three irrigation water types that have been tested, only the one that
used tertiary treated wastewater alone without additional fertilizers was not capable of meeting tomato nutritional
needs, despite the fact that significant macronutrient savings were achieved. No negative effects on soil or
plant physiological performances were observed. Plants irrigated with wastewater showed similar growth and
productivity to those irrigated with fresh water and no significant differences in fruit quality were found,
highlighting the benefits of wastewater reuse for crop irrigation
Occurrence, diversity, and persistence of antibiotic resistant enterococci in full-scale constructed wetlands treating urban wastewater in Sicily
Full text linkEnterococci isolated from different sites of an urban wastewater treatment plant (consisting of three horizontal subsurface flow constructed wetlands) were investigated. One-hundred-thirty isolates were identified at species level and tested for resistance to eleven antibiotics, by microdilution method, and their clonal relatedness was established by SmaI-PFGE analysis. Results highlighted the persistence of enterococcal population in all effluents and the dominance of E. faecium species. A high incidence of antibiotic resistance against erythromycin, chloramphenicol, rifampicin and ampicillin was observed, with 120 strains (93%) showing a multi-drug-resistance. Numerous pulso-types with a unique pattern were detected indicating a high diversity within enterococcal population. The recurrence of some pulso-types in different effluents was disclosed and, within the same pulso-types, different resistance patterns were observed. Comparing the MIC values of strains from inlet and outlet, different trends were observed, highlighting a certain variability among constructed wetlands in affecting the antibiotic resistance among enterococcal population
Estimating the saturated soil hydraulic conductivity in a farm constructed wetland by the borehole permeameter infiltration method
Full text linkThe borehole permeameter infiltration method was used to determine the soil hydrodynamic properties at different depths in a farm constructed wetland (CW) in which the saturated soil hydraulic conductivity, K-s, was already investigated for the uppermost surface layer. With the aim to estimate K-s and the sorptive number alpha*, a non-linear curve fitting approach was used to fit both the Philip (1993) and the Reynolds (2011) models to the experimental infiltration data. The estimated parameters were compared with those obtained with the graphical approach by Philip (1993) and the empirical approach by Regalado et al., (2008). Both K-s and alpha* varied along the soil profile but also between the inlet and outlet zone of the CW. The graphical approach was not applicable whereas the empirical approach overestimated both K-s and alpha* compared with the non-linear fitting approach. Despite the differences among the considered approaches, the borehole permeameter technique confirmed that the subsurface K-s was at least two orders of magnitude lower than that obtained by the ring infiltrometer at the CW surface thus confirming the importance of conducting these experiments for the study of the groundwater recharge processes
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