Search results for "WATER"

A new strategy to maximize organic matter valorization in municipalities: combination of urban wastewater with kitchen food waste and its treatment w…

2017

[EN] The aim of this study was to evaluate the feasibility of treating the kitchen food waste (FW) jointly with urban wastewater (WW) in a wastewater treatment plant (WWTP) by anaerobic membrane technology (AnMBR). The experience was carried out in six different periods in an AnMBR pilot-plant for a total of 536 days, varying the SRT, HRT and the food waste penetration factor (PF) of food waste disposers. The results showed increased methane production of up to 190% at 70 days SRT, 24 hours HRT and 80% PF, compared with WW treatment only. FW COD and biodegradability were higher than in WW, so that the incorporation of FW into the treatment increases the organic load and the methane producti…

A comprehensive comparison between halophilic granular and flocculent sludge in withstanding short and long-term salinity fluctuations

2018

The effects of salinity fluctuations on the activity of autochthonous halophilic bacteria in aerobic granular sludge (AGS) and flocculent activated sludge (FAS) reactors were investigated. The response of nitrifiers and denitrifiers activity to drastic and moderate salinity shocks in the short-term (ST) and long-term (LT) was examined. The BOD5removal efficiency decreased only in the reactors subjected to the drastic LT salinity increase. Nevertheless, stable performances were achieved 18 days after the shock in the AGS-R1 (90%), whereas after 27 days in the FAS-R1 (82%). The loss in nitritation efficiency was higher in the FAS reactors and was proportional to the shock intensity. Nitritati…

Discussion of "extraction of the flow rate equation under free and submerged flow conditions in pivot weirs with different side contractions" by N. S…

2018

This paper is the discusison of the paper "Extraction of the flow rate equation under free and submerged flow conditions in pivot weirs with different side contractions" by N. Sheikh Rezazadeh Nikou, M. J. Monem, and K. Safavi.

Soil genetic erosion: New conceptual developments in soil security

2019

In the last decades, in some Mediterranean areas, pedodiversity decreased mainly due to pedotechnique application in large-scale farming that transformed original soils into Anthrosols. Supporting the consideration that soils can be considered as living systems, the original concept of 'soil genetic erosion' is re-proposed. Data, extrapolated and modeled from a Soil Information System in a study case representative of a Mediterranean landscape, predicted that most of the soil types would disappear in few years leading to a decrease of the soil diversity and originating soil genetic erosion. This circumstance is intentionally here told in form of a story where the fairy tale characters are s…

Testing soil water repellency in a Sicilian area two years after a fire

2019

The water drop penetration time (WDPT) technique was applied in 2018 to check persistence of soil water repellency (SWR) in a Sicilian mountain area affected by a wildfire on June 2016. A total of four sites, that were severely water repellent immediately after burning, were sampled. Depending on the site, wettable soil conditions, less SWR and maintenance of a noticeable SWR were detected two years later. At the site showing a near-constant SWR, WDPTs were particularly high in the top soil layer (0-0.03 m) and they appreciably decreased more in depth. Signs of decreasing SWR in drier soil conditions and in association with coarser soil particles were also detected at this site. High gradie…

Waste activated sludge dewaterability: comparative evaluation of sludge derived from CAS and MBR systems

2016

Nowadays, sludge dewatering is one of the greatest operational cost to wastewater treatment cycle. Specifically, 1t of fresh sludge to be disposed is composed, on average, by 0.25 - 0.30t of suspended solids, with an average cost for treatment and disposal around 280 - 470 €/t of suspended solids. Despite several technologies have been developed with the focus to reduce also the specific sludge production, still mechanical dewatering represents a crucial step to limit the amount of sludge to be disposed. Many physical–chemical parameters influence the sludge dewaterability: floc structure, particle size, bound water content, surface charge and hydrophobicity, Extracellular Polymeric Substan…

Closure to “Extraction of the Flow Rate Equation under Free and Submerged Flow Conditions in Pivot Weirs with Different Side Contractions” by N. Shei…

2018

Financial winners and losers since the privatization of the English and Welsh water and sewerage industry: a profit decomposition approach

2020

Evaluating changes in profit, price and productivity over time can be of great importance for regulated water industries. We investigate the drivers of profit, price (capital, labour and other inputs) and productivity change (cost efficiency change, technical change and scale effect) and the recipients of productivity change (consumers, the business itself, employees and other resource suppliers) of the English and Welsh water and sewerage companies over the period of 1995–2016. The results indicate that the profit decreased over time due to the negative quantity effect, which offset the positive price effect. A further decomposition of the quantity effect illustrates the negative impact of…

A Systematic Review of the Hydrological, Environmental and Durability Performance of Permeable Pavement Systems

2021

Due to urbanization, large portions of vegetated territory have been replaced by waterproof surfaces. The consequences are greater outflows, lower infiltration, and lower evapotranspiration. Pavement systems made with permeable surfaces allow the infiltration of water, ensuring reduction of runoff volume. In this paper, the methods of analysis of the hydrological and environmental performance of the pavement systems are reviewed in the context of urban drainage and regarding their durability. The purpose is to present an overview of the studies published during the last decade in the field. The Pubmed and Web Science Core Collection electronic databases were used to conduct the scientific l…

The role of extracellular polymeric substances on aerobic granulation with stepwise increase of salinity

2018

Abstract A granular sequencing batch reactor (GSBR) worked for 164 days to study the effect of salinity on aerobic granulation. The feeding had an organic loading rate (OLR) of 1.6 kg COD⋅m −3 ⋅d −1 and a gradual increase of salinity (from 0.30 to 38 g NaCl − ⋅L −1 ) to promote a biological salt-adaptation. First aggregates (average diameter ≈ 0.4 mm) appeared after 14 days. Extracellular polymeric substances (EPSs) analyses revealed that proteins were mainly higher than polysaccharides, and microorganisms metabolized EPSs as additional carbon source, mostly in feast phase, to face the energy demand for salinity adaptation. No significant worsening of organic matter removal was observed. Th…