Search results for "WASTE"

Relating ions concentration variations to conductivity variations in a sequencing batch reactor operated for enhanced biological phosphorus removal

2006

In this paper a deterministic relationship between ionic conductivity and phosphorus concentration variations in an enhanced biological phosphorus removal (EBPR) process is established. Conductivity shows a strong correlation with phosphorus in both anaerobic and aerobic stages, increasing or decreasing when phosphorus is released or taken up, respectively. Since the end of these processes can be detected by examining the conductivity profile in a cycle, useful information on the EBPR performance and stability is available. This information can be used for adjusting the length of the anaerobic and aerobic stages. Therefore, online process control based on inexpensive and easy to maintain se…

Biological nutrients removal and recovery

2020

Biogas production and saccharification of Salix pretreated at different steam explosion conditions.

2011

Abstract Different steam explosion conditions were applied to Salix chips and the effect of this pretreatment was evaluated by running both enzymatic hydrolysis and biogas tests. Total enzymatic release of glucose and xylose increased with pretreatment harshness, with maximum values being obtained after pretreatment for 10 min at 210 °C. Harsher pretreatment conditions did not increase glucose release, led to degradation of xylose and to formation of furfurals. Samples pretreated at 220 and 230 °C initially showed low production of biogas, probably because of inhibitors produced during the pretreatment, but the microbial community was able to adapt and showed high final biogas production. I…

Hybrid activated sludge/biofilm process for the treatment of municipal wastewater in a cold climate region: a case study.

2011

A hybrid activated sludge/biofilm process was investigated for wastewater treatment in a cold climate region. This process, which contains both suspended biomass and biofilm, usually referred as IFAS process, is created by introducing plastic elements as biofilm carrier media into a conventional activated sludge reactor. In the present study, a hybrid process, composed of an activated sludge and a moving bed biofilm reactor was used. The aim of this paper has been to investigate the performances of a hybrid process, and in particular to gain insight the nitrification process, when operated at relatively low MLSS SRT and low temperatures. The results of a pilot-scale study carried out at the…

Removal of DEHP in composting and aeration of sewage sludge.

2003

The potential of composting and aeration to remove bis(2-ethylhexyl) phthalate (DEHP) from municipal sewage sludge was studied with two dewatered sludges: raw sludge and anaerobically digested sludge. Composting removed 58% of the DEHP content of the raw sludge and 34% of that of the anaerobically digested sludge during 85 days stabilisation in compost bins. A similar removal for the anaerobically digested sludge was achieved in a rotary drum in 28 days. Less than 1% of DEHP was removed with the compost leachate. Although DEHP removal was greater from raw sludge compost than anaerobically digested sludge compost, the total and volatile solids removals were on the same level in the two compo…

Thermophilic aerobic wastewater treatment, process performance, biomass characteristics, and effluent quality

2003

Thermophilic aerobic wastewater treatment is reviewed. Thermophilic processes have been studied in laboratory and pilot-scale while full-scale applications are rare. The paper focuses on the microbiology of aerobic thermophiles, performance of the aerobic wastewater treatments, sludge yield, and alternatives to enhance performance of thethermophilic process. Thermophilic processes have been shown to operate under markedly high loading rates (30–180 kg COD m−3d−1).Reported sludge production values under thermophilic conditions vary between 0.05 and0.3 kg SS kg CODremoved, which are about the same or lower than generally obtained in mesophilic processes. Compared to analogous mesophilic treat…

Quantitative comparison of initial soil erosion processes and runoff generation in Spanish and German vineyards.

2016

The aim of this study was to enable a quantitative comparison of initial soil erosion processes in European vineyards using the same methodology and equipment. The study was conducted in four viticultural areas with different characteristics (Valencia and Málaga in Spain, Ruwer-Mosel valley and Saar-Mosel valley in Germany). Old and young vineyards, with conventional and ecological planting and management systems were compared. The same portable rainfall simulator with identical rainfall intensity (40 mm h− 1) and sampling intervals (30 min of test duration, collecting the samples at 5-min-intervals) was used over a circular test plot with 0.28 m2. The results of 83 simulations have been an…

Contribution of raindrop impact to the change of soil physical properties and water erosion under semi-arid rainfalls

2017

Soil erosion by water is a three-phase process that consists of detachment of soil particles from the soil mass, transportation of detached particles either by raindrop impact or surface water flow, and sedimentation. Detachment by raindrops is a key component of the soil erosion process. However, little information is available on the role of raindrop impact on soil losses in the semi-arid regions where vegetation cover is often poor and does not protect the soil from rainfall. The objective of this study is to determine the contribution of raindrop impact to changes in soil physical properties and soil losses in a semiarid weakly-aggregated agricultural soil. Soil losses were measured und…

The way forward : Can connectivity be useful to design better measuring and modelling schemes for water and sediment dynamics?

2018

For many years, scientists have tried to understand, describe and quantify water and sediment fluxes, with associated substances like pollutants, at multiple scales. In the past two decades, a new concept called connectivity has been used by Earth Scientists as a means to describe and quantify the influences on the fluxes of water and sediment on different scales: aggregate, pedon, location on the slope, slope, watershed, and basin. A better understanding of connectivity can enhance our comprehension of landscape processes and provide a basis for the development of better measurement and modelling approaches, further leading to a better potential for implementing this concept as a managemen…

Real-time PCR detection of Ochroconis lascauxensis involved in the formation of black stains in the Lascaux Cave, France

2012

A real-time Polymerase Chain Reaction (PCR) assay was developed to detect and quantify Ochroconis lascauxensis in the Lascaux Cave in France. This fungus is the principal causal agent of the black stains threatening the Paleolithic paintings of this UNESCO World Heritage Site. The black stains outbreak could not be stopped in spite of using intensive biocide treatments. A sensitive and time-saving protocol is needed for determining the extent of the colonization. Sets of primers that target the ITS and RPB2 regions were designed and evaluated for specificity against O. lascauxensis. Genomic DNA extracted from five species of Ochroconis and 13 other fungal species frequently isolated from ca…