Search results for "Environmental engineering"
showing 10 items of 2674 documents
Cu-B alloy - analysis of use possibility as fuel cell cathode catalyst
2016
In recent years there has been a development of non-conventional and renewable sources of energy. One such sources of energy are fuel cells. Fuel cells are ecological and high efficiency sources of electric energy. However, the use of fuel cells on a large scale is limited, mainly by the high cost of catalysts. Platinum is most commonly used as the catalyst. But due to the high price of platinum there’s a need for finding other catalysts. Replacement of platinum will contribute to the fast development of green energy sources. This paper presents a study of possibility of using Cu-B alloy as catalyst for oxygen electrode in fuel cells. Researches were done in glass vessel, on a copper electr…
Electricity Production from Yeast Wastewater in Membrane-Less Microbial Fuel Cell with Cu-Ag Cathode
2023
Wastewater has high potential as an energy source. Therefore, it is important to recover even the smallest part of this energy, e.g., in microbial fuel cells (MFCs). The obtained electricity production depends on the process rate of the electrodes. In MFC, the microorganisms are the catalyst, and the cathode is usually made of carbon material (e.g., with the addition of Pt). To increase the MFC efficiency (and reduce costs by reducing use of the noble metals), it is necessary to search the new cathode materials. In this work, the electricity production from yeast wastewater in membrane-less microbial fuel cells with Cu-Ag cathode was analyzed. In the first place, the measurements of the sta…
Microbial fuel cell with Ni-Co cathode
2017
Wraz ze wzrostem poziomu życia wzrasta zarówno zużycie energii, jak i ilość ścieków. Istnieje jednak możliwość produkcji energii z jednoczesnym oczyszczaniem ścieków. Urządzeniem, które może zrealizować to zadanie jest mikrobiologiczne ogniwo paliwowe. W ogniwach tego typu bakterie osadu czynnego wykorzystane są do produkcji energii podczas oczyszczania ścieków. Jednym z ograniczeń tego rozwiązania jest niska gęstość uzyskiwanego prądu. Możliwe jest jednak podwyższenie tego parametru przy wykorzystaniu odpowiedniego katalizatora elektrod. W artykule przedstawiono możliwość wykorzystania stopu Ni-Co jako katalizatora katody. Badania obejmowały przygotowanie elektrody oraz porównanie zmian st…
Wastewater treatment and electricity production in a microbial fuel cell with Cu–B alloy as the cathode
2019
The possibility of wastewater treatment and electricity production using a microbial fuel cell with Cu&ndash
Effect of the junction angle on turbulent flow at a hydraulic confluence
2018
Despite the existing knowledge concerning the hydrodynamic processes at river junctions, there is still a lack of information regarding the particular case of low width and discharge ratios, which are the typical conditions of mountain river confluences. Aiming at filling this gap, laboratory and numerical experiments were conducted, comparing the results with literature findings. Ten different confluences from 45 ∘ to 90 ∘ were simulated to study the effects of the junction angle on the flow structure, using a numerical code that solves the 3D Reynolds Averaged Navier-Stokes (RANS) equations with the k- ϵ turbulence closure model. The results showed that the higher the junction angle, the …
Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.
2010
Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties…
RAVITA Technology : new innovation for combined phosphorus and nitrogen recovery
2018
Abstract Present phosphorus (P) recovery technologies mainly contain P recovery from sludge liquor or ash. These types of technologies are suitable for large wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR), digestion and/or incineration. In Finland and other Nordic countries, strict P discharge limits require chemical precipitation, thus EBPR alone is not sufficient. Ammonium recovery from wastewater, on the other hand, is not so often discussed. However, recovery from WWTP reject waters would decrease the energy demand of ammonium synthesis by Haber-Bosh technology and the energy demand of the WWTP's biological process. Helsinki Region Environmental S…
Biological nutrient removal model No.1 (BNRM1)
2004
This paper presents the results of the work carried out by the CALAGUA Group on Mathematical Modelling of Biological Treatment Processes: the Biological Nutrient Removal Model No.1. This model is based on a new concept for dynamic simulation of wastewater treatment plants: a unique model can be used to design, simulate and optimize the whole plant, as it includes most of the biological and physico-chemical processes taking place in all treatment operations. The physical processes included are: settling and clarification processes (flocculated settling, hindered settling and thickening), volatile fatty acids elutriation and gasÐliquid transfer. The chemical interactions included comprise aci…
Influence of sludge age on enhanced phosphorus removal in biological systems
1996
The phosphorus removal process was studied in a bench-scale plant for a period of 300 days. The process was observed to depend greatly on two parameters: the amount of volatile fatty acid (VFA) taken up in the anaerobic stage and sludge age. For a given sludge age, phosphorus release versus VFA uptake in the anaerobic stage could be fitted to a straight line, while phosphorus uptake in the non-anaerobic stages fitted a logarithmic curve. Thus, phosphorus removal occurred within a limited VFA uptake range. The range width and the phosphorus removal capacity varied with sludge age.
Effect of wastewater management on phosphorus content and sedimentary fractionation in Mediterranean saline lakes
2019
The La Mancha Húmeda Biosphere Reserve is the largest wetland district in the Iberian Peninsula, containing many temporary saline lakes undergoing different anthropogenic pressures. Eleven of these lakes were selected to assess phosphorus (P) burial, fractionation and mobilization in their sediments. Wastewater inputs, wherever they occurred, favored accumulation of all P sedimentary fractions, which took place mainly via precipitation with divalent cations (i.e. calcium or magnesium) and as buried organic matter, both representing relatively occluded P forms, although they can also be involved in P release. P immobilization would be partially restrained in the volcanic lakes of the region,…