Encontrados 11 documentos, a visualizar página 1 de 2

Biofilms formed on humic substances : response to flow conditions and carbon co...

Stream biofilms are exposed to dynamic conditions of flow velocity and organic carbon availability. Thus, the aim of this study was to investigate the response of biofilms formed with and without humic substances (HSs) to an increase in flow velocity (0.04–0.10 m s-1) and HSs concentration (9.7 ± 1.0 to 19.8 ± 0.4 mg L-1 C). The highest amount of biofilm, measured as volatile suspended solids and total countabl...

Economic and environmental assessment of small and decentralized wastewater tre...

The aim of the present work was the assessment of economic and environmental aspects of decentralized energy-saving wastewater treatment systems. The formulated investment and operation cost functions were adjusted by a power law function. The different wastewater systems serving population settlements between 50 p.e. and 250 p.e., presented associated investment costs varying from €400/p.e. to €200/p.e. and an...

Quantification of humic acids in surface water: effects of divalent cations, pH...

Humic acids (HAs) content of raw water is an important analytical parameter in water treatment facilities because HAs in the presence of chlorine may lead to the formation of dangerous by-products (e.g., trihalomethanes). The concentration of HAs in water is not directly accessible by common analytical methods due to their heterogeneous chemical structure. The aim of this study was to compare two methods to ass...

Characterization of biofilms formed in humic substances by fluorescence in situ...

Characterization of biofilm formation on a humic material

Biofilms are major sites of carbon cycling in streams. Therefore, it is crucial to improve knowledge about biofilms’ structure and microbial composition to understand their contribution in the self-purification of surface water. The present work intends to study biofilm formation in the presence of humic substances (HSs) as a carbon source. Two biofilm flowcells were operated in parallel; one with synthetic str...

Life cycle assessment of wastewater treatment options for small and decentraliz...

Sustainability has strong implications on the practice of engineering. Life cycle assessment (LCA) is an appropriate methodology for assessing the sustainability of a wastewater treatment plant design. The present study used a LCA approach for comparing alternative wastewater treatment processes for small and decentralised rural communities. The assessment was focused on two energy-saving systems (constructed w...

Energy-saving wastewater treatment systems : formulation of cost functions

Natural interactions between water, soil, atmosphere, plants and microorganisms include physical, chemical and biological processes with decontaminating capacities. Natural or energy-saving wastewater treatment systems utilize these processes and thereby enable a sustainable management in the field of wastewater treatment, offering low investment and operation costs, little or no energy consumption, little and ...

Characterization of biofilm formation on a humic material

Monitoring natural organic matter in surface water by UV spectroscopy : effects...

The aim of this study was to evaluate the effects of dissolved magnesium and calcium ions on the determination of humic substances in water by spectrophotometry at 254 nm. Quantifications were carried out for different pH values, both with and without filtration of the samples. The smallest effects were observed for unfiltered samples and neutral pH values.

Energy-saving wastewater treatment systems : formulation of cost functions

Natural interactions between water, soil, atmosphere, plants and microorganisms include physical, chemical and biological processes with decontaminating capacities. Natural or energy-saving wastewater treatment systems utilize these processes and thereby enable a sustainable management in the field of wastewater treatment, offering low investment and operation costs, little or no energy consumption, little and ...