scholarly journals The control of small and medium sized public wastewater treatment plants in the Veneto region (North Italy): general situation, critical issues and case studies

2017 ◽  
Vol 12 (4) ◽  
pp. 761-779
Author(s):  
M. Ostoich ◽  
F. Serena ◽  
A. Pozzobon ◽  
L. Tomiato
Keyword(s):  
Wastewater Treatment ◽  
Case Studies ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
River Basin Management ◽  
Critical Parameters ◽  
Organic Load ◽  
General Situation ◽  
Veneto Region ◽  
Critical Issues

Abstract Water bodies' quality objectives are defined in accordance with the Urban Wastewater Treatment Directive 91/271/EEC and the Water Framework Directive 2000/60/EC. For regulation and control of small-sized waste-water treatment plants (WWTPs), responsibility is delegated in Italy to Regional Authorities that fix specific regulations (Water Protection Plan WPP included in the River Basin Management Plan RBMP) in collaboration with the District Authorities. Small (<2,000 population equivalent – PE) and medium sized (2,000–10,000 PE) WWTPs in the Veneto Region (North Italy) represent about 10% of the total organic load (Imhoff systems included). This also comprises some industrial discharges. Due to the urban sprawl, plants are spread over the regional territory. In the Veneto Region, data from the official census reveals there are n. 248 plants under 2,000 PE and 135 plants in 2,000–10,000 range while the total number of authorized plants is 488 for a total potentiality of 9,141,572 PE. Data from institutional controls performed by the Veneto Regional Environmental Agency (ARPAV) on WWTPs has been recovered for all the WWTPs with up to 10,000 PE in the provinces of Venice, Treviso and Vicenza (for a total of 306,118 PE and for a total of 164 plants) in the period 2008–2015 and elaborated to assess critical parameters and plants. The general situation, critical issues and case studies have been presented and discussed. Organic load, nutrients and Escherichia coli are the most critical parameters considering the regional WPP.

scholarly journals Characteristics and performance of small and medium wastewater treatment plants in Greece

2017 ◽  
Vol 12 (3) ◽  
pp. 520-533
Author(s):  
E. Gavalakis ◽  
P. Poulou ◽  
A. Tzimas
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Organic Load ◽  
Wastewater Management ◽  
Effluent Quality ◽  
Future Challenges ◽  
And Performance

Wastewater management in Greece is being regulated by the Urban Waste Water Treatment Directive (UWWTD) and as a result many wastewater treatment plants (WWTPs) have been constructed during the last 30 years and are in operation. The present work aims to outline the progress regarding the implementation of the specific environmental policy, present deficiencies and future challenges, while an evaluation of the performance is conducted for small-medium and large WWTPs focusing on the influent and effluent quality characteristics. In Greece the existing level of treatment provided is related to secondary treatment for the removal of organic load, which in most cases is supplemented by nitrogen removal (for more than 85% of the WWTPs) and phosphorus removal. With respect to the characteristics of the raw municipal wastewater these correspond to typical low to medium strength sewage. Compliance to the UWWTD effluent standards for BOD5, COD and SS is achieved in more than 90% of the WWTPs, while in terms of nutrients, 80% of the WWTPs efficiently remove nitrogen and approximately 45% of the WWTPs remove phosphorus.

Controlling the Settling of Activated Sludge in Pulp and Paper Wastewater Treatment Plants

1999 ◽  
Vol 40 (11-12) ◽  
pp. 223-229 ◽  
Author(s):  
Frédéric Clauss ◽  
Christel Balavoine ◽  
Delphine Hélaine ◽  
Gaëtan Martin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Pulp And Paper ◽  
Organic Load ◽  
Forest Industry ◽  
Filamentous Bulking ◽  
Mineral Particles ◽  
Mineral Powder

Forest industry wastewaters are difficult to clean: hydraulic and organic load variations, filamentous bulking or pin-point flocs negatively impact depollution processes. The addition of a fine, mineral, talc-based powder, Aquatal, into the aeration tanks of wastewater treatment plants connected to pulp and paper factories has been successfully tested since end of '97. The first case-study presents full results obtained over a period of 18 months in a 20,000 p.e. plant connected to a paper factory. The mineral powder was regularly added to control sludge volume index, thereby ensuring low suspended solids concentration in the outfluent. Plant operators could easily adapt biomass concentration to match organic load variation, thereby maintaining pollution micro-organisms ratio constant. In a second case study, a trouble-shooting strategy was implemented to counteract filamentous bulking. A one-off, large dosage enabled the plant operator to deal effectively with poor settleability sludge and rapidly control sludge blanket expansion. In both cases, the main common characteristics observed were an increase in floc aggregation and the production of heavier and well-structured flocs. The sludge settling velocity increased and an efficient solid/liquid separation was obtained. After a few days, the mineral particles of Aquatal were progressively integrated into the sludge floc structure. When the mineral powder was added to the activated sludge in the aeration basin, chemical interactions frequently encountered with other wastewater treatment additives did not pose a problem. Moreover, with this mineral additive, the biological excess sludge displayed good thickening properties and dewatering was improved. Despite the addition of the insoluble mineral particles, the amount of wet sludge expelled did not increase. Aquatal offers a rapid solution to floc settleability problems which so frequently arise when physical or biological disorders appear in forest industry wastewater treatment plants.

scholarly journals Investigating the impacts of extraneous water on wastewater treatment plants

2016 ◽  
Vol 75 (4) ◽  
pp. 847-855 ◽  
Author(s):  
S. Rödel ◽  
F. W. Günthert ◽  
T. Brüggemann
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Wastewater Treatment Plants ◽  
Measurement Data ◽  
Practical Investigations ◽  
Organic Load ◽  
Sewer Pipes ◽  
Purification Efficiency ◽  
Theoretical Approaches ◽  
Local Water

To demonstrate the effects of increased extraneous water on operation, purification, and energy efficiency, two wastewater treatment plants (WWTPs) have been investigated in detail under the research project ‘Sealing of sewer pipes – Effects on the purification performance of WWTPs and their impact on the local water balance’. Both treatment plants, after evaluating and analyzing the measurement data and information about them, were compared in the light of existing literature and other practical investigations. Furthermore, the results were assessed with respect to transferability to other treatment plants. In WWTP 1, extraneous water reduction led to lower energy consumption of certain plant components such as the pumping station and aeration. An increased percentage of extraneous water had an impact on the wastewater characteristics (e.g. organic load) in WWTP 2. A decrease in extraneous water increases the concentration of biodegradable matters; however, an increase in extraneous water increases the loads in the effluent. The results are in accordance with the theoretical approaches described in the literature and confirm the correlations between extraneous water and purification efficiency and energy consumption of WWTPs.

Odour emission capacity of wastewaters - standardization of measurement method and application

1998 ◽  
Vol 38 (3) ◽  
pp. 61-69 ◽  
Author(s):  
Franz-Bernd Frechen ◽  
Wulf Köster
Keyword(s):  
Wastewater Treatment ◽  
Liquid Phase ◽  
Case Studies ◽  
Mass Flow ◽  
Measurement Method ◽  
Wastewater Treatment Plants ◽  
Ambient Air ◽  
New Method ◽  
Sewer Systems ◽  
Emission Capacity

Odorous emissions from sewer systems and wastewater treatment plants can cause serious annoyance in the vicinity. Odorants which are present in a liquid phase are emitted into ambient air at the liquid-gaseous interface. The amount and the variation of emitted mass flow of odorants is significantly influenced by the amount of odorants which are present in the liquid. Up to now, however, no measurement method was available to describe this parameter, which can be called “Odorants Emission Capacity”. The paper describes a standardized method of determining the “Odorants Emission Capacity” and shows results and consequences from several case studies where this new method was applied.

Case studies in dynamic modelling of large-scale wastewater treatment plants

1995 ◽  
Vol 1 (3) ◽  
pp. 185-198 ◽  
Author(s):  
Imre Takacs ◽  
Gilles G Patry ◽  
Bruce watson ◽  
Bruce GALL
Keyword(s):  
Wastewater Treatment ◽  
Case Studies ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Dynamic Modelling

scholarly journals ENZYMATIC WASTE WATER TREATMENT

World Science ◽  
2021 ◽  
Author(s):  
Nancey Hafez
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Water Treatment ◽  
Metal Ions ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
High Energy ◽  
Enzymatic Reactions ◽  
Biological Interactions ◽  
Physico Chemical

Enzymes are biocatalysts provided by cells and are used in most metabolic methods. Most enzymes are consisting of proteins containing tertiary amino acid which bind to co enzyme or metal ions. Enzymes are accelerating biochemical processes by some mechanisms to chemical catalysts e.g metals, metal oxides and metal ions. Enzymes can be very effective under conditions e.g (temperature, atmospheric pressure and PH). Many enzymes have hydrolyzing, oxidizing and reducing characters. Enzymatic reactions always provide less side effects reactions and fewer waste by products. That is why microbial Enzymes can give an effective and environmental safe alternatives as metabolic inorganic chemical catalysts which can be used in all over pharmaceutical industrial processes. Enzymes are used in waste water treatment. Treatment technologies depend on physico-chemical approaches in wastewater treatment plants which require skills, high operation costs (in terms of high energy and chemical demand). Wastewater treatment is operated to protect the quality of limited freshwater resources, which are most times the final discharge points of effluents, and also, to promote the reusability of expended clean water; amounts of hazardous aromatic byproducts are still generated [3, 4]. The observation shows that wastewater treatment plants, though liable to remove microcontaminants such as heavy metals, and to a far lesser extent, aromatic contaminants, were originally structured for the removal of solid wastes, ecofriendly organic matter and eutrophication stimulants from wastewater, thereby reducing eutrophicating pollution loads; the micropollutants may only be moderately affected by the chemical, physical and biological interactions within the treatment plants.

scholarly journals Energy Benchmarking and Optimization of Wastewater Treatment Plants in Greece

2020 ◽  
Vol 2 (1) ◽  
pp. 36
Author(s):  
Popi Christoforidou ◽  
George Bariamis ◽  
Maria Iosifidou ◽  
Eri Nikolaidou ◽  
Petros Samaras
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Specific Energy Consumption ◽  
Water Environment ◽  
Organic Load ◽  
Technical Data ◽  
Environmentally Sustainable ◽  
Crucial Component

Wastewater treatment, as a crucial component of the urban water environment, consists of several energy-consumptive stages, therefore efficiency and energy savings measures are essential to maintain them as environmentally sustainable and economically viable. Operational and technical data from WWTPs in Greece have been collected as well as a sample from 61 facilities with key energy profile components. Energy consumption was assessed by specific key performance indicators (KPIs); specific energy consumption expressed per population equivalent (from 3 to 150 kWh/PE), per cubic meter treated (from 0.2 to 2.0 kWh/m3) and per unit of organic load removed (from 0.03 to 7.13 kWh/CODremoved).

scholarly journals Content changes of adsorbable organically bound halogens during sludge centrifugation and drying

2011 ◽  
Vol 57 (No. 1) ◽  
pp. 30-36
Author(s):  
K. Hrich ◽  
B. Groda
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Material Balance ◽  
Water Treatment Plant ◽  
Waste Water Treatment Plant ◽  
The Czech Republic ◽  
Balance Analysis ◽  
Adsorbable Organically Bound Halogens

A wastewater treatment plant in Brno may be one of the wastewater treatment plants in the Czech Republic using a dryer for dewatering the sludge. The results of an adsorbable organically bound halogens balance analysis measured on the sludge dryer at the waste water treatment plant in Brno are demonstrated in this work. The aim of this work was to calculate the material balance in the treatment process (centrifugation and drying). Control places were chosen and then samples of water and sludge (at the inlet and outlet of the system) were collected. The adsorbable organically bound halogens concentration was detected in these samples by the coulometric method.

Upgrading of Small Municipal Wastewater Treatment Plants with Heavy Dairy Loading by Introduction of Aerated Submerged Biological Filters

1990 ◽  
Vol 22 (7-8) ◽  
pp. 191-198 ◽  
Author(s):  
Hallvard Ødegaard ◽  
Bjørn Rusten
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Combined Treatment ◽  
Organic Load ◽  
Municipal Wastewater Treatment ◽  
Biological Filter ◽  
Municipal Wastewater Treatment Plants ◽  
Insufficient Knowledge ◽  
Biological Filters

Most of the dairies in Norway discharge their wastewater to the municipal sewers. Insufficient knowledge about the organic load coming from the dairies, has resulted in inadequate design and organic overloading in the municipal wastewater treatment plants of this category. Several of the plants that originally based their biological process upon RBC as the bioprocess, have experienced mechanical breakdown of the RBC system. The submerged biological filter (SABF) has been introduced as an alternative biofilm method that may be used when broken down RBC-plants (or activated sludge plants) are to be upgraded. The paper describes results from pilot-plant experiments on dairy waste when the SABF is used for pretreatment, as well as results from plants in practice where the SABF is used for combined treatment of the dairy and municipal wastewater. It is shown how pretreatment in a balancing tank may be established, and results from the use of an alternative floating biofilm media are given.

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