A Methodology Proposal for Selecting the Optimal Location for Small Hydropower Plants

The hydropower potential in the Republic of Serbia, as the most important renewable energy source, has been estimated at around 17000 GW·h per year, where approximately 2000 GW·h could be obtained from small hydropower plants (SHP). Small hydropower plants in Serbia currently produce 150 GW·h. Accordingly, the share of the electricity production from small hydropower plants in the total electricity production in Serbia is too small. The paper presents a model for the selection of optimal locations for small hydropower plants, which includes an ecological criterion, along with technical and economic criteria. The ecological criterion is eliminatory, i.e. those parts of the watercourse that border on or pass through protected natural assets are not taken into account when considering potential optimal locations for SHPs. All technical and economic criteria are included in the calculation of the weighted arithmetic mean with the aim of determining the optimal position for the construction of small hydropower plants. The model is implemented in the SHPOP software and its application is demonstrated on five watercourses in Southeastern Serbia

Tehničke smernice za obezbeđivanje protivpožarne vode iz javnih vodovodnih sistema

In many European countries as well as in America there is no current common legislation requiring that public waterworks provide fire flows. Most public water supply systems provide fire water services to their community. In our country public waterworks do not have any decrees, regulations or technical norms either at state or local levels regarding fire flow supply from the public water supply system. Criteria for providing fire water and their classification are analyzed in this paper. Guidelines are recommended based on the determined parameters and criteria to improve the fire water supply from public distribution water systems. Recommended Technical guidelines are in compliance with the new Fire Prevention Act [19].U mnogim evropskim zemljama i Americi trenutno nema jedinstvenih zakona koji od javnih vodovodnih kompanija zahtevaju da obezbede protivpožarne protoke. Većina javnih vodovodnih sistema pruža protivpožarne usluge zajednici koju opslužuju. U našoj zemlji javna vodovodna preduzeća ne poseduju uredbe, propise i tehničke normative u vezi sa obezbeđenjem protivpožarnog protoka iz javnog vodovodnog sistema, kako na državnom tako i na lokalnom nivou. U radu je prikazan predlog tehničkih smernica-preporuka za poboljšanje obezbeđivanja vode za protivpožarne potrebe iz javnih vodovodnih distributivnih sistema. Predlog tehničkih smernica je usaglašen sa novim Zakonom o zaštiti od požara

Future quantities of sludge from wastewater treatment plant on the territory of AP Vojvodina

In the framework of the research, an assessment of the future amount of waste sludge that would be generated after the construction of the planned 200 waste water treatment plants (WWTPs) that should be built on the territory of Autonomous Province of Vojvodina in the Republic of Serbia was carried out. It is estimated that the annual production of waste sludge will be slightly more than 81 thousand tons (dry sludge) per year. The methods of sustainable use (circular economy of sludge) and the method of safe disposal of sludge resulting from wastewater treatment were also analyzed. Starting from the possible use in Anaerobic Digestion processes for recharging biogas, the residual sludge from Anaerobic Digestion is excellent for use in agriculture. Well-watered sludge can also be used in the cement production industry, or if the sludge is burned (to reduce the final amount of waste), the ash can be used in the construction industry for the production of bricks or concrete/mortar, and finally sludge has potential for possible use for recharging biofuel, bio-plastic etc. Finally, there is a real potential for the use of waste sludge in AP Vojvodina

Tehničke smernice za obezbeđivanje protivpožarne vode iz javnih vodovodnih sistema

In many European countries as well as in America there is no current common legislation requiring that public waterworks provide fire flows. Most public water supply systems provide fire water services to their community. In our country public waterworks do not have any decrees, regulations or technical norms either at state or local levels regarding fire flow supply from the public water supply system. Criteria for providing fire water and their classification are analyzed in this paper. Guidelines are recommended based on the determined parameters and criteria to improve the fire water supply from public distribution water systems. Recommended Technical guidelines are in compliance with the new Fire Prevention Act [19].U mnogim evropskim zemljama i Americi trenutno nema jedinstvenih zakona koji od javnih vodovodnih kompanija zahtevaju da obezbede protivpožarne protoke. Većina javnih vodovodnih sistema pruža protivpožarne usluge zajednici koju opslužuju. U našoj zemlji javna vodovodna preduzeća ne poseduju uredbe, propise i tehničke normative u vezi sa obezbeđenjem protivpožarnog protoka iz javnog vodovodnog sistema, kako na državnom tako i na lokalnom nivou. U radu je prikazan predlog tehničkih smernica-preporuka za poboljšanje obezbeđivanja vode za protivpožarne potrebe iz javnih vodovodnih distributivnih sistema. Predlog tehničkih smernica je usaglašen sa novim Zakonom o zaštiti od požara

Rationalisation and reliability improvement of fire-fighting systems - the Novi Sad case study

Water supply systems are commonly used to supply fire-fighting water in most EU countries. To provide fast access to water, the standard practice is to install a huge number of hydrants along the entire water supply network. Pipe diameters and working pressures in the network are designed for a combination of the maximum hourly water demand and fire-fighting needs. However, in poorly managed water supply systems most of the hydrants are out of order. Although hundreds of hydrants exist in the network, the reality is that fire water tankers are usually refilled at just a few locations that are equipped with reliable hydrants maintained by the fire brigades. This paper presents a somewhat different approach for the provision of fire-fighting water. The approach discussed in the paper is based on the concept being introduced in the city of Novi Sad, Serbia, by cooperative efforts of the municipal Water Supply and Sewerage Company and the fire-fighting service. In addition to presenting the experience gained in the case study, some generic conclusions are drawn. As an alternative to having a number of unreliable and small hydrants distributed throughout the network, the new concept proposes the construction of several strategically positioned filling stations, with high-flow-rate pillar hydrants and good access roads for the manoeuvering of fire water tankers. If properly designed and distributed around the city, such filling stations would increase the reliability of fire-fighting operations. The filling stations' design methodology presented in this paper is composed of a fire-risk spatial assessment, a hydraulic check of water supply network operations and a worst-case traffic load analysis. By employing the proposed methodology, not only can the reliability of fire-fighting operations be increased, but if accepted and implemented the methodology can lead to leakage reduction and improvements in water quality and the system's energy efficiency. In the test case of Novi Sad, a large number of hydrants were replaced by 14 filling stations that have been designed and constructed. A hydraulic model of the water supply network was calibrated using pressure-drop tests and flow capacity measurements of the existing hydrants. The model was used to examine the performance of the designed filling stations during their parallel operation. The paper presents the results of the test application and recommendations for the possible implementation of the concept

Mountain Road-Culvert Maintenance Algorithm

The objective of this research was to determine the probability of road overtopping occurrence for a road culvert caused by surface runoff from the upstream catchment. A hydrological–hydraulic model was used for the development of an algorithm for road culvert maintenance based on the overtopping occurrence probability (CMOOP algorithm) for small mountain catchments. The hydrological model defines the regression dependence between the runoff hydrograph peak values and the probability of occurrences, whereas the hydraulic model calculates the culvert flow capacity by including in the calculation the level of sediment that culvert is filled with. The relationship between occurrences of overtopping and peak runoff value was defined using the runoff hydrograph transformation model in the accumulation on the upstream side of the road. In addition to the calculation of overtopping occurrence probability for the existing culvert condition, the CMOOP algorithm was used to analyze the impact of rehabilitation and reconstruction works from the perspective of legally based safety criterion for road overtopping occurrence probability (SCROOP). The CMOOP algorithm was appled to 67 concrete culverts located in a mountain road section in the Republic of Serbia. The results show that the application of rehabilitation works on selected culverts will increase the percentage of culverts that satisfy SCROOP from 49.25% to 89.55%, which confirms that the accumulated stone sediment is the main reason for the SCROOP unfulfillment