Controlling negative effects of sewage water overflow

U radu se opisuje mješovita kanalizacija čije su značajke rasteretne građevine kojima se za vrijeme kiša nepročišćene otpadne vode zajedno s oborinskim vodama prelijevaju u prijamnike. Cilj građenja rasteretnih građevina je prije svega ekonomski. Preljevne vode onečišćuju okoliš, što treba kontrolirati. Kontrola je složena, skupa i dugotrajna. Preduvjet za uspješno rješavanje problema je donošenje nacionalne strategije i dugoročnih planova za upravljanje rasteretnim građevinama.The mixed sewage disposal system, characterized by overflow facilities, through which untreated waste waters and rain water are together evacuated into the final discharge zone, is described. These overflow facilities are built primarily for economic reasons. Overflowing waters pollute environment, and must therefore be controlled. This control is complex, expensive and time-consuming. Development of national strategy, and the long-term overflow facility management plan, are the main preconditions for successful resolution of this problem

SELECTION OF FOOD WASTE MANAGEMENT OPTION BY PROMETHEE METHOD

: Food waste management performed following the EU Circular Economy Strategy principles poses a problem in small islands. There are several standard food waste management methods on islands; however, there are two specific methods which must be considered along with their positive and negative impacts. These two specific methods are discharging food waste into the city’s sewer system and transporting waste to the mainland, i.e., to regional waste processing facilities. This paper presents a multi-criteria decision analysis to evaluate different waste management options and their applicability in small islands such as Vis. The results of this study indicate that the best food waste treatment option for small islands is discharging food waste into the city’s sewer system to be processed with wastewater through wastewater treatment. The PROMETHEE method used in this study has proved to be a useful tool for solving the food waste management problem

Berechnung des Nachhaltigkeitsindex für das Management von Speiseabfällen

Zbrinjavanje otpada hrane je problem čije se rješavanje treba provoditi u skladu s principima hijerarhije otpada i kružnog gospodarstva. To je biološki lako razgradivi otpad koji ima štetan utjecaj na okoliš, a važan je biološki resurs koji se može koristiti za poticanje kružnog gospodarstva. Upravljanje je zbog lake razgradivosti zahtjevno i složeno. Postoji više rješenja s različitim učinkom na osnovne dimenzije održivosti. Jedno od rješenja koja se u svijetu koriste je upuštanje kuhinjskog otpada hrane u kanalizaciju otpadnih voda. Cilj je smanjiti štetna ispuštanja u urbani i prirodni okoliš i ojačati održivost sustava upravljanja otpadom hrane i kanalizacije. Rješenje mora biti održivo u skladu sa lokalnim prirodnim i društveno-ekonomskim značajkama. Održivost se može ocijeniti na više načina ovisno o raspoloživosti podataka i razine obrade problema. U radu je prezentirana primjena indeksa održivosti na primjeru otoka Raba. Dobiveni indeks održivosti potvrđuje da je predloženi koncept označava zadovoljavajući napredak prema održivosti.Waste food disposal is a problem whose solution should be implemented according to the principles of waste hierarchy and circular economy. This is easily biodegradable waste that has an adverse impact on the environment and is an important biological resource that can be used to stimulate circular economy. Due to easy degradability, the management is challenging and complex. There are more solutions with different impacts on the basic dimensions of sustainability. One solution used globally is letting out kitchen food waste into the sewerage. The objective is to reduce harmful discharges into urban and natural environments and to strengthen the sustainability of food waste management and sewerage systems. The solution has to be sustainable according to local natural and socio-economic characteristics. Sustainability can be assessed in more manners, depending on data availability and problem processing level. The paper presents the sustainability index implementation on the example of Rab Island. The obtained sustainability index confirms that the proposed concept marks a satisfactory progress towards sustainability.Die Entsorgung von Speiseabfällen ist ein Problem, das im Einklang mit den Prinzipien der Abfallhierarchie und der Kreislaufwirtschaft gelöst werden soll. Es handelt sich auch um biologisch leicht abbaubare Abfälle, die eine negative Auswirkung auf die Umwelt haben, sind aber eine wichtige biologische Ressource, die die Kreislaufwirtschaft fördern kann. Das Management von Speiseabfällen ist wegen ihrer leichten Abbaubarkeit anspruchsvoll und komplex. Es gibt mehrere Lösungen mit unterschiedlichen Auswirkungen auf die Grunddimensionen der Nachhaltigkeit. Ein in der Welt angewandtes Entsorgungsverfahren ist die Einleitung von Speiseabfällen in die Abwasserleitung. Das Ziel dieses Verfahrens ist, die schädliche Einleitung von Speiseabfällen in die urbane und natürliche Umwelt zu reduzieren sowie die Nachhaltigkeit der Systeme zur Management von Speiseabfällen und des öffentlichen Kanalnetzes zu stärken. Das Entsorgungsverfahren muss gesellschaftlich und wirtschaftlich nachhaltig und im Einklang mit regionalen natürlichen Merkmalen sein. Die Nachhaltigkeit kann auf mehrere Weisen berechnet werden, und zwar abhängig von der Verfügbarkeit von Angaben und der Ebene der Problembehandlung. Im Beitrag wird die Anwendung des Nachhaltigkeitsindex am Beispiel der Insel Rab dargestellt. Der berechnete Nachhaltigkeitsindex bestätigt, dass das hier vorgeschlagene Konzept ein zufriedenstellender Fortschritt in Richtung Nachhaltigkeit ist

A framework for application of renewable energy in urban water systems

This paper presents possible concepts of using renewable energy sources (RESs) in urban water systems (UWSs). The hydro and biomass energy generated by UWSs are typical renewable sources of energy, but these have limited capacity. Solar and wind energy sources are standard global RESs characterized by large capacity and intermittent production. However, technological challenges associated with the use of the sun and wind means that these sources cannot directly and continuously supply a UWS with electric energy. Thus, it is necessary to hybridize them with conventional sources through the electric energy grid system or the use of electric energy storage (EES) including pump storage hydroelectric (PSH) plants. The analysis presented in the paper determined that green energy is possible and relatively easy to implement in a UWS. The use of RESs contributes to the straightening of urban energy sustainability and the reduction of CO2 emissions from UWSs

Design of water storage reservoirs based on flow generation

U radu je opisan pristup gospodarenju volumenima akumulacija na osnovi primjene generiranih serija ulaznih podataka o dotocima. Za generiranje serija dotoka u akumulaciju upotrebljen je Thomas – Fieringov model. Kao primjer za ilustraciju navedena je postojeća akumulacija Boljunčica u Istri. Ovdje provedene analize daju i praktičan doprinos budućem upravljanju s tom akumulacijom u smislu osiguranja metodološkog pristupa pri određivanju potrebnog prostora u zaplavu akumulacije.An approach to water reservoir management, as based on the use of generated series of input data about water inflow, is described. The Thomas - Fiering model is applied for generation of flow series. The existing Boljunčica reservoir in Istria is used as a practical example. The analyses performed on this project are a practical contribution to the future management of this reservoir because they provide a methodological approach for defining necessary space in the flood zone of the reservoir