University of Architecture, Civil Engineering and Geodesy (UACEG)

Municipal and industrial wastewater treatment

Ecology and Environment Protection

Operation of water and wastewater treatment plants

PhD - Diploma: Modelling of the Activated Sludge Biological Nitrogen and Phosphorus Removal Processes, University of Architecture, Civil Engineering and Geodezy (UACEG), Sofia
MSc - Diploma: Civil engineer on Water Supply and Sewerage, Subject: Water and Wastewater treatment, UACEG, Sofia;
MSc - Diploma: Applied Mathematics and Informatics, Technical University Sofia;

English - fluent, Russian - reading competence

Research experience - participation and coordination of international research projects, publication of the results in peer reviewed journals and books;
Teaching students – lectures and supervising of MSc and PhD thesis.
Design of new or upgrade of existing municipal WWTPs (e.g. ISPA and cohesion funds);
Design of industrial WWTPs – Coats, Litex Motor Corporation
Preparation of feasibility studies for the water cycle in the municipalities (cohesion funds);
Preparation of River Basin Management Plans in accordance with WFD (EU funds);

Preparation of flood risk managment plans (Danube river basin)
EU Commission expert - evaluating of projects in the EU Commission under FP4, FP5, FP6, FP7, H2020 in the field of research on water, environment protection, education, SMEs, preparation of action plans for structural funds;
Review and evaluation of big municipal water infrastructural project (above 10 000 p.e.) and tender documentation (cohesion funds) – external consultant to Ministry of Environmental and Waters, Bulgaria.

Consultant of the World Bank and the European Investment Bank

Circular economy - phosphorus recovery from sludge and wastewater

Wastewater treatment - eco-efficient technologies, modeling
Integrated river basin management
Water saving practices
Flood and drought management

• Research experience – researcher and project leader. Research topics: WFD implementation, in particular modelling of the quality of temporary rivers (European Commission funded project); removal hazardous compounds from wastewaters and sludge; biological processes modeling (in WWTPs and rivers); water saving technologies (industrial and domestic); flood and drought management (European Commission funded projects); nutrients (N and P) removal and recovery in WWTP; eco-efficiency of product systems
• International cooperation – preparation and participation (scientist and leader) in seven cientific projects funded by the EU Commission with total more than 50 partners (universities, agencies, research centres, NGOs) from EU Institutions.

Initiative for the future of the great rivers

Bulgarian Association of the Waters;
Chamber of Engineers in the Investment Design (KIIP);
 

National projets:

2018-2023 - perational programme "Scienece and education for smart growth", project "Clean technologies for sustainable environment - water, energy, solid wastes for circular economy"

2015 - Basin directorate project for preparing of flood risk managemnt plan of Danube river basin

2009 - Basin Directorates project for preparing of national catalogue of measures and program of measures for the water bodies in Danube river basin and Black Sea river basin in order to fulfil the Water Framework Directive objectives

2013, Preliminary design of WWTP of the Marinka village (2000 p.e.)

2011, Consultancy for the design of WWTP for sanitary landfill leachate (regional landfill in Gotze delchev town)

2010, Design of WWTP for domestic wastewaters in industrial unit (car producing factory in Bahovitsa)

2009, Pre-investment study and design of a WWTP of Jakoruda town (7000 P.E.)
2009, Pre-investment study for reconstruction of the WWTP of Vetrino village (2000 е.ж.)
2008, Consulting of foreign engineers for design of a WWTP of 9 villages around Sofia (30 000 е.ж.)
2005, Engineering design of the upgrade of the existing WWTP of Varna city (450 000 PE) for nitrogen and phosphorus removal;
2002, Engineering design of industrial WWTP for COATS, Bulgaria. Leading engineer. The technological scheme includes equalization, flocculation and sedimentation. The WWTP was built in 2002 and has been working successfully. The design and the construction were financed by COATS, BG.
2002, Leading engineer in the expert evaluation of problem situation in WWTP “Giorgetti”. Elin Pelin
1998, Evaluation and expert advice for rehabilitation of two WWTPs (Municipal, Parada and industrial, Aveiro)
1995, Identification of the wastewaters and proposal for treatment technology of CHIMKO

2012-2015 Coordinator for UACEG for a Bulgarian - Swiss project "Innovative P-recovery from waste sludge (INNOVA P-recovery)" No. IZEBZO_143004/1

2011-2014 Coordinator for Bulgaria for a research project, funded by DG Research of the EU Commission "Meso-level eco-efficiency indicators to assess technologies and their uptake in water use sectors"

2011-2014 Member of the Steering Committee of EU funded project under Regpot call: “Strategic & Technological Advancement in Research on AgroEnergy””

2011-2013 Coordinator for Bulgaria for a project, funded by DG Environment of the EU Commission “Assessment of water Balances and Optimisation based Target setting across EU River Basins”

2006-2008 PHARE (CADSES) project, “Monitoring, forecasting and best management methods for flood prevention in Mediterranean areas”, (2,5 Milion Euro, 13 partners, 60 000 Euro for Bulgaria);
2005-1009 Contact person for Bulgaria of 6th EU Program Integrated Project (14,2 Million Euro, ), “Mitigation of Water Stress through new Approaches to Integrating Management, Technical, Economic and Institutional Instruments” (36 partners, 208 000 Euro for Bulgaria;
2002-2005 Scientific coordinator for Bulgaria of 5th EU Program project (4,5 Million Euro) “Evaluation and improvement of water quality models for application at temporary waters in South European catchments”, 2002/2005 (13 countries, 120 000 Euro for Bulgaria)
1998-2001 Scientist and administrative manager of FP4 EU Inco - Copernicus project "Bioremediation Techniques for Detoxication of Hazardous Pollutants in Industrial Waters and Sludges", (4 countries, total budget of 240 000 Euro)
1996-1998 Lecturer in “TEMPUS” Project N 11454, “Environmental Biotechnology”

Professor, PhD

wastewater treatment technologies, eco-efficiency of urban systems, temporary waters, modeling, water quality, nutrient removal, efficient water use, river basin management

Bulgarian representative in Cost action ES1403- Nereus (New and emerging challenges and opportunities in wastewater reuse)

Books and chapters of books
1. Ribarova, I., Stanchev, P., Assimacopoulos, D.. Co-benefits of innovative water saving solutions in an urban water system in "Advances in Water Hydrology”
2. Understanding and Managing Urban Water in Transition, Grafton, Q., Daniell, K.A., Nauges, C., Rinaudo, J.-D., Chan, N.W.W. (Eds.) (Chapter 3 - Coping with extraneous water in sewerage systems. – authors Dimova, G., Ribarova, I. and De Carne, F.) 2015, Springer, ISBN 978-94-017-9800-6
3. Sludge treatment at municipal WWTPs, I. Ribarova, 2010, ZEN Electronics, ISBN: 978-954-92688-1-2
4. Water resources planning and management, Eds. Grafton, R.& Hussey, K. (Chapter “Collaborative flood and drought risk management in the Upper Iskar Basin, Bulgaria” - authors Daniell, K., Ribarova, I., Ferrand, N.), 2011, Cambridge University press, p.395-419
5. Use Of Economic Valuation In Environmental Policy: Providing Research Support For The Implementation Of EU Water Policy Under Aquastress, Ed.Ph. Koundouri (Chapter “Industrial water management as a water stress mitigation option: the Bularian and Polish case studies” - authors Wintgens, T., Dimova, G., Ribarova, I., Druzynska, E., Caruk, M., Vamvakeridou-Lyroudia, L.S, Tarnacki, K., Melin T., Savic D., 2009, Taylor & Francis, ISBN: 0415453232, p.124-196
6. Water saving in agriculture, industry and economic instruments, Part B – Industry (Chapter “Example for water stress mitigation in a region with metallurgical industry” – authors G. Dimova and I. Ribarova), 2009, Aquastress summarizing report
7. Water Stress Mitigation: The Aquastress Case Studies, Ed. D. Assimacoppoulos, (Part 2 “Sharing water under conditions of scarcity and stress” – author I. Ribarova). 2009, Aiga publishing
8. Critical issues n the water quality dynamics of temporary waters. Evaluation and recommendations from the tempQsim project, Eds Jochen Froebrich and Melanie Bauer, (chapter 10: SW Bulgaria – Iskar, authors I. Ribarova, Pl. Ninov, J. Topalova), 2006, Hannover
9. Biodegradation of xenobiotics, Ed. J.Topalova (chapter V Modelling of the processes of the degradation of the xenobiotics – author I. Ribarova), 2003, Sofia (in Bulgarian)

Peer reviewed journals

1. Stanchev, P., Ribarova, I. (2016). Complexity, assumptions and solutions for eco-efficiency assessment of urban water systems, Journal of cleaner production, 138, 229-236
2. Ribarova I., Dimitrova S., Lambeva, R., Wintgens, T., Stemann J.,
Remmen, K. (2017). Phosphorus recovery potential in Sofia WWTP in view of the national sludge management strategy, Resources, Conservation and Recycling, 116, 152-159
3. Dimova, G.. Tzanov, E., Ninov, Pl., Ribarova, I., Kossida, M. (2013). Complementary Use of the WEAP Model to Underpin the Development of SEEAW Physical Water Use and Supply Tables, Procedia engineering, 70 (2014), 563-572
4. Ribarova, I., Stanchev, P., Dimova, G., Assimacopoulos, D. (2013). A first iteration of an eco-efficiency assessment of Sofia’s urban water system, Procedia engineering, 70 (2014), 1411-1420
5. Inman, D., Blind, M., Ribarova, I., Krause, A., Roosenschoond, O., Kassahund, A., Scholtend, H., Arampatzis, G., Abrami, G. McIntosh, B. and Jeffrey, P, (2011). Perceived effectiveness of environmental decision support systems in participatory planning: Evidence from small groups of end-users, Environmental modeling and software, vol. 26, issue 3, year 2011, pp. 302 – 309
6. Daniell, K., Máñez, M., Ferrand., N., Kingsborough, A., Coad, P., Ribarova, I. (2011). Aiding multi-level decision-making processes for climate change mitigation and adaptation, J of Regional Environmental Change, Vol.11, No.2, pp. 243-258.
7. Daniell, K., White, I., Ferrand, N., Ribarova, I., Coad, P., Rougier, J.E., Hare, M., Jones, N., Popova, A., Rollin, D., Perez, P., Burn, S. (2010). Co-engineering participatory water management processes: theory and insights from Australian and Bulgarian interventions, Ecology and Society 15 (4): 11.
8. Ribarova, I., Assimacopoulos, D., Jeffrey, P., Daniell, K., Inman, D., Vamvakeridou-Lyroudia, L., Melin, T., Kalinkov, P., Ferrand, N., Tarnaki, K., (2011). Research-supported participatory planning for water stress mitigation. J. of Env. Planning and Management, vol. 54, issue 2, p.283-300
9. Todorova Y, Belev. R., Topalova, J., Ribarova, I. (2009). Analogous simulation of nutrient transformation processes in stream sediments, Water SA, vol.35, N5
10. Gallart, F. , Amaxidis, Y., Botti, P, Cane, G., Castillo, V., Chapman, P., Froebrich, J., Garcia-Pintado, J., Latron, J., Llorens, P., Lo Porto, A., Morais, M., Neves, R., Ninov, P., Perrin, J., L., Ribarova, I., Skoulikidis, N., Tournoud, M.J., (2008). Investigating hydrological regimes and processes in a set of catchments with temporary waters in Mediterranean Europe / Etude des regimes et processus hydrologiques dans un ensemble de bassins versants aux eaux temporaires dans l'Europe Mediterraneenne, Hydrological Sciences Journal - Journal des Sciences Hydrologiques, ISSN: 0262-6667, Vol: 53, Issue: 3, 618-628
11. Ribarova I., Pl. Ninov, D. Cooper (2008). Modeling nutrient pollution during a first flood event using HSPF software: Iskar River case study, Bulgaria, Ecollogical modelling, vol.211, pp. 241-246
12. Skoulikidis N., L. Dilberto, M. Tournoud, M. Morais, U. Uehlinger, J. Garcia, I. Ribarova, A. Butturini, J. Froebrich (2005). Temporary Mediterranean rivers: importance of episodic flow pulses for nutrient dynamics, Geophysical Research Abstracts, Vol. 7, 07484, SRef-ID: 1607-7962/gra/EGU05-A-07618
13. Kukurin K., I. Ribarova, P. Kalinkov, P. Ninov, J. Topalova, G. Dimova, J. Froebrich (2005). Introduction of the inundated area as a parameter for evaluation of river dryness, Geophysical Research Abstracts, Vol. 7, 07484, SRef-ID: 1607-7962/gra/EGU05-A-07484
14. Ribarova I., J. Topalova, I. Ivanov, D. Kozuharov, R. Dimkov, C. Cheng, (2002). Anaerobic Sequencing Batch Reactor as an Innitiating Stage in Complete PCP Biodegradation, Wat. Sci. Tech,. 2002, vol. 46, 1-2, pp 565-569.
15. Cheng Chia-Yau, Ribarova I., (1999). Activated Sludge system Modelling and Simulations for Improving the Effluent Water Quality, Wat. Sci. Tech., vol.39, N8, pp.93-98
16. Arsov R., Ribarova I., Nikolov N., Mihailov G., Topalova Y., Khoudary E (1999). Two Phase Anaerobic Technology for Domestic Wastewater Treatment at Ambient Temperatures, Wat. Sci. Tech., vol.39, N8, pp.115-122
17. Topalova Y., Ribarova I., Dimkov R., Arsov R., (1995). Microbiological Features of Nitrification Denitrification Biological Excess Phosphorus Removal System in the Presence of oNP as an Inhibitor, Wat. Sci. Tech., Vol.32, N 7, pp.103-110
18. Arsov R., Ribarova I., Topalova Y., Mihailov G., (1995). On the Kinetics of Nitrification Denitrification Biological Excess Phosphorus Remоval Processes, Wat. Sci. Tech., Vol.32, N 7, pp. 95-102

Conference proceedings
1. Ribarova, I., Stanchev, P., Dimova, G., (2014). Complexity, assumptions and solutions for eco-efficiency assessment of urban water systems, Systems engineering procedia (under review, presented in a conference 17th European roundtable on sustainable consumption and production)
2. Levidov, L., Blid, M., Nilsson, A., Skenhall, S., Ribarova, I., Popova, A., Stanchev, P., (2014). Facilitating multi-stakeholder discussions
on eco-innovation for process upgrading, Systems engineering procedia (under review, presented in a conference17th European roundtable on sustainable consumption and production).
3. Ribarova, I., Ninov, Pl., Volk, M., Melone F., Moramarco T., Safiolea E., Panagopoulos Y., Zdralewicz M., Berni N., Ghinescu A. (2009). Comparision of eight rainfall-runoff models for flood simulations, in “Integrating Water Systems”, Eds Boxall&Maksimovic, 2010 Taylor&Francis Group, London, ISBN 978-0-415-54851-9, page 755-761
4. Vamvakeridou-Lyroudia, L., S., Inman, D., Ribarova, I., D. Savic (2009). Modelling water saving in the upper Iskar region, in “Integrating Water Systems”, Eds Boxall&Maksimovic, 2010 Taylor&Francis Group, London, ISBN 978-0-415-54851-9, page 767-773
5. Daniell, K. A., Coad, P., Ribarova, I., White, I., Ferrand, N., Rougier, J. E., Tsoukiàs, A., Haines, P., Jones, N., Popova, A., Burn, S., Perez, P., (2008). Participatory risk management approaches for water planning and management: insights from Australia and Bulgaria, Proceeding of 13th IRWA World Water Congress, 1-4 Sept, Montpellier, France
6. Ninov Pl., I. Ribarova, P. Kalinkov, G. Dimova (2008). Application of the HSPF Model for Flood Simulation with Analysis of the Results in Terms of Monitoring Uncertainties /Case Study of the Lesnovska River, Bulgaria/, iEMSs 2008: International Congress on Environmental Modelling and Software, Barcelona
7. Ribarova I., Pl. Ninov, K.A. Daniell, N. Ferrand, M. Hare (2008). Integration of technical and non-technical approaches for flood identification, Water Down Under 2008, Adelaide, Australia, pp 2598-2609, ISBN 0-858-25735-1
8. Vamvakeridou-Lyroudia, L.S., Savic, D.A., Tarnacki K., Wintgens T., Dimova, G. and Ribarova I. (2007). “Conceptual/System Dynamics Modelling Applied for the Simulation of Complex Water Systems”, in Water Management Challenges in Global Change, Proc. Int. Conf. CCWI 2007 and SUWM 2007, Ulanicki, B., Vairavamoorthy, K., Butler, D., Bounds, P.L.M. Memon, F.A. (Eds), Leicester UK, 3-5 Sept. 2007, Taylor & Francis Group, London UK, 159-167.
9. Tarnacki K., I. Ribarova, E. Drużyńska, G. Dimova, T. Wintgens, T. Melin (2007). Water stress mitigation in the industrial sector – common approach in the Przemsza (Poland) and Iskar (Bulgaria) river catchments, World Water Week 2007, Stockholm
10. Dimova G., K.Tarnacki, T.Melin, I.Ribarova, L.Vamvakeridou-Lyroudia, N.Savov, T. Witgens (2007). The water balance as a tool for improving the industrial water management in the metallurgical industry – Case study Kremikovtzi Ltd., Bulgaria, IWA 6th Conference on Wastewater reclamation and Reuse for sustainability, 9-12 October. Antwerpen, Belgium
11. Ninov Pl., I. Ribarova (2006). First flood event modeling: case study Upper Iskar, International conference “Balkan Economic reconstruction and Ecology”, 21-23 June, 2003, Sofia
12. Ninov Pl., I. Ribarova, N. Nikolaidis, R. Tsoraki, P. Kalinkov, K. Kukurin, J. Topalova, (2006). Hydrological calibration scenarios of the HSPF model for the upper Iskar basin, XXIII Conference of the Danubial Countries on the Hydrological forecasting and hydrological bases of water management, 28-31 August 2006, Belgrade, Republic of Serbia
13. Topalova J., I. Ribarova, D. Purvanov, J. Todorova, L. Kenderov (2005). Assesment of the Iskar river water quality in Svoge-Eliseina section during the post-privatisation period, First international Conference with technical exhibition on water resources, technologies and services Bulaqua 2005, conference preprint book, pp.224 -233
14. Topalova J., I. Ribarova, Y. Todorova, P. Kalinkov, K. Kukurin, P. Ninov (2005). Large scale spatial/seasonal fluctuations of the microbial parameters of Iskar river: oversight to water quality, 6th International Conference of European Water Resources Association, Sharing a Common Vision for our Water Resources, 7 – 10 September 2005, Menton (France)
15. Ninov Pl., I. Ribarova, N. Nikolaidis, O. Tzoraki, P. Kalinkov, K. Kukurin (2005). Testing of the HSPF model for simulation of the nutrients loads in the Upper Iskar basin, Proceeding of IWA Watershed and River Basin Managaement Conference, Canada, 12-15.09.2005
16. Ribarova I., J. Topalova, Pl. Ninov, Kr. Kukurin, P. Kalinkov, G. Dimova (2005). Assessment of the flush event significance for a river with typical seasonal run off, Proceeding of IWA Watershed and River Basin Managaement Conference, Canada, 12-15.09.2005
17. Topalova J., Y. Todorova, I. Ribarova, L. Kenderov (2004). Biodiversity of the bacterial segment of the system “water-sediment” of Iskar river, 1st National conference in Ecology, BAN, 4-5 November, 2004, pp. 331-338 (in Bulgarian);
18. Ninov Pl., I. Ribarova, N. Nikolaidis, R. Tsoraki, P. Kalinkov, K. Kukurin, J. Topalova (2004). Hydrologic simulation of Iskar river subwatershed using the HSPF model, International conference ERB2004 “Progress in Surface and subsurface water studies at the pilot and small basin scale”, Turin, Italy, 13-17 October, pp 167-170;
19. Kukurin K., I. Ribarova, P. Kalinkov, Pl. Ninov, J. Topalova, J. Froebrich (2004). Winter low flow spatial dynamics for selected reach of Iskar river upstream, XIII International Symposium in Ecology, 7-10 June, Sunny Beach, Bulgaria, pp.296-306
20. Cheng, C.Y., M. Nunes, I. Ribarova. (2002). Bioremediation of waters contaminated with pentachlorophenol using a simple hybrid bioreactor, IWA Regional Symposium on Water Recycling IWA Regional Symposium on Water Recycling in Mediterranean region, Iraklio, Greece, 26-29 September, Preprint book 1
21. Topalova J, I. Ribarova, R. Dimkov, D. Kozucharov, I. Ivanov (2001). Sustainability of municipal WWTPs towards Industrial discharges. A possible rehabilitation technology, Proc of Int. Conf on Sustainability of Water and Environmental Systems Rehabilitation, Banja Luka, Bosnia and Herzegovina, September, 2001.
22. Ribarova I., Arsov R., (1999). Optimisation of the biological stage in UCT - scheme for nitrogen and phosphorus removal from wastewaters, Anniversary Scientific Conference 50 years Faculty of Hydrotechnics, Sofia, vol. II, pp.77-82, (in Bulgarian)
23. Topalova Y., R. Dimkov, I. Ribarova, D. Kozuharov, I. Ivanov, C. Van Keer (1999). Feasibility Study of Bioremediation Potential of Activated Sludge Towards PCP: Intergrated Approach. Med. Fac. Landbouww. Univ. Gent, 64/5a, I3th Forum on Applied Biotechnology, Sept. 1999, Gent.;
24. Kozuharov D., Topalova J., Dimkov R., Ribarova I., Jordanova N., (1999). Bioindicative Potential of the Micro- and Metafauna in the Activated Sludge Towards oNP, X Scientific Session of the Faculty of Biology, Sofia University, May, (in Bulgarian)
25. Ribarova I., Cheng C.Y., (1998). The modelling as a tool for optimisation of the WWTP operation, National Conference Bul Aqua Tech’98, pp.92-94 (in Bulgarian)
26. Cheng Chia-Yau, Ribarova I., (1998). Modelling of the Activated Sludge System in Parada WWTP, 4th National Water Congres, Lisbon, (in Portuguese)
27. Topalova Y., Ribarova I. (1996). Structural and Functional Relations in the Activated Sludge in Nitrification Denitrification Wastewater Treatment Processes, International Symposium and Workshop Environment and Interaction, Porto, 18-19 November, paper 34
28. Topalova Y., Ribarova I., Dimkov R., Arsov R., (1995). Adaptive Response of the Activated Sludge in NDBEPR System to ortho-Nitrophenol as an Chemical Pollutant, VI Scientific Session of the Faculty of Biology, Sofia University, 17-19 May

Journals

1. Tsanov E., I. Ribarova, D. Alichkov (2011). Reducing the water consumption in the households, Facilities, 12 (40), 22-25 (in Bulgarian)
2. Borisov B., I. Ribarova, P. Kalinkov (2006). Methods for selection of the members of the Public Stakeholder Forums in the water sector: experience of Aquastress project, Bulaqua, 3, pp. 4-12
3. Topalova Y., I. Ribarova, Y. Todorova, Pl. Ninov, Kr. Kukurin, P. Kalinkov (2006). Evolution of the experimental plan in data collection and verification tactics in modelling of river water quality, Biotechnology and Biotechnologcal equipment, issue 3
4. Topalova Y., I. Ribarova, D. Kozuharov, R. Dimkov, I. Ivanov, C. Y. Cheng, (2006). Structural/functional changes in activated sludge in PCP-and oNP biodegradation technologies, Biotechnology and Biotechnologcal equipment, issue 3
5. Ribarova I. (2006). New approach for mitigation of the water stress: Aquastress project, Water work, 1/2 , pp. 37-38, (in Bulgarian)
6. Topalova Y. I. Schneider, Y. Todorova, I. Ribarova (2006). Self-purification Potential of Iskar River in Three Critical Points of Pollution, Balkan Ecology, vol. 9, No 4 (in press)
7. Ribarova I. (2006). A two-step modelling approach for water management support during the period of socio-economic development in the Upper Iskar region, Bulgaria, Bulaqua, 3, pp. 31-38
8. Njagolov I., I. Ribarova, D. Simidchiev, Pl. Ninov, (2006). Water problems in the Upper Iskar subbasin – DPSIR approach, Bulaqua, 2, pp. 15-19, (in Bulgarian)
9. Ribarova I. (2006). The results of an international scientific project TempQsim – an useful tool for management of the water resources in Bulgaria, Bulaqua, 2, pp. 11-14, (in Bulgarian)
10. Ribarova I. (2006). Laboratory simulations for conceptual support of RS-TempQ Model, Bulaqua, N1, pp. 28-32 (in Bulgarian)
11. Ribarova I., Pl. Ninov (2005). Comparative analysis of methods for determination of nutrient load on Iskar reservoir, Water for people, 3 (7), pp.5-7 (in Bulgarian)
12. Ninov Pl, I. Ribarova, K. Kukurin (2005). HSPF Hydrologic model and sensitivity analysis of its calibration parameters, Ecology and Industry, vol.7, N2, pp 240-243
13. Kalinkov P., I. Ribarova, J. Topalova, Pl. Ninov, Kr. Kukurin (2003). Measurement planning for application of HSPF model for Iskar river catchemnet before Iskar reservoir, Bul Aqua, N1, pp35-38 (in Bulgarian)
14. Ribarova I., Y. Topalova, R. Dimkov, I. Ivanov, D. Kozuharov, M. Nunes, C. Cheng (2003). Four activated sludge technologies for pentachlorophenol removal, Journal Biotechnology and Biotechnological Equipment, N1 (17), 96-104
15. Kozuharov D., Y. Topalova, R. Dimkov, I. Ivanov, I. Ribarova, C. Cheng, M. Nunes (2003). Adaptation, structure of the micro- and metafauna in activated sludge from the up flow reactor during the PCP detoxification, Journal Biotechnology and Biotechnological Equipment, N1 (17), 68-76
16. Kozuharov D., Y. Topalova, R. Dimkov, I. Ivanov, I. Ribarova, E. Koseva, C. Van Keer (2003). Adaptation limits of the changes of the micro- and metafauna in the activated sludge towards PCP in aerobic and anaerobic conditions flow process, Journal Biotechnology and Biotechnological Equipment, N1 (17), 58-68
17. Dimkov R., Y. Topalova, I. Ribarova (2003). On the functional and structural characteristics of the low trophic levels in nitrogen oxidizing semi-cycle in industrial wastewaters, Journal Biotechnology and Biotechnological Equipment, N1 (17), 42-52.
18. Topalova Y., R. Dimkov, D. Kozuharov, I. Ribarova, I. Ivanov, M. Nunes, C. Cheng (2003). Design for an effective control of the PCP-detoxication in HBR, Journal Biotechnology and Biotechnological Equipment, N1 (17), 42-52.
19. Topalova J, R. Dimkov, I. Ribarova, I.. Ivanov, D. Kozuharov, M. Velikova, L. Angelova (2001), Dehalogenase Activity - Indicator for the Initial Detoxication Of Pentachlorophenol at the step by step Adapted Activated Sludge, Journal of International Research Publications [serial online], http://ejournal.topcities.com, issue 2
20. Topalova, J., Kozuharov, D., Ivanov, I., Dimkov, R. & Ribarova I. (2001). Biotransformation of 2,4,5-Trichlorophenol and 3,4-Dichlorophenol: Relationship Activity/Population Structure of Aerobic Activated Sludge. Journal Biotechnology and Biotechnological Equipment, N1 (17), 37-42
21. Ribarova I., J. Topalova, I. Ivanov, D. Kozuharov, K. Kukurin, R. Dimkov (2001). Pentachlorphenol biodegradation in anaerobic and aerobic continuous flow processes. Biotechnology and Biotechnological Equipment, Sofia, Bulgaria, v. 15, N2, pp.86-89
22. Kozuharov D., J. Topalova, R. Dimkov, I. Ribarova, I. Ivanov (2001). Bioindicative potencial of the Micro- and Metafauna in the Activated sludge towards oNP. Biotechnology and Biotechnological Equipment, Sofia, Bulgaria, V.15, N2, 2001, pp.92-99.
23. Topalova Y., Ribarova I., (1998). Bioindicators in a Nitrification Denitrification System, Biotech. and Biotechn. Equipment, 1, , pp. 96-101
24. Ribarova I., (1995). Modelling of the activated sludge processes in biological nutrient removal from municipal wastewaters, Extract of the dissertation, Sofia, BG, (in Bulgarian)
25. Ribarova I., (1994). Kinetics of the biological phosphorus removal processes in activated sludge systems, UACEG Annual, Vol. XXXVII, (in Bulgarian)