Per Halkjær Nielsen
Impact in
- Pollution top 0.01%
- Wastewater Treatment and Nitrogen Removal
- Industrial and Manufacturing Engineering top 0.01%
- Constructed Wetlands for Wastewater Treatment
Papers in
- Co-authors
- Jeppe Lund Nielsen (96 shared papers)Mads Albertsen (65 shared papers)Kristian Keiding (23 shared papers)Michael Wagner (28 shared papers)B. Frølund (13 shared papers)Yunhong Kong (17 shared papers)Morten Simonsen Dueholm (52 shared papers)Holger Daims (12 shared papers)
- Journals
- Acta chemica Scandinavica/Acta chemica Scandinavica. B, Organic chemistry and biochemistry/Acta chemica Scandinavica. A, Physical and inorganic chemistry/Acta chemica Scandinavica. Series B. Organic chemistry and biochemistry/Acta chemica Scandinavica. Series A, Physical and inorganic chemistry (66 papers)Water Research (52 papers)Water Science & Technology (48 papers)Applied and Environmental Microbiology (23 papers)The ISME Journal (20 papers)
- Partner nations
- DenmarkUnited StatesGermany
In The Last Decade
Per Halkjær Nielsen
514 papers receiving 34.6k citations
Per Halkjær Nielsen's Hit Papers
Peers
Comparison fields: 5 of 200
- Pollution 19.0k
- Industrial and Manufacturing Engineering 6.4k
- Environmental Engineering 6.3k
- Ecology 10.3k
- Water Science and Technology 5.4k
Countries citing papers authored by Per Halkjær Nielsen
This map shows the geographic impact of Per Halkjær Nielsen's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Per Halkjær Nielsen with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Per Halkjær Nielsen more than expected).
Fields of papers citing papers by Per Halkjær Nielsen
This network shows the impact of papers produced by Per Halkjær Nielsen. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Per Halkjær Nielsen. The network helps show where Per Halkjær Nielsen may publish in the future.
Co-authors
The 25 scholars most cited alongside Per Halkjær Nielsen, linked wherever they have co-authored with each other. Click a name or a connecting line to browse the papers they share.
All Works
Showing the 20 most-cited of 538 papers — load more, or switch the sort, to bring in the rest.
| # | Work | ||
|---|---|---|---|
| 1 | Extraction of extracellular polymers from activated sludge using a cation exchange resin Hit paper breakdown → | 1996 | 2106 |
| 2 | Complete nitrification by Nitrospira bacteria Hit paper breakdown → | 2015 | 1986 |
| 3 | Complete nitrification by a single microorganism Hit paper breakdown → | 2015 | 1427 |
| 4 | Enzymatic activity in the activated-sludge floc matrix Hit paper breakdown → | 1995 | 1095 |
| 5 | Genome sequences of rare, uncultured bacteria obtained by differential coverage binning of multiple metagenomes Hit paper breakdown → | 2013 | 928 |
| 6 | In Situ Characterization of Nitrospira -Like Nitrite-Oxidizing Bacteria Active in Wastewater Treatment Plants Hit paper breakdown → | 2001 | 667 |
| 7 | The biofilm matrix: multitasking in a shared space Hit paper breakdown → | 2022 | 563 |
| 8 | Measurement of pools of protein, carbohydrate and lipid in domestic wastewater Hit paper breakdown → | 1994 | 533 |
| 9 | 1999 | 471 | |
| 10 | The activated sludge ecosystem contains a core community of abundant organisms Hit paper breakdown → | 2015 | 438 |
| 11 | Back to Basics – The Influence of DNA Extraction and Primer Choice on Phylogenetic Analysis of Activated Sludge Communities Hit paper breakdown → | 2015 | 408 |
| 12 | Expanded metabolic versatility of ubiquitous nitrite-oxidizing bacteria from the genus Nitrospira Hit paper breakdown → | 2015 | 403 |
| 13 | 2014 | 340 | |
| 14 | 1995 | 292 | |
| 15 | 2015 | 279 | |
| 16 | 2007 | 269 | |
| 17 | 2015 | 256 | |
| 18 | 2011 | 250 | |
| 19 | 2010 | 247 | |
| 20 | 2010 | 247 |
About Per Halkjær Nielsen
Per Halkjær Nielsen is a scholar working on Pollution, Ecology, Molecular Biology, Environmental Engineering and Industrial and Manufacturing Engineering, having authored 538 papers that have together received 35.5k indexed citations. Recurring topics across this work include Wastewater Treatment and Nitrogen Removal (232 papers), Microbial Community Ecology and Physiology (132 papers), Microbial Fuel Cells and Bioremediation (80 papers), Constructed Wetlands for Wastewater Treatment (51 papers), Water Treatment and Disinfection (41 papers), Genomics and Phylogenetic Studies (37 papers), Anaerobic Digestion and Biogas Production (30 papers) and Odor and Emission Control Technologies (28 papers). The work is most often cited by research in Pollution (19.0k citations), Industrial and Manufacturing Engineering (6.4k citations), Environmental Engineering (6.3k citations), Ecology (10.3k citations) and Water Science and Technology (5.4k citations). Per Halkjær Nielsen has collaborated with scholars based in Denmark, United States and Germany. Frequent co-authors include Jeppe Lund Nielsen, Mads Albertsen, Kristian Keiding, Michael Wagner, B. Frølund, Yunhong Kong, Morten Simonsen Dueholm, Holger Daims, Aaron Marc Saunders and Marta Nierychlo. Their work appears in journals such as Acta chemica Scandinavica/Acta chemica Scandinavica. B, Organic chemistry and biochemistry/Acta chemica Scandinavica. A, Physical and inorganic chemistry/Acta chemica Scandinavica. Series B. Organic chemistry and biochemistry/Acta chemica Scandinavica. Series A, Physical and inorganic chemistry, Water Research, Water Science & Technology, Applied and Environmental Microbiology and The ISME Journal.
Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.