About

Clarisa Long is the Max Mendel Shaye Professor of Intellectual Property Law at Columbia Law School. She holds a J.D. from Stanford University, obtained in 1994. Her current research focuses on the intersection of intellectual property law and competition policy. She serves on the committee of The Center for Cybersecurity at Columbia University’s Data Science Institute and is a former faculty director of Columbia Law School’s Program on Law and Technology. Long is a registered patent prosecutor with the U.S. Patent and Trademark Office. Prior to joining Columbia Law School in 2005, she was the Class of 1966 Research Professor at the University of Virginia School of Law. Her professional background includes clerking on the U.S. Court of Appeals for the Federal Circuit, being a fellow at Harvard Law School, and working as an associate at Wiley, Rein & Fielding in Washington, D.C. Before her academic career, Long was a molecular biologist conducting research in New Zealand and the United States, including at the National Institutes of Health. Her publications include books such as 'Genetic Testing and the Use of Information' and 'Intellectual Property Rights in Emerging Markets'.

Research topics

• Environmental chemistry
• Chemistry
• Environmental science
• Organic chemistry
• Environmental engineering
• Pulp and paper industry
• Biology
• Materials science
• Biophysics
• Engineering
• Biochemistry

Selected publications

• NYC Metropolitan Wastewater Reveals Links between Sars-Cov-2 Amino Acid Mutations and Disease Outcomes

  SSRN Electronic Journal · 2023-01-01

  articleOpen access
  PublisherDOI

• NYC metropolitan wastewater reveals links between SARS-CoV-2 amino acid mutations and disease outcomes

  The Science of The Total Environment · 2023-10-30 · 1 citations

  article
  PublisherDOI

• Comparative assessment of energy generation from ammonia oxidation by different functional bacterial communities

  The Science of The Total Environment · 2023-01-25 · 17 citations

  article
  PublisherDOI

• Impact of instrumentation reliability on mainstream suspended partial denitrification–anammox (PdNA)

  Water Environment Research · 2023-05-01 · 5 citations

  article

  Abstract This study successfully revealed the importance of probe reliability and sensitivity with ion sensitive electrode (ISE) probes on achieving high partial denitrification (PdN) efficiency; and decreasing carbon overdosing events that cause the decline of microbial populations and performance of PdNA. In a mainstream integrated hybrid granule–floc system, an average PdN efficiency of 76% was achieved with acetate as the carbon source. Thauera was identified as the dominant PdN species; its presence in the system was analogous to instrumentation reliability and PdN selection and was not a consequence of bioaugmentation. Up to 27–121 mg total inorganic nitrogen/L/d, an equivalent of 18–48% of the overall total inorganic nitrogen removed, was achieved through the PdNA pathway. Candidatus Brocadia was the main anoxic ammonium oxidizing bacteria species that was seeded from sidestream and enriched and retained in the mainstream system with observed growth rates of 0.04–0.13 day −1 . Moreover, there was no direct negative impact of methanol's use for post‐polishing on anoxic ammonium oxidizing bacteria activity and growth. Practitioner Points Stress testing with ISE sensors revealed the importance of probe reliability and sensitivity on PdN selection and PdNA performance. Up to 121 mg TIN/L/d was achieved via PdNA in a mainstream suspended hybrid granule–floc partial denitrification–anammox (PdNA) system. Candidatus Brocadia was the dominant AnAOB species with observed growth rates of 0.04–0.13 day–1. There was no direct negative impact of methanol's use for post‐polishing on AnAOB activity and growth.

  PublisherDOI

• Mainstream partial denitrification‐anammox in sand and expanded clay deep‐bed polishing filters under practical loading rates and backwashing conditions

  Water Environment Research · 2022-05-01 · 7 citations

  article

  Abstract This study focused on evaluating the feasibility of expanded clay and sand as media types for mainstream partial denitrification‐anammox (PdNA) in deep‐bed single‐media polishing filters under nitrogen and solids loading rates as well as backwash conditions similar to conventional denitrification filters. The surface roughness and iron content of the expanded clay were hypothesized to allow for enhanced anammox retention, nitrogen removal rates, and runtimes. However, under the tested loading rates and backwash conditions, no clear benefit of expanded clay was observed compared with conventional sand. This study showed the feasibility of PdNA in filters with both sand and expanded clay with PdN efficiencies of 76% and 77%, PdNA rates of 840 and 843 g N/m 3 /d and TIN removal rates of 960 and 964 g N/m 3 /d, respectively. Glycerol demands were 1.5–1.6 g COD added per g TIN removed , thus indicating potential carbon savings up to 75% compared with conventional denitrification. Overall, this study showed for the first time PdNA filters performing at nitrogen removal rates double that of previous PdNA studies under realistic conditions while providing insights into the media choice and backwashing conditions. Future research on expanded clay backwash conditions is needed to provide its full potential in PdNA filters. Practitioner Points Hydraulic and TSS loading rates similar to conventional denitrification can be applied in PdNA filters. Conventional sand can be used when retrofitting conventional denitrification filters into PdNA filters. Carbon savings up to 75% can be achieved with glycerol when retrofitting conventional filters into PdNA filters

  PublisherDOI

• Startup strategies for mainstream anammox polishing in moving bed biofilm reactors

  Water Environment Research · 2022-05-05 · 13 citations

  article

  This study evaluated startup strategies for mainstream polishing anammox moving bed biofilm reactors (MBBRs) without anammox bacterial (AMX) biomass inoculation. Two types of startups were tested: anammox only (no external carbon addition) and partial denitrification/anammox (PdNA) with glycerol addition. Reactors were started with either virgin carriers or carriers with a preliminary biofilm from a mainstream aerobic integrated fixed-film activated sludge (IFAS) process. Three pilot-scale startups were completed under the following conditions: anammox-only with preliminary biofilm carriers, PdNA with preliminary biofilm carriers, and PdNA with virgin carriers. AMX presence was confirmed via quantitative polymerase chain reaction (qPCR) after 57, 57, and 77 days, respectively. Prior to AMX detection, average influent concentrations of ammonia and nitrite ranged from 1.7-2.7 mg/L and 0.98-1.8 mg/L, respectively. This study demonstrated that AMX can be grown on carriers without AMX seeding under mainstream conditions (temperature 17-29°C, low ammonia and nitrite), regardless of whether nitrite came from upstream or partial denitrification within the reactor. This study also showed that using preliminary biofilm carriers can decrease startup time by approximately 1 month. These results address critical questions for moving mainstream anammox processes to full-scale implementation, and suggest that PdNA MBBRs are feasible and sustainable for full-scale ammonia, nitrate, and nitrite polishing to meet stringent total nitrogen requirements. PRACTITIONER POINTS: This research will help utilities develop methods for starting up mainstream anammox MBBRs without the barrier of anammox biomass seeding. Preliminary biofilm carriers accelerated startup time in a PdNA MBBR, but a virgin carrier reactor started up in a similar timeframe, contrary to expectations. Also, contrary to expectations, high concentrations of ammonia and nitrite are not necessary for startup of an anammox or PdNA MBBR.

  PublisherDOI

• Nitrogen removal capacity and carbon demand requirements of partial denitrification/anammox MBBR and IFAS processes

  Water Environment Research · 2022 · 20 citations

  • Chemistry
  • Environmental engineering
  • Environmental chemistry

  A pilot study was conducted to investigate the carbon demand requirements and nitrogen removal capabilities of two mainstream partial denitrification/anammox (PdNA) processes: a two-zone, moving bed biofilm reactor (MBBR) process and an integrated fixed-film activated sludge (IFAS) process. The first MBBR zone conducted PdNA, while the second operated as an anammox zone. Operation of the IFAS process was conducted in two phases. The first phase of the operation involved minor external carbon addition, while the second phase of the operation involved controlled external carbon addition. The MBBR process produced an average effluent TIN concentration and chemical oxygen demand (COD)/TIN ratio of 2.81 ± 1.21 mg/L and 2.42 ± 0.77 g/g. The average effluent TIN concentrations and COD/TIN ratios for the IFAS process were 4.07 ± 1.66 mg/L and 1.08 ± 0.38 g/g during phase 1 and 3.30 ± 0.96 mg/L and 2.18 ± 0.99 g/g during phase 2. Despite having relatively low and unstable partial denitrification (PdN) efficiencies, both mainstream PdNA processes exhibited low effluent TIN concentrations and carbon requirements compared to nitrification/denitrification. Successful operation of the PdNA IFAS process indicates that mainstream PdNA can be implemented with minimal capital costs in a water resource recovery facility's second anoxic zone. PRACTITIONER POINTS: Low effluent TIN concentrations can be maintained in mainstream PdNA MBBR and IFAS processes with low external carbon demand. MBBR and IFAS PdNA processes do not require consistent or high PdN efficiencies to maintain low effluent TIN concentrations. IFAS and MBBR PdNA processes exhibit similar TIN and NH3 removal efficiencies. PdNA can be implemented in a second anoxic zone, using IFAS technology for anammox retention, with minimal capital costs.

  PublisherDOI

• Analysis of SARS-CoV-2 amino acid mutations in New York City Metropolitan wastewater (2020-2022) reveals multiple traits with human health implications across the genome and environment-specific distinctions

  medRxiv · 2022-07-17 · 4 citations

  preprintOpen access

  Abstract We characterize variant diversity, amino acid mutation frequency, functionality and associations with COVID-19 infections in one of the largest datasets of SARS-CoV-2 genome sequences collected from wastewater in the New York metropolitan area. Variant diversity differed within parts of the New York City sewershed and between wastewater sludge and influent samples. P314L, D614G and T3255I occurred in >95% of wastewater samples. Enhanced infectivity, transmissibility and escape from antibody neutralization were dominant traits in the wastewater. Strikingly, over 60% of the most frequently occurring mutations were found in regions other than the spike (S) protein, and nearly 50% remain uncharacterized for functional impacts warranting further investigation. We demonstrate strong correlations between P314L, D614G, T95I, G50E, G50R, G204R, R203K, G662S, P10S, P13L and mortality rates, percent positive test results, hospitalization rates and % of population fully vaccinated. The results from our study suggest that there are relatively understudied mutations in the spike protein (H655Y, T95I) and understudied mutations occurring in non-spike proteins (N, ORF1b, ORF9b and ORF9c), that are enhancing transmissibility and infectivity among human populations, warranting further investigation.

  PublisherOA PDFDOI

• Glycerol-driven denitratation: process kinetics, microbial ecology, and operational controls

  Environmental Science Water Research & Technology · 2022-01-01 · 5 citations

  article

  This study implicated stoichiometric limitation of influent organic carbon, unique microbial community enrichment, and differential nitrate and nitrite reduction kinetics as determinant factors in glycerol-driven denitratation.

  PublisherDOI

• Enrichment of a denitratating microbial community through kinetic limitation

  Environment International · 2022-02-03 · 13 citations

  articleOpen access

  Denitratation, or the intentionally engineered accumulation of nitrite (NO2–) from selective reduction of nitrate (NO3–), can be combined with downstream anammox to reduce chemical and energy use associated with conventional nitrification and denitrification. This study aimed to enrich a denitratating microbial community capable of significant NO2– accumulation by applying added kinetic limitation to an already stoichiometrically-limited, glycerol-driven denitratation process. Operation at solids residence time, SRT=3.0 d, resulted in optimal denitratation performance and a microbial community dominated by NO3–-respirers, noted by one order of magnitude lower total copy numbers of nirS and nirK gene transcripts compared to longer SRTs. Selective NO3– reduction to NO2– was achieved at all SRTs although longer SRTs (less kinetic limitation) supported microbial communities more capable of full denitrification as described by a lower NO2– accumulation ratio (NAR=42±5%) and higher steady-state nitrous oxide (1.5 mg/L N2O-N) accumulation. Shorter SRTs (more kinetic limitation) led to higher observed yields (Y=0.63 mg-COD/mg-COD) with more electrons dedicated for cell synthesis (fs=0.56±0.10), which potentially contributed to the accumulation of NO3–. Enrichment of a denitratating-dominant microbial community by optimizing kinetic limitation operating parameters could support significant NO2– accumulation and reduce chemical and energy use for biological nitrogen removal when combined with downstream anammox.

  PublisherDOI

Frequent coauthors

• Kartik Chandran

  Columbia University

  23 shared

• Anand Archana

  9 shared

• Matthew Baideme

  United States Military Academy

  5 shared

• Haydée De Clippeleir

  5 shared

• Charles Bott

  Hampton Roads Sanitation District

  5 shared

• Justin Macmanus

  Virginia Tech

  4 shared

• Luke Plante

  Cornell University

  4 shared

• Rahil Fofana

  District of Columbia Water and Sewer Authority

  4 shared

Education

• Ph.D.

  University of Virginia School of Law

• B.A.

  Harvard Law School

• M.S.

  National Institutes of Health

• B.S., Molecular Biology

  Unknown