PFAS remediation
Air sparging, soil washing, phytoremediation, pump-and-treat, and treatment-train thinking for PFAS-impacted soil and groundwater.
Open remediation toolkitAquentis Enviro
Specialist PFAS remediation, contaminated-site strategy, LC-MS/MS data interpretation, and industrial wastewater expertise for evidence-led environmental decisions.
About the practice
Rigorous science, translated into practical environmental decisions.
Aquentis Enviro is the independent consultancy of Dr Rajneesh Gautam, an environmental scientist and chemical engineer specialising in PFAS remediation and industrial wastewater treatment.
Rajneesh helps organisations turn complex contamination challenges into practical, evidence-based solutions: from bench-scale tests and numerical modelling to field implementation, partner coordination, and regulatory reporting.
The work is built for scrutiny: clear assumptions, transparent data interpretation, and recommendations that a technical team, regulator, or project board can act on.
Dr Rajneesh Gautam (PhD)
Founder and Principal Consultant
What Aquentis does
Focused expertise for high-stakes environmental work.
Support for industry, consultancies, regulators, and research consortia where PFAS, groundwater, and industrial effluent decisions need specialist depth.
Numerical modelling
Contaminant transport, desorption, volatilisation, mass balance, and kinetics modelling in Python and MATLAB to support design and scale-up.
See decision toolsAnalytical interpretation
PFAS quantification, suspect screening, and data interpretation across soil, water, foam, treatment streams, and co-contaminants.
View lab evidenceSite investigation and risk
Conceptual site models, groundwater and soil sampling design, exposure pathways, and risk-based decision support for impacted sites.
Review experienceIndustrial treatment
Anaerobic membrane bioreactors, high-strength industrial effluents, biomethane recovery, fouling indicators, and performance evaluation.
Open AnMBR tabReporting and project leadership
Regulator-facing reports, technical review, proposal writing, Horizon Europe coordination, and work package leadership across partners.
Discuss supportHow I work
A clear path from contamination problem to defensible decision.
Most engagements follow three stages, scaled to the size of the question and the evidence already available.
1
Assess
Review site data, conceptual model, and regulatory drivers; define the contamination problem, receptors, and what success looks like.
2
Model & test
Bench-scale experiments, LC-MS/MS interpretation, and numerical modelling of PFAS fate, transport, and treatment performance to compare options.
3
Recommend
Translate the evidence into a practical, costed remediation strategy and clear technical reporting for partners, regulators, and stakeholders.
Remediation toolkit
Choose the right method for the site, not the other way around.
PFAS treatment depends on source strength, hydrogeology, receptors, regulatory drivers, and operational constraints. Aquentis compares those factors before recommending a path.
Track record
Experience across research, industry, and regulation.
Hands-on remediation research combined with regulator-facing review, proposal leadership, and industrial wastewater engineering.
6+Years spanning academia, regulators, and EU research consortia.
15+Q1 publications in highly reputed journals.
20+Bachelors and Industrial Masters projects supervised in environmental-chemical engineering.
Mar 2023 - presentUppsala, Sweden
Principal Investigator and Senior Researcher
Swedish University of Agricultural Sciences (SLU), SGI, and SGU. Leads SLU work in Horizon Europe REMEDYOS and SGI/SGU-funded PFAS projects covering air sparging, soil washing, phytoremediation, and numerical modelling.
Aug 2023 - Feb 2024Melbourne, Australia
Doctoral Engineering Intern - Groundwater Remediation
Environment Protection Authority (EPA) Victoria. Reviewed remediation projects and environmental audit reports, and built a remediation technology database to support agency guidance.
2019 - 2024Melbourne, Australia
PhD Researcher - Chemical Engineering
Victoria University, Institute of Sustainable Industries and Liveable Cities. Investigated submerged anaerobic membrane bioreactor systems, dynamic fouling models, and biomethane recovery for high-strength industrial effluents.
Aug 2016 - Jul 2019Lucknow, India
Assistant Professor - Water and Wastewater Engineering
BBA University. Taught water and wastewater engineering, advanced hydraulic structures, and supervised student research projects.
From field to lab
Real sites, real samples, real treatment questions.
Use the field and laboratory evidence to connect technology choices with site-specific constraints.
Consulting and collaboration
How Aquentis can help your organisation.
Specialist PFAS and industrial wastewater support for the people who have to make defensible environmental decisions.
Industry and site operators
Remediation feasibility, technology selection, monitoring design, and performance evaluation for PFAS-impacted sites.
Engineering consultancies
Specialist input on PFAS fate and transport, numerical modelling, LC-MS/MS interpretation, and remediation reporting.
Regulators and agencies
Evidence review, guidance development, and technical briefings, with experience across EPA Victoria and Swedish frameworks.
EU Horizon and consortia
Work package leadership, proposal writing, and scientific coordination across multinational research partnerships.
Collaboration experience
Built for multi-partner environmental projects.
Through academic and project roles, Rajneesh has worked alongside partners across multiple countries — within the EU, Australia, India, and beyond — spanning research consortia, geotechnical and environmental agencies, regulators, and industry. Aquentis Enviro brings that multi-country, multi-partner experience to every engagement.
Featured research · case study
Air sparging + foam fractionation for AFFF-impacted soil.
A controlled column study on field-contaminated soil from a Swedish airport firefighting-foam (AFFF) site, testing how much PFAS air sparging can move out of saturated soil — and capture in foam.
Paired soil columns were run side by side — one with water flow only, the other with water plus injected air — so the added effect of sparging could be isolated. Air sparging sharply increased the share of PFAS transferred from soil into the mobile water and foam phases, especially for the surface-active sulfonates and fluorotelomers that are hardest to treat. The rising foam acted as a dedicated capture pathway, while short-chain PFCAs moved mainly with the water.
3.5% → 21%PFHpS exported (water-only → with air)
up to 38%of PFOA captured in foam
~30×rise in aqueous PFOS under sparging
The practical takeaway: for saturated PFAS source zones, pairing air injection with controlled foam recovery offers a targeted way to mobilise and capture the most surface-active PFAS — provided field design controls where the mobilised mass goes.
Selected publications
Research credibility behind the consulting.
Selected peer-reviewed work in PFAS remediation, environmental risk, analytical screening, and anaerobic membrane bioreactor systems.
Chemical Engineering Journal - 2026
Evaluating the influence of air sparging technique on PFAS desorption and mobilization in soil using short-term column experiments
Gautam, R. K., Kleja, D. B., Enell, A., Montelius, M., Pettersson, M., Mottaghipisheh, J., and Ahrens, L.
J. Hazardous Materials Advances - 2025
PFAS contamination in key Indian states: environmental impacts, regulatory challenges, and predictive exposure
Gautam, R. K., Mottaghipisheh, J., Verma, S., Singh, R. P., Muthukumaran, S., Navaratna, D., and Ahrens, L.
Scientific Reports - 2025
Combined RP-HILIC for suspect screening of persistent, mobile, and toxic substances in surface water
Mottaghipisheh, J., Gautam, R., and Ahrens, L.
Current Opinion in Environmental Science and Health - 2026
Environmental risks associated with PFAS contamination in water: challenges and emerging management strategies
Mahajan, M., Gautam, R. K., Pathak, H. K., Singh, R. P., and Wikurendra, E. A.
Chemical Engineering Journal - 2024
Sustainable operation of a submerged anaerobic membrane bioreactor (SAnMBR) with ceramic ultrafiltration
Gautam, R. K., Olubukola, A., Verma, S., Muthukumaran, S., and Navaratna, D.
Biochemical Engineering Journal - 2023
Biomethane recovery and microbial community dynamics of a high-biomass submerged AnMBR treating abattoir wastewater
Gautam, R. K., More, S., Jegatheesan, V., Muthukumaran, S., and Navaratna, D.
Journal of Environmental Management - 2022
Membrane cake fouling mechanism to estimate design parameters of a submerged AnMBR treating high-strength industrial wastewater
Gautam, R. K., Kamilya, T., Verma, S., Muthukumaran, S., Jegatheesan, V., and Navaratna, D.
Let’s work together
Bring specialist science into your next environmental decision.
For PFAS remediation, contaminated-site review, wastewater treatment, or research collaboration, Aquentis Enviro would be glad to hear from you.