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Sr. Process & Solutions Engineer

Marietta, GAFull-time (Onsite)

The Mission

At 4Earth, we are building advanced resource recovery technology that plugs seamlessly into factories and mission-critical infrastructure to turn waste into value. We need to engineer treatment systems that perform reliably with real industrial wastewater, variable feed conditions, and demanding operating environments.

We are looking for a Process Engineer who takes personal responsibility for what happens between the inlet and the outlet. You will connect biology, chemistry, fluid dynamics, and membrane separation into complete systems that work. We want a builder who gets their hands dirty, runs experiments, troubleshoots equipment, and stays close to the hardware from the first calculation to the first successful startup.

The Role

You will own the process architecture of our technology A–Z. This is a role at the intersection of Water Treatment, Process Engineering, and Product Development. You will turn process designs into operating equipment. You will be:

  • Designing complete treatment systems from feed characterization to startup.
  • Building, testing, and commissioning systems alongside our mechanical and electrical engineers.
  • Turning pilot results and field experience into repeatable, scalable products.

What You Will Build

The Treatment Train
Design integrated systems combining pretreatment, biological treatment, membrane separation, and downstream polishing. Select technologies around feed characteristics, effluent targets, reliability, and operating cost.
The Biological & Membrane Core
Design and optimize membrane bioreactor (MBR) and membrane filtration systems. Own the operating conditions that determine treatment performance, membrane fouling, cleaning requirements, and long-term stability.
The Process Blueprint
Develop mass balances, process flow diagrams, P&IDs, equipment specifications, and control narratives. Translate calculations into pumps, tanks, valves, instrumentation, and operating sequences that the team can build and control.
The Operating System
Plan and execute pilot testing, startup, and performance validation. Diagnose problems using samples, operating data, and direct observation. Feed every lesson back into the next design.

The DNA We Are Looking For

Experimentalist First
You calculate, build, sample, and test. You can point to systems you personally helped bring to life and explain what failed, what you changed, and what worked.
First-Principles Thinker
You understand why biology becomes unstable, membranes foul, or pressure losses increase. You form a hypothesis, design a test, and let the evidence guide the next iteration.
Extreme Ownership
You stay with a problem through resolution. You move quickly, make sound engineering decisions, and take responsibility for performance in the field.
Cross-Disciplinary
You connect process requirements with mechanical design, automation, and manufacturing. You work comfortably with engineers, fabricators, operators, and customers.

Critical Requirements

Hands-On Ownership
3+ years of relevant process engineering experience, with direct involvement in designing and building water or wastewater treatment systems. Hands-on startup or commissioning experience is strongly preferred.
MBR & Membrane Experience
Practical experience with MBR and membrane treatment systems, including biological process fundamentals, membrane sizing, operating parameters, fouling management, and cleaning strategies.
Complete-System Thinking
Experience integrating multiple treatment stages into a working system. You understand how upstream decisions affect downstream performance, residuals handling, and overall reliability.
Process Design & Equipment Selection
Ability to develop mass balances, PFDs, P&IDs, and process narratives, and specify pumps, blowers, tanks, valves, membranes, and instrumentation.
Troubleshooting & Validation
Ability to interpret water quality and operating data, identify root causes, and safely test improvements against measurable performance targets.
Site Visits, Customer Engagement & Technical Sales
You will visit customer sites, define treatment requirements directly with customers, and support technical sales through process assessments, solution development, and clear communication of system capabilities.

Nice to Haves

  • Reverse osmosis (RO) experience, including pretreatment, recovery optimisation scaling control, and concentrate management.
  • Experience taking industrial wastewater reuse or resource recovery projects from pilot testing to full-scale operation.
  • Experience translating process requirements into PLC control sequences and designing modular systems for manufacturing and serviceability.

Why 4Earth?

We are doing the hard thing—re-engineering the water cycle to secure the future. Here, you will see your engineering become physical systems, test your ideas against real operating conditions, and help shape a product from the ground up. If you want to build technology that turns industrial waste into lasting value, join us.