Related Experiment Video
Updated: Jun 1, 2026
07:34
Biogas Purification through the use of a Microalgae-Bacterial System in Semi-Industrial High Rate Algal Ponds
Published on: March 22, 2024
Zero-power autonomous buoyancy system controlled by microbial gas production.
Peter K Wu1, Lisa A Fitzgerald, Justin C Biffinger
1Department of Physics, Southern Oregon University, Ashland, Oregon 97520, USA.
The Review of Scientific Instruments
|June 7, 2011
Summary
A novel zero-power ballast control system enables devices to float and submerge using only a gas source. This innovation allows for long-term underwater monitoring without external power, utilizing microbial gas production.
Area of Science:
- Marine engineering
- Biotechnology
- Environmental monitoring technology
Background:
- Underwater monitoring systems often require significant power for buoyancy control.
- Existing ballast systems can be complex and energy-intensive.
- There is a need for autonomous, low-power solutions for long-duration underwater deployments.
Purpose of the Study:
- To develop and test a zero-power ballast control system for underwater devices.
- To demonstrate the feasibility of using a gas source for buoyancy control.
- To explore applications in water quality monitoring and autonomous underwater vehicles.
Main Methods:
- Construction and testing of a zero-power ballast control system.
- Utilizing a gas source (initially a pump, then microbial gas production) to alter device buoyancy.
- Implementing the system with sensors and data loggers for water quality monitoring.
- Testing the system's operational parameters, including submerged and buoyant state durations.
Main Results:
- The zero-power ballast system successfully achieved periodic flotation and submersion.
- The system operated for over 24 hours using gas produced by Clostridium acetobutylicum.
- Demonstrated successful periodic maneuvering (30-minute cycle) using only microbial gas production.
- Confirmed the system's potential for autonomous, indefinite operation when combined with microbial fuel cells.
Conclusions:
- A zero-power ballast control system is feasible and effective for underwater applications.
- Microbial gas production offers a sustainable and power-free solution for buoyancy control.
- This technology enables long-term, autonomous underwater monitoring systems, reducing operational costs and environmental impact.
Related Concept Videos
01:11Buoyancy and Stability for Submerged and Floating Bodies
In fluid mechanics, buoyancy and stability are key concepts for understanding the behavior of submerged and floating bodies. When a stationary body is fully or partially submerged in a fluid, the fluid exerts a force on the body known as the buoyant force. This force acts vertically upward through a point called the center of buoyancy, which is the center of the displaced fluid volume. According to Archimedes' principle, the magnitude of the buoyant force is equal to the weight of the fluid...
01:23Microbial Fuel Cells
Microbial fuel cells (MFCs) are bioelectrochemical devices that generate electricity by exploiting the metabolic processes of electrogenic bacteria. These systems provide a renewable energy source and serve as an innovative method for treating organic waste, such as wastewater.A typical MFC consists of two chambers: an anoxic (oxygen-free) compartment that houses the bacteria and an oxic (oxygen-rich) compartment that contains oxygen as the terminal electron acceptor. Many MFCs use proton...
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
01:18Bioreactor Controls-II
In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the fermentor via a sparger...
01:28Bioreactor Controls-I
Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using...