Rotating Media Wheels for Algae-Bacteria Wastewater Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wastewater treatment technologies are energy-intensive, have a large carbon footprint, and struggle to efficiently grow algae or phototrophic bacteria, leading to high greenhouse gas emissions and limited biomass production, which hinders effective wastewater treatment and renewable energy production.
Innovation Solution
A multi-functional system utilizing rotating media wheels with integrated algae and phototrophic bacteria growth, where algae provide oxygen through photosynthesis, reducing the need for external energy and enhancing biomass production, while capturing CO2 to promote algal growth and reduce greenhouse gas emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional activated sludge or bio-film systems are used for wastewater treatment, then treatment effectiveness is achieved, but energy consumption increases significantly (1.3-2.5 MWh per MG for activated sludge, 0.8-1.8 MWh per MG for bio-film)
Solution Approach 1:
The patent combines algae and bacteria into a single symbiotic system where algae perform photosynthesis to produce oxygen and consume CO2, while bacteria decompose organic matter and produce CO2. This merging eliminates the need for external aeration energy while maintaining treatment effectiveness through the complementary metabolic activities of both organisms.
Solution Approach 2:
The algae-bacteria system is self-sustaining: algae generate oxygen through photosynthesis that bacteria use for respiration and organic matter decomposition, while bacteria produce CO2 that algae use for photosynthesis. This internal resource cycling eliminates external energy inputs for aeration and CO2 supply, making the system self-service and energy-independent.
2Reliability
If conventional wastewater treatment processes are used, then treatment is achieved, but greenhouse gas emissions increase (3.4% of all GHG emissions in the U.S.)
Solution Approach 1:
The patent converts harmful CO2 emissions from bacterial respiration into a beneficial resource for algae photosynthesis. The CO2 that would normally be released into the atmosphere is instead captured and utilized by algae to produce oxygen and biomass, transforming a harmful greenhouse gas into a useful input that drives productive algal growth and oxygen generation.
3Productivity
If conventional systems are used, then treatment operates, but biomass production for renewable energy is limited
Solution Approach 1:
The algae-bacteria system performs multiple functions simultaneously: wastewater treatment through organic matter decomposition, oxygen production for bacterial respiration, CO2 sequestration from bacterial respiration, and biomass accumulation for renewable energy. This multi-functionality allows the system to generate substantial biomass as a byproduct of treatment operations, whereas conventional single-function systems produce minimal biomass.
4Quantity of substance
If algae are grown in conventional systems, then some biomass is produced, but algae growth is inefficient due to mechanical problems and clogging
Solution Approach 1:
The patent extracts algae from conventional mechanical bioreactor systems and places them in a natural aquatic environment (pond or lake). This removal eliminates mechanical components such as mixers, aerators, and monitoring equipment that cause clogging and operational complexity. Algae grow naturally in the water column, converting waste nutrients and CO2 into biomass without mechanical intervention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system significantly reduces energy consumption and greenhouse gas emissions, achieves efficient wastewater treatment, and produces substantial biomass for renewable energy and other applications, creating a self-sustaining and cost-effective solution for wastewater management.
Implementation Method 1
The algae utilize the CO2 produced by the bacteria to grow through photosynthesis
Implementation Method 2
The bacteria convert the organic carbon in the wastewater into inorganic carbon (CO2) that is utilized by the algae growing in the system
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A self-sustaining wastewater treatment facility abates greenhouse gas abatement, captures CO2 and produces biomass to address multiple critical environmental needs. The facility includes an array of rotating media wheels that create an optimum ordered mixing of algae for sustained growth. Biomass harvested from the rotating media wheels may be provided to other processing facilities to produce, for instance, bio-fuels. Waste CO2 from the processing facility may also be returned to the treatment system for enhanced algae growth. Bacteria are provided to form a symbiotic relationship with the algae, fueled by sunlight to effectively remove toxic materials from the wastewater. The multi-functional facility may also be integrated into a regenerative facility in which the biomass obtained from the algal and bacterial colonies is used in a separate facility and byproducts of the operation of the separate facility are used by the multi-functional facility to fuel further algal growth.