Science

Signed in as:

filler@godaddy.com

Account

1. Introduction

Indoor air quality (IAQ) is critical to human health. According to the World Health Organizations (W.H.O.), air quality is the single largest environmental risk to human health, accounting for 1 in 10 deaths worldwide, and we spend more than 90% of our time indoors. Clearly, conventional air treatment and control technology is not doing enough.

Moss biofiltration is a potential solution, harnessing living systems to not only trap pollutants but also degrade and transform them. Drawing on the remarkable evolved biological "technology" found in natural ecosystems, our approach leverages the unique morphology and biology of moss — coupled with its resident microbial communities — to create a regenerative air-cleaning system.

This section explains how moss biofiltration works, from the microscopic interactions on its surface to some of the engineering principles behind our BIOM Alpha design.

Please note that moss biofiltration is a novel and complex technology. While we are extremely enthusiastic about this technology, we are humbled by the complexity of the involved physical, chemical, and biological processes. The following sections describe moss biofiltration as we understand it today; this is not gospel, and this section may evolve as we continue to rigorously interrogate our hypotheses and explanations for observed data, and as we undergo 3rd party testing.

"Only by patient study of a plant’s growth does one comes to see that nature operates by a hidden order that reveals itself only to the diligent observer"

Theophrastus, Inquiry into Plants, Book I, Chapter 5

2. Mechanisms of Moss Biofiltration

2.1 Physical Filtration

Moss is built like a filter. It exhibits a fractal, mat-like structure that provides an exceptionally high surface area relative to its volume. This structural complexity means that as air passes through moss disks, particulate matter (PM) and gaseous contaminants are efficiently intercepted.

High Surface Area: The microscopic arrangement of moss structures, which can split in fractal patterns until they are a single cell thick, increases contact between the air and the bioactive moss surface. The tiny size of moss mats also means we can stack a lot of moss in a small volume, compared to regular plants.
Exposed Morphology: Unlike regular plant leaves that have a protective waxy cuticle to prevent air exchange with the atmosphere, moss cells and external structures are exposed and interface directly with the air.
Porosity and Water Retention: The high porosity of the moss mat allows for uniform airflow and low pressure drops, while the water content within the moss aids in capturing soluble pollutants and facilitating subsequent microbial action.
Charged Surface: The moss surface uses ion pumps to create a charge gradient across its external membranes. This creates a filed that attracts air particles (used by moss for food in nature).

2.2 Microbial Degradation

Unlike inert filters, moss hosts a diverse consortium of microorganisms similar to those found on a forest floor, or in the soil surrounding plant roots, or in sites that have been contaminated by oil spills or other toxic waste. These microbes possess highly adaptable metabolic pathways capable of degrading an extremely broad range of contaminants.

Dynamic Microbial Consortia: Over time, the microbial community adapts to the specific pollutants in its immediate environment, increasing the efficiency of degradation. This adaptation is akin to a living system “learning” to break down even the most recalcitrant compounds.
Enzymatic Breakdown: The microorganisms use enzymes to convert harmful compounds—such as volatile organic compounds (VOCs), formaldehyde, and other toxic gases—into harmless byproducts like water and carbon dioxide.
What's in it for the Microbes? Microbes get energy by breaking apart the chemical bonds of toxic compounds. By breaking apart VOCs and solid organic components of particulate matter, they also use these compounds as a carbon source.
Complementary Function: This biological degradation works in tandem with physical filtration/capture; as particles are trapped on the moss surface, they become accessible to the microbial community for further breakdown. This means that the moss surface is never saturated and can continue to perform efficient capture of air toxins indefinitely.
[Anti Fungal Properties: Although this is less well understood, we have observed that after placing mold and moss in a Petri dish, the mold dies (given that the moss is healthy). Although we have not directly measured mold spore destruction in an air filtration context, we hypothesize that the anti-fungal defense mechanisms of moss may be useful in attacking airborne mold.]

2.3 Photosynthetic Air Regeneration

A standout feature of moss biofiltration is its ability to regenerate air through photosynthesis. Under controlled lighting conditions provided by high-power LED grow lights, moss performs photosynthesis.

CO₂ to O₂ Conversion: During photosynthesis, moss absorbs CO2 (including that from human respiration) and converts it into oxygen.
What We Thought: Moss is typically observed as a low-light slow grower. In nature, it tends to occupy shady areas with low nutrient levels where other plants cannot survive. For this reason, the conventional wisdom was that moss does photosynthesis slowly.
What We know Now: By giving moss high light levels and assisting CO2 diffusion with fan-driven airflow, we have observed the highest rates of moss photosynthesis ever recorded (to our knowledge), at rates (measured in µmol CO2 per m2 or moss per second) rivaling some of the fastest photosynthesizes in the entire plant kingdom.
Energy Efficiency: Compared to regular plants with large 3D canopies and leaf-structures, moss requires less input light energy to drive photosynthesis. Because we can place grow lights very close above the moss mat, we can achieve extremely high photosynthetic spectral power distributions (in laymen's terms: brightness) without using a lot of electricity.
Synchronized Mechanisms: As the microbial processes degrade contaminants, photosynthesis simultaneously refreshes the air, ensuring that by the time air exits the biofilter, it is both free of pollutants and enriched with oxygen.

3. Integrated Dynamics of Biofiltration

The effectiveness of moss biofiltration lies in the integration of physical-chemical, microbial, and photosynthetic mechanisms:

Airflow Dynamics: Air is drawn upward through a series of moss disks contained within a clear plenum. The high surface area and porosity ensure that even under high air flux , contact between the air and the moss is maximized.
Contaminant Capture and Breakdown: As air flows through the moss, particles and VOCs adhere to the surface. The resident microbial community then enzymatically degrades these compounds. Detailed experimental work confirms that contaminants like formaldehyde are reduced significantly faster than with conventional filters.
Benefits of Stacking: In addition to packing a huge amount of moss biomass in a small volume, stacking the moss disks also gives rise to a gradient of water-contents; the moss at the bottom and top of the tube is closer to the dry outdoor air and is thus dryer, and the moss in the middle of the tube is more saturated with water. This range of water-contents means we are able to capture a wide range of toxins, some of which are attracted to water (hydrophilic) while others are repelled by water (hydrophobic).
Regenerative Photosynthesis: Simultaneously, the moss utilizes the grow lights and input CO2 from your space to conduct photosynthesis, converting CO2 into O2 and further enhancing air quality. This dual process of degradation and regeneration makes the system into something that we think of as more than just an air purifier: it is a fresh air generator.