Hydrogen sulphur elimination in earthern ponds - How Nanobubbles can help

PROBLEM IDENTIFICATION STEPS

Dissolved oxygen and H2S mapping in pond

• Digital (Flourescent) (Optical) DO meter
• Measure at 20-30 centimeter above pond bottom
• Measure at Peak DO time (2-3 pm afternoon) and Lowest DO time (4-5 am morning before sunrise)

Sampling location

Pond corners (where slow moving water occurs)

Pond centers

Below paddle wheels of deep water pond (> 2 meters)

Perimeter of feeding area (if auto-feeder in use)

For H2S measurement:

Sulfur reducing bacterial colonies on TCBS

Bottom sludge smell and color

Electronic H2S gas meter in water

NAKASHIMA PROPOSAL

For Prevention  

Soil neutralization : lime

Bottom clean-up & dry-up before & after cultivation

Probiotic solution

For Reactive and Mitigation  

Feed control (reduction)

Bottom waste removal (for lined pond)

Water parameter control (pH, DO)

Based on Mapping data of low DO & high H2S zones in pond

Horizontal aeration by fine bubble solution can be arranged

For Emergency

• Oxygen Nanobubbles (Pure Oxygen in use)

USEFUL FEATURES OF FINE BUBBLES

Oxidized by dissolved oxygen and hydroxyl radicals , toxic form of un-anionized H2S is converted to Sulphate SO4 (non-toxic)

Nanobubbles (< 1 micrometer) and Microbubbles (10-60 micrometers) with slow rising velocities can remain and be suspended for a period of time long enough to be spread by water flow currents created by the fine-bubbled-water flow and the paddle wheels (the most commonly used in outdoor aquaculture)

Fine-bubbled water is made near the bottom sludge to provide necessary dissolved oxygen to the fish/shrimps and nitrification process supported by microbiome in the bottom sludge