1. Algae are simple plant-like organisms that live in water and range from single-celled to multicellular forms. They contain chlorophyll but lack true roots, stems, and leaves. 2. Algal growth occurs in three basic forms: planktonic, filamentous, and macrophytic. 3. Algal blooms can be harmful if they produce toxins, deplete oxygen levels, or clog filters and pumps. Controlling nutrient levels and using ultrasound, UV light, aeration, or barley straw can help regulate blooms.

2. WHATARE ALGAE?
 Algae are photoautotrophic cells that contain
chlorophyll, have simple reproductive
structures, and do not have true roots, stems
or leaves.
 They have a clearly defined nucleus and are
classified as Eucarya.
 Pigment-bearing plants found in nature
either submerged under water, free-floating,
living under sub-aerial conditions
 They range from unicellular, or single celled,
to fairly complex multicellular organisms.
 The size of average individual algal cells is
approximately 0.0010 mm in diameter.

3. FORMS OF ALGAE:
Algal growth occurs in three basic forms:
 Planktonic algae are single-celled, microscopic algae that
float freely in the water, can turn the water into yellow, gray,
brown or red.
 Filamentous algae are sometimes referred to as “thread
algae” or “pond scum”. Filamentous algae occur as fine
green threads that form floating mats, which are often
moved around the pond by wind.
 Macrophytic algae resemble true plants in that
they appear to have stems and leaves.

4. TYPES OF ALGAE:
• Diatoms: exist singly and sometimes form colony. Yellowish or Brownish and found
in freshwater.
• Chlorophyta: commonly known as green algae. Found in water, moist soil or trees.
• Euglenophyta: found mostly in ponds when polluted by runoff from agricultural
fields.
• Dinoflagellata: green or colorless. They are responsible for the phosphorescence
visible at night in tropical sea.
• Chrysophyta: golden algae. Found in saline and fresh water.
• Phaeophyta: Brown algae. Mostly found in ocean.
• Rhodophyta: Red algae. Found in ocean, in warm temperate and tropical climates.
• Cyanobacteria: blue green algae. they may form filaments, sheets or even hollow
balls. They contain chlorophyll A which give the cells a typical blue-green color.
Unlike bacteria, they contain chlorophyll.

5. DEVELOPMENT OF ALGAL BLOOM:
 Algal Bloom is a rapid growth or accumulation
of microscopic algae in water
 Bloom which are harmful to animals or the
ecology via production of natural toxins are
called Harmful Algal Bloom
 Blooming at a concentrations of millions of cells
per milliliter or ten of thousands of cells per
liter.
 They grow rapidly in stagnant waters when
exposed to sunlight and temperatures above 4
degrees Celsius.
 Phosphates and nitrates in the water
encourage their growth.

6.  Algal growth is influenced mainly by water
composition, temperature and light intensity.
 Sodium Carbonate acts as the catalyst for the
growth of algae by providing dissolved Carbon
Dioxide for enhanced photosynthesis in the
presence of nutrients.
 Runoff from fertilized fields, lawns and pastures,
septic tanks and leach fields accelerate nutrient
loading and algal growth in the pond

7. PROBLEMS AND CAUSES:
 Increase water temperatures
 High nutrient concentrations
 Drought – less water, low flows
 Cause Oxygen depletion following the death and decay of an algal
bloom
 Taste and odour problems in drinking water and sometimes
accompanied by an earthy, pungent or musty smell
 Form dense growths that make fishing, swimming, and other
recreational uses nearly impossible.
 Result in higher BOD requirements.
 Some algae, like red algae and blue-green algae, can produce
toxins that damage the human nervous system and the liver
 Raise treatment costs for drinking water
 Filamentous algae can clog filters and pumps.
 Algae can lead to undesirable pH shifts in the course of their
growth in a lake or reservoir, usually toward the alkaline side

10. ALGAE CONTROL
• Mats of filamentous algae may be removed with a rake, screen wire, or similar
devices. However, this control method is very labour intensive and provides only
temporary control.
• Filamentous algae can be picked up by hand.

11. • Reducing fertilizer usage (for lawns, gardens, and farms), and by eliminating
residential, municipal, and agricultural wastewater discharge
• For water tank:
Always use a completely opaque water storage tank
Add 1/4 teaspoon of *bleach to every gallon of water you store
Add 4 parts of *chlorine to every 1,000,000 parts water

12.  Control Algae with the LG Sonic e-line
 It is environmentally friendly, cost effective.
 This technology uses ultrasound to inhibit algal growth.
 Designed for applications such as large ponds and farm ponds, large water
reservoir.
 Eliminate up to 90% of existing algae and prevent growing of new algae
 Chemical-free solution that is safe for fish and other aquatic life
 Requires little maintenance to prevent frequent site visits

13. Control Algae with the LG Sonic e-line
• Ultrasound are sound waves with frequencies higher than the upper audible limit
of human hearing (22 kHz). At specific frequencies, these sound waves can be
used to control algae growth.
• It create a sound layer in the top layer of the water. The sound layer has a direct
impact on the buoyancy of the algae.
• The algae cells will sink to the bottom and are unable to photosynthesize and
eventually die due to a lack of light.
• The sound waves can spread through the water column over hundreds of meters.

14. 1. The ultrasound creates a sound layer in the top layer of the water.
2. The ultrasound affects the buoyancy of the algae, fixing them in the water column.
3. Due to a lack of sunlight and nutrients, the algae will die and sink to the bottom of
the reservoir.
4. The algae are degraded by the bacteria present

15. ULTRAVIOLET METHOD.
• The UV sterilizer utilizes a germicidal fluorescent lamp that produces light at a
wavelength of approximately 254 nanometers (2537 Angstroms).
• As the light penetrates the algae, it mutates the DNA preventing
growth/multiplication of the organism.
• UV light will only penetrate clear saltwater to a depth of 5mm.
• The longer the amount of time the water is being exposed to the UV light, the
more killing power is available.

16. Aeration:
• Adding dissolved oxygen to your pond through aeration can help to reduce the
occurrence of algae blooms by removing their food sources.
• Diffused aerators use compressors to inject air at the bottom of your pond, where
it bubbles up to the surface
• By splashing the water in the air, the aeration device is not only adding valuable
oxygen, it is also helping to vent gases such as carbon dioxide which is being
produced in large amounts during the decomposition process.

17. Algae control by use of Barley straw bales:
• When Barley straw bales are submerged in the water storage, they start to degrade.
• When barley is decompose, it releases enzymes that will slightly change the pH of
the water.
• Algal cells already present are not killed, but the growth of new cells is minimized.
• For the maximal effect, the straw bales should be replaced every 1.5 to 3 months.
• This system is mostly applied on a domestic scale like in small garden ponds in
gardens.

18. Using Chemicals and All Natural Products together to eliminate algae
• Chemical intervention involves treating the water with a variety of additives,
such as alum, lanthanum, phoslock.
• Using algaecide like copper algaecide Cutrine Plus works great and is EPA
approved for use in drinking water reservoirs, irrigation conveyance systems.
• Copper sulfate, chlorine, potassium permanganate are also use. However, at
certain levels, copper sulfate becomes toxic.

19. BIOLOGICAL CONTROL OF HARMFUL ALGAL BLOOMS:
• Use of biological control (biocontrol) agents such as the predatory bacteria
(bacillus bacteria), viruses, grazing by zooplankton (like copepod)
• the following seven attributes that defined a good predatory bacterial agent:
 adaptability to variations in physical conditions;
 ability to search for or trap prey;
 capacity and ability to multiply;
 prey consumption;
 ability to survive low prey densities;
 wide host range and
 ability to respond to changes in the host.
• bacterial agents are considered more suitable than viruses as biocontrol agents
because bacteria can survive on alternate food sources during non-bloom periods.
• grazing of the algae by zooplankton which in turn enhances predator biomass,
controls algal growth and regenerates nutrients

20. Uses of Algae as Energy source, Fertilizer, Food and Pollution control:
• Algae can be used to make Biodiesel: Algae can be grown to produce biomass,
which can be burned to produce heat and electricity and reduce CO2 emission.
• Food supplement: It contains an extensive fatty acid profile, including Omega 3
and Omega 6. It has an abundance of vitamins, minerals, and trace elements in
naturally-occurring synergistic design.
• They are used as fertilizers, soil conditioners and are a source of livestock feed.
• Algae are used in Wastewater Treatment facilities, reducing the need for greater
amounts of toxic chemicals than are already used