What is a pond based treatment plant?
Pond based treatment plants are those treatment systems which are used as tertiary and sometimes as pre or primary treatment. The sludge is digested with the help of micro-organisms present in the water with the help of aquatic plants like algae. The treatment units help in the stabilisation of sludgethat is digestion of sludge. Sludge digestion and effluent treatments are carried out in this process.
In the schematic diagram shown above, it is simply clear that wastewater effluent, agricultural waste, sullage, grey water and sludge is directed towards the pond system in which after a fixed duration (which is retention time of the pond), the influent is stabilised and treated and can now be further used.
Types of Pond Systems
There are three types of pond systems each one of which works with a specific type of micro-organism.
1. Aerobic Ponds – here microbes work only in the presence of oxygen,
2. Anaerobic – microbes can work in the absence of oxygen,
3. Facultative – A mixture of both types of micro- organisms.
Algal Pond System
Algal pond system is a water purification technique of treated effluent, sullage and grey water. Treated water from algal ponds or aerated lagoons are further treated in ponds with aquatic plants and screened before discharging effluent.
This pond system is the most common algae farming system already commercially used in for food production and wastewater treatment. In recent years, many companies have begun to focus on this growth model of bio-fuels and chemicals.
The Open-Pond system uses shallow (usually one foot deep) ponds about one to several acres in size, and algae are exposed to natural solar radiation (sunlight) which aids in sludge conversion to biomass. Ponds are usually called raceway ponds because their shape resembles a racetrack. They often use paddle wheels or other water transfer devices to maintain algae circulation.
The harvesting process is often a two-step process based on the unique properties of algae and process requirements. Generally, some of the water in the pond is harvested daily and the algae biomass in the water is concentrated. The biomass is then further processed, for example, extracting oil for conversion to biodiesel, kerosene, or another oily product. Residues or even whole biomass can be dried and used as animal feed. An open pond system for producing bio-fuels has already been developed.
The leftover sludge is then discarded using any one of the three ways-
1. Biogas Generation
2. Protein Extraction
3. Material Recovery
Arrangement of Ponds
1. In Series:
Ponds are either arranged into series arrangement, in which each pond is connected and dependent upon its predecessor pond.
2. In Parallel:
Here ponds are arranged in parallel series. It is advantageous to use as failure of one pond does not affect the function of other pond.
How can Netsol Water help?
There are various combinations of ponds which are used to get the desired result in the effluent which are discussed above. It is a cheaper material recovery method.
Netsol is India’s leading wastewater treatment solution company which covers all the needs of any water and wastewater treatment scheme on all levels. We have the expertise to provide wastewater solutions at domestic, industrial and municipal level.