Page 61 - GRIHA Manual Volume IV - Introduction to National Rating System
P. 61
52 Griha Manual: Volume 4
Treatment methods
The treatment methods range from physic-chemical to biological and in the latter group, from
aerobic to anaerobic methods. Wastewater treatment is a combination of physical, chemical, and
biological processes.
Figure 1 Types of waste water treatment methods
Conventional technologies
There are several kinds of wastewater treatment systems in use, ranging from conventional low-
cost options and decentralized small systems to complex, large, capital-intensive, centralized
systems, and from containment systems to primary and secondary treatment methods. Among the
conventional technologies are cesspools, septic tanks, imhoff tanks, wastewater stabilization ponds,
anaerobic ponds, aerobic/facultative stabilization ponds, polishing/maturation ponds, duckweed
ponds, rootzone treatment systems (vertical flow reed beds, horizontal flow reed beds), trickling
filters, and so on. All these systems have certain advantages and disadvantages.
New technologies
There are a number of emerging technologies, which are improved versions of the conventional
technologies and use lesser energy or machines. This section will elaborate further on these
technologies, which can be applied at decentralized levels.
1. DEWATS systems
DEWATS stands for decentralized wastewater treatment system and is promoted by the Centre for
Scientific Research (CSR), Auroville, Tamil Nadu in India. This system is applicable for both ‘grey’ and
‘black’ domestic wastewater.
Treatment methods
The treatment methods range from physic-chemical to biological and in the latter group, from
aerobic to anaerobic methods. Wastewater treatment is a combination of physical, chemical, and
biological processes.
Figure 1 Types of waste water treatment methods
Conventional technologies
There are several kinds of wastewater treatment systems in use, ranging from conventional low-
cost options and decentralized small systems to complex, large, capital-intensive, centralized
systems, and from containment systems to primary and secondary treatment methods. Among the
conventional technologies are cesspools, septic tanks, imhoff tanks, wastewater stabilization ponds,
anaerobic ponds, aerobic/facultative stabilization ponds, polishing/maturation ponds, duckweed
ponds, rootzone treatment systems (vertical flow reed beds, horizontal flow reed beds), trickling
filters, and so on. All these systems have certain advantages and disadvantages.
New technologies
There are a number of emerging technologies, which are improved versions of the conventional
technologies and use lesser energy or machines. This section will elaborate further on these
technologies, which can be applied at decentralized levels.
1. DEWATS systems
DEWATS stands for decentralized wastewater treatment system and is promoted by the Centre for
Scientific Research (CSR), Auroville, Tamil Nadu in India. This system is applicable for both ‘grey’ and
‘black’ domestic wastewater.
