Success Story
Sulur is a small town about 20 km from Coimbatore in Tamil Nadu. People of this town no longer hold their noses while passing the drain water Nullah. Reason, they know the drain water will soon become clean water and get pumped back into the river.
The town has a population of about 30,000 and 6,500 households. There are two lakes namely Sulur Big Tank and Sulur Small Tank. Water is pumped from the river Noyyal through a 3 km stretch into these two tanks. The river water first fills the Big Tank and later the Small Tank. Major quantity of the untreated drainage water enters the Small Tank through the Nullah at several points. The drainage water drains into the Big Tank also in one place. About 27 lakh litres of water is supplied daily to the town.
The perturbed town Panchayat decided to find a solution. And a Pilot Study was undertaken on Cost Effect Sewage Treatment Plant for augmentation of irrigation water supply. This technology needs very little space. Equipment required is also minimal. Therefore, the investment and maintenance cost is low.
Cleaning Process
Drainage water is stopped and collected at a point before it enters the tank and is diverted to a collection zone. Solid waste is stopped at the entry point by filtration. Roughly 75% of the town’s waste water is collected here. A 3hp Electric motor, pumps the water to the collection zone. Here a powder containing microbes is poured on the water. 1.5 hp compressor motors are used for pumping oxygen into water, with this the microbes start multiplying and the cleaning process begins. The base water now moves to another bin where the sludge settles down. The sludgeless water is shifted into another bin through pipes. In the first collection tank 40 mm. Stones are used for lining the tank. The 2nd tank uses 20 mm stones to line the floor. The third tank has sand as a lining. When drain water is passed through these tanks, the solid material stays below and only clean water goes out to the last tank. This helps in containing E-Coli Bacteria to a great extent.
Aim of the Study
The Study aimed at developing a cost effective sewage treatment plant using Bio-Remediation Technology and Root-Zone Technology; avoiding the pollution of surface water and well water in Sulur small tank and below small tank and developing feasibility of safely disposing techniques and reusing the treated water for agriculture purpose.
Scope of Study included analysis of raw wastewater; planning and design of Sewage Treatment Plant; Making MoU for Technological partnership and financial partnership; Implementing the pilot plant Sewage Treatment Plant and Report writing and Documentation.
Methodology
For the Sewage Treatment Plant, two types of technologies were already available. One is the conventional method like Aerated Lagoons and Oxidation Ditches, which need huge land area, don’t have maintenance problems. The other technologies like Trickling filter, Activated Sludge Process, Rotating Biological Contactor and Rotating Biological Reactor, which need heavy mechanical and electrical machineries. These technologies have maintenance problems.
The second cost effective technology is a blending of old and new concepts thus reducing the land area and avoiding the heavy mechanical and electrical equipment. The technology was given by M/s Green Solutions, Coimbatore. Sulur Panchayat office also has participated by contributing 25% of the cost for the Study.
ImplementationThe plant was completely designed and constructed by the Environmental Cell Division of State PWD. The State Government contributed Rs. 15 lakh and the local body Rs. 5.4 lakh. Suitable additional works were carried out to improve the efficiency of the operation of the plant. The trials conducted after the modifications were successful.
“Bioclean” is a proprietary blend of carefully selected naturally occurring micro-organisms, enzymes and growth stimulating factors. It is a balanced formula of 90 different microbial strains, which work synergistically to lower the toxicity level in the system and to create a healthier and better environment. These microbes use the polluting organic matter in the effluent stream as a food source and convert it into the safe by-products such as water, carbon dioxide and methane gas. They were selected on the basis of accelerated reproduction rates and their ability to perform specific functions, such as good floc formability to help settling or the ability to degrade specific compounds.
Biodegradation is the Earth’s natural process of converting organic, matter into environmentally safe by-products. This process is accomplished through naturally occurring micro-organisms such as bacteria and fungi.
Bacteria are the primary decomposers of all organic waste. The microbes use the polluting organic matter in the effluent stream as a food source and convert it into safe by-products. The micro-organisms, called the biomass, are the powerhouses of all wastewater systems.
The success of this project has led to a number of queries from other places. Perhaps more Sulurs are on the anvil.
*Director (Media & Communications)