According to CPCB, India’s sewage treatment plants treat only one-third of the sewage generated daily. In the light of poor wastewater management, the government of India actively encourages industries and municipalities to develop wastewater treatment plants.
Why should you invest in a wastewater treatment system?
- To meet the government’s wastewater discharge limits.
For example, wastewater from petroleum and oil refineries shall not have suspended solids more than 20.0 mg/l, according to CBCP.
- To comply with the pH, BOD, COD, nitrite limits, and other parameters set by the Indian government for wastewater discharge.
- To save money by reducing the need for freshwater because treated water can be used for industrial purposes and irrigation.
- To address the problem of water scarcity.
However, before investing in a wastewater treatment system, many important factors are considered.
Essential points to consider before investing in a wastewater treatment system?
The population of your facility must be considered before the installation of any wastewater treatment plant. Moreover, the amount of wastewater generated must meet the capacity of the septic tank. A minimum of 50% utilization of the plant is necessary to analyze the efficiency of its performance.
- Utilization time
Whether the plant will be used all year or only for a short period must be identified because some plants are not made to cope with load changes and might be a trouble if your wastewater treatment plant is not utilized round the clock. If such a continuous system is installed for short-term use, it won’t operate efficiently.
- Plant design
Before installing any wastewater treatment systems in your facility, plant design is a critical factor to consider.
For example, the capacity of a wastewater treatment plant is 2000 MLD, but wastewater generated is 3500 MLD, which creates imbalance and does not give efficient results.
Moreover, investment in a trustworthy and trusted source of equipment is necessary for a better design and to avoid malfunctions of treatment plants like,
- Undersized balancing tanks
- Badly designed clarifiers
- Inadequate aeration tank
- Insufficient treatment capacity
- Operation and maintenance contracts
To reduce expenses, many plant agencies employ unqualified personnel that is not trained and have little knowledge of operation and maintenance services. Moreover, well-trained operation personnel and experienced staff charge an amount that reflects their skills and expertise but industries and municipalities hesitate to pay and fail to run a well-operated wastewater treatment system.
Many manufacturers claim that their plants do not require maintenance and service for several years, which is valid only if the plant is not often used. However, many plants require maintenance every six months or every year, and yearly service saves costs.
Operation and maintenance contracts are essential things to find out when buying a sewage treatment plant.
- The warranty period of tanks
The tanks do not crack or bend in the initial period after installation, but when the system and ground have fully settled 2 to 3 years after installation, they contort or crack. Here, a 12-month warranty will be of no use. Unfortunately, many manufacturers have reduced the warranty period of the tank to only 12 months, so an extended warranty period must be asked.
- Mechanical seals
Avoid buying a treatment plant whose tanks are made in halves and are joined using bolts, rubber seals, etc., and also a plant that has sealing rings for the pipes to slide through. Inlets and outlets must be welded as a part of the tank because all seals eventually perish, leads to leakage, and cannot be replaced.
- Internal moving parts
If internal parts like gearboxes, motors, discs, etc., are moving, they might catch corrosion because of sewage. This reduces the life of the parts, and as they are expensive, it might not be a good idea for long working life.
- Position of air blowers
Many manufacturers, to reduce costs install air blowers inside the tank, claiming that it improves the appearance. However, inside the tank, the atmosphere is humid and results in the malfunctioning of the blowers. Furthermore, condensed water droplets from the tank’s lid fall on the blowers in cold weather, leading to their failure. Therefore, electric air blowers must be contained in a water-proof kiosk outside the tank.
- Future expansion plans
If the expansion of the plant is estimated in the future, it must be designed in a way that favors its extension. For example,
- Pumping station design must facilitate amplifying its capacity without disrupting the plant.
- The plant piping layout must allow the installation of additional treatment units in the future.
- Space must be provided within buildings to replace equipment like pumps, blowers, and boilers with larger capacity.
- Area of installation
Space availability is always a matter of concern in installing wastewater treatment plants. Moreover, as it produces high noise and pungent odor, building it in an area near any residency is not a great idea. However, ventilation systems in treatment plants can help up to some extent.
Challenges to consider before investing in a wastewater treatment plant
- Energy consumption
Energy consumption is the biggest challenge in any wastewater treatment plant, and in municipal sewage treatment, the biological treatment utilizes 50-60% of the plant’s energy.
Solution: When your facility is situated in an area where the availability of electricity is limited, a non-electric plant is a convenient option. Moreover, the biological treatment produces methane gas that can provide energy.
- Sludge production
Sludge is produced during many treatment processes, but a significant concern is the disposal of excess sludge.
Solution: Sludge can be recycled to extract organic material helpful for agricultural purposes. Moreover, many advanced technologies can lessen sludge production.
Water treatment plants require a large area for installation, and produce a high amount of noise, and pungent odor. In addition, as the population increases, municipalities must expand their treatment facilities, which increases the cost.
Solution: Some leading-edge technologies increase biomass concentration and use smaller basins ranking high in footprint minimization.
Reusing treated water can minimize freshwater use from natural sources like rivers, ponds, lakes, and groundwater. Thus, wastewater treatment is necessary to protect one of the natural resources – water.