India's manufacturing industry is making notable progress on the global stage, indicating a clear path of growth. Given the extensive scale of daily industrial operations, India generates millions of liters of wastewater and sewage each day.
In an ideal scenario, all industrial wastewater would be thoroughly treated before being released back into the water cycle, however, the practical situation falls short of this standard.
There's a noticeable disparity between the capacity of our wastewater and sewage treatment systems and the daily volume of wastewater generated in India. At present, our capacity for treating industrial sewage stands at millions of liters per day. The inadequacy in our sewage system highlights the significant portion of untreated industrial sewage, pointing to the absence of a proper treatment system.
What is wastewater treatment in an industrial environment?
Water is an essential element of the manufacturing processacross various industries, such as beverages, automotive, and textiles industries require a lot of water for their operations. Along with these operations, water accumulates various pollutants that require proper removal.
Since these pollutants are harmful, there's a need to process and transform them into a safe effluent suitable for discharge back into water bodies. This underscores the necessity of treating and purifying wastewater to remove impurities. However, the substantial difference between sewage water treatment capacity and the actual volume of wastewater generated indicates that not all wastewater undergoes treatment before disposal.
Effects of Wastewater Pollutants on the Ecosystem
Excessive levels of nitrogen, phosphates, or decomposing organic material in aquatic environments can cause an abnormal proliferation of plant growth. The overgrowth of these plants can lead to the release of toxins, resulting in oxygen depletion. This situation often creates "dead zones," rendering the aquatic ecosystems uninhabitable.
Untreated wastewater poses risks to both aquatic and non-aquatic creatures, including humans. However, the direct ingestion of untreated wastewater is not the only concern. Contamination of the food chain from polluted upstream wastewater occurs when algae, fish, and subsequent predators like bears become contaminated, causing a toxic cascade throughout the ecosystem.
Wastewater pollution contributes to the occurrence of red tide, leading to extensive mortality of aquatic life and the contamination of significant water volumes, rendering entire freshwater systems unsuitable for human consumption.
There are different approaches to sewage treatment, which is why there are quite a few types of sewage treatment plants. These wastewater treatment plants are present all around the world, and the only difference is in the way they treat their wastewater.
Although there are localized differences, these treatment plants generally conform to similar models.These are the main types of plants that are present worldwide:
Rotating Disc System
The utilization of rotating disc systems in sewage treatment plants is becoming increasingly prevalent. Despite being a relatively modern system, it can be integrated into existing sewage treatment plants, resulting in the production of sanitized and purified effluent.
These sewage treatment plants are ideal for managing the wastewater in densely populated areas. One significant advantage is the reduced frequency of de-sludging, typically occurring every 12-18 months in a rotating disc system plant. This infrequent maintenance helps save on time, effort, and costs.
The low maintenance characteristic is a primary factor motivating the transition of numerous contemporary plants to this system. However, although it doesn't necessitate regular de-sludging, it does demand servicing every 6-12 months to maintain optimal performance.
Activated Sludge Plant
This is another common type of sewage treatment plant. These plants involve the use of oxygen and microorganisms to cleanse the sewage.This process revolves around oxidizing the pollutants, which creates a sludge-type substance.
Submerged Aerated Filter System
The submerged aerated filter system is considered one of the simpler sewage treatment options. It demands very little maintenance and comprises only a few moving parts, making it incredibly easy to keep operational.
This type of sewage treatment plant, often referred to as an SAF system, proves advantageous for facilities looking to cut costs without compromising the sanitation process. Despite its straightforward nature, the SAF system efficiently purifies sewage before its release into oceans and rivers.
Additionally, these systems utilize an automated de-sludging mechanism, eliminating the need for manual de-sludging, thereby saving both time and expense.
Sequencing Batch Reactors
This system is one of the most flexible types of sewage treatment plants. It operates through a sequential process within a single tank, eliminating the necessity to transfer sewage between multiple treatment stages.
The reason this is a popular system is its flexibility. A sequencing batch reactor sewage treatment plant adeptly manages both concentrated and diluted sewage without difficulty. Additionally, these treatment plants bear a lower environmental impact, signifying a significant advantage of this sewage treatment system.