Sustainability in Every Drop: STP for Sugar Processing

Sewage refers to wastewater containing significant levels of organic and inorganic solids, originating from diverse establishments like commercial, industrial, or residential areas, among others.

What is a Sewage Treatment Plant?

A Sewage Treatment Plant (STP) processes sewage from different establishments to render it safe for disposal.

It performs physical, chemical, and biological methods to eliminate impurities, yielding treated wastewater safe for environmental release. Sewage treatment also generates sewage sludge, a semi-solid waste, which undergoes additional treatment before becoming suitable for disposal or land application.

Why do we need a STP Water Treatment Plant?

Treating sewage wastewater is crucial to prevent its unprocessed discharge into natural ecosystems. Without proper treatment, sewage disposal can lead to contamination, harm to aquatic life, and the spread of diseases.

Commercial and industrial facilities must adhere to specified quality standards when treating sewage before releasing it into the sewer system. To achieve this, a sewage treatment plant is installed nearby to eliminate detrimental contaminants before environmentally friendly disposal.

Why Reuse or Recycle Water?

Though a vast portion of the Earth is covered by water, only a limited amount is freshwater. The majority of this freshwater is frozen in Antarctica and Greenland. Approximately 1% of freshwater is accessible for use. In our daily lives, we use water primarily for washing, bathing, and toilets. Recycling water for purposes other than drinking can help reduce the demand for fresh water.

Therefore, it is very important to process the sewage discharge from each structure and repurpose the treated water for activities like washing, toilet use, and floor cleaning.

Advantages of a Sewage Treatment Plant

Dependable and rarely experiences issues during routine maintenance

Can be deployed on difficult or confined sites where a main sewer is unavailable

Economical in the long term, with only installation, power, and maintenance costs involved

How Does Sewage Treatment Plant Benefit the Sugar Factories?

Sewage treatment plants offer significant benefits to sugar factories by addressing the environmental challenges posed by the residues from sugar mills. The organic residues, being highly putrescible, present environmental risks if not treated and disposed of properly. The cane sugar production process is crucial for various food processing units, and efficient wastewater treatment becomes imperative in mitigating these environmental impacts.

In India, where sugarcane is manually harvested, the transportation of soil and trash to the factory, along with the harvested sugarcane, is a common practice. Wastewater treatment plays a vital role in managing the environmental impact of heavy waste discharge and odour issues associated with untreated effluents from sugar mills. These untreated effluents, if released into the environment, can disrupt the ecological balance and adversely affect the surrounding organisms.

The sewage discharges from sugar mills contain a range of chemical pollutants, including oil, grease, carbonate, bicarbonate, nitrite, phosphate, suspended solids, dissolved solids, volatile solids, and various toxicants. Proper wastewater treatment addresses these pollutants, preventing changes in temperature, humidity, oxygen supply, and exposure to pesticides. This ensures the preservation of the physical, chemical, and physiological spheres of the biota, contributing to the overall sustainability of sugar production.

Stages Of Sewage Treatment

The sewage treatment process typically involves several stages to effectively treat wastewater and remove impurities. The five key stages of sewage treatment are:

1.Preliminary Treatment:

Preliminary treatment involves the removal of large, solid materials and debris from the raw wastewater. This is typically done through screening and grit removal processes, preventing these materials from interfering with subsequent treatment stages.

2.Primary Treatment:

In primary treatment, the partially clarified wastewater is introduced into large settling tanks. Heavy solids, including sludge, settle to the bottom of the tanks, while clearer water moves to the next stage. Primary treatment aims to remove a significant portion of suspended and settleable solids.

3.Secondary Treatment:

Secondary treatment is a biological process where microorganisms, often bacteria, break down organic pollutants in the wastewater. This occurs in aeration tanks, providing an oxygen-rich environment for the microbes to thrive. The result is a reduction in the concentration of organic contaminants.

4.Tertiary Treatment:

Tertiary treatment is an additional step to further enhance the quality of the treated water. Various advanced processes, such as filtration, chemical treatment, or additional biological methods, are employed to remove remaining impurities and improve the water's clarity before it is discharged or reused.

5.Sludge Treatment and Disposal:

The sludge generated during the treatment process is separated and treated separately. Sludge treatment involves processes such as thickening, dewatering, and sometimes digestion to reduce volume and make it more suitable for disposal or beneficial reuse, such as in agriculture.

These stages collectively contribute to the comprehensive treatment of sewage, ensuring the removal of contaminants and producing treated effluent that meets environmental standards.