A way to handle sanitary waste

With a better scientific system coming soon, is Bengaluru finally finding a way to deal with it?

After sending 60-70 tonnes of sanitary waste to landfill every day for years, the Bruhat Bengaluru Mahanagara Palike (BBMP) now aims to manage the waste as scientifically as possible.

In 2021, the BBMP invited bidders through a tender to install sanitary pad vending machines and incinerators in the BBMP hospitals, public toilets, schools, colleges, offices, etc. This was envisioned as a localised model that would reduce the burden on the collection system while disposing of the sanitary waste with the help of localised incineration. This aimed to utilise the budget granted under the Shubhra Bengaluru scheme.

The scheme mandated that the napkins provided would be totally free of plastic. When three bidders applied for it, the special commissioner of Bangalore Solid Waste Management Limited (BSWML) noted that the incinerator cost was too high and the BBMP was already collecting sanitary waste separately, which could be burned in bigger incinerators at the transfer points. Consequently, the proposal was rejected.

Exports say sanitary waste incineration—commonly used for disposing of pads, tampons, diapers, and other menstrual or hygiene products—may seem convenient, but it can have several harmful side effects, especially if not properly regulated or if done on a small scale, like local incinerators. 

Incinerating sanitary waste in open or closed conditions without maintaining norms has several ill effects. Open burning in landfills or unauthorised areas pollutes the air, soil, and water. If improperly handled, Ash from incinerators often contains toxic residues and can contaminate soil and water.

While alternatives such as cloth pads and menstrual cups are available, they are not very popular yet due to the lack of awareness among the middle and upper class, and the lack of access to safe toilets and clean water among the poor.

Thus, high-temperature, pollution-controlled incinerators are the only solution to avoid sanitary waste from going to landfills.

A solution in the offing

“There’s a plant in Gauribidanur that collects and processes upto 4 tonnes per day using the incineration method. They bury the leftover ash deep underground. Another plant processes 1.5 tonnes per day and uses the same methods,” says a BBMP official. 

He says these are stopgap arrangements because the BBMP does not have its own sanitary waste disposal infrastructure yet. He says the BBMP pays a whopping Rs 18 per kg to dispose of this waste, including collection and transportation.

The city produces 60-70 tonnes of sanitary waste per day. This arrangement caters to less than 5.5 tonnes of waste. The rest reaches landfills if it does not go to the BWSSB drainage.

To help the situation, BBMP has initiated a plan to develop three plants of a total capacity of 25 tonnes each in Gunjur and Kogilu. These plants will use plasma gasification technology, says S N Balasubramaniam, general secretary of the BBMP Garbage Contractors’ Association, who also has a stake in managing these plants through his firm that won the tender.

The land allocation is expected to be completed soon, and the project is expected to begin by June or July.

“We are not happy with how the sanitary waste is managed now. Once this system takes off, we will provide every cart with a separate bag to collect sanitary waste, which would be pooled in dry waste collection centres in the ward, and then taken to these facilities,” explains Balasubamainam. 

“We will follow the no-garbage-on-ground principle strictly,” he says. Every ward produces at least 50-60 kg of sanitary waste daily, while there could be more in many wards. The gasification technology needs continuous feeding of waste, and a shortage of waste would lead to a stoppage of functions.

What is plasma technology?

Plasma technology in incineration — often called plasma gasification — is an advanced waste treatment process that uses extremely high temperatures (generated by plasma) to break down waste into its basic molecular components. It is considered a cleaner and more efficient alternative to traditional incineration.

Plasma is a superheated, electrically charged gas, sometimes called the fourth state of matter (after solid, liquid, gas). It is created by passing a gas (like air or nitrogen) through an electric arc at very high voltage, reaching temperatures of 3,000°C to 10,000°C.

The sanitary waste fed into this system breaks into synthesis gas such as hydrogen, carbon monoxide, and inert slag (a glassy, non-toxic solid residue). The syngas can be cleaned and used to generate electricity or fuels. The extreme temperatures destroy dioxins and other complex toxins, making the emissions more manageable. The inert slag is sometimes usable in construction.

“This is a European technology. We will send the live emission reports to pollution monitoring systems at Central Pollution Control Board (CPCB). There will be no hazardous gases in this technology,” says Balasubramainam, adding that the technology is being used in only a few places in India, such as Tirupati, Leh Ladakh and Bhubaneswar, and not yet majorly in any city municipality. He feels that every zone in BBMP has a scope for such plants.

The challenges include the high initial cost of equipment and maintenance, the need for electricity to generate plasma arcs, and the need for precise controls to operate efficiently and safely.

Plasma incinerators are more common in high-tech or industrial settings and less common in municipal waste systems. If implemented, Bengaluru would be the first city to use it. If the proposed three plants work according to expectation, a day when all the daily sanitary waste is incinerated this way would not be far.