Waste and Sewage Management: A Swiftly-Expanding Problem
India is seeing record population increases, particularly in urban areas. Five states alone—Maharastra, West Bengal, Chennai, Uttar Pradesh, and Kolkata—generate nearly twenty-five tonnes of municipal waste annually.
The existing waste-management infrastructures cannot keep pace with this rapid population growth, and all the corresponding waste.
Trash to Treasure in Surat
Surat City faced the consequences of rapid urban growth. In 1994, an epidemic of plague broke out in Surat. The plague was directly linked to open waste dumping. This crisis forced Surtis to rethink their waste management practices. Realising that they needed to supply the electricity for waste management plants, and that spaces for waste disposal were quickly getting maxed out, Surat began to implement an innovative series of programmes.
These programmes have been so effective in improving sanitation that in 2013, The Times of India judged Surat as India’s best city. The criteria were the state of the city’s “mobility, water supply network, cleanliness, public amenities, pollution control, greenery, safety and easy processes of getting work done at the corporation.”
Surat’s daily output of over 1,400 tonnes of garbage is now used to help generate the needed electricity for running the waste management plants. Dry waste becomes refuse-derived fuel (RDF). RDF generates electricity, and is more environmentally-friendly than burning coal.
The leftover wet waste from the RDF production is converted into organic manure. Krishak Bharati Cooperative Limited (KRIBHCO) and local farmers buy this manure from the city of Surat. This increases municipal revenues, and subsidises the electricity used by waste treatment plants.
Progressive waste management in Surat doesn’t stop there. The Anjana sewage treatment plant in Surat extracts biogas (methane) from sewage water. The electricity generated from the biogas is used to power the water treatment plant.
Sludge, a by-product of biogas extraction, is treated and sold to famers as manure. This generates more income for the city, and helps to defray the overall cost of waste treatment. The Anjana plant is one of ten sewage treatment plants in Surat that follow the same innovative practices.
Surat is also working on a plan to recycle plastic waste into crude oil.
Building the Future with Plastic Bricks
The ever-increasing plague of plastic waste is a growing hazard in Indian communities. Without the means to manage plastic refuse, Indians tend to either burn the discarded plastic, or to dump it indiscriminately. The incineration of plastic waste has led to an increase in lung disease. And plastic discarded without incineration ends up polluting waterways, making clean water an even scarcer commodity.
Lise Fuglsang Vestergaard spent three months in a rural Indian village, studying its waste management. Although there are no external waste management services for the village, they had figured out ways to manage every type of waste—except for soft plastic. Vestergaard, a Danish design and engineering student, witnessed the environmental degradation that resulted from this lack.
Vestergaard then devised a means to recycle the unwanted plastic into a useful building material. In a solar-powered process, the discarded plastic is transformed into bricks. (Discarded foil crisp packets can also be included in the plastic bricks’ components; this is an excellent way to upcycle another ubiquitous and troublesome form of waste.)
These plastic bricks—laboratory-tested to withstand six tonnes of pressure—are then fashioned into sturdy homes, which are better able to endure the ravages of monsoons than the region’s traditional clay-brick homes. (Vestergaard plans to cover the plastic bricks with clay, so they look less conspicuous in the midst of clay homes.)
Vestergaard is piloting her invention in the village of Joygopalpur, West Bengal. The project has even brought new jobs to the village.
Cooking up Organic Waste Management Solutions
The vast majority of Indians live in villages. Most of the women in these villages still use traditional cooking methods, including smoke-generating indoor fires. The smoke from these cooking fires causes ongoing eye and lung irritation for the women.
Kerosene is one of the most popular cooking fuels in India today. However, the price of kerosene keeps rising, making it increasingly less affordable. Families in rural areas, who tend to be less affluent, are more burdened by these price increases.
In India, eighty percent of cooking fuels are imported. If India could harness its own resources to produce its own cooking fuels, its citizens would greatly benefit.
Sintex, a global plastics and textile manufacturer headquartered in Kalol (Panchmahal), offers a scalable solution to India’s heavy dependence on cooking fuel imports.
Using all types of organic waste, such as cow dung, vegetable scraps, and even human excrement, the Sintex Floating Type Biogas Plant produces clean biogas cooking fuel for farmers and other private citizens.
Biogas is somewhat similar in composition to natural gas. Unlike the organic process that creates natural gas over millions of years under the surface of the earth, the biogas plant can produce fuel within a fortnight.
The process is fairly simple: Bacteria breaks down the organic waste; the methane gas generated is captured for use as cooking fuel. The leftover sludge is perfect for a low-odour fertilizer—or even farm animal bedding—since its bacteria and pathogens are killed by the anaerobic digestion process used to produce biogas.
In this scenario, even so-called “waste products” at each step of the cycle are recycled for gain. Farmers deposit crop and animal waste into the biogas plant, receive clean cooking fuel, and then enrich their soil with the remnants of the biogas production.
Other companies, such as Vijaya Solar and Arjun Agri Industries (in Salem, Tamil Nadu) offer similar biogas plants. In 2013, Biotech Renewable Energy invented an anti-mosquito version, to help control mosquito growth in the biogas plant itself. This particular innovation cuts down on the spread of disease.
Anaerobic digestion produces biogas. It is the same solution that Surat uses for its municipal sewage management, only on a much smaller scale. Consumers can install the biogas plant that is appropriately sized for their household, and for the amount of organic waste available. The one cubic metre biogas plant, for example, can provide enough cooking fuel for a family of four.
Although the price tag is a bit steep for the average Indian citizen, the biogas plant pays for itself in fuel generation—not to mention fertilizer production—within two years of purchase (based on manufacturer estimates). The Indian government also offers to subsidize one-third of the purchase price, which should help toward making the initial outlay more affordable.
Companies like Green Power Systems are working to improve biogas production with innovations such as organic waste shredders, sludge dewatering systems, predigestors, and sludge mixers.
Some inventive Indians, such as teenager Chitlange Sahas from Aurangabad, have even built their own home biogas plants. Chitlange’s homemade biogas plant costs about 90% less than a similar commercial plant.
Whether purchased or assembled at home, biogas plants change organic waste from a burden to a benefit.
Earthy Waste Recycling
Although managed with cutting-edge technology, the essential process is very simple. It harnesses the natural capabilities of earthworms to process organic waste in an extremely environmentally-friendly manner.
Organic waste (including garden, paper, and food waste) is first fed into a shredder until it reaches a pulp-like consistency. The shredder also mixes the organic waste.
The waste is then added to the organic digester, which uses the natural recycling capability of millions of earthworms to convert the waste into compost and liquid fertilizer (“vermiwash”).
The aerobic processes of vermiculture work without any of the dangers of fire, explosion, or asphyxiation sometimes associated with biogas’ anaerobic digestion process. While vermiculture may not produce fuel like biogas production does, it effectively and ecologically manages waste.
Beneficial Waste Management
The technologies surveyed in this post can help protect the environment, generate domestic power, fertilize India’s fields, build stronger houses, and safeguard India’s people against diseases caused by poor waste management.
Next week, LEAF Society’s blog will delve into a related issue, one fraught with cultural taboos and controversy: menstrual waste management.
Michelle Baumgartner is a freelance writer and editor. One of her current projects is an internship with LEAF Society. Michelle’s company, StellaWriting LLC, provides blogging, online content, and marketing materials for businesses and nonprofit organizations.