Sustainable solid waste management
Pakistan generates approximately 49.6 million tons of solid waste and 4.36 billion cubic metres (BCM) of domestic and industrial wastewater a year, which has been increasing more than 2.4% annually.
Like other developing countries, about 60-70% of solid waste and merely 1% of the total wastewater is treated prior to its disposal.
Pakistan lacks waste management infrastructure, resulting in serious environmental problems. Mostly municipal waste is either burnt, dumped or buried on vacant plots, posing threat to the health and hygiene of the general population.
Karachi, Pakistan’s largest city, generates more than 16,500 tons of municipal waste daily, whereas Lahore generates 7,690 tons, Faisalabad 5,017 tons, Rawalpindi 4,500 tons, Peshawar 2,048 tons and Quetta 716 tons.
Therefore, all major cities face enormous challenges of how to manage the urban solid and sewage waste.
Poor capacity, lack of financial resources, lack of waste management equipment and technology, lack of urban planning and low public awareness contribute to the problem. The solid and sewage waste management lacks a proper system and therefore the following situation arises:
Solid waste collection system is not visible.
Solid waste is commonly dumped in open spaces on the streets.
Lack of segregation of solid waste at source.
Open burning of trash is a common practice as there are no controlled sanitary landfill sites.
Citizens are not aware of sustainable waste management, which poses a threat to environment and public health.
Sustainable sewage and solid waste management has emerged as an ever increasing challenge that is posing a threat to the humanity on earth.
Unsustainable waste management has led to the pollution of soil, water and air resources.
Pakistan with very weak municipal institutional capacity fails to manage waste and therefore untreated solid and sewage waste is dumped on land, into water bodies and may become air borne through dust and emissions of greenhouse gases (GHG) into the atmosphere.
Sewage and solid waste-related diseases cause over 5 million deaths in a year.
Various recycling techniques are used to handle the problem, however, lack of technology, capacity and resources makes it hard for the developing countries to embark on such ventures.
Developed countries use their resources and technology to manage it on a sustainable basis but in most of the developing world the problem is not properly managed.
To address these new challenges, a variety of new wastewater treatment technologies such as membrane filtration systems, automatic variable filtration (AVF), advanced oxidation processes (AOP) and UV irradiation have been proposed, tested and applied to meet both the current and anticipated treatment requirements.
Pakistan still uses the outdated techniques of sewage and solid waste management.
Recycling of valuable material like plastic, tin, paper, glass, etc is now gaining momentum in the informal sector as scavengers collect such items for selling them at the recycling points in urban centres. However, the decomposable solid and sewage waste is still posing real challenges as there is no recycling arrangement nor is there any price tag on their trade.
Therefore, the decomposable waste is dumped in open spaces all over cities and urban centres. As the decomposition starts, smell and bad odour pose another challenge to the surrounding cities and urban centers.
Biogas is produced from the anaerobic digestion (AD) of organic matter, such as manure, MSW (municipal solid waste), sewage sludge, biodegradable wastes, and agricultural slurry, under anaerobic conditions with the help of microorganism, which offers hope for recycling such decomposable waste.
Anaerobic digestion is widely considered as an environmentally friendly technology for various organic waste including sewage sludge.
Although the implementation of anaerobic digestion as an alternative treatment method for sewage sludge is in operation in many advanced countries, the developing countries lack such sustainable sewage recycling techniques.
Thus, two immediate marketable products such as biogas as a source of energy and organic fertilisers are immediately harvested from this system.
As anaerobic digestion is carbon neutral, it can earn carbon credit as an additional source of earning.
Opportunities of waste to energy also exists in Pakistan as the National Electric Power Regulatory Authority (Nepra) has announced a competitive upfront tariff of $0.10007 per kWh for waste-to-energy projects based on a 25-year operational period, with overall capacity cap of 250 megawatts where the share of each province and federal territory has been kept at 50MW.
The construction period for these power plants is limited to 24 months.
The Methane Pledge, led by the US and already committed to by over 100 countries including Pakistan at the UNFCCC COP-26 held in the UK, offers an excellent opportunity for not only boosting waste-to-energy projects but also for technology transfer and resource mobilisation in developing countries like Pakistan.
The writer is PhD in natural resources management and has worked in national and regional air quality regulating and monitoring agencies.