Organic Fertilizer

From Urban Solid Wastes To Roof-Top Gardening

Shishir Reza :
Urbanization is one of the 21st century’s most transformative trends. Cities are the dominant force in sustainable economic growth, development and prosperity in both developed and developing countries. In developing countries, urbanization is taking place at a rapid pace. Currently 54% of the world’s population (4 billion people) resides in urban areas. By 2030, 2 billion people will have migrated to cities, placing unprecedented pressure on infrastructure and resources, particularly those related to water, soil etc.
Both local shipping and long-distance trade are required to meet the resource demands important in maintaining urban areas. Carbon di-oxide (CO2) emissions from the transport of goods also contribute to accumulating greenhouse gases and nutrient deposits in the soil and air of urban environments. In addition, shipping facilitates the unintentional spread of living organisms, and introduces them to environments that they would not naturally inhabit.
In Dhaka City, Around 250 industries are discharging chemical pollutants into the Buriganga and Sitalakkhya Rivers. Every day 4,000 tons solid waste & 22,000 tons tannery waste mixes with water in Buriganga River. Different industries and their contribution to pollution in Dhaka are: Pulp & paper – 47.4 per cent; pharmaceuticals – 15.9 per cent; Metals – 14 per cent; Food industry – 12.1 per cent; Fertilizers/pesticides – 6.6 per cent. In urban areas, sewages are discharging directly into the rivers and low-lying part around the urban areas.
The management of waste is one of the obligatory functions of urban governance institutions in Bangladesh. The yearly escalation in urban population of Bangladesh is over 3.3 per cent. Population Division of UN (2016) has mentioned the urban Population Status in Bangladesh: it was 23.8 per cent in 2000; 30.4 per cent in 2010 and 2016 it is now 34.9 per cent. It can be 38per cent of the total population by the year of 2020. at the same time waste generation has also augmented proportionately with the intensification of urban inhabitants. Disposal of solid wastes in all the urban areas is inadequate. Each day 4000 tons solid waste and 22000 tons tannery waste mixes with water in 4 rivers of Dhaka City. Although there are 1000 street cleaners in the Dhaka City Corporation, most of the streets are never swept. Nowadays, in south city corporation – 3500 tons waste are generated where 1900 tons are processed. But 1600 tons are out of processing. Poles apart industries and their contribution to pollution in Dhaka City are: Pulp & paper – 48%; pharmaceuticals – 16%; Metals – 15%; Food industry – 12%; Fertilizers/pesticides – 7%. In this context, identifying degradable materials from household garbage, industrial wastes, we may plan to manufacture organic fertilizer to use in urban roof-top gardening.
Roof-top gardening are very unique and beautiful. This means that home owners will probably use less insulation on their roofs when they build and they will also use less energy to both heat and cool their homes. Studies have shown that roof-top garden can reduce cooling costs by 25 per cent during the summer months alone. Green roofs are energy-efficient, reduce heat instability and less energy for cooling or heating can lead to significant cost savings. Roof-top gardening also burns fewer crude oil that is fewer greenhouse gases, which is great for everyone. In Dhaka city, there are 6,000 rooftop gardens. To encourage people to set up such gardens, the two Dhaka City Corporations may take a decision to reduce holding tax if any family goes for rooftop gardening.
The many benefits of rooftop gardens in urban zone to public, private, economic and social sectors, as well as to the global environment are really inclusive and sustainable. Eco-friendly rooftop garden can generate oxygen which is an excellent way to ensure sustainable cities and communities. Integration of city corporations, community peoples and agricultural extension network make a platform to transform organic materials from solid waste to inject in roof-top gardening in Dhaka.
Although Bangladesh is making some efforts to resolve some of urban environmental crises, no efforts will be adequate to face these challenges without identifying the underlying causes nationally and addressing them locally. To make our cities livable, we need a great push from within the government. Decentralization of power, empowerment of local governments and the establishment of more city councils could be some good first steps. In order for Bangladesh to truly become a developed country, our urban centers would need to be transformed into global cities by 2041. That will require more research and effort to discover a sustainable urban planning strategy that would best suit our cities and communities.
Principle of Intelligent Urbanism for Bangladesh
This principle of intelligent urbanism states there is a level of human habitation intensity wherein the resources that are consumed will be replaced through the replenishing natural cycles of the seasons, creating environmental equilibrium. Intelligent urbanism induced opportunities are in urban area: primary education, skill development; primary health care, potable water security, solid waste disposal and hygiene; urban facilities like storm drainage, street lights, roads and footpaths; recreation and entertainment; Transport, energy, communications; public participation; Finance and investment mechanisms; urban open space where goods and services can be produced; and rudimentary economic infrastructure.
If we search for sustainable urbanization through intelligent urbanism theory, we have to address disparities between rich and poor, insecurity and social unrest, diversion of resources to safety and security and inability to cope with demand for services. In urban area of Bangladesh, people are so much insecure to access drinking water, electricity, gas lines, clay, cables and drainage water road, beggar free footpath. As we are targeting for middle income country by 2021, greening the transportation system, ecological hazards free high-rise buildings, co-ordination among RAJUK, DCC, WASA; polluters-pay industrial system, context demands to employ theory of intelligent urbanism.
The planetary crises both for rural and urban area are uprising day by day due to global warming and climate change. The world urbanism day demands the nexus among environmental security, heritage conservation, mass people oriented appropriate technology, infrastructure-efficiency, time-oriented land use planning, social security access, transit-oriented development, decentralization, public participation, regional integration, human to humane development and institutional integrity for good looking sustainable cities and communities.
Concluding Remarks
Bangladesh is on the way of middle income country. Time offers to value the people’s development or collective wellbeing. In this context, the concept of nudge by behavioral change is essential to address environmental, social and climatic crises urban area. It can be such a ways – contemplation (aware and behavior towards the problems), preparation (intends to take action), actions (practices to desired behavior), maintenance (works to sustain the behavior change).  

(Shishir Reza, environmental analyst & Associate Member of Bangladesh Economic Association)