Agricultural Wastes
Sources: The waste generated by agriculture includes waste from crops and live stock. In developing countries, this waste does not pose a serious problem as most of it is used e.g. dung is used for manure, straw is used as fodder. Some agro-based industries produce waste e.g., rice milling, production of tea, tobacco etc. Agricultural wastes are rice husk, degasses, ground nut shell, maize cobs, straw of cereals etc.
Effects: If more C: N ratio, wastes like paddy husk or straw may cause immobilization of nutrients if applied on the fields. It occupies to large land areas if not properly disposed.
MANAGEMENT
WASTE TO ENERGY
i) Gasification: It is the process in which chemical decomposition of biomass takes place in the presence of controlled amounts of oxygen, producing a gas. This gas is cleaned and used in an internal combustion engine to produce electric power. Without clean up also, the gas can be used in boilers to produce electric power. This technology is highly suited to generate electric power from agrl wastes like rice husks, groundnut shells etc.
ii) Pyroalysis: It is similar to gasification except that the chemical decomposition of biomass wastes take place in the absence or reduced presence of O2 at high temp. Mixtures of gases result from decomposition including H2, NH4 Co, CO2 depending on the organic nature of waste matter. This gas used for power generation.
2. Biogas production: Animal wastes, food processing wastes and other organic matter are decomposed anaerobically to produce a gas called biogas. It contains methane and CO2. The methane can provide gas for domestic use. The byproduct of this technology is slurry, settled out at the bottom of the digester. This can be used as manure.
3. Agricultural waste like corn cobs, paddy husk, bagasse of sugarcane, waste of
wheat, rice and other cereals, cotton stalks, coconut wastes, jute waste etc can be used in making of paper and hard board.
Waste production can be minimized by adopting the 3 R’s principle: Reduce, Reuse and Recycle
These are processes that involve integrated waste management practices (IWM).
They can reduce the wastes generated by approximately 50 %.
Reduce (Waste prevention): Waste prevention, or “source reduction,” means
consuming and discarding less, is a successful method of reducing waste generation.
Backyard composting, double sided copying of papers, purchasing durable, long- lasting environmentally friendly goods; products and packaging that are free of toxics, redesigning products to use less raw material production and transport packaging reduction by industries are the normal practices used and have yielded substantial environmental benefits. Source reduction prevents emissions of many greenhouse gases, reduces pollutants thereby saves energy, conserves resources, and reduces wastes for new landfills and combustors. It reduces the generation of waste and is generally preferred method of waste management that goes a long way toward saving the environment.
Re-use: Re-use is the process, which involves reusing items by repairing them, donating them to charity and community groups, or selling them. Reusing products is an alternative to recycling because the item does not need to be reprocessed for its use again. Using durable glassware, steel using cloth napkins or towels, reusing bottles, reusing boxes, purchasing refillable pens and pencils are suggested.
Recycling: The process of recycling, including composting, has diverted several million tons of material away from disposal. Recycled materials include batteries, recycled at a rate of 93%, paper and paperboard at 48%, and yard trimmings at 56%. These materials and others may be recycled through drop off centers, buy-back programs, and deposit systems. Recycling prevents the emission of many greenhouse gases that affect global climate, water pollutants, saves energy, supplies valuable raw materials to industry, creates jobs, stimulates the development of greener technologies, conserves resources for our children’s future, and reduces the need for new landfills and combustors. For example, by recycling of solid waste in 1996, the United States prevented the release of 33 million tons of carbon into the air roughly the amount emitted annually by 25 million cars. Recycling can create valuable resources and it generates a host of environmental, financial, and social benefits. Materials like glass, metal, plastics, and paper are collected, separated and sent to processing centers where they are processed into new products. The advantages of recycling are: it conserves resources for future generation, prevents emissions of greenhouse gases and pollutants, saves energy, supplies valuable raw materials to industries, stimulates the development of greener technologies, reduces the need for new landfills and incinerators.
6.9 DISASTER MANAGEMENT
Natural calamities of different types and intensities affect nations all over the world. The Indian subcontinent is very vulnerable to droughts, floods, cyclones,
earthquakes, landslides, and forest fires. While not all natural calamities can be predicted and prevented, a state of preparedness and ability to respond quickly to natural calamity can considerably mitigate loss of life and property and human suffering, and restore normalcy at the earliest.
‘Post Disaster Management’ and ‘Disaster Mitigation’ :
The post disaster approach towards dealing with natural disasters, involving problems such as evacuation, warnings, communications, search and rescue, fire- fighting, medical and psychiatric assistance, provision of relief, shelter, etc, is generally referred to as ‘Post Disaster Management’ . It is a primarily a ‘Reactive Mechanism’ to the natural disasters.
‘Mitigation’ means lessening the negative impact of the natural hazards. It is defined as sustained action taken to reduce long term vulnerability of human life and the recovery property to natural hazards. While the preparatory response and the recovery phases of emergency management relate to specific events mitigation activities have the potential to produce repetitive benefits over time. It is a ‘Proactive approach’ to natural disasters.
Multidisciplinary and Multi- sectoral nature of Disaster Management:
Disaster management is a multidisciplinary area in which a wide range of issues
that range from forecasting, warning, evacuation, search and rescue, relief, reconstruction and rehabilitation are included. It is also mult-sectoral as it involves administrators, scientists, planners, volunteers and communities.
Guidelines for effective management of mitigation program.
1. Pre- disaster mitigation can help in ensuring faster recovery from the impacts of disasters.
2. Mitigation measures must ensure protection of the natural and cultural assets of the community.
3. Hazard reduction methods must take into account the various hazards faced by the affected community & their desires and priorities
4. Any mitigation programme must also ensure an effective partnership between the Govt, Scientific, private sector, NGOs and the community
The main elements of a mitigation strategy
1. Risk assessment and Vulnerability analysis: This involves the identification of hotspot areas of prime concern, collection of information on past natural hazards, information on the population and infrastructure.
2. Applied research and technology transfer: There is a need to establish or upgrade observation equipment and networks, monitor the hazardous properly, improve the quality of forecasting and warning.
3. Public awareness and training: Training to be given to officials & staff of various Departments involved in state & district level of the Government and NGOs.
4. Institutional mechanisms: There is need to emphasize on proactive and predisaster measures rather than post-disaster response. It is thus essential to have a permanent administrative structure which can monitor the developmental activities across departments and provides suggestions for necessary mitigation measures. The national disaster management centre (NDMC) can perform such task. Professional like architects, structural engineers, doctors and chemical engineers who are involved with management of hazardous chemicals, can be asked to form groups that can design specific mitigation measures.
5. Incentives and resources for mitigation: Provide stable source of funding for all mitigation programs.
6. Land use planning and regulations .
7. Hazard resistant design and construction.
8. Structural and Constructional reinforcement of existing buildings: This can be done by the insertion of walls, specially on chored frames, construction of new frame systems, designing residential electrical equipment above flood level, designing water storage tanks to be able to withstand cyclonic winds, earthquakes & floods.
Some of the causes, effects and mitigation measures of the disasters commonly occurring in India are detailed below:
Floods : Floods can be caused by natural, ecological or anthropogenic factors either individually or as a combined result. Human activities such as deforestation and shifting cultivation can also contribute to floods. Heavy rainfall is the main cause of floods in the rivers. The breaches to tanks and reservoirs due to inflow of large quantities of water from excessive rainfall also result in floods. Floods occur sometimes in a flash due to intensive rains at the time of cyclones. Next to Bangladesh, India is the most flood – affected country in the world. The west coast of India has an advantage of having it has western ghats with thick forests which act as natural buffer to floods.
Effects: floods cause heavy suffering to people living in low lying areas because the houses and the properties are inundated or washed away. Most of the victims are rural folks who are economically poor. Floods also damage standing crops and livestock.
The mitigation measures for floods include both structural and non structural measures.
The structural measures include
1. Reservoirs for impounding monsoon flows to be released in a regular manner after the peak flood flow passes.
2. Prevention of over –bank spilling by the construction of embarkments and flood walls
3. Improvement of flow conditions in the channel and anti erosion measures.
4. Improved drainage
The non structural measures include
1. Flood-plain management such as Flood Plain zoning and flood proofing including disaster preparedness
2. Maintaining wet lands
3. Flood forecasting and warning services
4. Disaster relief and public health measures.
5. Flood insurance
Case study
Since 2006, Mumbai faces flooding in most of the Suburban Locations Like
Andheri, Dahisar, Goregaon, Malad Subway, Milan Subway, Santacruz, Chembur,Dombivali, Worli etc which are low line areas and also highly affected during Monsoon and Heavy rainfall. Because of Unstable weather, Mismanagement of Natural Resources by People, Old or No proper drainage systems and Real Estate development, Mumbai is underwater Mostly every year even if Bombay Municipal Corporation tries it level best to help the disaster.
Flood 2006 will never be forgotten by any person who was in Mumbai during that day, Everything was like stand Still, the Transportation, Private Vehicles, Mobile Services and all major communication and transport channels stopped. Still salute to mumbaikers for the Humanity shown that day by helping each others at there level best. Someone helped giving Biscuits and Few by preparing whatever fast food like Vada pav, samosas etc. Lots of NGO’s and Private organizations came up for the help. All this happened within couple of hours of very heavy rain in Mumbai. Many lost there lifes and many saved it loosing just there belongings like Mobiles and bags etc. Every person stayed where they were for next 24 hours.
Flood 2007 of Mumbai was not as hard as 2006, few of the slums and people stying in low line ground floor locations faced terrible problems. People of Mumbai are now tough enough to face such flooding disaster’s and bomb blasts and Epidemics and Diseases because of flood. Mumbai In 2008 and 2009 Flooding in Mumbai is comparatively low because of not so heavy rainfall. Almost opposite situation like cloud seeding experiments are undertaken to save mumbai from low rainfall.