Showing posts with label waste management. Show all posts
From Waste To Energy
Posted by Unknown in Bio Gas, Fertilizer, Manure and Compost, Pakistan, waste management on Saturday, 23 March 2013
By Tahir Ali
Despite huge potential and benefits, biogas technology has not been given due attention in Pakistan. With inflation, energy shortage aggravating with each passing day, there is a renewed interest in the technology as this type of gas can be used both for cooking and power generation and its residue as fertilizer and it can also decrease domestic fuel budget, deforestation and pressure on national power grid. It can also contribute towards sustenance of ecosystem and conservation of biodiversity in the country.
Over 4000 biogas plants were installed in Pakistan by the government between 1974 and 1987. But later, it withdrew the financial support which reduced the growth rate of this technology. Only 6,000 plants were installed till 2006. But the potential is even bigger.
There are currently around 47 million big animals in Pakistan. A medium size animal produces around 10 kg of dung per day. Even if its 50 percent is collected, the availability of dung comes to 233 million kg a day that can produce around 12 million cubic meters of biogas a day. Estimates say since 0.4m gas could suffice the cooking needs of a million Pakistanis, the fuel requirement of over 20 percent of them could be met only from biogas. It will also produce 19 million tons of bio-fertilizer per year, which can boost agricultural productivity.
Biogas plants are popular in Pakistan’s neighbourhood and even developed countries. There are almost two million bio-gas plants in India and the facilities have been built even in UK and US through official patronage. Around 89 such plants in the US are consuming 13 per cent or 95000 tons of waste to produce about 2500 mega watt of electricity that suffices for 2.3mn households.
In Nepal, where around 80 percent of the population lives in rural areas with no electricity, over the past 20 years, the biogas sector partnership, an NGO, has installed around 210,000 biogas plants to provide biogas for cooking and lighting. Each plant is estimated to have reduced Nepal’s carbon emissions by around 4.7 tonnes a year.
According to a United Nations report, cattle are responsible for 18 percent of the greenhouse gases that cause global warming — more than cars, planes, and all other forms of transportation put together. Their environmental impact could be minimised by converting their manure into a renewable source of energy.
The environmental protection agency (EPA) estimates that cattle emit about 5.5 million metric tons of powerful greenhouse gas, methane, per year into the atmosphere. The University of Texas, Austin, estimates that by using around one billion tonnes of manure produced annually in the United States for power/gas generation could also help eliminate 99 million tonnes of net greenhouse gas emissions there.
As per Pakistan Centre for Renewable Energy Technologies (PCRET) report, a family size biogas plant annually produces energy equivalent to 10056Kg wood, 22200 Kg animal dung, 1104 lit kerosene oil, 540 kg L.P.G or 9000 Kwh of electricity.
Khyber Pakhtunkhwa too, despite having one million camels, 6mn cattle, 2mn buffaloes and over 12mn sheep and goats, has failed to utilise the waste of these animals for launching of bio gas plants on a big scale.
In the cattle breeding and dairy farm in Charsadda, a bio gas plant has been in operation but the innovative technology has not been disseminated on a mass scale in the province.
Under the project “development and promotion of biogas technology for meeting domestic fuel needs of rural areas and production of bio-fertilizer”, PCRET plans to install 368 biogas plants in rural areas of the country by June this year.
The government of Italy in November last year decided to provide Rs50 million to set up 436 biogas plants in six districts of Khyber Pakhtunkhwa, including Peshawar, Charsadda, Nowshera, Abbottabad, Haripur and Mansehra.
Launched in 2008 with a target of 2500 such plants, PCRET has already installed over 2100 family size biogas plants in different parts of the country.
Earlier, based on a feasibility study, a programme implementation plan for domestic biogas of Pakistan was finalised with the support of rural support programmes network, NGOs and farmers’ organisations and is implemented by Pakistan biogas development enterprise. The construction of 30,000 biogas installations in 4 years will be supported in four provinces, including Khyber Pakhtunkhwa with a total investment of Rs2.7bn. Rs244mn would be disbursed as investment rebate support to the households who spend on the technology.
However, the potential is too enormous to be satisfied with this number. Animal waste is usually wasted. In Landhi Karachi alone, around 0.35mn cattle-heads are kept in a 3km area that produce thousands of tons of waste but 80-90 of it is thrown in the sea. A Canadian firm Highmark Renewables with the help of KESC plans to establish world’s biggest biogas plant at a cost of around $70 million that would produce up to 30 mega watt of power and 400 tons of residue bio fertiliser.
Some more facts
Any farmer having at least three animals can establish this plant with a one-time investment of Rs40,000 to 50,000
Gas produced in a small bio-digester which contains about 20 kg of dung should be enough to meet the fuel requirement of a small family. Based on these calculations, a bio-digester for any number of animals can be designed. However, the plant must be water/gas-tight. Enough manure and water must be added to it every day.
Firewood, dung and crop residues are major sources of energy for rural and low-income urban households. In 1992, firewood provided fuel to about 60 percent of rural and low income families followed by dung in dry form at around 18pc.
Only 4pc of Pakistan’s total area is covered by forest with only 5pc area protected. To control deforestation, adoption of biogas is the best technology and option in Pakistan.
It seems strange as to why biogas plants have not been installed to reduce the speed and scale of deforestation, especially in the forest-rich Malakand and Hazara divisions.
Around 70 percent population in KP lives in the rural areas. Most farmers have two or more cattle whose dung mixed with an equal proportion of water can be used to produce biogas. Any farmer having at least three animals can establish this plant with a one-time investment of Rs40,000 to 50,000.
If individual farmers are not ready or cannot afford the expenses, a few families with domestic animals could jointly install such a plant in their neighbourhood. And by selling the gas to families that cannot contribute manure daily for having no animals, the maintenance expenditure, if any, could be financed with this money.
The government needs to give more attention and funds to spread this technology to the countryside. Media should also create awareness among the rural community and NGOs and foreign investors should be encouraged to spread it.
A typical biogas plant consists of a digester where the anaerobic fermentation takes place, a gasholder for collecting the biogas, the input-output units for feeding the influent and storing the effluent respectively, and a gas distribution system.
How Farm Waste Provides Clean Energy for Homes | A Project By UNEP
Posted by Unknown in Bio Gas, Biofuel, Pakistan, Sustainable Agriculture, Sustainable and Renewable Energy, waste management on Sunday, 27 January 2013
A
project backed by the United Nations Environment Programme (UNEP) is
working to make clean energy a reality for households in a rural region
of Pakistan.
Sanghar,
a farming district in Sindh province in east-central Pakistan, is home
to nearly two million people. Wheat, cotton, sugar cane, rice and maize
are grown here, providing livelihoods and food for local communities.
In
the villages and towns of the district, access to reliable sources of
energy is difficult. Indeed, in households all over Sanghar, women
prepare meals and heat water by burning wood or biomass in rudimentary
stoves that release choking, black smoke.
Now
a new project backed by the United Nations Environment Programme (UNEP)
is working to make clean energy a reality for local households.
Realizing
that the district was a rich source of agricultural waste, UNEP's
International Environmental Technology Centre (IETC), based in Japan,
began working on a project to convert agricultural waste left in the
fields into clean, sustainable energy.
As
a first step, the IETC worked with the Mehran University of Engineering
and Technology in Jamshoro to quantify the amount of agricultural waste
in the district. A survey found that 2.5 million tonnes of waste ?
wheat and canola straw, cotton stalks, cotton gin waste, sugarcane tops,
bagasse, rice straw and husks, and banana plant ? was produced in the
district, although not all was available for conversion into energy.
A
subsequent calculation found that the energy potential of the available
waste was equivalent to 1.07 million tonnes of fire wood, or 910
million units of electricity (with a conversion efficiency rate of 20
per cent). If this energy potential was fully realised, the converted
waste could meet the energy demands of roughly 400,000 households (at
2400 units per household).
Further
research was done to determine how agricultural waste was managed and
used, to avoid future conflicts. For instance, it was learnt that 20 per
cent of sugarcane tops was being fed to animals, but 80 per cent was
being burnt in the fields, along with the entire quantity of banana
plant waste and about 70-80 per cent of rice straw. These materials
could therefore be used for energy conversion without impacting on food
supplies or other needs.
The
next step was to decide which technology to use. Several were
considered, but after careful analysis a biogas plant was selected, as
it had the twin benefits of being able to supply clean fuel (biogas) to
surrounding households and produce a good supply of compost, which could
be used as fertilizer. A site was chosen at the back of the Sanghar
Sugar Mills, which agreed to provide the land and funds to build the
plant.
Built
at a cost of two million rupees (about US$ 23,000), the biogas plant
opened on 1 August 2011. It is producing 50 cubic metres of biogas a
day, using 400 kilograms a day of agriculture waste. As well, it
produces 200 kilograms a day of liquid fertilizer and 150 kilograms a
day of solid fertilizer.
The
biogas produced is enough to provide energy to about 20 households,
putting to good use a resource that would otherwise have gone to waste.
For more information, please contact:
Surya Prakash Chandak, Senior Programme Officer, UNEP International Environmental Technology Centre, Email: surya.chandak@unep.org
Moira O'Brien-Malone, UNEP Division of Technology, Industry and Economics, Tel: +33 1 44 37 76 12, Email: moira.obrien-malone@unep.org
Waste Contamination from Salmon Farms
Posted by Unknown in Aquaculture, Environmental Issues, Fish Farming, Pollution, Salmon, waste management, Water on Friday, 25 January 2013
(Pure Salmon Campaign)
Tens of thousands of farmed salmon confined to net pens produce a huge
amount of waste: chemical, biological, organic, and inorganic. For more
than 25 years, researchers around the world have recognized the harm
from salmon farm waste and its long-term impacts on water quality,
fisheries resources, and sea-bed ecology.
The Waste Problem
Salmon
net pens discharge untreated sewage, including contaminated feed laced
with chemicals, toxic residues, nitrogen, phosphorus, and copper and
zinc — not to mention diseases and parasites — directly into coastal
waters throughout the world. In addition, tons of contaminated salmon,
together with processing wastes — bones, entrails, and even the
carcasses of seals, sea lions, and other predators — are dumped in
landfills or processed for fertilizer or animal feed.
Sewer Systems in the Sea
Experts
have calculated that factory salmon farms, each extending over several
acres of coastal waters, discharge extremely high concentrations of
untreated sewage.
According
to Scotland's World Wildlife Fund, salmon farms there produce nitrogen
wastes equal to a human population of more than nine million people.
Even industry insiders concede that a typical 200,000-fish salmon farm releases:
- nitrogen equal to 20,000 humans,
- phosphorus equal to 25,000 humans, and
- fecal matter roughly equivalent to a city of 65,000 people.
In
2000 and 2001, nutrient discharges from aquaculture in the Northeast
Atlantic, including Scotland, Denmark, Norway, and Ireland, were
estimated at almost 40,000 tons of nitrogen and 6,600 tons of
phosphorus.
Pollution from Nutrients
Sewage and other wastes from salmon farming causes far-reaching environmental harm by:
- contaminating the sea-bed and its shellfish species,
- contributing to the antibiotic resistance of shellfish and wild fish, and
- causing eutrophication that triggers toxic algal blooms.
The
accumulation of sewage on the seafloor under and around salmon farms
directly harms marine biodiversity. Scientists in Scotland, Norway,
Ireland, and Canada have all shown that some of these effects may last
several years and extend for several hundred meters away from
salmonfarm. Divers have also found biological "dead zones" under salmon
farms — areas on the sea-bed devoid of marine life. This problem is so
prevalent that every few years salmon farmers relocate their net pens to
prevent the sea-bed from completely dying. As a result, salmon farms
are gradually moving further offshore and contaminating a larger area of
once healthy water.
Pollution from Chemicals
Salmon
farm sewage often contains chemicals and contaminants that easily enter
the food chain and accumulate as they move up it, ultimately reaching
humans. Among these chemicals are:- copper
- zinc
- tributyltin, a fungicide
- oxytetracycline and oxolinic acid, both antibiotics
- ivermectin, an anti-parasite compound
- emamectin benzoate, cypermethrin, azamethiphos tefl ubenzuron, and dichlorvos — all insecticides.
- polychlorinated biphenyls (PCBs).
The
abuse of antibiotics by large salmon farming operations has not only
led to chemical resistance in wild fish species but also raised health
concerns for humans whose diets already include milk, eggs, and meat
products containing unknown amounts of similar drugs.
Pollution from Mass Mortalities
Massive
farmed salmon deaths (euphemistically referred to as "morts" in the
industry) add to the burden of pollution from commercial salmon farms.
Industry-wide, mortality rates in factory salmon operations range from
10 percent to 40 percent. Outbreaks of infectious diseases, such as
Infectious Salmon Anaemia, may necessitate the slaughter of 100 percent
of a farm's stock, as it did in Scotland in 1998-99 when eight million
fi sh had to be killed to stem the spread of disease.
The
sheer volume of dead fish can only be measured in tons. In British
Columbia, for example, where factory farms produce 70,000 tons of salmon
annually, an estimated 20,000 tons of dead fish have to be discarded
each year. Globally, production of almost 1.9 million tons of salmon
produces a disposal problem for several thousand tons of dead and dying
salmon.
In
many parts of the world, thousands of tons of dead farmed salmon are
dumped every year in landfills. Because most salmon farms are in remote
locations, dead fish are often expediently dumped in isolated areas
rather than farmers paying to ship the waste to legitimate treatment
sites. In Scotland, for example, one company was caught dumping
thousands of disease-suspected farmed salmon on an environmentally
sensitive beach.
Alternative
disposal methods involve depositing fish in large silos and applying
chemicals to hasten decomposition. Dead salmon, some diseased and others
contaminated with chemicals, may also be used by farmers for fertilizer
or converted to compost and applied to farms and gardens. Still other
salmon "morts" end up in pet food or as feed on mink farms.
Closing the Net on Waste
Alternatives
to irresponsible dumping and waste discharge have been tried for
several years. Scotland's Environmental Protection Agency experimented
with various systems until the late 1990s when it yielded to industry
pressure and concluded that the cost of requiring new technologies was
"not viable for commercial salmon production under present economic
conditions." Similar studies in Canada, with treatments for waste water
from salmon farms, were also declared "uneconomic" and discontinued.
Although
dead salmon and their wastes can be safely disposed of with various
filtration and treatment systems to protect marine ecosystems, the
salmon farming industry has resisted all such proposals in the interest
of keeping costs low to offer the cheapest product possible. The savings
to consumers, however, means a far heavier price must be paid by wild
salmon, the shellfish industry, and traditional commercial fishing
livelihoods. More to the point, no one yet knows the true cost of cheap
farmed salmon to human health.
- S. J. Cripps and L. A. Kelly, “Reductions in wastes from aquaculture,” In D. J. Baird et al. (eds.), Aquaculture and water resource management, Blackwell Science, Oxford, 1996. See also J. R. Henderson et al., “The lipid composition of sealoch sediments underlying salmon cages,” Aquaculture, 158:69 (1997), pp. 83-89.
- M. MacGarvin, “Scotland’s secret? Aquaculture, nutrient pollution, eutrophication and toxic algal blooms,” WWF Scotland, Aberfeldy (2000), wwf.org.uk/fileLibrary/pdf/secret.pdf>.
- R. W. Hardy, “Urban legends and fish nutrition,” Aquaculture Magazine, Nov/Dec (2000), issues00/00articles/ND2000Urban.pdf>.
- Scottish Executive, “Eutrophication assessment of aquaculture hotspots in Scottish coastal waters,” Paper presented to OSPAR by the Scottish Executive, May 2003, .
- D. J. Wildish et al., “Acoustic detection of organic enrichment in sediments at a salmon farm is confirmed by independent groundtruthing methods,” Marine Ecology Progress Series 267 (2004), pp. 99-105, .
- K. Haya, “Environmental impacts of chemical wastes produced by the salmon aquaculture industry,” In B. T. Hargrave [ed.]. Environmental Studies for Sustainable Aquaculture 2002 Workshop Report, (Canadian Technical Report), Canadian Bulletin of Fisheries and Aquatic Sciences, 2411 (2002), .
- P. W. Balls, “Tributyltin (TBT) in the waters of a Scottish sea loch arising from the use of antifoulant treatment netted by salmon farms,” Aquaculture, 86 (1987), pp. 227–237.
- C. D. Miranda et al., “Diversity of tetracycline resistance genes in bacteria from Chilean salmon farms,” Antimicrobial Agents and Chemotherapy 47 (2003), pp. 883–888, .
- “Fears raised by salmon dump,” The Sunday Times, July 17, 2004, posted on “Aquaculture Corner,” of the Mangrove Action Project, org/map/ltfrn_159.htm>.
- G3 Consulting, Salmon Aquaculture Waste Management Review & Update, Report prepared for British Colum
