Indian researchers convert textile waste into rich manure VERMI COMPOSTING

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http://blog.taragana.com/n/indian-researchers-convert-textile-waste-into-rich-manure-112362/ 

 

Indian researchers convert textile waste into rich manure 

 

July 17th, 2009

 

HISSAR - Earthworms and some animal manure could convert waste from the textile industry into a rich compost for agriculture, researchers here have found.

Most gardeners will tell you earthworm is their best friend as it aerates the soil and helps break down the soil materials, releasing nutrients for improved plant growth.

A particular species of earthworm, known as Eisenia foetida, thrives in rotting vegetation, compost, and manure. This species is grown commercially for composting because of its skills at converting organic waste into rich compost.

Vinod Garg, Renuka Gupta and Priya Kaushik of Guru Jambheshwar University of Science and Technology here say the red earthworms could be used to produce compost from the huge volumes of solid sludge produced by the textile industry.

Sludge from the textile industry is usually difficult to dispose of. Landfill and incineration are not viable options given environmental concerns and expense. The industry is under pressure to find a green, sustainable and cost-effective disposal method.

Garg and colleagues have now tested vermicomposting of solid textile mill sludge that has been spiked with urine-free cow and horse dung, collected from local farms, in a six-month pilot-scale experiment using E. foetida.

The composting process changes the physical and chemical properties of the test mixtures significantly, the team found. The vermicomposts are much darker than the original materials and form a compost-like, homogeneous mixture after 180 days.

The team also found that the earthworms grow well in this manure-enhanced sludge, said a release of the university.

These findings were published in the International Journal of Environment and Pollution.

attached growth airlift reactor (Agar) solution in South Africa

 

 

http://www.engineeringnews.co.za/article/innovative-biological-wastewater-treatment-solution-extends-natures-capacity-2009-07-24

 

Israeli firm launches wastewater treatment solution in SA

 

By: Shannon O'Donnell

24th July 2009

 

Israeli wastewater treatment solutions provider Aqwise has launched its
patented attached growth airlift reactor (Agar) solution in South Africa,
exploring for opportunities in the promising local market.

Aqwise is an advanced wastewater treatment solutions provider for the
industrial and municipal markets.

The Agar technology integrates fixed filmed and suspended growth
technologies and is considered the next generation in biological wastewater
treatment methods. The Agar technology combines a distinctive, fully open
and fully protected moving biomass carrierwith a highly efficient aeration
and mixing design. This results in a greater effective surface area for
biomass growth and the best oxygen transfer efficiency.

If an industrial plant is required to produce a higher-quality effluent
owing to increased regulatory requirements or the implementation of
water-saving measures, the Agar solution alters the biological environment.

This creates optimal conditions for enhanced removal of a wide variety of
pollutants, including organic load and nitrogen.

Aqwise business development manager Idan Tendler tells Engineering News that
the Agar technology significantly increases the capacity and efficiency of
existing wastewater treatment plants, while reducing the size of new plant
deployments.

The Agar system also has a limited footprint, making it a good solution for
industrial plants or municipalities that have limited spaceand are unable to
expand. "The solution offers significant space efficiencies in the
implementation of new reactors with a 30% to 60% reduction in reactor volume
when compared with conventional systems," says Tendler.

He explains that, by using Aqwise's solutions, mines and municipalities can
cope with more stringent water-sector regulation, ageing infrastructure and
a growing population. Industrial plants can meet the strict regulatory
requirements for discharging wastewater into the environment or into
municipal collection systems, and solve typical industrial problems, such as
variable inflow, seasonal peaks and high organic loads.

"The solutions may additionally facilitate in-plant reuse of the treated effluent with up to zero liquid discharge," he says.

Tendler explains that the Aqwise range of solutions may be applied to any
type of bio-logical process upgrade, including existing oxidation ponds and
activated sludge.

Further, the Agar technology can avoid or significantly decrease sludge
circulation, reducing the ongoing operation attention needed. "This makes
the system ideal for industrial plants with limited wastewater treatment
operations resources and minimal ongoing attention," he says.

Aqwise's technology is also currently being tested in reducing the amount of
iron in ground-water being released by mines into the environment.

• O'Donnell visited Israel recently, courtesy of the trade and economic
office of the Israeli embassy in Pretoria

Edited by: Martin Zhuwakinyu

mechanical composting..its problems

Almost all the large cities of the developing countries in the region in the past installed imported mechanical composting plants (for instance, built six). Most are now defunct and the remaining ones are not operating at full capacity (e.g., Bangkok, Hanoi, Shanghai, and Tokyo). The reasons why centralized mechanical MSW composting plants are not functioning effectively, are underutilized, or are closed down include: (a) high operating and maintenance costs compared to open landfilling (including foreign exchange costs for replacement parts of imported plants); (b) the cost of compost is higher than commercial fertilizers (both cost to purchase, and labor cost to apply to the fields); (c) incomplete separation of materials such as plastic and glass, making the compost poor for agriculture application; and (d) poor operation and maintenance of the facilities.

There are many technical and aesthetic problems to be solved in the composting of MSW. As one small example, an important, privately run vermiculture experiment in Indonesia failed when toxics in the MSW killed the earthworms.

 

Composting can be viable, especially for smaller cities with intensive agricultural areas near cities. Many international agencies and environmental consulting firms are offering Asian cities technology for composting as the process is increasingly gaining importance in all parts of the world. An issue here is whether the equipment offered is appropriate for the wastes of that particular place

 

Although one of New Delhi's plants has been closed, another is still operating. The compost is absorbed by the city's parks department, an example of how city procurement policies can help the marketing problem. In Kathmandu, the compost from a municipal plant was in high demand by local farmers in the late 1980s and early 1990s, and the plant continued with a simple windrow system after the machinery broke down. It was forced to close recently when residents of new housing estates protested.

Recently, however, private firms, alone or in public-private partnership, have revived centralized composting in a few places. Bangalore's windrow compost plant is reported to be cost-effective since privatization, although there are now NIMBY ("Not In My Back Yard") pressures at the site. There are experiments with new techniques for producing compost by processing partly decomposed wastes at dump sites (being done by a private company subsidized by the Bombay and Ahmedabad municipal corporations).

The subcontinent has wide experience with anaerobic digestion of cattle dung, and it was assumed that similar digesters could be adapted to ferment MSW, but producing animal-dung-like slurries from urban organic waste proved energy-intensive and the product was poor. A major problem with anaerobic digestion is that MSW used as feedstock tends to float. A number of design changes have to be achieved to produce small-scale digesters. Research is being done in Bangalore at the Indian Institute of Science, but there are no reports of successful large-scale anaerobic digestion.