The ArrowBio Process is a waste treatment system coming under the umbrella of Mechanical Biological Treatment (MBT). The process is an alternative to the landfill and incineration. The ArrowBio process aims to treat the components of waste as recoverable resources as opposed to a disposal problem. ArrowBio also converts the biodegradable component of household waste into soil improver and biogas which is in turn converted into green electricity. The first commercial ArrowBio facility was installed in January 2003 at the Hiriya just outside Tel-Aviv in Israel. The ArrowBio Process is marketed internationally by Arrow Ecology Ltd and in the UK & Ireland by Oaktech Environmental.



The Dan Association of Towns Waste and Recycling Park at Hiriya in Tel-Aviv, Israel. Location of first commerical ArrowBio facility.

Process Description

ArrowBio consists of two integrated yet distinct phases:

Water-based Separation

In the first phase unsorted household waste is processed directly as tipped from the collection truck. Organic and inorganic materials are separated through a unique, liquid-based technology, involving gravitational settling, screening and hydro-mechanical shredding of organic solids.

The first stage end products are clean recyclables such as glass, ferrous and non-ferrous metals and plastic (separated into PET, HDPE & film plastic). Items such as batteries are carefully removed, without breakage, thereby avoiding leakage of potentially toxic materials. The other intermediary product is a dilute organic stream now ready for the next, biological stage. The first stage thus performs two functions; separation and preparation of the waste, without additional machinery or effort.

In addition to removing inorganic and other non-biodegradable materials, the liquid-based separation simultaneously conditions the organic material for rapid biological action. This is accomplished by bringing the organic matter into solution or fine suspension. This slurry has a high chemical oxygen demand.





Anaerobic Digestion/Waste Water Treatment Plant

In the second stage the liquid is then sent to a series of tanks which support the high-rate transformation of the organic wastes to biogas (on average 75% CH4). This process is facilitated by naturally occurring microbial communities, in two highly controlled sequential bioreactors. ArrowBio utilises an advanced variant anaerobic digestion technique called up-flow anaerobic sludge blanket (UASB) digestion. Biogas production by this method far exceeds in-house energy needs.

The solid organic matter is thoroughly stabilised and usable directly as an organic fertiliser. Excess water is either cleaned and removed from the system or recycled and sent as liquid to the upfront separation stage, and so the system is autonomous with respect to energy and water.

The biogas is consumed by electricity generators, producing five times the electricity the plant requires to operate.




-- 11:57, 27 April 2006 (UTC)

External Links

ArrowBio International Site Arrow Ecology Ltd (Tel-Aviv, Israel)

ArrowBio UK and Ireland site Oaktech Environmental (Manchester, UK)

ArrowBio Video

Juniper MBT Report Independent Evaluation of Different MBT Technologies by Juniper Waste Management Consultants

EA Report English & Welsh Environment Agency Waste Technology Data Centre Report