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DOWN TO EARTH MATTERS: ENVIRONMENTALLY RESPONSIBLE SEWAGE TREATMENTS
by Sarah Greenlees

We have treated the oceans as a "supermarket and a sewer."ⁱ Sylvia Earle, a prominent oceanographer and conservationist, was recently quoted as saying in Time magazine. As a result we put at risk Earth's capacity to balance carbon dioxide and other gases in the atmosphere as well as destroying some of the least explored ecosystems.

A recent study into the world's rivers led by Charles Vörösmarty of City College, New York (published in Nature magazine; 30 September 2010; "Rivers in Crisis") revealed that 80 percent of the world's population live in areas where rivers are in a threatened state.ⁱⁱ

As architects strive to have a low impact on the land, the impact that is put on waterways also needs to be considered, and this makes treatment of sewage one of the most important factors of environmentally responsive design.ⁱⁱⁱ

In developed countries the municipal plants can, on the whole, deal with the capacity. However, in developing countries the municipal plants are often oversubscribed and have trouble keeping up with the rate of development. Feeding into the municipal line merely avoids the problem of responsible sewage management rather than finding a solution.

In light of this, two Malaysian companies are experimenting with solutions that aim to enhance sewage treatment and management. Hasegawa & Xavier Associates Sdn. Bhd. is proposing to use a modified version of the Infinity BioSolve system—a more efficient and flexible system that can digest sewage to a higher level than current systems and remove virtually all pathogens—for a project in Kota Kinabalu, and Arkitrek Sdn. Bhd. is in the process of constructing two prototype biogas digesters in Sabah.

ⁱ Time; Oct 4, 2010; Walsh, Bryan; "Code Blue. One woman's quest to save our oceans the simplest way: protect them"
ⁱⁱ www.mongabay.com; Sept 29, 2010; Hance, Jeremy; "Rivers Worldwide in peril: society treats symptoms, ignores causes"
ⁱⁱⁱ The aim of all sewage treatment is to raise the quality of the effluent. Effluent quality is measured in Biological Oxygen Demand (BOD). It is a measure of the oxygen that the effluent would take up when dumped into a river (required by aerobic microorganisms to decompose the organic matter in a sample of water such as that polluted by sewage). If the discharge BOD is high, it will grab oxygen from the river and can result in the river 'dying' due to a lack of oxygen. Therefore, the lower the BOD the less harmful the effluent will be.

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