Welcome Rakan Sarawak April 2005

Rangkaian Khidmat Awam Negeri Sarawak

A MONTHLY SUPPLEMENT OF RAKAN SARAWAK BULLETIN

(People, events, activities and programmes which make for a total quality-managed Sarawak Civil Service)

ISSN 1394-5726

Online Publisher:

Contents provided by:

Arsenic Detection In Drinking Water…Suitable Technology Should Be
Developed For Individual Households And Small Communities

The incidence of arsenic poisoning due to drinking water contamination is extremely rare in our country. But in Bangladesh and some other parts of the world, it is a worrying phenomenon.

There have been major developments in the treatment of arsenic groundwater in the last few years but high costs are hampering the introduction of these technologies in developing countries, especially in places where there is no centralised ater system.

The technology for arsenic removal for piped water supply is moderately costly and requires technical expertise. It is inapplicable in some urban areas of developing countries and in most rural areas worldwide.

New types of treatment technologies, including co-precipitation, ion exchange and activated alumina filtration are being field-tested. There are no proven technologies for the removal of arsenic at water collection points such as wells, hand-pumps and springs. Simple technologies for household removal of arsenic from water are few and have to be adapted to, and proven sustainable in each different setting. Some studies have reported preliminary successes in using packets of chemicals for household treatment. Some mixtures combine arsenic removal with disinfection.

One example, developed by the WHO/PAHO Pan American Centre of Sanitary Engineering and Environmental Sciences in Lima, Peru (CEPIS), has proven successful in Latin America. A newly-designed equipment by research scientists for arsenic removal based on a new technology is being tested - Membrane Distillation (MD), which actually removes arsenic completely in a simple and reliable way.

Bangladesh... Pumping the deep aquifer at 700 gallons a minute to test the aquifer properties

This technology is now being developed to prototype and pilot stages. Laboratory tests certify that the technology removes As+3 as well as As+5 to below the detection level (< 3 micrograms per litre) of state-of-the-art measuring instruments (AAS Graphite), i.e. more than 99.97% removal of both As+5 and As+3.

An added advantage of the technology is that it does not require expert monitoring and is easy to maintain and service and therefore could be used in small plants, at wellheads and in individual households. In Bangladesh, several thousand people had been diagnosed with arsenic-related diseases and millions were at risk from arsenic poisoning from drinking ground water with arsenic in excess of acceptable limit.

The state water authorities including environmental departments are constantly monitoring drinking water supply sources to prevent any occurrence of arsenic seepage from the ground.

Susceptible... No proven method of removing arsenic from water collection points such as wells and springs in areas with high incidence
of arsenic in the ground