Possibilities of exchanging know-how, scientific partners and information between China Society of Geochemistry and Brazilian Association of Geochemistry-SBGq

The Brazilian Society of Geochemistry--SBGq founded in 1985, is located at Rio de Janeiro, Brazil, having more than 300 affiliates that represent most of the principal Brazilian universities. The main SBGq way of divulgation is an international magazine-Geochimica Brasiliensis and a site： www.sbgq.org.br/. Regular meeting of SBGq is realized in each two years in odd years The last meeting it has been realized together the Geochemistry of Portuguese Language Countries and Geochemistry Symposium of the MERCOSUL countries （Argentina, Brazil, Paraguay and Uruguay）. During the even years are realized specific meeting as Environmental Geochemistry in Tropical Countries. The SBGq is associated with other Brazilian scientific societies as Latin American Association of Organic Geochemistry--ALAGO. During its existence the SBGq has published approximately 3000 papers related to the environment, lithogeochemistry, isotopes, surface geochemistry, organic geochemistry, coastal environmental geochemistry, secondary environments, hydrogeochemistry, exploration geochemistry, magmatic geochemistry, rare earth geochemistry, geochemistry of carbonations, biogeochemistry, mineral geochemistry, geochemistry vs. geochronology and geochemistry of precious metals.

Possibilities of exchanging know-how, scientific partners and information between China Society of Geochemistry and Brazilian Association of Geochemistry-SBGq

Recent surveys carried out to investigate the quality of groundwater in dug wells of Sri Lanka indicated that some areas in the Dry Zone have the fluoride problem in endemics proportions. In these studies it is clearly revealed that more than 50 percent of drinking water wells had fluoride levels exceeding 1.0 mg/L in the fluoride rich areas. Therefore, a technique for the defluoridation of fluoride-rich waters is necessary. This paper discusses the application of a simple technique of defluoriation of water, which is designed to distribute among the rural communities in Sri Lanka. More than 5000 water samples were analyzed to determine the fluoride content in dug wells. The fluoride levels of the water samples were measured by digital fluoride meter using standard reagents and colourimetric method in the field itself. The newly designed household defluoridator is 100 cm in height, 20 cm in diameter and is fabricated using PVC pipes. The inner pipe is 2 cm in diameter with a circular perforated plate fixed at 5 cm from the base of the filter. The outlet is fixed 5cm below the top of the filter. The filter unit is packed with broken pieces of freshly burne bricks measuring 8-16 mm in size and up to 75 cm in height. The fluoride-rich water is fed through the inlet pipe. At the beginning the filter unit is filled with fluoride-rich water and kept for at least 12 hours to obtain an equilibrium. Thereafter, fresh fluoride-rich water is fed through the inlet pipe and an equal volume of defluoridated water comes out automatically through the outlet pipe.