كليدواژه :
پزشكي , صاف سازي , تصفيه آب , بستر صافي , آنتراسيت
چكيده لاتين :
Increase in population and water demand is the reason why conventional rapid sand filters are not able to meet the water consumption demands. Anthracite as a filter bed medium (low density & large particles) is able to provide increased filtration rate. As anthracite is more expensive than sand, it is not possible to use it in many developing countries. Two series of tests were conducted: 1- Anthracite characteristics determination: Determination of "carbon, ash, sulfur, moisture and volatile matter content, rate of solubility in acid and base, relative density, hardness and crushing rate during the backwash. 2- Pilot plant tests: Measurement of turbidity, residual chlorine, total organic carbon, coliform content and surface over flow rate were preformed at the school of public health , Isfahan. For statistical analysis, the two statistical tests;T-test and co variance were used. The mean of "turbidities removal" in local and imported anthracite were 85.96 and 80.5 percent respectively (no significant value P>0.05) .The mean of "residual chlorine removal" in local and imported anthracite were 59.6 and 61/2percent respectively, (no significant value P>0.05). The mean of "total organic carbons removal" in local and imported anthracite were 47.2 and 63.4 percent respectively (significant value P<0.05). The mean time for receiving 1m height in filter pilot were 29min 30sec and 33min 42sec in the local and imported anthracite respectively (no significant value P>0.05).The local anthracite structural characteristics do not meet relevant standards, which is due to insufficient thermal processing.Reduction of residual chlorine and total organic carbon content in dual media filters is very complex and more studies are needed. "Surface over flow rate" results and also higher turbidity removal (5.5%) shows that imported anthracite has a more convenient grading than the local type. The study results show that local anthracite does not have a good grading for water treatment and needs revision on the grading.