Urban Storm runoff Quality and Sediments with Heavy Metals in Shiraz City Infiltration Pond and Investigation of Sorbent Materials fot Polution Reduction

Heavy metals are considered one of the most important environmental pollution and are dissolved form or adsorbed to the suspended solides in the urban storm runoffs and infiltratire ponds. In this article the heavy metals of urban storm runoff and sediments of infiltration pond in Shiraz city have been investigated. The results show different pollutions in the urban storm runoffs such as dissolved heavy metals with low consentration, although most of them adsorbed to the suspended solids and displaced. Based on the result, (95-100)% Iron, (91-100)% Copper, (79-100)% Zinc and (47-100)% Manganese , have been adsorbed on the suspended solids of storm .Heavy metals such as Zinc, Iron and Copper are also existed in the surface layer of infiltration pond and existence of them in the bottom layer represents that these metals have been moved downward; however the upper layers have sufficient adsorption capacity. For treatment of urban storm runoffs contamination, different sets of batch adsorption tests in the laboratory scale have been conducted with some low cost adsorbents such as, sawdust, flyash and sand. In order to zinc metal has a most mobility in the soil, so it has been selected and optimum ph for maximum adsorption of it obtained.Treatment of total dissolved solid by sawdust represent that maximum adsorption is 39% for 20 g/l adsorbent also; greatest removal of suspended solid is 80% for 10 g/l sawdust. Therefore to protect the groundwater resources under infiltration ponds and achieve the desired water quality management goals, such low cost adsorption systems could be carefully designed before ponds by using sufficient site specification information of storm quality.