investigation of heavy metals in water and sediment on massjed soleymantembi river before and after of wastewater entrance

background: this study was carried out to determination of heavy metals (cd, cr, cu, fe, pb, ni and zn) concentration in upstream and downstream of the entry of the wastewater (untreated urban, traditional slaughterhouse waste, leachate from solid wastes has accumulated in river and  run off waters flowing across the city ) to the tembi river. methods: samples were collected for 1 year, before and after the entry of the wastewater to the river. after dryness, digestion and thicken in laboratory, the samples were analyzed by flame atomic absorption aparatus. findings: results indicated that the average concentration of these metals in water on downstream was more than of upstream as well as in sediment. the comparison of the mean concentrations of heavy metals in water of the tembi river with drinking water standards and those in the water used for agriculture suggests that the mean concentration of cu and zn lies in the standard range for drinking water and the mean concentrations of mn ,zn and pb lies in the standard range of agricultural water. in addition  the average concentrations of cd, cr, pb, ni was higher than of the surface water standards. the highest average concentration on downstream for pb in water and for mn in sediment was 1.9 and 820 ppm, respectively. also the lowest average concentration on upstream was for cd in water and sediment with concentration of 0.07 and 10 ppm, respectively. conclusion: using of this water for recreational purposes, washing and fishing is not good for human health and the environment; it is necessary to take serious order to control the entry of the sewage, treat it before entering the river and manage the quality of water and the sediments of the river .