Metallic pollution caused by elements Zn, Cu, Fe, Pb, Ni, Cd, and Hg in water and sediments of Aras River within a specific area in Ardabil province of Iran is considered. Water and sediment samples were collected seasonally and once respectively from the five selected stations. Regarding WHO published permissible values, only Ni concentration in spring and summer water samples has exceeded the acceptable limit up to four times greater than the limit. The concentration of metals Ni, Pb, and Fe in river water shows a direct relationship with river water discharge and the amount of precipitation. Enhanced soil erosion, bed load dissolution, and runoffs may play a key role in remarkable augmentation of metallic ions concentration. Furthermore, excessive use of pesticides which contain a variety of metallic ions (mainly Cu) in spring and summer may also result in an increase in the metals' concentration. The potential risk of Ni exposure to the water environment of the study area is assigned to juice, dairy products, edible oil, and sugar cane factories as well as soybean crop lands which are located within the sub-basin of Aras River in the study area. Regarding the sediment samples, the bioavailable metal concentrations indicate an ascending order from the first station towards the last one. In comparison with earth crust, sedimental and igneous rocks the reported metallic concentration values, except for Cd, lie within the low-risk status. Regarding Cd, the reported values in some stations (S2, S4, and S5) are up to ten times greater than that of shale which may be considered as a remarkable risk potential. The industrial and municipal wastewater generated by Parsabad moqan industrial complex and residential areas, in addition to the discharges of animal husbandry centers, may be addressed as the key factors in the sharp increase of metallic pollution potential in stations 4 and 5.

Aras (situated on the frontier river) is one of Iran's important rivers which is situated on the west North of the country. The concentration of heavy metals in this river was studied around Ardabil province during the 1389 in all four seasons (spring, summer, autumn, winter). The cluster analysis technique with the help of the results gained from density of metals like (Zn, Cu, Fe, Hg, Ni, Pb, Cd) was used in the water of Aras river for classifying quality of the river. According to the gained results from the cluster analysis, the stations were divided into three groups with high pollution (HP), medium pollution (MP) and low pollution (LP). In general, S3, S5 stations with high pollution, S2, S4 stations with medium pollution and S1 station with low pollutions are classified in the water of Aras River.

No abstract

In studies of groundwater, the issue of quality as well as quantity has particular importance, and as long as conditions of groundwater quality and quantity in different dimensions such issues are not analyzed, it cannot explain the general characteristics of the aquifer. In this study, to investigate the heavy metal pollution in Karaj plain, fi rst, from 59 selected source of plains were sampled and the samples were analyzed using atomic absorption. Map of the metal pollution refers to segregation were prepared. After the analysis conducted on selected samples of Karaj plain, concentration maps for heavy metal cadmium, lead, copper, cobalt was prepared for seasons to seasons probe and low-water of plain. According to classical statistics, as well as the results statistically signifi cant difference between the stations were obtained in terms of the concentration of these elements. The results showed that there are significant differences between the two seasons. In view of the heavy metals concentration maps of the southern part of the plain interpolation sampling points was observed in terms of emissions is much higher than the average standard of the World Health Organization. Stations located in the southern plains, such as Safar Abad Fashafouiyeh, Mahmoud Abad, Ghanbar Abad, Ghamsar, Kahrizak, Hesar-e Chupan and etc. in all the elements in this study were plain compared to the upstream areas of concentration and excessive pollution. But certainly in the long-term trend of groundwater contamination and no space will be followed by many environmental risks.

Background: The feasibility of converting organic wastes into vermicompost and the effect of adding such wastes onto the substrate on the growth and reproduction of the earthworm 'Eisenia fetida' were investigated in the present study through a factorial experiment with completely randomized design in triplicate, consisting of two factors. Methods:The first factor with nine different treatment combinations included control, potato (P), carrot pulp (C), vegetables (V), sawdust (S), potato, vegetables, carrot pulp (PVC), sawdust, potato, carrot pulp (SPC), vegetables, sawdust, potato (VSP), and carrot pulp, vegetables, potato, sawdust (CVPS), and the second factor was related to two different substrate concentrations of 100 and 150 g. This research was carried out using a basket method in Tonekabon County in 2021. The base substrate of earthworms was animal manure positioned in boxes and washed with urban tap water to reach a pH value of 6.5-7. After ripening the vermicompost, the boxes were emptied and the number of worms was counted individually. Results:The results of analysis of variance showed a significant difference in the number of cocoon between the studied treatments (P<0.1), but no in the number of worms between the groups. The maximum number of cocoon (mean= 605) corresponded to the sawdust treatment combination (S) and the minimum number of cocoon (mean= 185) was found in the vegetable treatment combination (V). Conclusions: Overall, the results of this study demonstrated that the treatment of manure bed with sawdust wastes provided the optimal conditions for the growth and reproduction of earthworm 'Eisenia fetida.