Wastewater is the water consumed by people which has been contaminated in various ways and therefore cannot be used by consumers. Due to the presence of various harmful chemical compounds, microbes and dangerous pathogenic agents, wastewater can cause many problems in various ways such as contaminating water, soil, agricultural resources and creating clinical risks for human health. Due to the dangerous effects of wastewater in urban sources, raising the quality of people's health and reducing pathogenic factors, governments are always trying to treat urban Sewerage. There are a wide range of different methods for urban wastewater treatment that can be used. Common methods and systems that countries use for Wastewater treatment have many problems. The high cost of wastewater treatment and high energy consumption by these systems can be part of these problems. Biological methods can be an alternative to the existing methods in countries for wastewater treatment. The use of different organisms such as plants is one of these biological methods that have less environmental impact and is a type of technology based on the use of plants to remove pollutants and pathogens from Wastewater at a low cost that is compatible with the environment. According to the bioremediation effects of plants Ceratophyllum demersum and Potamogeton pectinatus which have been identified in various articles these plants were used as sanitary wastewater treatment agents. In the present study, wastewater samples were collected from industrial areas and species Ceratophyllum demersum and Potamogeton pectinatus were placed in aquariums containing wastewater. Various physiological parameters such as pH, Electrical Conductivity, Total Suspended Solids, Total Organic Carbon, Total Dissolved Solids and nitrogenous chemical compounds such as NO3 and NO2 as well as phosphorous compounds such as PO4 were investigated in the presence of plants and before the treatment of plants. Also, the bacterial test was done to check the allelopathic property of the studied species. In addition, the concentration of heavy metals copper, cadmium and nickel in wastewater as well as plant tissue was measured in order to investigate the phytoremediation ability of species Ceratophyllum demersum and Potamogeton pectinatus. The results showed that all the physiological parameters of the wastewater except for pH and bacterial test decreased in the presence of treated plants in the wastewater. It was found that the Potamogeton pectinatus species compared to Ceratophyllum demersum could have a better effect in reducing pH, Total Organic Carbon, and No2 in wastewater and showed more accumulations of Cd and Cu and had a greater phytoremediation ability in cadmium and copper, but the Ceratophyllum demersum species decreased It had more No3, Po4 and the total number of bacteria in the wastewater, and it was able to accumulate more nickel and show a higher phytoremediation ability. Also, the results of correlation showed that Total dissolved solids showed a positive correlation with Electrical Conductivity, copper, cadmium, phosphate and Total Organic Carbon respectively. Electrical Conductivity has a positive correlation with copper, cadmium, nickel, phosphate, Total Suspended Solids, Total Count Bacteria and Coliform bacteria. pH showed a negative correlation with the heavy metals nickel, cadmium, nitrogen dioxide and Total Organic Carbon. It was found that the concentration of the heavy metal copper in the plant showed a positive correlation with all parameters except for pH, Total Dissolved Solids and EC, and nickel metal also correlated with all parameters. Except for copper, PH, Total Dissolved Solids and Electrical Conductivity showed a positive correlation. In addition, the concentration of cadmium metal showed a positive correlation with all physiological and chemical parameters except heavy metals copper and nickel and pH, Total Dissolved Solids and Electrical Conductivity. The amount of nitrate has a positive correlation with nitrogen dioxide, phosphate, Total Suspended Solids and Total Count Bacteria, and the amount of nitrogen dioxide has a positive correlation with phosphate and Total Organic Carbon. Phosphate was positively correlated with Total Suspended Solids, Total Organic Carbon, Total Count Bacteria, Coliform bacteria. Also, Total Suspended Solids showed a positive correlation with Total Organic Carbon, Total Count Bacteria and Coliform bacteria. Total Organic Carbon and Coliform bacteria showed no correlation with any of the physiological and chemical parameters, but Total Count Bacteria only showed a positive correlation with the number of Coliform bacteria. It is suggested that the above plants can be used to treat wastewater and find a biological way to reduce heavy metals in wastewater.
