Background and objective: Hydrogen peroxide solution with stabilized formulation with oligodynamic amounts of silver ion (trade mark: Nanosil) recently became a popular disinfectant for fruits, vegetables, surfaces, medical instruments and so on.Methods: This study was based on determining efficiency of hydrogen peroxide-silver ion complex in six different concentrations measured through removal of total coli forms from samples taken from Qom wastewater. All six different concentrations of disinfectant were incubated separately with wastewater for one hour. Sample size was 12 and sampling was done weekly. Results: In the concentration of 80 and 480 mg/l, logarithmic removal value of total coli forms was 1.9 and 4.5 respectively. In CT value 8600(mg/l).min and more, the total coli forms effluent standard for surface water discharge and agriculture irrigation was achieved (Iranian environmental protection agency act).Conclusion: Use of hydrogen peroxide-silver ion complex as a water and wastewater disinfectant, has some benefits such as elimination of hazardous by products, measurable residual amount and so on. However its application in wastewater effluent is more costly than other usual disinfectants so it is not economically advisable.

In this research polypyrrole (PPy) and polyaniline (PAni) conducting polymers which were synthesized chemically on the surface of wood sawdust (SD). These electroactive polymers as coated form on sawdust then were used for sorption or removal of silver ion from aqueous solutions under simple open circuit conditions. The effects of some important parameters such as pH, initial concentration, sorbent dosage, and contact time on uptake of silver ion were also investigated in this research. The experiments were carried out using both batch and column systems at room temperature. The treatments of the data were carried out using both Freundlich and Langmuir adsorption isotherms. In order to find out the possibility of the regeneration and reuse of the exhausted adsorbent, desorption studies were also performed. It was found that conducting electroactive polymers such as PPy or PAni are efficient sorbents for removal of the silver ions from aqueous solutions. Sorption/desorption processes can be simply carried out with pH control with satisfactory performance. Recovery percentage observed for PAni/SD in column study was more than PPy/SD and SD, under the same operational conditions.

A sensitive spectrophotometric method was studied for the determination of silver ion in the presence of several interfering metal ions with high concentrations. This method relies on the formation of a complex between silver and 2-[2-(5-nitrothiazolyl)azo]-4,6-dibromophenol (NTADBrP). The new method was applied to determine the silver content in the metal alloys used in dental amalgam. The detection limit for the silver ion was 0.139 μg/mL, and the range of concentrations following Beer's law was from 1.0 to 50.0 ppm. The average percentage of silver present in the dental fillings was 38.9% with a standard deviation of ±0.01% and a recovery rate of 97%. UV-Vis spectrophotometry was used to compare it with the actual percentage of silver in the dental filling material, as indicated by the manufacturer, with no statistically significant differences.

Monitoring the levels of toxic Hg2+ metal ions in an aquatic environment is an important issue because this ion can have an adverse effect on human health and the environment. Therefore, the detection of Hg 2+ ions in water is a very important issue for improving human health and water quality. Metallic nanoparticles such as gold and silver nanoparticles (AuNPs & AgNPs) have received much attention due to their colorimetric properties as well as localized surface plasmon resonance (LSPR) properties. AuNPs and AgNPs can easily change their color (AuNPs: Red to Pink/Blue; AgNPs: Yellow to blue) which is easily discriminated by visual inspection. Functionalization of AuNPs and AgNPs offers an excellent application in many scientific worlds as the choice of ligands/functionalizing groups is of utmost importance for their colloidal stability and function of the nanoparticles. In this review, we have discussed the colorimetric sensors of gold and silver nanoparticles based on the functionalization of organic ligands, polymers, amino acids, and proteins for the detection of Hg 2+ ions in an aqueous medium.

Background: Ion silver from the internal surfaces tubes and generators inter to industrial wastewater by corrosion process. These ions have harmful effects on plants, animals and humans.Iron oxide is commonly used to removal chemical contaminates. However, the used of nanoparticles in removing pollutants is more effective than the mass. In this study, using of iron oxide nanoparticles for removal silver ions from synthetic industrial wastewater was investigated and the effective parameters were optimized for the better removal.Method: This study is a experimental-laboratory that iron oxide nanoparticles was synthesized by exposing nZVI into air and then Ag+ removal efficiency was studied in batch system. Also, the impact of the important field parameters including pH, iron oxide nanoparticles concentration, retention time, and temperature were investigated. After centrifugation and filtration, the amount of ion silver was determinate by flame atomic absorption.Results: The results of this research showed that iron oxide particles were reacted with Ag+ in nano scale. The maximum removal at pH=3, nano iron oxide concentration 35 g L-1 and 25oC was %99.2. In optimum condition (pH=3, nano iron oxide concentration 10 g L-1, 5 hours reaction time and 25°C temperature) %87 of Ag+ was removed.Conclusion: The concentration of nano iron oxide and pH had significant effect on the Ag+ removal. The results showed that Ag+ removal in acidic pH controlled by absorption on surface then reduction by atomic core. While, removal in basic pH controlled by absorption. The studies showed that iron oxide nanoparticles have high ability to remove Ag+ and decrease of chemical pollution of Ag+ from industrial wastewater.