[Survey of electrocoagulation process in the removal of pathogen bacteria from wastewater before discharge in the acceptor water]

Due to population growth and expansion of agricultural industry in recent years, wastewater treatment is unavoidable. Therefore, using the Electrocoagulation process with aluminum electrodes to eliminate bacteria in hospital wastewater. This study is a pilot-scale batch that to verify removal rate of bacteria in hospital wastewater by using direct current electric. In this study, the effects of variables such as time [30, 60, 90 min], voltage [10, 20, 30 v] and type of electrode [Al] on the efficiency of bacterial removal were studied. The results shows that with increasing contact time and voltage, removal efficiency increases. The results indicate that the retention time and voltage changes can have different effects on bacterial removal efficiency. The rising voltage and time are causing increase bacterial removal efficiency due to the rapid production of hydrolysis products. The research results indicate that electric voltage treatment is effective for rapid removal of microorganisms in hospital wastewaters.

Study on the reuse of zamyad factory wastewater treatment plant effluent in irrigation

Considering the population increase in the cities and also the increase of per capita water consumption in these societies, the use of treated effluents for the green area irrigation has been taken into consideration. Human ever-increasing needs to green area in municipal societies and on the other hand the limitations in water supplies cause a new review in wastewater reuse. Also making use of treated effluents in irrigation has some limitations including clogging of the soil porosities, increasing of the chemicals and toxic substances to plants and increasing the probability of groundwater pollution. In this research, considering the indicators using recognition of the effluent's quality, at the first stage compound samples of domestic wastewater treatment effluents of Zamyad Factory were taken. The samples were tested from the viewpoint of quality. Results showed that the indicator of Sodium Adsorption Ratio, Sodium Percentage, amounts of chloride, and electrical conductivity comparing to Food and Agriculture Organization and Department of the Environment of Iran standards were higher than the standard levels. Also parameters such as TDS, TSS, BOD, COD, anions and cations were in standard levels. Results also showed that the increase of some of the undesirable parameters was not related to the operation of wastewater treatment plant. Therefore, in order to make the standard effluent, different methods may be proposed and the most practical and economical one is dilution by using 50% mixing with raw water