Purpose The research was focused on evaluating phytotoxicity of sewage sludge from two selected wastewater treatment plants in Czech Republic. Methods Laboratory experiments were carried out with samples of sewage sludge, which were focused on the evaluation of their phytotoxicity by using the PhytotoxkitTM testing set. Specifically, the inhibitory/stimulating effect was established on the growth of roots from the seeds of white mustard (Sinapis alba L. ). The chosen proportions of sewage sludge were 10%, 30% and 50%. The test was conducted in three repetitions. Additionally, the research also included a comparison of the effect of compost addition to the sewage sludge and its potentially increased stimulating effect on the growth of roots from the seeds of white mustard (Sinapis alba L. ). Ratios of compost were 5%, 15%, 25% and 50%. The test was conducted in three repetitions. Results Stimulating effect on the growth of white mustard (Sinapis alba L. ) was demonstrated only in samples with the sludge proportion of 10%. The results also show that the addition of compost reduced phytotoxicity of sewage sludge in all three tested ratios (5%, 15%, 25% and 50%). Conclusion It was found out that the addition of compost resulted in the decreased phytotoxicity of all tested sewage sludge samples, and hence in their suppressed inhibitory effect.

This study investigated the occurrence and removal of 12 antibiotics (ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, nalidixic acid, azithromycin, clarithromycin, roxithromycin, lincomycin, novobiocin, sulfamethoxazole, trimethoprim) at four sewage treatment plants (STPs): two STPs in Kyoto, Japan and two STPs in Beijing, China. The STPs differed in design and operation conditions, utilized a variety of secondary treatment processes. The antibiotics were frequently detected in influents and effluents, and ranged from ng/L up to lower mg/L. In influent, clarithromycin (1.1–1.6 mg/L) and levofloxacin (3.6–6.8 mg/L) were detected in the highest concentration in Japanese and Chinese STPs, respectively. The overall elimination of the antibiotics were differed between STPs and ranged from negative to>90%. These data demonstrate that there are detectable levels of antibiotics are discharging from STPs, and only some of these antibiotics are being removed in a significant proportion by STPs. It was also observed that biological nutrient removal based sewage treatment processes (anaerobic– anoxic–oxic: A2O; and anoxic–oxic: AO) have relatively higher antibiotics removal efficiencies than oxidation ditch (OD) processes.

Urban centers, due to population density and the density of water supply and wastewater collection and disposal facilities, need to be provided with care, reinforcement and special measures to deal with the effects of natural events, especially floods. The area of aAbfa in Tehran The northernmost region of Tehran is considered. while the main rivers that affect the settlements of Tehran and its vital arteries and are always considered as a risk factor for the flood. The rivers in northern Tehran, despite the average discharge rate, have relatively high flood flows that can cause severe floods in the downstream areas. The research method was based on descriptive-analytical method and conducted by library and field studies. In the research stages, firstly, the effective sub-criteria for the vulnerability of the research area were determined and were weighted by AHP-FUZZY method. As a result, the effect of each of them on the vulnerability of the indicated indicators was determined and distributed using the TOPSISIS model. Runoff modeling was performed using maximum daily rainfall of Tehran's meteorological stations, which was used to estimate the runoff height of the studied area using Arc CN-Runoff method. Overall, the results of sewage vulnerability in the 20-year runoff scenario, Most vulnerable In two categories High and very high (29. 27%)In the area of one Tehran was observedWhile the lowest vulnerability was seen in low and very low (94. 66%) areas in Zone 6, the results were cleared, Tehran is one of the four other areas of Tehran's water and sewage Due to the high cumulative facilities with high economic value (sewage pipes and manholes), high cumulative risk centers (gas stations and transmission lines), aging texture, gradient, high population density, condition of facilities (in terms of diameter and depth of brokerage Specifically with respect to the Preference index hydrology and wells In particular watercourse north Tehran (Darakeh Darband, Velenjak, maqsud beyk, Jamshideh Darabad and Lark) An obstacle to the placement of the facility buried in deep depth for protection and security are the and other variables, There is a substantial risk that no.

The use of ArcGIS software for determining the sewage design de data has been investigated in this thesis. In addition visual Basic program was used for sewage analysis on studying zone (Nabovat minacity in the IIam province). Research stages are as following:The data needed for design such as sewer pipe length, zone area covering a sewer and interpolation of earth height digits in site of manholes were determined by ArcGIS software.Then data related to characteristics of topography and statistical data (e.g. population and water and wastewater capita) in the studying geographical zone were prepared.This data are basis of sewage designing and these were prepared by valid references (e.g. books about geographical and statistical data) and through reference to related foundations and firms (e.g. Iran statistics center, water and wastewater firm and consulting engineering company for using of data related to neighbor zones of designing zone because of approximate similarity of description data demanded for designing).In the next stage the data was output by Arc GIS software, Data analysis was performed through a Visual Basic program.This research Results have specified that usage of ArcGIS software and visual Basic programing have brought about facilities for sewage design.

The Ravanj sewage treatment plan is in south of Delijan located in Markazi province. Rananj is located in mounted area and stoned layer coursed a dangerous condition because of no water drainage. So, water and sewerage management company decided to solve this problem by evaluation of its treatment. Refining of waste water done by Hans bioshoft package is used. This package is a safe, trouble free and environmentally friendly, has on biological filtering of odors, and can be installed on the ground in different levels. After installation the Hans bioshaft system, BOD and COD for out flow samples were measured. The results shown that the BOD and COD out flow are higher than standard BOD and COD proposed environment standard. We proposed some of recommendation for solving this problem. At the end, the results shown that the BOD and COD out flow were gone to suitable range.

Background: Human group A rotaviruses are the most common cause of severe diarrhea among children <5 years of age worldwide. Rotaviruses are widely present in environmental water. The aim of this study was to detect the human group A rotaviruses in urban sewage, hospital sewage and river water samples in Alborz province using ELISA method. Materials and methods: This cross-sectional study was carried out on 76 samples collected from both influent and effluent water of 4 sewage treatment systems, hospital sewage, Karaj and Baraghan rivers in Alborz province. All samples were concentrated using pellet method. Afterwards, human group A rotaviruses were detected using ELISA method. Results: In total, rotaviruses were identified in 6 samples (7. 89%) using ELISA method. Three positive samples (50%) were related to the raw sewage influent and three positive samples (50%) were related to the Karaj river. The frequency of rotavirus detection in summer, autumn and winter was 1 sample (16. 66%), 3 samples (50%) and 2 samples (33. 33%), respectively. Conclusion: This study showed the contamination of environmental water by human group A rotaviruses. Therefore, it is necessary to constantly monitor sewage treatment systems and river water for detecting rotaviruses.

With the development of industries and agriculture, the issue of water supply and the consequent challenge of sewage is becoming increasingly important. Water recycling and the use of treated sewage is the most desirable option for water supply. Considering the operating costs of modern sewage treatment plants, the economic aspect of the issue should be considered in order to provide treatment costs in addition to the desire of wastewater consumers. In Mashhad, before 2016, all existing sewage treatment plants were stabilized by the traditional method and their treatment costs were not significant. Therefore, most of the sewage received income was spent on developing the sewage collection network. But in 2016, with the opening of two modern treatment plants in Mashhad, with a capacity of 60, 000 and 65, 000 cubic meters per day, each of which can bring the quality of effluent to standards of discharge to surface water, the issue of sewage price and the total treatment price of each cubic meter of sewage become important. Also, by imposing penalties based on quality parameters, certain subscribers such as restaurants and hoteliers can be directed to pre-treatment before evacuation to the network. In this article, based on the extracted results during one year of operation of these two treatment plants, comparisons have been made in terms of construction costs, operation, consumables, personnel and finally the output of both treatment plants which should introduce the advantages and disadvantages of both methods in terms of ease of operation and economic efficiency and in the construction of treatment plants, the type of treatment method should be selected with more awareness.