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Background and purpose: Treatment and disposal Septage in developed countries is subject to strict regulations and standards, but in most developing countries, there is no decent standard. Septage if not treated properly can create many problems. This quantitative and qualitative study of urban Septage was done in East Mazandaran (Sari, Behshahr, Neka and Galogah) to provide administrative approaches. Materials and methods: Primarily related agencies and offices that discharged septage and discharge tanker operators in the region were identified. The data including the capacity of tankers, the frequency of discharges, septage type, discharge locations, etc. was collected. The sampling was performed in 14 times on different days. The samples were then transferred to the laboratory at 4 ° C. All experiments were performed according to standard methods for the examination of water and wastewater. SPSS.18 was used to analyze the data. Results: From 45 tankers operating in the study area, 30.7 percent had a business license. About 85 percent of septage transport was domestic (toilet, shower, etc.) and 15 percent was industrial wastewater. Total transferred septage of East Mazandaran cities, was 50 cubic meters. The values of TSS, BOD, and COD were lower than EPA guidelines. However, the values of TKN, NO3, NH4, and TP were slightly more than EPA guidelines. The minimum and maximum COD for septage was 2000 and 20000 mg liter, respectively. The maximum BOD5 was 7907 mg per liter. Average total coliform and fecal coliform per ml were 33790000 and 39550000, respectively. The maximum ammonia nitrogen was about 900 ppm. Maximum Kjeldahl nitrogen in East Mazandaran septage was more than 2500 mg per liter. Conclusion: Short-term treatment with alkali is easy to use and affordable which reduced MPN/100cc to less than 1000. Furthermore, combining three anaerobic baffled reactors (ABR) with activated sludge and sludge drying beds is applicable for treating septage in Eastern cities of Mazandaran. Therefore, authorities should focus on new methods for treating wastewater to reduce such environmental problems.

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Background and purpose: Municipal wastewater treatment plant effluents are amongst the main available water sources. Reuse of these effluents requires further standards beyond secondary standards. Therefore, removal of organic pollutants and some compounds such as nitrate and phosphate from effluents should be done at a greater extent. In this study, removal of these compounds from secondary effluent was examined using an absorbent of iron oxide nanoparticles (MNPs Fe₃O₄).

Materials and methods: The research was carried out using actual effluent of urban wastewater treatment plant in laboratory scale. The iron oxide nanoparticles (MNPs Fe₃O₄) was used for removal of target pollutants by investigating different parameters such as pH, initial concentration, contact time, and adsorbent dosage using optimization of one factor at a time. Afterwards, the optimum condition was determined by adsorption and kinetic isotherms.

Results: The average BOD₅, COD, nitrogen, and phosphorus in wastewater treatment plant effluent were found to be 25, 43, 63 and 8.6 mg /L, respectively. The optimum conditions for adsorption of these pollutants by Fe₃O₄MNPs were obtained at pH 3, 15 min contact time and absorbent dosage of 1 g/l. Removal of PO₄^3-, NO^-₃, BOD₅ and COD in the optimum condition was obtained to be 54, 11.5, 56, and 75%, respectively, and the maximum adsorption capacities for target pollutants were 4.7, 1.6, 14, and 32 mg/g.  The results showed the adsorption by Fe₃O₄ followed the Freundlich model and pseudo first-order kinetic for COD and PO₄^3- and pseudo second-order kinetic for BOD₅ and NO^-₃ removal.

Conclusion: Iron oxide nanoparticles (MNPs Fe₃O₄) is suitable for removal of some pollutants (COD, BOD₅ and PO₄^3-) from the secondary effluent, but this absorbent is not effective for nitrate removal.