Landfill leachates and leachate sediments were investigated in order to survey the discharge of uranium (U) from municipal solid waste (MSW) landfills and municipal solid waste incinerator (MSWI) bottom ash landfills. Concentrations of U in the leachates were as high as or higher than concentrations of Cd, a metal more often discussed when considering the environmental effects of landfill leachate. However, the U concentrations in leachate were no greater than levels occurring naturally in water. The U concentrations in leachate sediments were also the same as or lower than those reported in lake sediments around the world. Size charge fractionation of U in freshly sampled leachate showed that the metal was present mainly as either non-labile dissolved complexes or free anions, which have intermediate to high mobility and eco-toxicity. This is in contrast to other heavy metals, such as Cd, which are generally particulate bound in leachate. However, based on all the results of the investigations, it was concluded that leaching of U is not of major concern in MSW and MSWI bottom ash landfills.

This study aimed at the examination of the efficiency of a roughing filter in nitrate and Chemical Oxygen Demand (COD) removal from fresh leachate from a municipal solid waste landfill. Sampling was done at three rates of 0. 5 m/h, 1 m/h, and 1. 5 m/h from input and output of the filter to determine the concentration of nitrate and COD. The average efficiencies of COD removal at filtration rates of 0. 5 m/h, 1 m/h, and 1. 5 m/h were 84, 88, and 85%, respectively. The average removal efficiencies of nitrate at filtration rates of 0. 5 m/h, 1 m/h, and 1. 5 m/h were 88, 88, and 85%, respectively. The effluent concentrations of COD and nitrate were lower than the environmental protection agency standard values (P<0. 05). Based on the results, nitrate removal with a roughing filter was better than COD removal.

Introduction: Increasing the volume of waste leads to an increase in waste collection, transportation and final removal costs. Also high percentage of humidity leads to the destruction of collection and transportation machines and to increasing the leachate produced in landfill site and polluting the soil and surface and underground water. So there are several attempts to solve these two problems. This study was to design and produce a unique bin which extracts, reduces and collects leachate from urban wastes and also reduces dry wastes volume.Methods: This applied study was conducted to design and produce an innovative indoor mechanical waste compactor for the first time in Shahroud University of Medical Sciences in Iran within 6 months of time and cost about 500 dollars. To test the effectiveness of the device, experiments (3 times) were performed using dry and wet wastes. After filling the tank with 18 liters of waste and triggering the force transmission crow (for moving compactor sheet) by a 30- year- old, 60-kilogram person, the humidity percentage and the volume before and after the compaction were measured.Results: This device is capable of making a notable decrease in volume of waste and separating waste humidity up to 45 percent of initial amount (in average). Repeating the experiment with dry waste also showed the capability of device up to 40 percent in waste volume (in average).Conclusion: This waste bin can extract, reduce and collect a lot of leachate from solid wastes and thus reduce its environmental impacts and remove problems of wastes collection process.

Organic and mineral compounds generated as products of waste mineralization within biological processes and accompanying physical and chemical processes are washed out by percolating rainwater through the deposit of wastes in landfill and form leachate that has created many health and environmental concerns. This study intended to determine the efficiency of reducing COD, BOD5, TS and color of Hamadan landfill leachate by using carbon nanotubes. Experiments were performed in batch reactor and changing effective factors such as pH, time and concentration of iron nanoparticles. The efficiency of carbon nanotubes were investigated using a statistical test, One-Way ANOVA software SPSS-12. Highest removal efficiency was at concentrations of 2500 mg/ L NZVI, pH=2.5 and 10 minutes reaction time, 58.23%, 12.5%, 66.87%, 80% for COD, BOD, TS and color, respectively. The project results showed high potential for carbon nanotubes into absorbing organic use for treatment or pretreatment of Hamadan landfill leachate.

In this research, physical, chemical and biological treatability of Tehran solid waste leachate was studied. Results indicate that the amount of COD for the fresh raw leachate of Tehran is equal to 66,608 mg/l. The leachate is transferred to an equalization tank for storage and pH control process. After neutralization, leachate is introduced to an up flow and down flow anaerobic reactor. The effluent of anaerobic reactor is conducted to a sequencing batch reactor. Sequence batch reactor (SBR) effluent was pumped in to sand and activated carbon filters, after chemical coagulation and clarification. Results showed that anaerobic reactor with detention time of 3 days had a 35% COD removal and increasing the detention time to 4.5 days would improve the COD removal to 45%. Nutrient adjustment with phosphorus and nitrogen increased the initial 23% efficiency of sequence batch reactor to 44%. The effluent COD of SBR reactor was 21,309 mg/l. Recycling of aerobic reactor effluent with incoming feed to anaerobic reactor reduced the anaerobic reactor influent COD to 20,000 mg/l and this caused 53% and 57% COD removal in the anaerobic and aerobic effluent, respectively. The total systems COD performance increased to 80% and SBR effluent COD eventually reduced to 4,000 mg/l. Coagulation, flocculation and sedimentation processes were practiced to make the 4,000 mg/l effluent COD comply with environmental standards of Iran. The optimum coagulant found to be ferric chloride with the dosage of 50 mg/l at pH of 12, which reduced 10% of COD to an amount of 3,676 mg/l. The effluent was stored in a tank and then pumped in to pressure sand filter and afterwards to activated carbon filter. The COD removal was three and 90% for sand and activated carbon filters, respectively. The total process reduced the remaining COD to 36 mg/l, which is in compliance with environmental standards of Iran.

Effects of initial concentrations of Moringa oleifera seed coagulant for removing Chemical Oxygen Demand and Total Dissolved Solids from municipal solid waste leachate have been evaluated at an optimum pH of 7 and temperature of 318 K. The kinetic data obtained from the experiments were fitted to the pseudo first-order, pseudo second-order, Elovich and intraparticle diffusion models. Based on a regression coefficient (R2), the equilibrium (kinetic) data were best fitted with the Elovich model (R2=0.993 for Chemical Oxygen Demand and R2=0.996 for Total Dissolved Solids) than that of other models. The results of the kinetic models study indicated that the adsorption capacity of Moringa oleifera seed as a coagulant for removing Chemical Oxygen Demand and Total Dissolved Solids in a leachate increased up to 100 mgL-1, beyond which, the adsorption capacity got reduced. Finally, the present study concluded that Moringa oleifera seed coagulant could be employed effectively for Chemical Oxygen Demand and Total Dissolved Solids removal in a municipal solid waste leachate.

Vetiver plant is tolerant to acidity and temperature variations. Has rapid growth for biomass production and has high tolerance to organic and non-organic compounds in municipal waste leachate for example heavy metals. So this plant is good for landfill cultivation. In this study, physiological responses to municipal waste leachate were studied. Statistical design was a randomized complete block and each block treated with different concentrations of latex at levels of zero, 15, 30, 45 and 60 percent compared to the original latex waste. The leachate collected from the Shiraz landfill and brought into the greenhouse. The physiological characterization including leaf area, dry weight, chlorophyll, anthocyanin, proline, soluble sugars and total protein were measured. The result indicated that the dry weight, chlorophyll and anthocyanin decrease with increasing of latex concentration. The leaf area, leaf relative water, soluble sugars and total protein increased with increasing latex concentration. Proline concentration at 15 percent of leachate increased significantly compared to controls, whereas at higher concentrations decreased. According to the results, it is recommended that 45 percent of leachate in a landfill can be used to irrigate Vetiver. This is the maximum concentration of leachate that Vetiver plant can survive as green space. Primary filtration of leachate before using is recommended. If the aim is more growth or perfume application from root, less concentration of leachate is better.

7500 tons of municipal solid waste produced in Tehran city is land-filled in Kahrizak disposal site. The leachate of the waste has created a lake with 180000m3 in volume. A plant is under construction to treat the leachate. A significant amount of biogas can be produced in anaerobic digestion phase in the treatment plant reactor. The designing process of a power plant in accordance with the produced biogas has been discussed in the present study. In the present investigation the air pollution from power plant has also been modeled. The leachate organic load (BOD=34400 mg/L and COD=53900 mg/L) is considerably higher when compared with other countries due to higher amount of organics available in Tehran wastes. The results indicate that an amount of 33504 m3/d biogas can be produced in Tehran's landfill that eventually would be sufficient to run a power plant of 3.4 MW capacities. The plant which is designed by Thermo flow software is consisted of two gas turbine units with 2 MW capacities so that the total capacity is 4MW. About 10% of the generated power is for in-plant consumption and the rest can be sold. The results of the air pollution modeling using Screen 3 software reveal that CO and PM amounts are in allowed range but N2O exceeds the standard limits. The high temperature of the outlet gases emitted from gas turbines makes it possible to warm up water and regulate the anaerobic reactors temperature.

Leachate production and management is a challenging environmental issue in municipal landfills and depots in Iran. Leachate contains toxic materials, heavy metals, and organic and microbial pollutants on a significant scale. Its uncontrolled entrance into the surface, groundwater, and soils can also substantially inverse impacts on human health and natural habitats. In Mazandaran province, during the last decades, depots and landfilling of municipal and industrial waste have led to environmental degradation in its eco-sensitive natural zones and brought a series of health, social, and security challenges to the region. Due to the region's high precipitation rate and landfills with no cover, these places practically convert into an extensive resource for leachate production. To diminish the environmental impacts, a lot of work has been done in recent years to develop a sort of leakage gathering system and treatment plants in these landfills, based primarily on an overall estimation. In this study, a calculating computer model has been developed for leakage production based on regional climate conditions and the characteristics of municipal waste. This model is different from the HELP model, which is commonly used for sanitary landfills and is specifically developed for the waste depots of the Mazandaran province. In this model, hydrological methods, which are based on the water balance in the landfill sites, were used for the calculation. The developed model was uploaded as an online service for public use. By referring to the internet address provided, the developed model in the landfill part and the leachate section, the amount of produced leachate for the landfill site of Mazandaran province can be calculated. Also, the leachate volume of the Babol Anjilsi landfill has been calculated as a case study. As a result of this study, the lowest and highest amount of the production leachate for hot and dry months of the year (June and July) and for wet and rainy months (October) was about 63.39 and 260.07 cubic meters per day, respectively.