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The amount of waste is increasing daily; however, the available land area is limited. This problem can be overcome by segregating waste and other alternatives by accelerating landfill stabilization using landfill bioreactors. In this study, anaerobic bioreactor A with daily use of water and the leachate, anaerobic bioreactor B with the addition of water and reuse of the leachate daily, and a control bioreactor with the addition of water were used. The parameters measured were the pH, temperature, humidity, chemical oxygen demand (COD), and biochemical oxygen demand (BOD) of the leachate. The reuse of the leachate and addition of water to the bioreactor accelerated waste degradation and caused high humidity. The average COD and BOD in each bioreactor on day 40 were stable. On day 45, the BOD (74.925 mg/L) was below 100 mg/L and the average COD (781 mg/L) was stable below 1000 mg/L. These results were for all bioreactors except for the control bioreactor, which only received water addition treatment; its COD value was below 1000 mg/L on day 50, at 989 mg/L. Waste decomposition was stabilized, with the BOD below 100 mg/L and the COD below 1000 mg/L.

In order to investigate the effect of treated wastewater on heavy metals and fecal coliform in plant and soil, a field experiment was conducted in RCBD with three treatments in four replications during 2016-2017 in Borkhar, Isfahan (Iran). Treatments including well water, semi-treated wastewater and combination of well water and wastewater were applied in consecutive cultivation of wheat and forage corn. The amount of heavy metals in the soil did not change after two seasons of wastewater application compared to well water. The amount of fecal coliform in both plants was increased in the irrigation water treatment compared to the well water, which was more evident in the corn plant, which is related to the high moisture content of this plant at harvest stage. Due to the improvement of soil nutrient concentrations after two seasons of continuous application of wastewater and no increase in the amount of heavy metals in the soil, the use of wastewater for agricultural production is permissible. But according to the fecal coliform index, it is recommended not to be used for the production of crops harvested at high humidity and conditions for the survival of pathogens.

Odour is a major concern as they are termed hazardous to the surroundings as well as life forms when they are exposed to the environment. Odour emission is also one of the indicators of environmental changes that impact the environment. Among the different sources of odour emission, in the dumping yard itself, different types and ages of waste are dumped in the municipal solid waste (MSW) dumping yards. This study aims to relate odour emission and concentration changes caused by different weather patterns. Different periods of waste (fresh waste, moderate waste, and ripened waste) and weather seasons (summer and winter) affect the odour concentrations. Mixtures of gases and intolerable odours are major components of the MSW dumping yard. The odour concentration was monitored in the different periods of waste (moderate wastes) at different locations in the MSW dumping yard. In this study, it was found that meteorological conditions are also one of the main influences on odour concentrations in the environment. In this study, a comprehensive investigation of odour pollution from a local MSW dumping yard has been performed. The odour concentration indicates that the maximum range of aromatic hydrocarbon chemical compounds (volatile organic compounds) reported was T-butylbenzene at 1.41µg/m3 and the minimum range was Sec-butylbenzene at 0.07µg/m3. This study will provide information on odour emissions in urban areas and how VOC (Volatile Organic Compounds) components are present and affect the dumping yards surrounding those areas

Contamination of groundwater by chlorinated solvents such as trichloroethylene (TCE, tetrachloroethylene (PCE), and 1,1-dichloroethylene (1,1DCE) is a widespread problem that can seriously threaten human health and the environment. These compounds are often present as dense nonaqueous phase liquid (DNAPL) mixtures in the subsurface that serve as a long-term groundwater contamination sources. The objective of this study is to test the effectiveness of different in-situ flushing agents (SDS, Tween 80, MCD, and water) for the recovery of DNAPL mixtures (TCE, PCE, 1,1DCE) entrapped in heterogeneous aquifer media. A series of batch tests were first performed to assess the multiphase behavior of water-DNAPL mixture-reagent system. Intermediate scale tank experiments were then performed to compare the performance of the reagent solutions. The flushing breakthrough curves were also used to investigate the impact of solubilization agents on mass-flux reduction/mass-removal behavior relationships. Performance of agents on DNAPL mixture source zone remediation was found to be in the following order: Tween 80>SDS>MCD>>Water. Individual DNAPL constituents exhibited transient effective solubilities that depend on the reagent contents and DNAPL compositions. Although high fractions of DNAPL source zones in heterogeneous porous media were removed through chemical flushing (SDS, Tween 80, MCD, and water), the heterogeneous system exhibited an extended multi-step concentration behavior. The results emphasized that in the early stage, some portion of the organic liquid is hydraulically accessible (matrix) whereas the later stage of mass removal was controlled by the more poorly accessible mass (pool) associated with higher-saturation zones. Our results also showed that the distribution and the emplacement of organic liquid, flow-field heterogeneity, sorption and desorption, and flushing solution all influenced the DNAPL mixture removal. The results from this study underline the need for understanding the multiphase behaviour of a system, particularly when DNAPL mixtures are present, prior to field-scale remediation implementation.