جستجوی مقالات مرتبط با کلیدواژه « leachate » در نشریات گروه « پزشکی »

Water resources are often exposed to pollutants related to urban waste disposal. This study aimed to determine the quality of water sources around the landfill of Langrod City in 2021.

This cross-sectional study selected two springs upstream, two water sources (well and spring) downstream of the landfill site, and a river (with two sampling stations) near the landfill site as the studied water sources. Sampling and analysis of physical (temperature, turbidity and TSS), chemical (pH, EC, TDS, BOD5, COD, nitrate, sulfate and heavy metals) and microbial (coliform and E.coli) parameters of water quality and soil samples of the region with Standard methods were performed. The data were analyzed by comparison with Iranian standards, Schuler and Wilcox indices.

In all water samples, the turbidity was more than the desired level, and the concentration of all chemical parameters was lower than MCL in the Iranian standard for drinking and irrigation. In the downstream well of the landfill, the total concentration of nitrite and nitrate measured compared to the recommended values in drinking water was almost four times the Iranian standard. The number of coliform and E. coli in all water sources was higher than the permissible limit of Iran's standard for drinking. The quality of all water samples, based on the Schuler diagram (drinking), was acceptable to good, and according to the Wilcox index, except for the downstream river of the landfill, they were in the medium salty category and were relatively suitable for agriculture.

The quality of water sources upstream and downstream of the Langrod urban waste landfill site was similar, and the water quality of the river downstream of the landfill was high salty and suitable for agriculture with the necessary considerations (drainage).

Municipal and hospital waste land fills that have various contaminants, especially pharmaceuticals, provide a suitable habitat for resistant bacteria which play a special role in the transfer of resistance genes. Therefore, the abundance of microorganisms and the antibiotic resistance of bacteria in soil and leachate samples of municipal and hospital waste burial sites in Hamedan city were investigated.

The characteristics of soil and leachate as well as the abundance of their microorganisms were tested and counted. Also, the percentage of bacteria resistant to ten commonly used antibiotics ampicillin, amoxicillin, cefixime, gentamicin, streptomycin, tetracycline, doxycycline, chloramphenicol, lincomycin and metronidazole was investigated. In addition, the response of bacteria from two virgin soils and new rubbish landfill to different concentrations of three antibiotics, ampicillin, gentamicin and tetracycline, were measured.

The log of population of fungi, actinomycetes, pseudomonas, and enterobacters, was the highest in new rubbish landfill. They were 5.35, 5.28, 6.13, and 5.98 respectively. The percentage of bacteria resistant to all ten antibiotics was higher in samples of new rubbish landfill than in other locations and lower in virgin soil than in other locations. These results were also seen in the dose response of ampicillin, gentamicin and tetracycline antibiotics. The inhibitory concentrations of these antibiotics for new rubbish landfill bacteria were 1500, 1000 and 100 mg/l, respectively. But for virgin soil, they were much less (10, 18 and 50 mg/l respectively).

In general, this research showed that municipal and hospital waste landfills provide a suitable habitat for antibiotic-resistant bacteria, which may increase the transfer of resistant genes among soil native bacteria. Therefore, the bacteria that reach the soil through waste can be more harmful.

 and Aim The leachate from oil sludge compost into the environment, which is resistant to decomposition, causes several environmental problems. Therefore, it needs to be treated using efficient processes. This study aimed to investigate the efficiency of the modified Fenton process for treating these oil sludge leachates.

In this experimental study, leachate samples were collected, and then modified Fenton solution was prepared by adding Fe2 (SO4) 3 to H2O2. Then the effect of time parameters (15, 30, 60, 90, and 120 minutes), modified Fenton concentration of 20, 50, 100, and 200 mg/l with pH 3, 5, 9, and three initial concentration of COD (500, 1000 and 1500 mg/l) was examined.

This study has been registered in Arak University of Medical Sciences with codes 2645 and 2765.

 The reduction of COD and TPH in the optimal time of 60 minutes, initial COD of 500 mg/l, pH of 3, and Fenton concentration of 200 mg/l were 9.04 and 77.42%, respectively. The experiments showed that the removal efficiency of COD and TPH with increasing residence time and the concentration of modified Fenton are directly proportional and with decreasing, the initial concentration of COD and pH is inversely proportional.

 The use of modified Fenton is an efficient method for treating leachate from petroleum sludge compost.

One of the major challenges facing landfill operation is the pollution caused by leachate infiltration beneath the landfill site. Comprehensive leachate management requires knowledge of production rate and factors affecting it Therefore, in this study, HELP software was used to calculate leachate quantity and analyze input data.

After designing a landfill by the existing conditions in Urmia city, the quantity of leachate was calculated using HELP software. Then, in different scenarios, the effects of precipitation, Curve number, and removal of the geomembrane layer on leachate production -were investigated. Finally, the impact of similar layer aggregation on the simulation process was discussed.

According to the results, 7.67% of precipitation is converted to leachate. NO significant correlation was observed between precipitation and leachate production in a short period of time due to the absorption of rain by landfill layers. However, for the long term, as the absorption capacity was reached leachate produced. With increasing the Curve number from 70 to 90, leachate production decreased by 23%. Also, the removal of geomembrane from the final coating increased the amount of leachate by 78.46%. Furthermore, by replacing a 76cm dense clay layer instead of capping geomembrane layer, the same leachate generation rate was observed. Re- running the software after layer aggregation showed a slight difference in leachate estimation compared to the baseline state.

Leachate generation modeling and identifying influential parameters with the aim of HELP software, may be helpful in landfill leachate management prior to its construction.

Today, the issue of urban solid waste or urban waste is one of the most serious problems in the whole world. Composting plants have a significant amount of time from the production and production stage to the sale and consumption stage. In this study, the effect of compost age on the quality of the compost factory was carried out in Isfahan City waste management organization.

To conduct this study, a compost mass of about 300 tons of newly produced compost and prepared for sale at a particular site from the plant and was done in a special place of four and nine weeks. There are ammonia, nitrate, ammonium, phosphorus, potassium, total nitrogen, mineral nitrogen, organic nitrogen, sodium, calcium, magnesium, carbon, density, EC, pH, oxygen, sulfur, and the ratio of carbon to nitrogen was done at any time with three iterations of the experiment.

Findings indicate that ammonia, nitrate, ammonium, total nitrogen, mineral nitrogen, EC, pH, moisture, density, and the ration of carbon to nitrogen in the initial compost are respectively as follows: 1800, 58.35, 28.2314, 14000, 2400, 11600, 145.7, 245.7, 85.6, 286, and 54.12. Finally in the 9th week, they changed as follows: 145.873, 325.81, 61.1122, 63.15065, 63.1215, 13850, 71.5, 35.7, 005.5, 5.279 and 04.22. The amount of ammonia, ammonium phosphor, mineral nitrogen, EC, moisture and density was reduced with a significant difference whereas other factors increased with a significant difference. The results of phosphor were not significantly different. Also, the results of the study revealed that ammonia, ammonium, phosphorus, total nitrogen, nitrogen, EC and COD in the zero weeks were respectively as follows: 244.26, 314.05, 298.73, 1153.6, 325.36, 6289.2, 37.088 and 3635.24, whereas in the ninth week, they changed as follows: 110.36, 141.89, 285.43, 366, 148.98, 217, 728.15, 5733.76. The amount of ammonia, nitrate, ammonium, total nitrogen, mineral nitrogen, organic nitrogen, as well as EC reduced with a significant difference, but the amount of COD increased with a significant difference. The results of phosphor and nitrate were not significantly different. 

Ultimately it can be concluded that the quality of compost is decreased with time lapse and the more it passes after the compost production, the less the food elements in the compost consumed by vegetarians would be.

Leachate from solid waste in uncontrolled landfills can have many effects on the environment and human health. The purpose of this study was to investigate the variation of physical and chemical properties of leachate from Isfahan Compost Plant Reception Hall during time.

In the present study, samples were collected from leachate of a compost plant in Isfahan for 12 months during the years in 2016 and 2017. Different physico-chemical properties including biochemical oxidation, chemical oxygenation, total soluble solids, total suspended solids, nitrate, total nitrogen, phosphorous, pH, EC, sodium, calcium and potassium, as well as concentration of 9 metallic elements of iron, lead, nickel, chromium, cadmium, magnesium, zinc, copper and manganese in the leachate were measured during the time.

Concentration of potassium, calcium, sodium, sulfate, nitrate, phosphorus, total nitrogen, TSS, TDS, COD, BOD in leachate samples was in the range of 2150-5216.04, 698-70000, 1530-4600, 1302-4547, 192-3944.30, 0-4149, 7-7900, 9614-87000, 8368-77850, 71200-116800, 47800-75000 mg/l, respectively. The pH and EC of the leachate varied in the range of 4.23-5.30 and 21.30-49.7 dS/M, respectively. In addition, the concentration of heavy metals of iron, lead, nickel, chromium, cadmium, magnesium, zinc, copper and manganese, ranged from 49-220, 0.57- 23, 0.5-0.25, 0.5-7.5, 0.1-0.94, 0.03-2.50, 566-1090, 12.50-39, 0.28-9 and 3.50-33 mg/l, respectively.

The amount of BOD5 and COD was higher in April and March, in which the average rainfall was higher than other months. Also, TDS in June, with zero rainfall, was higher compared to other months. Comparing the mean concentration of elements (except chromium), the physical and chemical parameters of the leachate with the effluent discharge standards of the Iranian Environmental Protection Agency indicated that the concentrations was several times higher than the standard limit. The results of leachate analysis showed that leachate from municipal waste from the compost station line of Isfahan had a high potential of environmental contamination, which should be controlled and monitored continuously.

In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production.

Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA.

The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl2 of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl2 (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester.

The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of biogas.

Background & objeftive: In the Rafsanjan sites have been considered in the studied region for landfill construction, where the leachate diffusion caused by landfill for groundwater resources, which is the only source of water supply in this region, is a serious threat. The aim of this research is to study the trend of changes in the contamination concentration due to diffusion of a hypothetical landfill based on the geological and hydrogeological conditions of Rafsanjan plain in order to represent the effect of leachate diffusion and contamination spread across groundwater resources.
Methods and Materials:Transmission of contamination has been studied on the basis of changes in concentration at two initial and final points of landfill by MT3DMS model daily and for 22 years period. The concentration of leachates has been considered 2 and 4 g / l, and its diffusion rate has been assumed 1.5 and 3 cm per day.
The slope of the concentration increase in the propagation process and delayed diffusion at the beginning of the landfill with 2 and 4 g/l concentration and 1.5 cm rate during 15 and 17 years have an increasing trend, respectively and later it would have a decreasing trend. At the end of landfill, 90% increase in contamination will occur for 2 g/l concentration in the first five years and 4 g/l concentration in the first 9 years and it will have a fixed trend over the next few years.
In the various transmission processes after the penetration of the infection into the aquifer, the concentration of contamination is initially low and increasing over time and if the concentration of the source of the penetrating source of constant intensity is constant, the maximum concentration of aquifer pollution is fixed at a certain value. the type of transmission process has a huge impact on this constant value. So that in the propagation-diffusion process, the average in the first 5 years of this value is fixed and in a delayed state, it reaches a constant value after close to 22 years.

Groundwater is exposed to environmental pollution. The leachate produced by wastes in transfer station or municipal solid waste landfill is one of the sources of pollution. In this view, present study was carried out to evaluate the groundwater quality around of municipal solid waste transfer station in Ardabil at 2017.
In this cross sectional study, 6 wells (one control well in the upstream and 5 wells in the downstream) around the ardabil municipal solid waste transfer station were selected according to the existing criteria, and the quality parameters of the samples (Turbidity, pH, EC, TDS, BOD5, COD, Nitrate, Heavy Metals, Coliform and Fecal Coliform and ...) were analyzed according to the standard methods. Also, particle-size analysis of soil was carried out in sampling area and data analysis was performed using Excel software and compared with existing standards, guidelines and standards.
In all samples, except for lead (0.07-1 mg/l), Coliform (0-28 MPN/100ml) and Fecal Coliform(0-4 MPN/100ml), other parameters were lower than recommended limit by the criteria and available standards. Also, the amount of sulfate (593.6 mg/l) in well 4 and total Hardness (530 mg/l) in well 3 were higher than the standards recommended for drinking and agricultural purposes.
The results of the study showed that the Municipal Solid Waste Transfer Station in Ardabil had no significant effect on the groundwater quality in the surrounding area.

Introduction and Currently, leachate production and its management are major environmental problems associated with the operation of solid waste landfill. Herein, we sought to evaluate the efficiency of combined processes of coagulation and modified activated bentonite with sodium hydroxide as abiosorbent in the final treatment of leachate.
This experimental-laboratory study included chemical coagulation using polyaluminum chloride (PAC) and modified bentonite. We investigated the effect of critical operating parameters on landfill leachate treatment. These operating parameters included pH (2-10) and PAC concentration (5-25 mg/l) in chemical coagulation process, contact time (15-150 min), solution pH (2-10), bentonite concentration (0.3-1.5 g/l), and temperature (25, 35, and 45ºC) in adsorption process.
The overall efficiency rate of this process in removal of total chemical oxygen demand (COD) was 93%, with the optimum PAC concentration of 30 mg/L, pH=6 in the chemical coagulation phase, reaction time of 60 min during the adsorption process, bentonite concentration of 0.5 g/L, pH=6, and temperature of 25ºC. The kinetics of COD adsorption on modified bentonite conformed to the pseudo-second-order model.
The application of combined processes of chemical coagulation and activated bentonite is highly efficient in removing major pollutants in leachate.

Background and Currently, leachate production and its management are major environmental problems associated with the operation of solid waste landfill. The aim of this study was to evaluate the efficiency of combined processes of coagulation, ozonation, and advanced oxidation using UV-activated oxone in treatment of landfill leachate of Zahedan, Iran.
Materials and This experimental-laboratory study included chemical coagulation using poly aluminum chloride (PAC), ozonation, and chemical oxidation using potassium peroxymonosulfate (oxone). For the purpose of this study, the effect of critical operating parameters on treatment of landfill leachate was investigated. These operating parameteres included: pH (3-8) and concentration of PAC (50-250 mg/l) in chemical coagulation process,time of ozonation (5-20 min), pH of solution (2-10), concentration of oxone reactant (150-750 mg/l), contact time with oxone (60-360 min), temperature (20-45ºC), and intensity of UV lamp in oxidation process using oxone (8, 15, 30 W).
According to the results, the overall efficiency rates of this process in removal of total coliform, fecal coliform, total phosphorus, total nitrogen, biochemical oxygen demand (BOD), and chemical oxygen demand (COD)were 99%, 99%, 97%, 100%, 91.1%, and 85.62%, respectively, with optimum PAC concentration= 250 mg/L, pH= 6 at the chemical coagulation phase, ozonation duration= 20 min, reactiontime= 180 min during oxone-based oxidation process, oxone concentration= 750 mg/L, pH= 5, temperature= 25ºC, and UV lamp intensity= 8 W. Furthermore, the BOD5/COD ratio increased from 0.42 to 0.72 after completion of the treatment process.
Current study showed that application of combined processes of chemical coagulation, ozonation, and advanced oxidation using UV-activated oxone are highlyefficient in removing major pollutants from waste landfill leachate.

Background and Infiltration of leachate produced by municipal solid waste into the ground water poses a serious environmental hazard due to its high content of hydrocarbons and heavy metals. The leachate is the primary source of soil and water pollution. In this paper the risk of heavy metals discharged from leachate in to groundwater in Hamadan landfill has been assessed using Industrial Waste Management Evaluation Model (IWEM).
The concentrations of heavy metals (Cu,Pb,Ni and Cd) in leachate were determined by atomic absorption spectrophotometry and the risk of these metals discharge into groundwater was assessed by IWEM using Monte Carlo analysis.
Based on the obtained IWEM and EPACMTP results, geosynthetic cover was recommended for this matter.
The most appropriate option for groundwater protection in Hamadan landfill was recommended to be geosynthetic cover (Composite linear). Owing to the high probability of leachate infiltration into groundwater, there is need to be made stricter management decisions in this regard. Also, it is necessary that IWEM is used for prevention of leachate infiltration into groundwater.

Background and aims: Considering the grate polluting potential of landfill leachate and in order to prevent environmental pollution, the present study set out with the aim of assessing the efficiency of electrocoagulation process for organics, nitrogen, phosphorous and turbidity removal from landfill leachate.
Materials and In the present descriptive-analytical experimental study, the sample of leachate was supplied from Aq-Qala Landfill and compost center in Gorgan. Landfill leachate treatment was consequently performed by an electrochemical reactor. The paper studies the factors affecting the efficiency of reactor, such as electrolysis time (20, 40, and 60 min), pH of solution (3, 7 and 9), and the electric potential difference (20, 40 and 60 V). All studied parameters were determined according to standard methods. Because of the nature of the project, there were not ethical issues in this study.
The highest removal of turbidity, COD, nitrate, and phosphorus in raw leachate were 59.14, 44.33, 40.81and 48.86, respectively, achieved at 60 V, neutral pH (6.5-6.9) and operating time of 60 min. The corresponding removal percentages for treatment plant effluent electrocoagulation were 88.9, 80.5, 59.16 and 62.35, respectively.
The results show that electrocoagulation process can be applied to leachate pre treatment in order to remove organic matter, turbidity, nutrients, and organics loading reduction and consequently to enhance the bio- degradability of leachate. Thus, the process can be considered as an effective alternative in the pre-treatment of wastewater in order to prevent environmental pollution and protection of water resources.