فهرست مطالب mehdi farzadkia

The high concentration of petroleum hydrocarbons, along with some other parameters such as aromatics, paraffin, naphthene, and heavy metals, has led to the sludge of oil sludge listed as hazardous materials with a specific source by the US Environmental Protection Agency. Therefore, the purpose of this study is to investigate the potential of oil-contaminated soil in changing the biodegradability indices of oil sludge.

Moisture, pH, total organic carbon, total nitrogen, total phosphorus, elemental analysis, and amount and type of TPH of oil sludge samples were identified. The microbial consortium was isolated from contaminated oil soil around the oil refinery and poultry manure. Finally, biodegradability indices of oil sludge were examined.

The results showed that the amount of organic carbon and nitrogen in oil sludge samples were 32.65 and 0.21%, respectively. Also, iron, calcium, and potassium with 5862, 2921, and 524 mg/kg, respectively, were the most elemental components in petroleum sludge. According to the SARA analysis, the highest TPH compounds in oil sludge samples included saturated compounds, aromatics, resins, and asphaltene with 70.45%, 15.2%, 10.9%, and 3.45%, respectively.

According to the results of biodegradability indicators of oil sludge, it can be concluded that the isolated consortium can be proposed as a suitable tool for the treatment of petroleum sludge at the bottom of crude oil storage tanks.

One of the most important factors in the contamination of aquatic ecosystems is agricultural pesticides. Paraquat is a water-soluble and non-selective herbicide, which has adverse health effects, such as respiratory distress and even death. This study aimed to evaluate the degradability of paraquat toxins using photochemical oxidation processes based on hydrogen peroxide (UV/HP) and persulfate (UV/NaPS/Fe2 +).

This experimental study investigated the effects of pH variables, concentrations of UV/HP and UV/NaPS/Fe2+, as well as the initial concentration of the pollutant on paraquat toxicity removal in a laboratory scale using a batch reactor of one liter. Moreover, the concentration of the residual paraquat and the amount of organic carbon removal were measured using High Performance Liquid Chromatography equipped with a visible Ultraviolet (UV) detector at 259 nm and a Total Organic Carbon (TOC) meter.   

The UV/HP and UV/NaPS/Fe2 + processes were able to remove 87.75% and 92.31% paraquat, respectively, at 120 min under optimum conditions. In addition, the amount of TOC removal in the UV/HP and UV/NaPS/Fe2 + processes  were 77.29% and 82.16%, respectively. The results showed that the kinetics of the UV/HP and UV/NaPS/Fe2 + processes  followed the first-order reaction.

The UV/NaPS/Fe2 + process was more effective than that of UV/HP regarding paraquat removal. As a result, the studied processes are proposed as effective, fast, and efficient methods to remove paraquat from aqueous solutions, which is economically feasible due to the low reaction time. The use of this process is also recommended as a complete refinement or pre-treatment process.

Sewage sludge management is one of the most challenging parts of sewage treatment in terms of economic, design and environmental issues. One of the common ways of disposing of sludge is its use in agricultural land. Due to the presence of various contaminants in sludge Sewage, its safe and effective use in agricultural land requires the development of a special Guidance.
This study was carried out to survey the guidelines of different countries regarding the application of sewage sludge on the ground and prioritize them according to the native conditions of Iran using multivariate analysis and expert opinion and using the AHP method.
Resultss: The United States, Australia, Canada, China, Japan, the European :union:, Russia, Turkey, and South Africa have the highest rating by applying the scores of indexes and taking into account the weight of the criteria in accordance with the standards of the US Environmental Protection Agency, respectively.
The analysis of the results of this study showed that among the various guidelines examined, the US Environmental Protection Agency (EPA) has the most executive capacity in terms of executive capacity, comprehensiveness, transparency and precision.

Environmental pollution by heavy metals has received much attention in recent years. Therefore, this study aims to remove lead and cadmium ions by using silica-coated magnetic nanoparticles modified with mercaptopropyltrimethoxysilane (MPTMS) from aqueous solutions.
In this study, Fe3O4@SiO2-SH magnetic nanoparticles were synthesized via the simplified co-precipitation method at 80°C. The structure and morphology properties of synthesized nanoparticles were characterized by XRD, FT-IR, SEM and TEM. Finally, the adsorption experiments were performed in aqueous media. All stages of this research were conducted ethically.
According to the results, Fe3O4@SiO2-SH nanoparticles have a uniform distribution with a spherical Fe3O4 core and SiO2 shell, modified by thiol functional groups. The efficiency of synthesized adsorbent in the removal of metal ions was also investigated considering parameters such as pH, adsorbent dose and contact time. The optimum conditions for lead and cadmium removal were obtained at pH 5 to 6, contact time 40 min and absorbent dose 0.8 g/L. The kinetic and isotherm studies underlined that the process of adsorption of both metal ions follows the second-order (R2> 0.98) and Langmuir isotherm (R2>0.98) models.
Based on the results obtained, synthesized Fe3O4@SiO2-SH magnetic nanoparticles can present proper efficiency in the removal of lead and cadmium ions from aqueous media under optimum conditions.

Amoxicillin is the most commonly used antibiotics that draws more attractions due to induce bacterial resistance.
This compound can enter the aquatic environment through different routes including sewage and waste disposal of medical health centers, veterinary and industries. The aim of this study was removal of amoxicillin from aqueous environments by Electro-Fenton process using modified graphite felt and synthesized Fe3O4 nanoparticles.
Fe3O4 nanoparticles were synthesized by co- precipitation method. Graphite felt also modified due to avoid aeration. The structural and physical characteristics of nanocatalyst and also modified graphite felt were analyzed by SEM, EDS and BET techniques. After optimization of pH and time variables, the parameters of applied current, amoxicillin concentration, catalyst load and the distance between electrodes were designed using Design Expert 7.0 software and optimized by the response surface method.
The graphite felt modification resulted in increase in surface area from 0.89 to 1.92 m2/g. The maximum removal of amoxicillin (97.11%) was obtained in optimal operational conditions (pH=3, time=60 min, applied current =180 mA, amoxicillin concentration=20 mg/L, catalyst load 1 g/L, the distance between electrodes =2 cm)
The result of this study indicated that electro-Fenton process using Fe3O4 nanoparticles and modified Graphite felt without external aeration is an effective method for amoxicillin removal.

Background and Catechol is a ring form organic compound with high toxicity that is used in petrochemical, pharmaceutical and manufacturing of pesticide. It has adverse effects on human and environmental health if discharged into the environment. The purpose of this study was removal of catechol using catalytic ozonation using core-shell magnetic nanoparticles of iron oxide doped with silica and titanium dioxide from aqueous solution.
We conducted a basic-applied study in which magnetic nanoparticle Fe3O4@SiO2@TiO2 was synthesized using sol-gel method. To determine the characteristics of nanoparticle, XRD, SEM and EDX tests were used. Then effect of different parameters on removal efficiency were investigated. These included solution pH (2-10), reaction time (0-60 min), dose of catalyst (0.2-3 gr/L), initial concentration of catechol (50-1000 mg/L), recycled test (7 times), and determining the mineralization and scavenger effect. The residual concentration of catechol was measured using high-performance liquid chromatography at 275 nm.
The optimal pH for the catalytic ozonation process was 8. The maximum efficiency of the process in optimal conditions (catechol concentration 1000 mg/l, pH=8, catalyst dosage 3 gr/L and dose of ozone 0.38 gr/hr) was 100% after 60 minutes of contact time. Kinetics of degradation of catechol followed first degree model. After reaction time the amount of mineralization was 91.5%. Reusability of catalyst was done 7 times and its efficiency decreased by about 4%. Scavenger (1 gr/l tert-butanol) decreased removal of catechol by 4.16%.
The catalytic ozonation process using Fe3O4@SiO2@TiO2 nanoparticles in an alkaline pH was found to be capable of eliminating high concentrations of catechol effectively.

The activated sludge process is the most widely used on a global scale for the biological treatment of both domestic and industrial effluents. One problem associated with the process, however, is the high volume of sludge produced. Excess sludge treatment and disposal account for up to 60% of the total operating costs of urban wastewater treatment plants due to the stringent environmental regulations on excess sludge disposal. These strict requirements have encouraged a growing interest over the last few years in reducing sludge volumes produced at biological treatment plants and a number of physical, chemical, and mechanical methods have been accordingly developed for this purpose. The proposed methods are disadvantaged due to their rather high investment and operation costs. An alternative technology that avoids many of these limitations is the worm reactor. In this study, the characteristics of this technology are investigated while the related literature is reviewed to derive the optimal conditions for the operation of this process in different situations.

Backgrounds & Elimination of phenolic compounds which is considered as resistant pollutants to biological degradation has a great importance. This study aims to investigate the electrochemical oxidation process efficiency in removal of phenol compounds using a continuous and divided rector.
The catalytic anodes of Ti/SnO2-Sb and cathodes of iron were employed in a reactor divided into anolyte and catholyte chambers by a cellulosic separator. The influence of initial phenol concentration (14.12‒40.88 mg L‒1), retention time (32.23‒82.77 min), and current intensity (0.18‒0.42 A) on TPh removal efficiency, TPh residual concentration, and energy consumption was investigated using response surface methodology.
The results showed that TPh removal efficiency strongly depends on retention time, followed by current intensity and initial phenol concentration. The importance order of factors affecting on TPh residual concentration were distinguished as initial TPh concentration > retention time > current intensity. The energy consumption in terms of kWh m‒3 is mostly affected by retention time and then current intensity, and irrespective of initial phenol concentration. Under the optimal conditions, removal efficiency of 93.21%, residual concentration of 1 mg L‒1, and energy consumption of 34.40 kWh m‒3 is achieved.
Based on the obtained results, the electro-oxidation is a very efficient process for diminution of wastewater phenolic content, and is able to set the allowable limits to discharge to the environment.

Background and Parabens are a group of Para-hydroxy Benzoic acid alkyl esters which extensively used as preservative in personal care products. Parabens have been recently found in wastewater¡ rivers¡ soil and dust. Therefore¡ the purpose of this study aimed to Monitor the occurrence of parabens from selected wastewater treatment plants (Shahrak Ghods and south of Tehran) and evaluate the performance of different treatment methods for removing these compounds.
In this study¡ the samples from influent and effluent were collected from Shahrak Ghods and South of Tehran wastewater treatment plant as Seasonal and Three samples per season. Concentration of Para-hydroxy Benzoic acid esters was determined by HPLC¡ CECIL¡ 4100 at 242 nm.
After sampling in the different seasons from the west and south treatment plants¡ two selective paraben concentrations (Methyl paraben and Ethyl paraben) were measured. The results showed that average concentration of Methyl paraben (MeP) and Ethyl paraben) EtP( respectively were 740.7 and 277.7 ng/L in the Influent and 179.3 and 45.8 ng/L in the effluent of Shahrak Ghods treatment plant. Also¡ the average concentration of MeP and EtP respectively were 835.3 and 295.3 ng/L in Influent and 132.8 and 29.7 ng/L in the effluent of South of Tehran treatment plant. In the next step¡ Risk assessment of effluent treatment plants discharging to environment with comparing the studies was done. According to the paraben concentration in the effluent of both treatment plants¡ discharge of effluent treatment plants whit selective contaminants¡ have little biological effects on ecosystems.
The removal efficiency of Shahrak Ghods treatment plant in removing parabens¡ was lower than the South of Tehran. But the effluent quality of both treatment plant was less than the Effluent discharge standard. So both of treatment plant have appropriate performance to removal contaminants.

Introduction and The nature and type of chemicals used in industrial processes, treatment and management of wastes resulting from them complicated. This study aimed to investigate wastewater management, manufacturing industries Savojbolagh city Alborz Province was from an environmental standpoint in 2013-2014
This study is type of cross-sectional. The three field visit, a questionnaire survey data and control / monitoring in industrial plants with more than 50 workers (totaling 108 units) were used. To do this research from the Environmental Protection Agency's questionnaire was used. The questionnaire included questions about the quantity, quality and wastewater management, industrial manufacturing setting. How to manage of industries Wastewater treatment plants, based on four indicators of wastewater production, production per capita, per capita of BOD, per capita of COD, from 1 to 6 are ranked. Rated for better environmental management in each index is defined.
The produced wastewater industries studied, 1942 cubic meters per day respectively. Food industry alone produces 59 percent of total industrial wastewater. The highest per capita BOD related to the industry (slaughterhouse) by g / d 320 per worker and the cellulose industry with the highest per capita COD g / d561 per person. 76% of Studied industries do not have any strategy to reduce the production of waste. 34% of industries have treatment plants that only 17% of the industry to comply with effluent discharge standards. The most common method of disposal of Treated wastewater and untreated are well absorbed.
Based on this assessment, management of industrial wastewater for agriculture (slaughterhouse) unfavorable and non-metallic mineral industries were favorable.

Uranium separation and removal are important from environmental, public health, and strategic veiwpoints. Scientits have put great efforts to develop technologies for uranium removal and regeneration because of its important applications and beneficial uses. In this study, efforts have been made to synthesize a modified form of Fe3O4@SiO2 and benzamide uranium complexes that can be exploited to remove and adsorb uranium onto an adsorbent that can be recycled. In the first step, Fe3O4@SiO2 was synthesized and later modified with trimethoxysilane. The adsorbent was subsequently characterized by SEM and FTIR. In a second step, experiments were performed to determine optimum stirring speed, contact time, ion strength, and adsorbent reusability. Finally, the performance of the adsorbent was tested in samples of real wastewater. SEM and FTIR analyses confirmed the satisfactory synthesis and modification of Fe3O4@SiO2 Nps. Statistical analyses revealed that although contact time, ion strength, and stirring speed were effective in adsorbent performance, they only led to a removal enhancement of 5% and a decrease of only 17% with increasing RPM to 250 and the enhancement of ion strength to 1.5M. The highest U(VI) removal efficiency in the synthetic solution was found to be 97%, which reduced to 49% in real wastewater samples. It was concluded that the nano-composite C14/SiO2_Fe3O4 adsorbent with its magnetic core and resistant surface not only offers the possibility for easy separation of urnaium from solutions but is also reusable and is only slightly affected by changes in stirring speed or ion strength. It, therefore, has a good capability for use as a U(VI) adsorbent in wastewater treatment.

Arsenic is considered as a heavy metal and toxic pollutants because of its potential harm to human health and environment protection. One of the mechanisms for arsenic removalfrom an aqueous solution is the adsorption process. the aim of this study was to evaluate arsenic adsorption from aqueous solution using activated carbon provided from walnut.
This was an experimental study. At first, the walnut was synthesized and was produced the adsorbent. Stock solution of arsenic was prepared (20, 40, 60, 80, 100, 120 and 140 mg/L). According to the Jar test by rapid mixing (7hr at 120 rpm) for evaluating the reaction kinetic and by slow mixing for evaluating the reaction stability (24 hr at 90 rpm), the effect of influencing parameters on adsorption process such as pH (5.5, 6.2, 6.9, 7.6 and 8.3), adsorbent dosage (10, 20 and 30 mg/l) and initial arsenic concentration (20, 40, 60, 80, 100, 120 and 140 mg/L) were evaluated. Also, to describe the experimental data, the Langmuir, Freundlich, were assessed. All experiments were conducted twice and the mean of percentage removal was obtained.
According to the Langmuir model, the maximum adsorption capacity of the activated carbon provided from walnut 3.15 (mg/g) were obtained. According to the Freundlich model, the maximum adsorption capacity of the activated carbon provided from walnut 2.05 (mg/g) were obtained. The results showed that increase in adsorbent dosage and decrease in pH increased the adsorption of arsenic. While increase in pH and initial arsenic concentration decreased arsenic adsorption.
activated carbon provided from walnut with regards to waste walnuts and found largely in many areas in Iran and low-cost synthesizing could be used to as adsorbent of arsenic adsorption.

One of the ways of optimizing the management of solid waste, is recycling which has considerable economic and environmental benefits. Whitout knowing the amount of the waste and its components, the possibility of accurate planning and optimization of the waste management system does not exist. The aim of this study was to evaluate a quantitative and qualitative and recycling potential of solid wastes in 13 regions of Mashhad.
This study was conducted during the 12 mounths of 2012 in 13 regions of Mashhad municipality. This research was needed to know the phisical analysis of waste, so the information and statistical analysis of Waste Management Organization of Mashhad was used.
The solid parts of studied waste were paper and cardboard (46.7%), bread (10.8%), plastic (9.7%), metals (6.8%), glass (5%) and others (20%). There was a significant relationship between the amount of solid wastes in winter and summer months. The total income from selling of recycled materials was 14,793,458,000 rials. The income from selling of recycled paper is higher than other dry wastes.
The amount of recycled dry solid waste was26.15%. It is recommended that by performing comprehensive studies and appropriate managemnt can effectively increase the percentage ofrecycling dry waste as well as proper recycling will lead to revenue and creating jobs in this sector.

Performance of wastewater treatment plants (WWTPs) in Urmia, Khoy, Miandoab, Salmas, and Bookan were evaluated during the years 2008 to 2011 based on the reliability approach. The approach predicts the overall performance of WWTPs and their processes and, thereby, makes the screening of treatment technologies possible. The required BOD5, COD, and TSS data were collected using the records available at West Azerbayejan Water and Wastewater Company, local surveys, and interviews with operators. Statistical analysis was performed by SPSS. The valid Niku modeling was employed to calculate the Rmeasured, Revaluated, COR, and expected percentages of compliance with discharge standards and a significant relationship was found among these parameters. The results also showed the log normal distribution of effluent characteristics. Furthermore,SBR and biolac processes exhibited higher values of Rmeasured (90-100%), Revaluated (93-100%), and expected percentages of compliance with the discharge standards (95-99.97%) in all the WWTPs studied but lower values of COR (0.41-0.64) than those in aerated lagoons. The coefficients obtained in this study can, therefore, be used for the development and construction designs of similar systems.

 In this study, management of industrial waste in industries located between Tehran and Karaj in 2009-2010 was examined. 

 This is a cross-sectional study which was done by site survey (Iranian environmental protection organization) questionnaire usage and results analysis. This questionnaire was consisted of 45 questions about industrial waste, quantity, quality, and management. A total number of industries with over 50 employees was 283, and Stratified sampling method was used. Sample of size 50 was selected from 283cases. 

 The major hazardous waste-generating industries include chemical and plastic. Private sectors disposed 45% of generated waste. Majority of wastes were buried (62%), and only 17% of industrial waste was recycled. 

 For hazardous waste reduction in this zone and health and economic attractions, the opportunity for reuse and recovery for these wastes must maximize in short-term and burial of industrial waste must be minimized. Industries such as chemical-plastic and electronics which have higher hazardous waste, in long-term, must be replaced with other industries such as wood cellulose and paper that have lower hazardous waste production rate.

Acidic sludge is a by-product from used motor oil reprocessing industries, which thousand tons of this sludge are disposed into the environment as a hazardous waste material daily. The acidic sludge contains unsaturated compounds that are polar and asphaltene. The bitumen under certain conditions is produced from mixing of bentonite, polymer styrene – butadiene – styrene (SBS), and acidic sludge.Context and The objective of this study was the recovery of acidic sludge to bitumen using additives such as bentonite and SBS. Also, the effect of additives with different weight percentages (wt%(on the performance parameters of bitumen was evaluated. At first, spilled oil was separated from the acidic sludge by a centrifugal concentrator. Then, concentrated acidic sludge and additives were mixed in together. Finally, the performance tests were carried out to compare the quality of acidic sludge with the obtained products.The results indicated that performance parameters such as softening point (SP), weight loss, penetration degree, PI, Frass breaking point, and temperature susceptibility (TS) were promoted from 37°C, 1.3%, 230 dmm, -0.07854, -5°C and 0.0451 to 54°C, 1%, 130 dmm, 2.7094, -11°C, 0.02721, respectively. According to the paired sample t-test analysis, a significant difference was found between the bentonite dosage and the improved performance parameters from concentrated acidic sludge and obtained products (pvalue ≤.001). The bentonite and SBS with 2 and 4 wt%, respectively were determined as the suitable additives in the recovery of acidic sludge to bitumen.

According to the existing documents a major portion of municipal solid wastes in Iran is being land filled and small portion of this material is recycled، while the municipal waste management in developing countries has moved towards source separation and recycling. This research was conducted by the purpose of estimating Qom municipal solid waste recycling potential and cost benefit،s in a 20-year vision since 2006. This Research is a cross-sectional study. Firstly، according to the reports given by waste management organization in Qom city، dry solid waste recycling in 2006 and 2011 was estimated. Then two scenarios consisted of 20 and 60 percents of recycling were estimated to process the solid waste in 2011 and 2028 for enhancing recycling level، and then cost benefit of them was determined The average of produced solid waste was 718 ton per day in Qom city in 2011. Due to this producing process in 1407 we will have 1145 ton solid waste per day in this city. Daily economic benefit of dry solid waste recycling in 2011 was 15801520 Rials. If the recycling programs promotes، this benefit can be increased to 63211640 and 189664400 Rials for 20 to 60%recycling level. Despite of 21 % potential for dry solid waste recycling in Qom city، nowadays about 5% of this substances are recycling. By upgrading the plan for 10 to 20 years، amount of economic benefit can be increased to 4 to 12 times.

Pharmaceutical products، particularly antibiotics، due to their cumulative and inappropriate effects and creating drug resistances، as inevitably pollutants، have been created a major concern in environmental control. Metronidazole (MTN) is one of these antibiotics. Hence، the aim of this study was investigation of MTN removal efficiency by catalytic ozonation process (COP) in presence of produced magnesium oxide nanocrystals as catalyst. The influences of several operational factors for their effects on removal were evaluated، including solution pH (3-12)، reaction time، MgO dosage (0. 25-4 g/L) and initial MTN concentration (1-40 mg/L). Also degradation kinetic، biodegradability improvement and mineralization rate were studied for the COP. For degradation kinetic the best compatibility was with pseudo-second order (liner type II) model. The optimum pH and MgO dosage for COP were determined to be 10 and 0. 25 g/L، respectively. Under optimum condition the complete removal of 40 mg/L MTN solution was observed after 20 min. The results illustrate that MgO nanocrystals markedly accelerated the MTN degradation in and the COP significantly increased BOD5/COD ratio and caused 94% MTN mineralization.

Thousand tons of acidic sludge is produced daily as by-product in the used motor oil refining industries. The acidic sludge contains unsaturated compounds which are non-polar and asphaltene. The objective of this study was performance improvement of acidic sludge by using the additives (bentonite, polymer SBS, sodium hydroxide and the lime) so that recovery to bitumen. The polymer styrene - butadiene - styrene (SBS) is bitumen modifier as one of the elastomer - thermoplastic with weight percentages (2 to 4 percent), bentonite due to the chemical structure as fillers, stabilizers and agent concentration with weight percentages (1,2,4,6,8,10) and lime and sodium hydroxide were used to decreasing acidity rate of acidic sludge and promoting the role of bentonite stability in bitumen with ratios equal (1 to 5 g) were mixed with acidic sludge of industry (samples 50 g) and their effect on the acidic sludge was investigated. Evaluation of studies indicated that because of increasing acidic sludge softening point, temperature from 25 to 48 oC, decrease weight loss from 3% to 1.25, promoting the penetration degree to 230 mm, Frass breaking point to -7 and penetration index (PI) to the degree standard set (+1), the acidic sludge properties and performance were modified. The measurement of last three parameters was unavailable in primary sludge. Environmental and health hazards of acidic sludge will be decreases by treatment and neutralization. Also obtained products can be used in the building and road construction according to its specific bitumen criteria and characteristics.

Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients (sodium, potassium, and sulfate) from silt-loamy soils. In this empirical, applied study, three polyethylene columns (height 50 cm, inner diameter 10 cm), filled with sandy clay loam soil, were randomly selected. Then, 10 kg of compost per square meter were sprayed onto the columns, and leachates exiting the columns were routinely analyzed for pH, electrical conductivity, sulfate, sodium, potassium, lead, chromium, and cadmium. Data analysis was performed with Excel and SPSS software using Kruskall-Wallis test. The data showed that the use of enriched and unenriched compost leachate decreased pH (from 7.43±17.0 to 6.7±0.25 and 7.07±0.11, respectively) and increased the electrical conductivity (EC) (from 1.8±0.3 mSiemens/m to 3.7±0.12 and 12.87±0.41 mSiemens/m respectively). Leakage of metals in the unenriched treatments was not significantly different from the control (p>0.78), but leakage with three metal-enriched compost applications was significant compared with control (p<0.001). Application of composts containing heavy metals onto loamy soils increases leaching of heavy metals from the compost into groundwater. Therefore, frequent use of compost endangers groundwater quality.

The quality of the compost produced is one of the most important and effective parameters in its marketing and external materials presence in the compost have specific consideration. This study was conducted to investigate the quantity and quality of foreign materials in the compost produced by Khomein and Tehran plants. This study was conducted on the compost produced by Khomein and Tehran plants in 9 months; 10 composite samples were gathered and the external constituents such as glass, plastic, metal, miscellaneous and sand were analyzed, then to compare the data t-test analysis was used. The average percentage of glass, plastic, metal, miscellaneous and sand in Tehran and Khomein compost were 0.62, 0.22, 0.84, 2.24 and 1.17, 0.17, 0.02, 1.36, 3.61, respectively; which were in accordance to the considered standards. Moreover, the statistical analysis showed that except the plastic, there was a significant difference (P < 0.0001) between the other parameters average in Tehran and Khomein’s composts. In general, the compost produced by Tehran and Khomein plants did not have any significant problem in terms of external materials. However, as the presence of external materials causes the farmers hesitation to buy the compost, the source separation of inorganic materials and prohibition of mixed compost production could improve the compost quality and its markets.