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Showing 7 results for Composting
Comparisons of Three Advanced Oxidation Processes in Organic Matter Removal from Esfahan Composting Factory Leachate
B Karimi, M.h Ehrampoush, M Mokhtari, A Ebrahimi,
Volume 4, Issue 2 (9-2011)
Abstract

 

Backgrounds and Objectives: Wet air oxidation (WAO) is one of the advanced oxidation process which is mostly used to reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substance and solid waste leachate.The objective of this paper is comparisons of three advance oxidation in organic matter removal in different conditions from Esfahan composing factory leachate
Material and Methods: The experiment was carried out by adding 1.5 Lit pretreated leachate sample to 3Lit autoclave reactor and adding 10 bar pressure at temperature of 100, 200 and 300 °C and pressure (10 bars) with retention time of 30, 60 and 90 min. leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 lit was taken and the three methodsWAO, WPO, and a combination of WAO/GAC were used for pre-treatments. Pure oxygen and 30% hydrogen peroxide was used as oxidation agent.
Results: The result shows significant improvement on the removal rate of COD (7.8-33.3%), BOD5 (14.7-50.6%)by WAO process.The removal efficiency of 4.6-34% COD, 24-50% BOD, was observed in the reactor.Adding theGACto the reactor improved removal efficiency of all parameters.Combination Process (WAO/GAC) removed 48% of COD, 31-43.6% of BOD.Combination process demonstrated higher efficiency than two other previous methods as BOD5/COD ratio of 90% achieved.
Conclusion: The WAO process presented in this paper is efficient for pretreatment of leachate, And the modified WPO process remove organic materials and ammonia moreover WAO/GAC can be considered as an excellent alternative treatment for removing reluctant organic matter (COD, BOD5) and organic nitrogen compounds, which found in leachate.

 


Efficiency of in-vessel composting process in removal of petroleum hydrocarbons from bottom sludge of crude oil storage tanks
K Naddafi, R Nabizadeh, S Nasseri, K Yaghmaeian, A Koolivand,
Volume 8, Issue 3 (12-2015)
Abstract

Background and Objectives: Remaining of crude oil in storage tanks usually results in accumulating oily sludge at the bottom of the tank, which should be treated and disposed of in a suitable manner. The efficiency of in-vessel composting process in removing total petroleum hydrocarbons (TPH) from bottom sludge of crude oil storage tanks was investigated in the present study.

Material and methods: The sludge was mixed with immature compost at the ratios of 1:0 (as control), 1:2, 1:4, 1:6, 1:8, and 1:10 (as dry basis) with the initial C:N:P and moisture content of 100:5:1 and 55% respectively for a period of 10 weeks. The moisture adjustment and mixing process were done 3 times a day during the composting period. Sampling and analysis of TPH and pH were done every week and every two days, respectively.

Results: TPH removal in the 1:2, 1:4, 1:6, 1:8, and 1:10 composting reactors was 66.59, 73.19, 74.81, 80.20, and 79.91%, respectively. Thus, initial adjustment of sludge to immature compost ratios plays a great role in reduction of TPH. The results of the control reactors indicated that the main mechanism of TPH removal in the composting reactors was biological process.

Conclusions: In-vessel composting by addition of immature compost as amendment is a viable choice for bioremediation of the bottom sludge of crude oil storage tanks.


Investigating the Trend of Changes of Organic Carbon, Nitrogen, Phosphorus, and Temperature During Oily Sludge Composting Process
A Koolivand, K Naddafi, R Nabizadeh, A Jonidi Jafari, M Yunesian, K Yaghmaiean, S Naseri,
Volume 9, Issue 3 (12-2016)
Abstract

Background and Objective: The performance of in-vessel composting process, as one of the most effective methods of oily sludge treatment, depends on factors such as nutrients and temperature. Therefore, it is crucial to investigate the trend of changes of these factors. The aim of the present study was to investigate the trend of changes of organic carbon, nitrogen, phosphorus, and temperature during the composting of bottom sludge of crude oil storage tanks.

Materials and Methods: The sludge was mixed with the immature compost at the various ratios of sludge to compost including 1:2, 1:4, 1:6, 1:8, and 1:10 with the initial C/N/P of 100/5/1 and then was composted for a period of 10 weeks. The process of mixing and moisture adjustment of the mixtures was done 3 times a day during the composting period. Sampling and analysis were performed every week for organic carbon, nitrogen, and phosphorus and every day for temperature.

Results: The research indicated that the concentrations of organic carbon, nitrogen, and phosphorus were decreased sharply during the first weeks of the process and then they were decreased gently. At the final stage of the composting, the ratios of C/N and C/P increased from 20:1 and 100:1 to 26:1 and 166:1, respectively. In addition, the temperature of the reactors was kept in the mesophilic range during the process period.

Conclusion: The similar trend of decrease of organic carbon, nitrogen, and phosphorus in the composting reactors is an indication of decreasing the activity of the microorganisms involved in petroleum hydrocarbons degradation.  


An Investigation on In-Vessel Composting of Pistachio Residuals with Different Additions
M Jalili, M Mokhtari, Aa Ebrahimi, F Boghri,
Volume 9, Issue 3 (12-2016)
Abstract

Background and Objective: About 1.35×105 tons of pistachio waste are produced in annually Iran that can result in environmental problems if managed improperly. . The purpose of this study was to investigate in-vessel composting of pistachio residuals with addition of cow manure and dewatered sludge as a recycling alternative.

Materials and Methods: Pistachios wastes were combined with weight ratio of 5.5:10 (dewatered sludge: pistachio waste) and weight ratio of 1:10 (Cow manure: pistachio waste) to achieve the carbon to nitrogen ratio of 25:1. The parameters measured were pH, EC, percentage of moisture, total and volatile solids, ash, organic carbon, temperature, and phenol. The 20th edition of SPSS software was used for t-test statistical analysis and comparing the results with standards and Microsoft Excel 2007 was used for drawing the plots.

Results: During the 60-days process of in-vessel composting of pistachio residuals with addition of cow manure, the ratio of carbon to nitrogen reduced from 25:1 to 13:1, dewatered sludge from 25:1 to 14:1; phenol amount in cow maneuver decreased from 4980 to 254 ppm and in dewatered sewage sludge from 6100 to 254 ppm. The maximum temperature in cow manure and dewatered sewage sludge treatments in the composting process reached to 51.9 and 48.9 ˚C respectively.

Conclusion: Results showed that the produced compost with cow manure has a higher fertilizing value compared with the dewatered sewage sludge due to its better organic degradation.


The efficiency of composting on the degradation of antibiotic metronidazole as a pharmaceutical waste
A Jonidi Jafari, M Farzadkia, M Gholami, M Mohagheghi,
Volume 11, Issue 2 (9-2018)
Abstract
Background and Objective: Nowadays, the increasing use of antibiotics to control diseases and mismanagement and inappropriate disposal of medicinal wastes cause environmental problems and threatens human health. The present study was conducted to determine removal of antibiotic Metronidazole as one of the most used drugs during the process of composting.
Materials and Methods: In this experimental study, a mixture of livestock manure, fruit, straw and sludge were used for the preparation of compost. Duration of the process was 40 days. Metronidazole was added to the compost reactors at three concentrations of 20, 50 and 100 mg/kg. Totally, 42 Samples were taken weekly. HPLC was used to analyze the samples. The experiment was repeated twice. SPSS22 software was used to analyze the results.
Results: The rate of Metronidazole removal after day 21 and end of the thermophilic phase was 99.9, 96.73 and 93.48 % in the reactors contained 20, 50 and 100 mg/kg, respectively. Increasing concentrations in the reactors caused the removal rate to decrease, while increasing removal time caused to increase the removal rate. At the end of the process, the removal rate for all three reactors was 99.99 %. The physico-chemical properties of the final compost were within the national standard.
Conclusion: The use of an aerobic composting process to degrade antibiotic Metronidazole is an economical, effective and, environmentally friendly method. At the end of the process, 99.99 % of Metronidazole was degraded.
 

Evaluation of stability and maturity indices during composting process from a mixture of poultry waste and sawdust by windrow method
Asghar Yavari, Mehdi Moradi Nazar, Seyedeh Maryam Sharafi, Amir Hossein Nafez, Meghdad Pirsaheb,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: It is important to determine the quality of the compost to use compost properly. The aim of this study was to determine the effect of mixing ratio of bulking agent on stability and maturity indices in poultry waste compost.
Materials and Methods: Two piles of sawdust mixture with poultry wastes and volume ratios of 1:1 (W1) and 2:1 (W2) were prepared by Windrow method and a pile containing poultry manure was used as control (W0). In order to determine the stability and maturity indices in compost, the most important physicochemical and biological parameters were studied.
Results: The thermophilic phase lasted about 7 weeks for W1 and about 4 weeks for W2. The initial C/N ratios in the W0, W1 and W2 were 27.10, 31.40 and 56.24, respectively, which eventually reached less than 20. The reduction of organic matter in the three piles was 8.30%, 62.59% and 85.53%, respectively. The thermophilic phase caused a sharp decrease in the population of indicator and pathogenic microorganisms in all piles. The highest dehydrogenase activity in W1 pile was 2.95 mgTPF/gDW.h and by decreasing temperature until the last day, its value decreased to 0.29 mgTPF/gDW.h.
Conclusion: The best ratio for mixing sawdust with poultry manure was 1:1 (v:v). Microbial and enzymatic activities are useful parameters for monitoring poultry composting process and determining the rate of compost stability, and the use of this compost in agriculture will improve soil quality.
 

Investigating earthworm survival in diesel-contaminated soil remediation reactors
Behnaz Abdollahinejad, Mahdi Farzadkia,
Volume 17, Issue 2 (9-2024)
Abstract
Background and Objective: Earthworms are important in soil formation. They maintain soil structure and fertility and can be used as indicators to evaluate various changes and impacts. Therefore, the present study was developed to investigate the effects of diesel pollutant on the population and survival of the earthworm species E.fetida in the co-vermicomposting process.
Materials and Methods: This experimental study was conducted over 90 days to investigate the effects of diesel concentration on the survival of E.fetida in the co-vermicomposting process. One kilogram of soil contaminated with diesel, vermicompost, and raw activated sludge was added to each reactor in a ratio of 0.25:0.35:1. 10. Additionally, 20 adult E. fetida were added to the reactors with diesel concentrations of 10 and 30 g/L after the adaptation process.
Results: The survival of earthworms and the formation of cocoons in reactor number 3 were higher than in other reactors. Additionally, the amount of diesel removal in reactor number 3 (diesel concentration: 10 g/kg dried soil +20 E.fetida) was higher (70.5%) compared to the other reactors.
Conclusion: The results of the study showed that earthworm reproduction is more sensitive than survival or weight change to higher concentrations of diesel-contaminated soil. The presence of petroleum compounds in the soil is harmful for the growth of E.fetida, and its acute effects on the production of earthworm cocoons were observed.
 

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