[Comparing the effects of Indomethacin and magnesium-sulfate in the treatment of preterm labor]

The prevalence of preterm labor in Iran is 6-10%, accounting for 80% of neonatal morbidity. The most effective tocolytic agents to delay the preterm labor have not yet been known. Therefore, this study aimed to compare the effects of Indomethacin [ICN] and Magnesium-Sulfate [Mgs] in delaying preterm labor and also to assess the maternal complications associated with the two drugs. This randomized clinical trial study was performed on 24-32 week pregnant women [n=60] at risk for preterm labor referred to Shabih-Khani maternity hospital in Kashan. The women were divided into two equal groups: intravenous Mg sulfate [control] or ICN rectal suppository [intervention] groups. Then, the delaying of preterm labor and also the maternal morbidity were assessed in both groups. No significant difference was seen in maternal and sociodemographic variables between the two groups. The delaying of preterm labor was the same for both groups and no case of preterm labor was seen in women during the first 48 hours of hospitalization. Moreover, there was no significant difference in variables [e.g. the maternal age, the number of gravida, gestational age, symptoms on admission, the number of prior preterm labors and a history of preterm labor] between the two groups. The most common complication in both groups was nausea. There was no case of oligohydramnios in the indomethacin group. Although the delaying of preterm labor was the same in both groups, Mg sulfate administration requires permanent nursing care. It seems that ICN can be used as one of primary tocolytic treatments in preterm labor

[Optimum operating conditions in the phytoremediation of contaminated soils with Lead and Cadmium by native plants of Iran]

In recent decade, phytoremediation technology is regarded very important because of its simplicity, inexpensiveness and use of natural resources and solar energy. In this study, we investigated the efficiency of remediation of contaminated soil with Lead and Cadmium by using native plants of Iran. We selected three native plants of Iran [Abutilon theophrasti, Amaranthus retoflexus and Zea maize] for this study. Extraction of soil and plant samples was performed by use of HNO3 ,HCl and HNO3, HClO4 and H2SO4 respectively. Concentrations of Lead and Cadmium in soil and plants were determined by Perkin-Elmer 603 atomic absorption spectrophotometer. Lead concentration in the roots of plants [Alkaline soil] was more than those in their shoots. In acidic soil [with exception of Zea maize], concentration of Lead in the shoots was more than its concentration in the roots of the plants. Concentrations of lead in the roots and shoots of Abutilon theophrasti, Amaranths and Zea maize in alkaline soil were [54.5 and 25.5 mg/kg], [69 and 37.6mg/kg] and [47 and 32mg/kg] respectively, and its respective concentrations in acidic soil were [71.4 and 92.5 mg/kg], [89 and 120.5mg/kg] and [85 and 66.7 mg/kg]. Cadmium concentrations in alkaline soil were [6.5 and 4mg/kg], [8 and 6.2 mg/kg] and [5.6 and 3.4 mg/kg] and in acidic soil were [5.8 and 4.5 mg/kg], [7.6 and 5.4mg/ kg] and [6 and 4.8 mg/kg] respectively. Plants in group 3 produced less biomass than those in control group, group 1 and group 2. Considering the increased rate of absorption of Lead and Cadmium and the amount of biomass produced by Zea maize and Amaranthus retoflexus in the acidic and alkaline soil, use of these native plants is recommended for refining the soil contaminated with heavy metals

[Effect of lithium on neuropathic pain induced by partial ligation of rat sciatic nerve]

Background: Neuropathic pain is a type of chronic pain resulting from injury to the peripheral or central nervous system. Moreover, lithium is the main medication used to treat bipolar [manic-depression] disorder and some recent studies have also confirmed the neuroprotective effects of lithium. Considering the most common cause of neuropathic pain, nerve injury, the present study was designed to evaluate the effect of lithium on neuropathic pain induced by partial ligation of sciatic nerve in rat

Materials and Methods: This experimental study was conducted on 40 adult male rats. Neuropathic pain was induced by a partial sciatic nerve ligation model and animals were randomly divided into five groups: a control group that underwent the surgical procedure without sciatic nerve ligation and four experimental groups which received normal saline and different doses of lithium [5, 10 and 15 mg/kg, i.p.]. Heat hyperalgesia, mechanical and cold allodynia were assessed at 3, 5, 7, 10 and 14 days after surgery

Results: According to the results, lithium [5, 10 and 15 mg/kg] significantly reduced heat hyperalgesia and cold allodynia induced by partial sciatic nerve ligation [P<0.01], while it reduced mechanical allodynia only at high doses [10 and 15 mg/kg]

Conclusion: Lithium has an analgesic effect on neuropathic pain induced by partial ligation of sciatic nerve in rat. Further investigations would be needed to confirm the analgesic effect of lithium and its mechanisms of action in neuropathic pain

[Assessing the effective dose of warfarin in treatment course of the patients referring to Kashan heart clinic]

The major problem in prescribing the therapeutic dose of warfarin, the most clinically used anticoagulant, is achieving its optimal International Normalized Ratio [INR]. This study was designed to determine the mean dose of warfarin among the patients admitted to Kashan Heart Clinic in 2008. In this cross-sectional study, the medical documents of all patients receiving warfarin in any medical indications were studied for demographic specification, INR results, smoking, other used drugs and the underlying diseases. The warfarin dose attained [INR equal to 2.4-2.6 for 3 consecutive test results] was regarded as the optimal dose. All unqualified cases in terms of INR criteria were excluded. Statistical analysis was done using ANOVA, Pearson, Spearman and t-tests. Seventy one out of 86 patients were included in the study. The mean daily dose of warfarin was 3.97 +/- 1.38 mg. Fourty six, 13, 11 and one patient[s] received warfarin for atrial fibrillation, prosthetic valve, congestive heart failure and embolic cerebrovascular accident, respectively. While warfarin dose had an inverse relation to age [P=0.01], it had no significant relation with sex [P=0.7], underlying diseases [P>0.07], smoking [P=0.2], other used drugs [P=0.07] and the patient weight [P=0.1]. The results showed that warfarin dose was higher among the patients with prosthetic valve [P=0.008]. The obtained effective daily and weekly dose of warfarin i.e. 3.97 +/- 1.38 and 27.83 +/- 9.77 mg, respectively could be used as a therapeutic clue for prescribing the appropriate dose and optimum INR

Removal of methyl tert-butyl ether [MTBE] from contaminated water by photocatalytic process

Methyl tert-butyl ether [MTBE] has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may result in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO2/O2 photocatalytic process. The effect of important operational parameters such as pH, oxygen flow, catalyst loading, and irradiation time were also studied. Concentration of MTBE and intermediates such as tert-butyl formate [TBF] and tert-butyl alcohol [TBA] were measured using a gas chromatograph equipped with flam ionization detector and combined with headspace sampler. The time required for complete degradation increased from 15 to 150 min, when the initial concentration was increased from 10 to 500 mg/L. The first order rate constant for degradation of MTBE from the hydroxyl radical was estimated to be 0.266 to 0.033 min[-1] as the concentration increased from 10 to 500 mg/L. Study on the overall mineralization monitored by total organic carbon [TOC] analysis showed that in the initial concentration of 100 mg/L MTBE, complete mineralization was obtained after 110 mm under UV-vis/TiO2/O2 photocatalytic process. The data presented in this paper clearly indicate that UV/TiO2/O2 advanced oxidation process provides an efficient treatment alternative for the remediation of MTBE contaminated water

[Study of natural organic matter characteristics and fractions in surface water resources of Tehran]

Natural organic matters [NOMs] are abundant in natural water resources and in many ways may affect the unit processes in water treatment. Although NOMs are considered harmless but they have been recognized as disinfection by-products [DBPs] precursors during the chlorination process. Formation of DBPs highly depends on the composition and concentration of NOMs. The objective of this study was to determine natural organic matter and its fractions concentrations in the surface water sources of Tehran. Water sampling was conducted monthly between May to July in three rivers of Lar, Jajrood and Karaj, as the main drinking water supplying sources in Tehran. Quantitative parameters of pH, EC, UV254 and DOC were studied based on standard methods. The XAD-7 resin method was used for fractionation of NOMs. Results showed that NOM concentrations in Lar, Jajrood and Karaj rivers were 8.53, 12.9 and 11.3 mg/L, respectively. The HPO [hydrophobic] fraction was predominant compared to the HPI [hydrophilic] fraction in water samples. The mean of total percent of HPO and HPI fractions were about 57% and 43%, respectively. Since the hydrophobic NOM fraction exhibits higher trihalomethane formation potential [THMFP] than hydrophilic part, Tehran water chlorination exhibits higher THMFP than haloacetic acid formation potential [HAAFP]. The information obtained from this study may be further employed in the design of the control techniques and management strategies for the water treatment plant, especially for DBPs reduction

Application of photocatalytic process for removal of methyl tert-butyl ether from highly contaminated water

The oxygenate methyl tert-butyl ether is added to gasoline to increase the octane level and to reduce carbon monoxide and hydrocarbon emissions by vehicles. The high mobility, water solubility, and resistance to natural attenuation associated with methyl tert-butyl ether may result in contamination of ground and surface waters. In this research the degradation of aqueous methyl tert-butyl ether at relatively high concentrations was investigated by UV-vis/TiO[2]/H[2]O[2] photocatalytic process. The effect of important operational parameters such as pH, amount of H[2]O[2], catalyst loading, and irradiation time were also studied. Concentrations of methyl tert-butyl ether and intermediates such as tert-butyl formate and tert-butyl alcohol were measured over a 180 min period using a gas chromatograph equipped with flame ionization detector and combined with headspace sampler. Results showed that the time required for complete degradation increased from 30 to ISO min, when the initial concentration was increased from 10 to 500mg/L. The first order rate constant for degradation of methyl tert-butyl ether from the hydroxyl radical was estimated to be 0.177 to 0.022 1/min as the concentration increased from 10 to 500mg/L. Study on the overall mineralization monitored by total organic carbon [TOC] analysis showed that in the initial concentration of l00mg/L methyl tert-butyl ether, complete mineralization was obtained after 110min under UV-vis/TiO[2]/H[2]O[2] photocatalytic process

Control of disinfection by products formation potential by enhanced coagulation

Jar-test experiments were conducted to study enhanced coagulation effectiveness in removal of disinfection by products [DBPs] from Zayandehrud River at Isfahan Province-the center part of Iran- in 2004. In this study, the removal of suspended and colloidal particles and natural organic matter [NOM] at various coagulant doses and coagulation pHs was assessed through raw and treated water measurements of turbidity, UV254 absorbance, TOC, and dissolved organic carbon [DOC]. The trihalomethane formation potential [THMFP] was also determined by a mathematical relationship with TOC. Results indicated that NOM removal was a function of coagulant type, coagulant dose, and pH of coagulation. In general, TOC, DOC, and UV254 absorbance removal enhanced with increasing coagulant dose. However, further increases in coagulant dosage had little effect on disinfection by-products precursors removal. Ferric chloride was consistently more effective than alum in removing NOM. Coagulation pH was appeared to be a determining factor for maximum NOM removal and the removal of DBPs precursors by enhanced coagulation was significantly enhanced at pH 5.5 in comparison with initial pH of water. Furthermore, it is specified that preadjustment of pH with sulfuric acid reduced the coagulant dosage and thus, production of sludge. The reduction in THMFP was consistent with the trends observed for DBPs precursors removal data [i.e. UV254 and TOC data]

Effect of organic loading on the performance of aerated submerged fixed-film reactor [ASFFR] for crude oil-containing wastewater treatment

An aerated submerged fixed-film [ASFF] bioreactor was developed to treat an artificial wastewater based on crude oil. Bee-Cell 2000 was used as support media having porosity of 87% and a specific surface area of 650 m[2]/m[3]. The system was able to achieve 83.14-97.05 percentage removal efficiencies of soluble chemical oxygen demand [SCOD] in the organic loading rate range of 0.84 to 9.41 g SCOD/m[2]day showed that the effluent SCOD concentration ranged between 18.93 and 100.93 mg/L at organic loadings experienced. Therefore, an ASFF process showed that it was feasible to treat high oily wastewater in order to meet the discharge standards

[Chromium [III] removal from tannery wastewater by precipitation process]

Chromium [III] salts are the most widely used chemicals for tanning processes, but 30-40% of the chromium amount remains in the solids and liquid wastes [especially spent tanning solutions]. Therefore, the removal and recovery of the chromium content of these wastewaters is necessary for environmental protection and economic reasons. The aim of this study was chromiam removal from tannery wastewater by precipitation process.Removal and recovery of chromium were carried out by using precipitation process. To this purpose, three precipitating agents were used; calcium hydroxide [[Ca[OH]2]], sodium hydroxide [NaOH] and magnesium oxide [MgO]. The effects of pH, stirring time, setteling rate and sludge volume were studied in batch experiments.Results showed that the optimum pH was 8-9, and the setteling rate of the process for magnesium oxide was much more than this rate for the other two compounds. Furthermore, a grainy, dense, easly settelable precipitate could also be formed when MgO was used as the precipitator. Whereas, precipitates forming by NaOH was very gelatinous and the setteling rate was low. Precipitates forming by Ca[OH]2 was not also desirable. Sludge's volume by MgO was much less than sludge volume produced by Ca[OH]2 and NaOH.TheMgO is an effective and suitable precipitating agent for removal of chromium from tanning waste water

Evaluation of ferric chloride and alum efficiences in enhanced coagulation for toc removal and related residual metal concentrations

Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter [NOM] to reduce the formation of disinfection by-products [DBPs], is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA's 3x3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal [aluminum/iron] concentration in the treated water was assessed as well. The removal of total organic carbon [TOC] was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably

[Efficiency of advanced oxidation and hydroxyl technology in methyl terciary - butyl ether [MTBE]]

Advanced oxidation processes have been demonstrated as the rapid and effective methods for the treatment of a vast range of the refractory pollutants. The aim of this study was to use ozone in reaction with hydroxyl radicals [high-PH] as the reaction accelerator for MTBE degradation in industrial wastewater and polluted water. The effect of O3 with the hydroxyl radicals [high-PH] was experimented for MTBE degradation in an aqueous phase. All the reactions were performed in a semi-continuous bubbling column reactor. The effects of PH, reaction time and rate of O3 needed to attain complete MTBE degradation were examined. MTBE ozonation in five different PHs [10,10.5,11,11.5 and 12] during 100 minutes for each PH was performed. The study showed that the PH=11.5 is the fittest PH for MTBE degradation by the radical reactions. In this pH [intermediates] /[MTBE] ratio was 0.6v / mM that it is 20% more than its nearest ratio [related to PH=11]. The least time [70 minutes] and needed ozone [5.3 moles] for 90% degradation of each mole of MTBE occurred at PH=11.5. The test performed to determine the rate of removed MTBE as a result of air stripping showed that this rate was 11-19.5% at different PHs during 100 minutes. There was no significant relationship between the rate of removed MTBE as a result of air stripping and the aqueous PH at PHs=10-12 at level of 5% error. MTBE is relatively resistant to degradation even in advanced oxidation processes, but with continuous oxidation can be degraded completely and the best PH for that is11.5

[Study the kinetics of activated sludge in integrated system [fenton oxidation,activated sludge] for removal of 2,4,6 trichlorophenol]

Introduction: 2, 4, 6 trichlorophenol [TCP] is one of the most toxic Chlorophenols and is very difficult to biodegradation. Advanced oxidation processes [AOPs] are the most effective processes for the degradation of persistent compounds, since the mineralization of recalcitrant compound by AOPs often requires long reaction time and strong dose of oxidant, the combination of this process with biological one considered as one efficient and economic method

Objective: Integration of Fenton oxidation with activated sludge as an efficient and economic method for removal of 2, 4, 6 trichlorophenol and on kinetics of activated sludge in this integrated system was studied

Materials and Methods: This study performed in pilot scale of Fenton oxidation / Activated sludge Integration for treatment of 2-4-6 TCP wastewater and all analytical methods were according to 19Th edition of standard methods

Results: The study results showed that intermediates in effluent from Fenton reactor [H2O2] /[Fe2+] =3 , [H2O2] / [TCP] =3 Oxidation Time = 1hr and pH= 3 [TCP] 0 = 120 mg/ equal COD=150 mg/L], was degraded by activated sludge process and COD reduction was %75. Increasing aeration time from 6 hr to 18 hr has no significant effect on removal efficiency [alpha =0.01]. ML VSS increasing from 200 mg/L to 800 mg/L after 21 days indicated that TCP concentration in Fenton reactor effluent didn't have inhibitory effect on microbial growth. Increasing of TCP concentration from 120mg/L to 240mg/L has no significant effect on removal efficiency, however removal efficiency decreases to %71. Activated sludge kinetics were studied and y= 0.66 mg/mg Kd =0.088 day-1 Ks = 109 mg/ L, K = 2.04 day-1 determined

Conclusion: As results this integrated system was an efficient method for removal of 2,4, 6TCP and result from increasing aeration time and TCP concentration, as sole substrate source for Activated sludge combined with Fenton oxidation was not adopted with Monod equation

Removal of chloroform [CHCL3] from Tehran drinking water by GAC and air stripping columns

The harmful substances, defined as trihalomethanes [THMs], were found to be formed during the disinfection of drinking water when chlorine was used as the disinfectant. In this research, the effectiveness of granular activated carbon [GAC] and air stripping [AS] packed column for the removal of chloroform [CHCL3] [as THMs basic indicator compound in many resources] in range of 50 to 300 micro g/L, from drinking water was studied. Pilots of GAC and air stripping columns were designed and set up. The study was carried out for the two cases of deionized and chlorinated Tehran tap water. Also the effects of flow rate, chloroform and TDS concentrations were considered in both treatment systems. Gas chromatography [GC] with electron capture detector [ECD] was used for determination of chloroform concentration in inlet and outlet samples. The obtained data were analyzed by SPSS and non-parametric KruskaI-Wallis method. Results showed a positive correlation between the flow rate and chloroform concentration, and removal efficiencies. The average of variations of removal efficiencies for AS and GAC columns with deionized water samples were, 89.9%, 71.2% and for chlorinated Tehran tap water were 91.2% and 76.4%, respectively. The removal of feed residual chlorine in these columns with 0.5, 0.8 ppm was 100%, respectively and re-chlorination for finishing water was recommended. Results showed AS to be considered more effective in chloroform removal for conventional water treatment plants as a finishing process

Characteristics of fenton's oxidation of 2, 4, 6 trichlorophenol

2, 4, 6 trichlorophenol [TCP] is one of the most toxic chlorophenols which is very difficult to biodegradation. Advanced Oxidation Processes [AOPs] is one of the most effective processes for degradation of persistent compounds. Since the mineralization of recalcitrant compound by AOPs often requires long reaction time and strong doses of oxidant, the combination of this process with biological one, is considered as an efficient and economic method. In this work degradation of 2, 4, 6 trichlorophenol in aqueous solution with Fenton reagent [H2O2 +Ferrous ion] was studied. The experiment was done in batch mode, and the initial concentration of TCP was 0.60mM. In pH=3, H202=1.8mM, Fe=0.6mM, more than 99% of TCP was degraded in 10 minutes after the reaction was started. Chloride ion generation as TCP degradation by product was investigated, and it was found that the scavenging effect of chloride is negligible. PH and UV215 absorbance analysis, after reaction completion, indicated that generated intermediates had the less chlorinated nature, acidic properties and nonphenolic structure. Chloride ion increases from 0 mg/L to 40 mg/L, pH decreased from 3 to 2.7 and UV215 absorbance decreased from 3.2 to 0.6, therefore it can be resulted that their biodegradability modified and their recalcitrance reduced. COD analysis indicated that TCP did not mineralize and in H2O2/TCP = 3 and oxidation time of 1 h, COD reduction was only 37%.

Evaluation of lyophilization effects on operational parameters and characteristics of activated sludge

Advances in microbial and biotechnology have given great impetus to the filed of pollution control. In some countries efforts are being focused on the application of biotechnology for wastewater treatment. Occurrence of microbial growth inhibitors in the biological reactor will affect their activity, which this in turn will lead to reduced performance of the system in pollutants removal. Restart up of the system, especially in the biological treatment of industrial wastewater, will require abundance time and cost. An effective solution to reduce these problems is to prepare and store dried concentrated sludge bearing the needed microorganisms to be used later. The most effective technique to produce such concentrated sludge is lyophilization in which a stabilized biological solid is produced through rapid freezing and then drying under high vacuum conditions. This study was carried out to investigate the lyophilization effect on the microbial quality of the activated sludge. In this regard, operational characteristics including OUR, SVI, soluble COD removal efficiency and predominant microorganisms species before and after lyophilization in a lab-scale experiment were used. The results showed that sludge lyophilization had no influence on microorganisms' performance and operational characteristics of the activated sludge. In addition, there was not a significant change in the sludge properties before and after lyophilization. Sludge microorganisms were viable after lyophilization. So, lyophilization was concluded to be a suitable technology for preparation and preservation of cells in activated sludge because of preserving viability, ease of h and ling and simplicity

Survey on physical, chemical and microbiological characteristics of PAH-contaminated soils in Iran

Polycyclic aromatic hydrocarbons [PAHs] are one of the important groups of organic micro pollutants [Xenobiotics] due to their widespread distribution and low degradability in the environment [atmosphere, water and soil]. Some PAHs exhibit carcinogenic and /or mutagenic properties and are listed by the United States Environmental Protection Agency [USEPA] and European Commission [EC] as priority pollutants. In this research three petroleum contaminated sites in Iran were selected in order to separate and classify PAH-degrading microorganisms. Samples were analysed for: soil physico-chemical properties, soil particle size distribution, Ultrasonic extraction of PAH [phenanthrene] and microbial analysis. Ultrasonic extraction method was shown to be a reliable procedure to extract a wide range of PAH concentrations from different soils, e.g. clay, silt, and clay-silt mixtures. Results showed that the extraction rate of phenanthreen in mentioned different soils was in the range of 85 - 100 percent. Results showed that two of three selected sites were contaminated with phenanthrene in the range of 10 - 100 mg/kg of soil, and had a reasonable population of PAH- degrading bacteria, which were enable to adaptate and degradate a concentration range of phenanthrene between 10 and 1000 mg/kg of soil. According to results, it can conclude that, the bioremediation of contaminated soils in Iran may be considered as a feasible practice

Trihalomethane in the drinking water of Tehran

Natural sources of water contain some halogenated organic compounds after disinfection by chlorine. Trihalomethanes are one group of the chlorination by products that suspected of being carcinogenic inhuman unfortunately, these compounds are in finished water of all treatment plants that use chlorine as a disinfectant. In this study, the concentration of total THMS of water treated in the water treatment plant No.1 of Tehran had been measured by spectrophotometric method, along the month of June, 1371. Results of experiments have shown that organic contents of Tehran drinking water were not considerable in the period of survey. The mean concentration of TTHMS in water samples is estimated to be 28 micrograms per liter and none of the analyzed samples was considered polluted

Application of pact system to increase Tehran oil refinery effluent treatment efficiency

This research was done in order to determine the basic criteria for 'Tehran Oil Refinery Effluemt TreatmentUnit' to prove the feasibility of the application of powdered activated carbon in aeration zone of activated sludge System. The main stages of this research included: determination of qualitative and quantitative characteristics of raw wastewater preparation of two pilot scale units of activated sludge [As] and powdered activated carbon technology [PACT], study of correlation between independent variables of powdered activated carbon concentration, hydraulic detention time, and microbial detention time with the concentrations of COD, B0D5 and TSS of the effluent. Results indicated the efficiency increase of Tehran oil refinery effluent treatment by PACT process, which besides increasing COD5, BOD5, Oil and TSS removal, improves also nitrogen and phosphorus removal Conditions and activated sludge sedimentation, comparing as system

Evaluation of a two-stage treatment of domestic sewage with anaerobic-aerobic microbial film

The objective of this research was to study the feasibility of a two stage continuous system employing anaerobic-aerobic microbial film for domestic wastewater treatment and the effect of iron on the behavior of sulfate reducing bacteria in anaerobic metabolism. A bench scale system with an anaerobic filter followed by aerobic fixed units used plastic media and was operated in up flow manner with hydraulic detention times of 6 hours, whereas the aerobic unit utilized diffused aeration. Raw domestic sewage was fed to the anaerobic unit, and the aerobic unit was fed with the anaerobic unit was fed with the anaerobic effluent. Although, the anaerobic filter did not show a considerable organic removal with domestic sex age it was improved when glucose was added to the influent to increase influent soluble COD. When glucose was added the anaerobic filter removed about 290 mg/1 of influent soluble COD. The aerobic unit produced an excellent effluent with COD, BOD5 and TSS concentrations of 37 mg/1, 9 mg/1 and 10 mg/l respectively. Overall, the system removed 95% of influent COD, 97% of influent BOD5 and 96% of influent TSS