The Pathogenesis and Management of Achalasia: Current Status and Future Directions

Achalasia is an esophageal motility disorder that is commonly misdiagnosed initially as gastroesophageal reflux disease. Patients with achalasia often complain of dysphagia with solids and liquids but may focus on regurgitation as the primary symptom, leading to initial misdiagnosis. Diagnostic tests for achalasia include esophageal motility testing, esophagogastroduodenoscopy and barium swallow. These tests play a complimentary role in establishing the diagnosis of suspected achalasia. High-resolution manometry has now identified three subtypes of achalasia, with therapeutic implications. Pneumatic dilation and surgical myotomy are the only definitive treatment options for patients with achalasia who can undergo surgery. Botulinum toxin injection into the lower esophageal sphincter should be reserved for those who cannot undergo definitive therapy. Close follow-up is paramount because many patients will have a recurrence of symptoms and require repeat treatment.

Diagnostic accuracy of sixty four multi-slice ct angiography in assessment of arterial cut-off and run-off in comparison with surgical findings

The accurate anatomic mapping and determination of the severity of arterial disease, an important health problem of the elderly, is of great significance. We aimed to determine the diagnostic value of 64-multislice CT angiography [MSCTA] in run-off and cut-off sites of arterial disease. Throughout the study, MSCTA followed by an operative intervention was carried out on a total of 38 patients with clinical signs and symptoms suggestive of arterial disease [AD] all of whom had the indication for vascular surgery. The mean age of patients was 34 +/- 15.86 [range, 23 to 93] years. MSCTA was executed using a 64-slice CT scanner, during the arterial phase of injecting the nonionic, contrast medium with a power injector at the rate of 5 ml/sec into the antecubital vein and exploration and revascularization of peripheral arterial disease was performed intraoperatively. Atherosclerosis and arterial disease, the most common causes of vascular occlusion, were more common in the lower extremities. According to MSCTA findings, the most frequent site of stenosis was the superficial femoral artery. Spearman's correlation coefficient showed a high degree of agreement amongst the raters. The sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV] and the accuracy of MSCTA compared to surgery were 83.8%, 96%, 96.8%, 81.3% and 89%, respectively. MSCTA findings were compared with surgery as a standard of reference, which showed concordance in the majority of cases [81.6%]. Cut-off sites were correctly identified by MSCTA in 97.3% of the patients and the most common sites of discordance were the run-off sites [18.2%]. MSCTA angiography as a novel diagnostic modality may be a suitable alternative and a viable choice for routine clinical diagnosis

Study the efficiency of the combined system of coagulation and flocculation/ozonation in treatment of fresh landfilI leachates in Tabriz city

Fresh leachate has a low pH and high amounts of BOD and COD which are mainly constituents with low weight molecular such as volatile fatty acids [acetic and propionic acids] .Management and treatment of leachate is an important subject in sanitary landfill operation and performance.The objective of this study is determining the efficiency of the integrated coagulation -flocculation and ozonation processes in fresh leachate treatment of Tabriz city. Quantitive parameters of pH, BOD[5], COD, alkalinity and TSS were studied based on standard methods.The study emphasizes of COD and TSS leachate removal.Alum, ferric chloride and PAC had been used as coagulants. Results indicated the superiority of Ferric chloride at the dosage of 1 g/1 in pH 10, which reduced 34% of COD and 54% of TSS.in the stage of ozonation the leachate sample coagulated by ferric chloride was treated by 3 g/h ozone gas at optimum pH and after 39 hours ozonation about 51% of COD and 18.2% of TSS were reduced. This study clearly indicates that there would be need to apply biological treatment [after coagulation - flocculation] and ozonation, various advanced oxidation processes and / or other treatment methods for further reduction of COD in leachate and meeting discharge standards

Improving efficiency of disinfection of water for non-contact UV system

The goal was to upgrade and/or uprate the traditional non-contact array by producing few modifications in the configuration of this model in order to maximize light receiving of water from the UV lamp and a better disinfection. An innovative non-contact model was made with a design based on irradiation of water, which was flowing as two thin waterfalls around a UV lamp in order to have direct germicidal rays from all positions of the lamp. By this water circulating and traditional water flow in an ordinary canal below the lamp, UV light would reach every drop of water effectively. Another model which had been studied was a simple stair type design in which a bare lamp was fixed over the shiny steel steps. Results of water disinfection in two flow rates of 12 and 24 L/min were compared with traditional design at exactly similar conditions. Disinfection in this new model produced more reduction in fecal coliforms concentration than the traditional array and the inactivation efficiency was specified to be 3.65 log reduction compared to 2.93 log, in the turbidity of 0.5 NTU. Besides, this new model was quite capable in disinfection of water with high turbidities up to 20 NTU. The reduction in disinfection efficiency at higher flow rates for new model was much less than traditional array. Results of water disinfection in the simple stair type were not wonderful and even it was less satisfactory compared to traditional model. The reason is that the flow of water was not set parallel to the length of the lamp

[Determining the efficiency of WWTP in khoy power plant and improving phosphorus removal by anoxic-oxic process]

Now a days modified activated sludge ways are used for standard removing nutrient substances from waste water that is named Enhanced biological phosphorus removal One of the most suitable ways is Anoxic-Oxic [A/O] process. The goal of this research is investigation and solving existing problems of Khoy power plant [P.P] waste water treatment plant [WWTP] and optimizing of phosphorus removal in it. This research is done full scale in this treatment plant. The treatment plant was operating with extended aeration process, and some problems had, so in the first stage with in investigation of total efficiency, problems and their reasons determined. In the second stage after operational modifications existing problems was solved and real efficiency of treatment plant particularly for phosphorus [P] removal determined. In the third stage changes, system converted to A/O process and new system was tested with Changing parameters like food/microorganism [F/M], return sludge ratio [RAS] and sludge retention time [SRT]. In the first stage the most important problems were over concentration of BOD, TSS, and P in effluent of treatment plant and overgrows of alga observed in parts of treatment plant and effluent receiving conduit. The main reason of high concentration of P was considered releasing of sludge. In the second stage operating condition modification efficiency of P removal increased from 50 to 62 percent. In the end of third stage value of P removal reached to%82 and the most suitable of anoxic contact time was determined 3 to 4 hours, SRT terry day and F/M ratio o.12, that the most effective change has been the decrease of SRT to three days. Adjusting of operating factors like SRT, RAS, sludge processing way in WWTP can increase P removal in them with in total efficiency remaining, such as in this case it was%12. In waste water treatment particularly for P removal the A/O process is suitable so in this project its effect on P removal efficiency has been%20

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

[UV-lamp intensity determination without use of radiometer]

Measurement of light intensity is a recommended practice for insuring the delivery of required germicidal dose in disinfection operations by UV lamps. Use of sensitive to light chemicals which is the base of actionometeric methods could be considered as a suitable manner for estimating the intensity of UV lamp in circumstances that special radiometers are not available. lodide-iodate mixture was used as an actinometer for this study. The light intensities of a UV lamp [LP 25W] were first determined by a special UVC radiometer at certain distances from the lamp. Then the test of determining the suitable period of time for irradiation of actinometer was accomplished. Finally the color changes of iodide - iodate solutions at the predetermined distances were evaluated at the wavelength of 352 nm. The latter analysis can be done by a common [visible] spectrophotometer. Results indicated that use of this actinometer is more suitable at the distances of 35 to 60 cm from the center of the lamp bulb, since iodode-iodate solution has a detectable color change at this range of distance in one minute irradiation which may be considered as a reasonable time for actionmeteric operations. Although all kinds of actinometers should not be regarded as precise as special radiometers and there would be need to use pure chemicals for actinometeric determination of light intensity, it can be claimed that the recommended procedure in this study which is the newest actinometeric method can be used in acceptable evaluation of UV intensity with least difficulty in providing necessary instruments

Evaluation of hollow fiber membrane bioreactor efficiency for municipal wastewater treatment

The membrane bioreactor technology has been proven to be a single step process in efficient treatment of wastewater, either directly or after pretreatment by reverse osmosis. In this study, a pilot scale experiment was studied to treat a synthetic municipal wastewater sample. The aerobic reactor with a submerged membrane used in this work was continuously aerated for organic matter oxidation, nitrification and phosphorous uptake as well as for fouling control. The mixed liquor was recycled from the aerated zone to the anoxic zone for denitrification. The membrane had a nominal pore size of 0.1 micro m and a filtration area of 4.0 m2. The performance of submerged membrane bioreactor was examined in order to determine the removal efficiency of organic compounds and nitrogen in different solid retention times [10, 20, 30, and 40 days] under a continuous inflow of the synthetic municipal wastewater. Results indicated that the submerged membrane bioreactor could efficiently remove the pollutants. Average removal rates of chemical oxygen demand, total Kejeldahl nitrogen removal, total nitrogen and phosphorous reached to as high as 99.3%, 98.1%, 85.5%, and 52%, respectively. Furthermore, concentrations of nitrate and nitrite in the last stage were well reduced and reached to 5.3 and 0.047 mg/L, respectively

Removal of hexavalent chromium from drinking water by granular ferric hydroxide

Removal of chromium can be accomplished by various methods but none of them is cost-effective in meeting drinking water standards. For this study, granular ferric hydroxide was used as adsorbent for removal of hexavalent chromium. Besides, the effects of changing contact time, pH and concentrations of competitive anions were determined for different amounts of granular ferric hydroxide. It was found that granular ferric hydroxide has a high capacity for adsorption of hexavalent chromium from water at pH 0.968. However, the disadvantage was that the iron concentration in water was increased by the granular ferric hydroxide. Nevertheless, granular ferric hydroxide is a promising adsorbent for chromium removal, even in the presence of other interfering compounds, because granular ferric hydroxide treatment can easily be accomplished and removal of excess iron is a simple practice for conventional water treatment plants. Thus, this method could be regarded as a safe and convenient solution to the problem of chromium-polluted water resources

Evaluation of possible options for reuse of Ardebil wastewater treatment plant effluent

Recent advances in wastewater treatment have resulted in production of well-treated effluents which are suitable for use in more different sectors. In fact, these reclaimed wastewaters would be regarded as new water resources in many regions. In this research, the area studied was the city of Ardebil in northwest of Iran. At present, the effluent of Ardebil wastewater treatment plant is discharged into Qaresoo River. In this study, different aspects of Ardebil wastewater reuse have been investigated. Sampling of the effluent was performed in winter 2006 and summer 2007; and parameters indicating the suitability of wastewater discharge and/or reuse were considered in accordance to the recommendations of Iran Department of Environment. All the analyses were accomplished according to the latest edition of standard methods. Results clearly showed that apart from the problem of total and fecal coliforms which were above the standard values[1000 MPN and 400 MPN per 100 mL] the reuse of the treated effluent in agricultural irrigation could be carried out without restriction. But, regarding the discharge of this effluent into surface waters and injection wells, it would be necessary to upgrade treatment processes for further reduction of a few parameters such as nitrate, ammonium and phosphate

[Qom wastewater disinfection with hydrogen peroxide-silver ion complex]

Hydrogen peroxide solution with stabilized formulation with oligodynamic amounts of silver ion [trade mark: Nanosil] recently became a popular disinfectant for fruits, vegetables, surfaces, medical instruments and so on. This study was based on determining efficiency of hydrogen peroxide-silver ion complex in six different concentrations measured through removal of total coli forms from samples taken from Qom wastewater. All six different concentrations of disinfectant were incubated separately with wastewater for one hour. Sample size was 12 and sampling was done weekly. In the concentration of 80 and 480 mg/1, logarithmic removal value of total coli forms was 1.9 and 4.5 respectively. In CT value 8600 [mg/l].min and more, the total coli forms effluent standard for surface water discharge and agriculture irrigation was achieved [Iranian environmental protection agency act]. Use of hydrogen peroxide-silver ion complex as a water and wastewater disinfectant, has some benefits such as elimination of hazardous by products, measurable residual amount and so on. However its application in wastewater effluent is more costly than other usual disinfectants so it is not economically advisable

Granular ferric hydroxide [GFH] as an adsorbent for removal of arsenate and arsenite from drinking water

The pollution of water resources with arsenic [As] is considered as a serious problem and there are several reports about pollution of superficial and underground water with arsenic, in particular arsenate and arsenite in our country specially in some areas of Kurdistan province. There are various methods for removal of arsenic from drinking water which are generally costly. In this study, granular ferric hydroxide [GFH] was used as a synthetic adsorbent for removal of arsenate and arsenite with concentrations of 0.5, 1.0 and 2.0 mg/L. The effects of changing contact time, pH and concentrations of competitive anions, concentration of iron added to water during removal of arsenic and the effect of sulfate and chloride ions on removal of arsenic and compatibility of adsorption with Ferundlinch and Langmuir equations were evaluated. Excel soft ware was used for data analysis. According to this study, GFH showed removal efficiencies of 95, 86.5 and 83.75 for arsenate and 91, 83.5 and 80 percent for arsenite [in initial concentrations of 0.5, 1 and 2 mg/L and at a PH of 7.5]. The dosage of adsorbent for this treatment was 0.5 g/L and 30 minutes was required for contact time. SO[4][2-] and Cl[-] revealed no significant effect on removal of arsenic. Adsorbability of both arsenate and arsenite by GFH followed Ferundlich isotherm with R[2]=0.96, whereas arsenate adsorption [with R[2] value of more than 0.94] complied more with Langmuir isotherm in comparison to arsenite adsorption [with R[2] value of more than 0.92]. Results of our study also indicated that the amount of iron added to water was much more than the standard value of 0.3mg/L used for dinking water. The results of our study showed GFH is highly efficient in removal of arsenate and arsenite after modification of water PH, but it has disadvantages of addition of iron to water, need of import of GFH and high cost. The problem of addition of iron to water can be managed by traditional methods

Application and optimization in chromium-contaminated wastewater treatment of the reverse osmosis technology

Chromium [Cr] is the most important element used to plate other metals and electroplating factories are still considered to be the most important industries which pollute the environment to this metal. This paper describes a study conducted to determine the efficiency of reverse-osmosis [RO] as a membrane technique for removal of Cr from wastewater samples synthetically prepared to be similar to electroplating effluents. The RO unit used in this study was a spiral wound module of 2521 TE made by a Korean CSM company. Synthetic wastewater samples containing Cr ions at various concentrations of 1 to 20 mg/L were prepared and subjected to treatment by RO, and quantitative analysis had been accomplished by a colorimetric method. Evaluation of optimized conditions of treatment had also been carried out by determining the effects of changing operating pressure, temperature and pH[s] of samples. Optimum conditions of Cr-treatment by RO in 10 g/L initial Cr concentration were determined to be in the pH range of 6 to 7 and in temperature of about 25°C at an applied pressure of 200 psi. Considering the efficiency of Cr removal which was as high as 99% at the optimized conditions it could be concluded that RO membrane process may be selected and developed as an effective alternative for treatment of metal-contaminated effluents of electroplating and similar industries

Study of the efficiency of electrolysis process in phosphorus removal from the wastewater effluent of treatment plants

Although primary and secondary treatment processes when completed by disinfection can remove 85% of both BOD, SS and inactivate nearly all of the pathogenic microorganisms, few pollutants such as soluble COD, nitrogen, phosphorus, and heavy metals are not completely removed from effluent. This may be regarded as a cause of trouble when larger volumes of these effluents are discharged into a small flow or a sensitive ecosystem. The aim of this study was to determine the efficiency of electrolysis process in removal of phosphorus from the wastewater effluent of treatment plants. This was an experimental study carried out by establishing a pilot reactor in the laboratory of water and wastewater microbiology of the school of public health [TUMS]. The capacity of this reactor was 20 liters. The reactor was put into operation under different conditions of influent flows, electrical potentials and pollutants concentrations. In all of these experiments, flow was continuous. All plates embedded in anode pole as a flocculating agent, revealed a 90% removal of phosphorous. The future of electrolysis process for removal of phosphorous and other similar pollutants from effluents will be promising. Application of this technology can lead to a much more perfect and economical wastewater treatment with no [or less] sludge production and a favorable environmental health condition

Evaluating of the disinfection and water quality effects on UV application in the primary stage of water treatment

Irradiation of water by UV has been considered as an attractive alternative for disinfection because its low-impact, pathogen killing capacity shows tremendous promise for meeting today's drinking water regulatory requirements. This study has been performed with the objective of utilizing medium pressure lamp in the preliminary stage of municipal water treatment, namely prior to water clarification and filtration. Raw water samples were irradiated for 30 s in a lab-scale closed reactor. Disinfection results showed nearly 2 log reduction in HPC for all the samples without formation of nitrite in excess of its MCL. As in a few previous works the formation of nitrite as an objectionable DBP had been reported, this study was extended by preparing synthetic water samples having different amounts of nitrate and turbidities. As far as the initial nitrate concentration dose not exceed 10 mg/L N-NO3, there would be no risk of nitrite increasing in excess of the MCL. Meeting the goal of at least 90% disinfection for water samples with turbidity levels of as high as 750 NTU is possible by utilizing medium- pressure UV lamp

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

Algae removal by electro-coagulation process, application for treatment of the effluent from an industrial wastewater treatment plant

Although stabilization ponds and lagoons are suitable treatment processes due to simplicity of operation and low per capital costs, the effluents of these systems have too high of a total suspended solids concentration to be discharged into receiving waters. This problem is mainly caused by algae. In this study, an electro-coagulation reactor was examined to remove algae from the final effluent of the wastewater treatment plant belong to Bu-Ali Industrial Estates [Hamadan City]. For the continuous flow electro-coagulation reactor used in these experiments three aluminum anodes were utilized. This type of metal was selected because it could introduce the flocculation agent into the effluent, thereby algae could be removed by both mechanisms of electro-flotation and electro-flocculation. The results of treatment were remarkably good and the efficiencies of total suspended solids [TSS] and chlorophyll a removal reached to as high as 99.5% and about 100% by applying a power input of about 550 W. In fact, this level of power input was needed for complete removal of algae in a low retention time of 15 minutes. Meanwhile, by applying less power input of about 100Wdm[-3], the required time for a relatively same treatment was reached to 30 minutes. It is expected that this method which is also known as a multiple contaminants removal process will be considered as a suitable alternative for final polishing of effluents from lagoons and similar treatment systems

Removal of cadmium from industrial effluents by electrocoagulation process using iron electrodes

The object of this study is the evaluation of cadmium removal from industrial wastewater by electrocoagulation process. For this study a glass tank in 1.56 L volume with four plate electrode was used to do experiments. The electrodes made of iron and connect to the positive and negative pole of DC power supply [bipolar mode]. The tank was filled with synthetic wastewater that was containing cadmium ion in concentration 5, 50 and 500 mg/L and then it was started up. The percent of cadmium ion removal was measured at pH 3, 7 and 10 and in electric potential range of 20, 30 and 40 volts. At the end of each stage of experiment, volume of produced sludge was measured. The results obtained at different electrical potential showed that initial concentration of cadmium can effect on efficiency removal and for higher concentration of cadmium, higher electrical potential or more reaction time is needed. On the other hand, if the initial concentration increases, the time required of process should increase too. The final pH for iron electrodes was always higher than initial pH. As expected, the results showed that for a given time, the removal efficiency increased significantly with increase of current density. The highest electrical potential [40V] produced the quickest treatment with >99% cadmium reduction occurring after only 20 min. The result showed that, in this process, the use of different electrical potentials can provide a wide range of pH for doing this process and electrocoagulation process [using iron electrodes] is a reliable, safety, efficient and cost-effective method for removal of cadmium from industrial effluents, especially designed for pH =10 and voltage = 40V

Determination of the ultrasonic effectiveness in advanced wastewater treatment

Ultrasonic technology may be used for water and wastewater treatment as an advanced oxidation process. Application of this technology, leads to the decomposition of many organic compounds during cavitation process. In this study, the efficiency of ultrasonic in advanced treatment of municipal wastewater has been investigated by use of an ultrasonic bath. COD and BOD[5] tests were used as the indicators of organic matter concentrations and three detention times for treatment were appointed at 10, 30 and 60 minutes. Two frequencies of 35 and 130 kHz for sonication were used. Results indicated that sonication can reduce 25% to 30% of COD in less than 60 minutes. Also, it was indicated that suspended COD was mainly converted to soluble COD during sonication. The rate of hydrogen peroxide production and thus the efficiency of treatment were higher at 130 kHz, but this efficiency was not much increased by prolonging sonication time. In other words, maximum efficiency was achieved at the initial time of sonication. Furthermore, no considerable change in nutrients concentration was detected and pH variations of samples were negligible [<0.3]. In contrast, significant temperature change occured which was about [18-20] degree C increase in 60 minutes. However, this temperature change had no considerable effect on treatment efficiency

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]