فهرست مطالب

مجله آب و فاضلاب
پیاپی 42 (تابستان 1381)

86 صفحه، بهای روی جلد: 5,000ريال
تاریخ انتشار: 1381/05/15
تعداد عناوین: 15

فارسی
English

انتخاب همه

Effect of Water Reuse on Organic Matter Concentration of Soil and its Self Purification

Hassanoghli, A. , Liaghat, A., Mirabzadeh, M. Page 2

Use of low quality water in agricultural irrigation lands has been common in many areas since long time ago. According to arid and semi-arid climate of Iran and the limitations of usable water resources, optimum application of each kind of available water (i.e.brackish and wastewater) is necessary. In this regard, the regional researches are needed by considering all local variables such as climate, native plants, culture, wastewater quality and so on.In order to investigate the effects of irrigation with domestic wastewater on soil organic matters content in the end of plant season and also the self-digestion rate of accumulated matters during non-plant period, a lysimetic study was carried out in Tehran area. A statistical “factorial experiments in form of randomized complete design” (3 * 3* 3) was used. Raw and treated domestic wastewater of Ekbatan complex and well water (control) have been applied for irrigation of raw eating vegetables such as parsley, carrot and tomato for two years.The results showed that the most increase of organic matter was happened by using the raw wastewater for irrigation of carrot planting, and the least for tomato. After two years and completion of self-digestion period, raw and treated domestic wastewater caused 48.8% and 17.4% increase in soil organic matter content respectively, but reduction of 31.59% was found in control treatment compared with the original amount (0.896%). There is direct relationship between the reduction rate of soil organic matter and the amount of organic matter exceeded by wastewater application. Therefore, the highest rate (14.9mg/100gr.day) was observed in raw wastewater irrigated lysimeters. Statistical analyses showed a significant difference in organic content and purification by means of irrigation water, quality crop, year and sampling time.

Abstract View Paper Original: Persian
Optimization of Upflow Fixed Bed Bio-Denitrification Reactors in Water Treatment

Ghaffarzadeh, M. , Torabiana. , Aminzadehb. Page 12

In this research, optimization of biological denitrification upflow fixed bed reactors was studied.A rectangular shape bench scale reactor filed with PVC corrugated plate was used. Our result showed that a minimum of 93 percent nitrate removal for a range of reactor detention time from 0.5 to 48 hours were achieved while the influent nitrate concentration was 100 mg/L. It means, nitrate removal/efficiency is independent of these parameters.Increasing of hydraulic detention time had more effect on effluent residual COD and nitrite concentration (denitrifiction product).It was found for detention time of more than one hour, nitrite concentration was about less than one ppm.Decreasing of hydraulic detention time to less than 0.5 hour caused a significant increase in effluent nitrite concentration. Our results also indicated that with increasing C/N ratio nitrate removal percentage increased and nitrite residual and also COD concentration decreased in effluent.Optimum C/N ratio (for hydraulic detention time equal to one hour and influent nitrate concentration equal to 100 mg/L) were found to be equal to 1.6. Considering this ratio, residual nitrate and COD concentration were determined. 3.7, 7.3, 0.09, mg/L respectively.This study also showed that with increasing nitrate concentration in influent, effluent nitrate concentration increased but nitrate removal efficiency almost remain constant. This was not observed for effluent nitrite. Effluent nitrite concentration is strongly under influence of influent nitrate concentration. This problem can be solved by reactor detention time modification. In summary, modification of operational condition of denitrification reactor has a significant effect on nitrate removal rate.

Abstract View Paper Original: Persian
Evaluation of Drought in Markazi Province by Analysis of Rainfall Data

Moradi Nezhad, A. , Agha Razi, H. Page 20

Iran is located in arid and semi-arid regions of the world. Low rainfall and drought during the recent years caused to intensify the water storage and salinity of water. Markazi province located in the dry zone and unfortunatly no comprehensive study been done in this area. In this paper the evaluation of drought was studied using rainfall data analysing method. One of the davantage of this method is easy access to rainfall data. On the other hand, rainfall particulary in the dry lands is a unstable factor which is useful indicator for study of drought. The rainfall date was obtained from synoptic station of Arak. The mean of annual rainfall from 1959-1998 was calculated and using statistical methods the trend of drought was studied.

Abstract View Paper Original: Persian
Investigation into the Removal of Nematods Eggs in Influent and Effluent of Shoosh Wastewater Treatment Plant

Miranzadeh, M.B. , Mahmoudi, S Page 32

The reuse of reclaimed wastewater has been increasing over the past decade, especially in arid and semiarid regions where reclaimed wastewater is used to conserve valuable potable water supplies. Careful consideration must be given to the hazards to health that may arise from the reuse of sewage, the hazards to health can be reduced by the treatment of sewage before use in agriculture. Conventional wastewater treatment processes such as activated sludge are generally very effective at removing nematodes eggs by sedimentation.WHO guidelines stated that the wastewater treatment system should produce an effluent with less or equal to one intestinal nematode egg per litre and less or equal to 1000 faecal coliforms per 100 ml to permit its reuse in unrestricted irrigation.In this research the efficiency of Shoosh Wastewater Treatment Plant (SWTP) in removal of nematods Eggs was investigatigated for eleven months during the years of 2000-2001. SWTP operates on activated sludge process and the grab samples of raw wastewater and effluent of system were taken daily every morning. Intestinal nematode eggs were counted according to standard method (APHA, 1995).The mean concentration of nematode eggs namely, Ascaris lumbricoides, Trichuris churia, Enterobios vermicularis and Hook worms were 4.4, 0.5, 0.9 and 1.1 eggs per litre, in raw sewage respectively. The concentration of total nematode eggs in raw sewage was 6.8 eggs per litre. The results of research showed that no nematode eggs were present in the final effluent throughout the period. Thus the effluent quality suitable for reuse in unrestricted irrigation. The results showed that activated sludge processes may remove 100 percent of influent intestinal nematode eggs.

Abstract View Paper Original: Persian
Investigation into the Quality of Major Metal Industries in Ahwaz City

Parhamh., . Jafarzadehn., Mahdaviani, A Page 37

Karoon, in Ahwaz area, receives 51% of metal industries effluents. These effluents contain metal pollutants and various chemical compounds that affect the quality of Karoon river. Some of the industries discharge wastewaters into the karoon river without full treatment. In addition, the effluent of the Ahwaz Steel Co., was discharged into Maleh Stream without treatment.In this research in order to determine the quality of the above industries wastewaters, on the final outlets of each industry, one sampling point was selected; and samples were taken six times in a year and were carried to the labratory under standard conditions. The necessary analysis were done according to standard methods. After statistical evaluation, results showed that Steel National Group discharges has the highest amount of pollution laod of oil and total suspended solid; and the most amount of chemical oxygen demand, chloride, and nitrate discharges in the environment belongs to steel industries.Moreover, the emission factor of each industry was calculated on the base of total production, water consumption, and the amount of wastewater production. Comparing the results indicated that the measured parameters are higher than national and international standard levels for discharging to the environment.

Abstract View Paper Original: Persian
Ultrasonic Flowmeters (Time-Transition) for Measuring Flow in Pressure Pipes and Evaluation of Accuracy

Araee, A.R Page 44

Technical advances in ultrasonic can significantly improve flow measurement in the continuous process industries. This technique exists for both liquid and gas flows, it also exists for wide range of pressure pipes (Full-Pipe) and channels with different sizes.Ultrasonic flowmeter can be installed on the pipe wall without the need of cutting the pipe or interrupting the flow.The manufactures claimed the accuracy is between (1 to 3)% of actual flow rate. This is a typical accuracy. However some of them improved this ultrasonic technology with five beam transducers. The test results show an accuracy range (0.15-0.2)% of actual flow. This accuracy is very important for oil industries and chemical factories.In this paper the principle of sound waves and measuring by ultrasound were introduced and transient time flowmeter calculation were determined. Finally the clamp-on ultrasonic flowmeter manufactured by a private company in Iran were tested and the results compared to those obtained from the others.

Abstract View Paper Original: Persian
Application of Cyclone in Water Treatment

Rahmani Page 52

In this investigation design, instalation and efficiency of cyclone in separation of particles from water were studied.A cyclone was designed with a diameter of 10 cm.In order to have uniform suspended particles synthetic samples were provided by granit factory. The efficiency of system was optained with varied flow and concentration of particles from inlet and outlet.The resultes showed that the removal efficency of particles increased with increased particles size and liquid velocity. In the range of selected velocity, the removal efficiency for particles over 144 micron was found between 79 to 93.5% and for particles over 5 micron was 51.2 to 63.1%.Due to ease of construction, cost and high efficiency, cyclones can be considerd as an suitable unit in seperation of particles in water and wastewater treatment.

Abstract View Paper Original: Persian
Criteria of Site Selection for Irrigation by Wastewater Effluent

Safari, Gh. , Vaezi, F Page 59

Municipal wastewaters are the most generally available source of wastewater that have been longly used specially for agricultural irrigation (sewage farms) in order to conserve fresh water. Although this practice often costs less than other forms of water reuse because it requires less additional treatment processes but it may cause excess risks when environmental considerations are not taken into account. In other words, agricultural reuse may degrade the quality of soil and water if required considerations not applied. Therefore, a sound program for selection of suitable site is extremely important. In this regard, the more important factors that are now essential to consider are as follow:Proposed or existing land use, site features including topography, proximity to water bodies, level of groundwater, soil permeability, vegetation, public access and proximity to dwellings. Furthermore, water balance for the site, storage requirements, nutrient balance assessment for the site and installation and maintenance requirements for such systems are another important factors required to be considered. A brief discussion of each are present in the paper.

Abstract View Paper Original: Persian

علمی مصوب

مجله آب و فاضلاب

Journal of Water & Wastewater

دوماهنامه فنی مهندسی

آخرین شماره | آرشیو

ISSN: 1024-5936 eISSN: 2383-0905

صاحب امتیاز:

مهندسین مشاور طرح و تحقیقات آب و فاضلاب

مدیر مسئول:

مهندس عباس پیراینده

سردبیر:

دکتر احمد ابریشم چی

تلفن نشریه: ۰۳۱-۳۲۶۸۲۴۱۲

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فهرست مطالب

مجله آب و فاضلاب پیاپی 42 (تابستان 1381)

مجله آب و فاضلاب

Journal of Water & Wastewater

مجله آب و فاضلاب
پیاپی 42 (تابستان 1381)