پديد آورندگان :
افخمي، حميده دانشگاه يزد - دانشكده منابع طبيعي و كويرشناسي - آبخيزداري , اسماعيلزاده، عصمت مجتمع مس سرچشمه - امور تحقيقات آب و محيط زيست , غريبي، خداكرم دانشگاه يزد - دانشكده مهندسي معدن و متالورژي - گروه استخراج , عزيزيان، ابوالفضل دانشگاه اردكان - دانشكده منابع طبيعي - گروه آبياري
كليدواژه :
آب شرب , هگزادكانول , مجتمع مس سرچشمه , تبخير , پساب , اكتادكانول
چكيده فارسي :
پساب سدهاي باطل شده و فاضلاب هاي روباز، يكي از منابع مهم تبخير و هدررفت آب است كه امروزه كمتر مورد توجه قرار گرفته است. در مطالعة حاضر، تأثير نسبتهاي مختلف از الكلهاي چرب، بر كاهش ميزان تبخير از پساب اسيدي سد باطل شده مجتمع مس سرچشمه بررسي شد. بر اين اساس، در شرايط آزمايشگاهي با استفاده از 5 تركيب متفاوت از دو الكل چرب هگزادكانول و اكتادكانول، ميزان كاهش تبخير به مدت يك ماه، بر روي دو نمونه پساب و آب شرب ارزيابي شد. نتايج به دست آمده نشان داد كه تأثير استفاده از تركيبات مختلف الكلهاي چرب بر كاهش ميزان تبخير از سطح پساب بين 2 تا 14 درصد كمتر از آب شرب است؛ اما اين تفاوت در تيمارهايي كه عملكرد بالايي در كاهش ميزان تبخير داشتهاند، كمتر از ساير تيمارها 51 درصد بهترتيب بالاترين عملكرد را در / 58 و 75 / است. همچنين، تركيب ( 7:3 ) هگزادكانول و اكتادكانول با كارايي 47 كاهش ميزان تبخير آب شرب و پساب سد رسوب گير داشت؛ در حاليكه استفاده از الكل هاي چرب هگزادكانول و اكتادكانول 20 درصد بهترتيب كمترين كارايي را در كاهش ميزان تبخير از پساب سد رسوبگير و آب / 18 و 98 / به صورت خالص با 18 شرب از خود نشان دادند.
چكيده لاتين :
Increasing global warming and decreasing rainfall is one of the serious concern in world. Population growth and increasing demand of water for irrigation, household and industrial purposes are annually faced with water shortages during the summer months. Lakes and reservoirs are the greatest resource of fresh water. One of the more serious problems faced by industry is the evaporation of water from this type of open storages that allows for the greatest loss of water by evaporation particulary during the harm months. In Sarcheshmeh tailing dam, for example, evaporation rate averages is about. 2250 mm per year while this dam is filled with water to a depth of 5000 mm. In this condition, approximately 45% water might be lost due to evaporation. Thus, employ techniques for reducing evaporation is necessary to aiming at the conservation of water through control of evaporation from open storages supplies. In order to increase water supplies by reducing losses through evaporation have been investigated in both the theoretical aspects and practical applications in a number of countries. The most important is the application of the chemical evaporation reducing layers to surfaces of large bodies of open water such as reservoirs, lake and the like. Such application is especially important in arid and semiarid areas for the purpose of reducing evaporation rates from water surfaces. Among the surfactants tested, biodegradable fatty alcohols of low toxicity presented the highest resistance to water evaporation. In the present investigation, have verified the influence of monomolecular films of fatty alcohols including Hexadecanol and Octadecanol in reducing the evaporation of two water samples collected from tap water and the reservoir of sarcheshme tailing dam during two months. For two sample water were provided, twenty steel rectangular container with dimensions 15*30*5. Six of containers were filled with 500mli tap water and six other containers were filled with water collected from reservoirs Sarcheshme dam. For each water samples, five containers were considered with monolayers film and a container of water with no monolayer was used as the control used monomolecular films in ten containers filled with two samples water, were including pure hexadecanol (C16), pure octadecanol (C18) and mixtures of 1:9 , 3:7 and 5:5 (m:m) of C16 and C18 (C16:C18) on the surface of the samples by adding small volumes of ethanol solution (40gr/L) using a sprayer. Values of cumulative evaporation were collected during a 29-Day Period from 17/07/2016 to 14/08/2016. In all samples tested, at the same condition, performance of fatty alcohol on drinking water and wastewater is different. it was observed that, in samples 1 that were been covered with a pure hexadecanol film, for container of drinking water, evaporation reduction of 32.2% was obtained, whereas for container of wastewater the same value of 18.2% was obtained. The results obtained with the C16:C18(1:9) mixture (samples 2) showed 39% saving water for drinking water and 32.2% saving water for wastewater. Mixtures of hexadecanol and octadecanol with weight ratios of 3:7 (samples 3) showed the highest performance in reducing evaporation (58.47%, 51.75%) of drinking water and waste water, respectively. For the C16 and C18 mixtures (samples 4), the best results obtained from drinking water and wastewater (47.5% and 45.5%) were at 1 to 1 proportions (C16:C18 (5:5)). The results obtained from pure octadecanol (samples 5) were poor. This monomolecular film showed 27.1% and 21% saving water in drinking water and wastewater respectively. According to the results obtained in the above, the minimum of difference between evaporation rate of drinking water and wastewater is related the mixture of C16:C18 (1:9). In presented experiments results, it was found that the water evaporation rate, for all of the tests were performed on wastewater using fatty alcohol, is higher than tests were performed on drinking water. It may be concluded that acidic condition and the organic and inorganic compounds in wastewater of sarcheshmeh tailing dam, with the effectiveness of the monomolecular film led to increase the evaporation rate. It is noticed that in mixed films, the differences in rate of evaporation losses of both drinking water and the wastewater was reduced when the proportion of octadecanol to hexadecanol was increased. It is well known that octadecanol films can reduce water evaporation better than hexadecanol films, but C16:C18 mixed films was reduced evaporation rate higher than pure films.
