The study of inorganic ion composition and chemical properties of rain water over Tehran city

Abstract

Concentrations of major inorganic ions (NH 4 ,Mg,SO 4 ,NO 3 ,NO 2 ,Na,Ca,HCO 3 ,F,Cl,Br,K), PH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), Total Alkalinity and Total Hardness in bulk precipitation samples collected in the Tehran city of I.R. of Iran were analyzed. Results show that concentrations of the found substances were higher over the Mehrabad station. The mean concentration of ions indicated that, HCO 3 , SO 4 and NO 3 and were the main anions, while Ca ,Na,NH 4 and Mg were the main cations. Measured PH had shown that autumn and winter precipitation were mostly acidic while the spring and summer were mostly alkaline. The pH ranged from 4.6 to 8.1 with a mean of 6.3. The alkaline cations Ca and Mg and also Bicarbonate anion acted as acid neutralizers and buffered the acidity of rain. The Bicarbonate anion had the highest concentration, among all other ions, over both stations and plays an important role in reduction of the acidity of the rain water. Study upon the potential sources of the ions over Tehran by means of Correlation Analysis, Enrichment Factor and Principle Component Analysis indicate that existence of Qom salt lake and desert in the south of the city were the main source of the Ca,Mg,K and Na . There are anthropogenic sources for SO 4 ,NO 3 , NO 2 ,F, Br ion's. The other ions HCO 3 and NH 4 were from anthropogenic and dust origin.

A Comprehensive Overview of the Hydrochemical Characteristics of Precipitation across the Middle East

“…In this study, the data of hydrochemical analyses (including field parameters (pH, TDS, and electrical conductivity (EC)) and the major and minor ions) were studied in 28 stations across the Middle East. These stations and their hydrochemical analyses in Shiraz [54], Ahvaz [26], Mahshahr [55], Sarcheshmeh [56], Tehran [24], Mashhad [57], Arak [28], Shahroud [58], Haraz [12], and Urmia [59] in Iran; Riyadh [60] and Dhahran [21] in the Kingdom of Saudi Arabia (KSA); Damietta in Egypt [61]; Karachi in Pakistan [62]; Ramallah [63] in Palestine; Tripoli, Hadath, and Nabatieh in Lebanon [64]; Jerdab [65] in Bahrain; Tartus, Palmyra, and Damascus in Syria [22]; Amman [11] and Eshidiya [27] in Jordan; Ankara [66] and Istanbul [67] in Turkey; Baghdad in Iraq [68]; and Faryab [69] in Afghanistan were chosen from the scientific papers in the literature.…”

“…To study the hydrochemical characteristics of precipitation more deeply and accurately, statistical and machine learning techniques can be applied. Statistical techniques (such as principal component analysis (PCA), the Pearson correlation coefficient, and cluster analysis (CA)) have been applied in numerous studies to investigate the hydrochemical characteristics of precipitation [11,[23][24][25][26][27][28]. In addition to statistical techniques, artificial intelligence (AI) techniques have also been applied in climatological studies, mainly in recent decades.…”

Role of Carbon Dioxide, Ammonia, and Organic Acids in Buffering Atmospheric Acidity: The Distinct Contribution in Clouds and Aerosols

“…In comparison, both the bicarbonate and the carbonate salts, widely existing in dusts, etc., can neutralize the acids and therefore decrease the acidity. This neutralization process is sometimes termed as “buffering” to indicate that the existence of dusts can alleviate acidifications. ,− We call for the use of “neutralization” instead of “buffering” for this process to avoid confusion in the future.…”