Chemical characteristics of natural watercourses in the Gurahont Depression

Transcription

1 Volume 15(3), , 2011 JOURNAL of Horticulture, Forestry and Biotechnology Chemical characteristics of natural watercourses in the Gurahont Depression Balaşcău G. D. 1* 1 U.S.A.M.V.B.Timişoara, Faculty of Agriculture *Corresponding author. gelu_balascau@yahoo.com Abstract We present, in this paper, the chemical characteristics of natural watercourses in the Guranhont Depression. The chemical composition of the water has been determined through quantitative and qualitative chemical analysis. The area of the Gurahont Depression is located hydrographically in the Crisul Alb Basin. Key words water, characteristics, substances, indices chemical content, compounds, Water, named by some the matrix of life, by others the life s elixir, is the most widespread liquid covering about 2/3 of the earth s surface, and also the most important liquid in life being, practically, indispensable [1]. Despite all its importance in the living world, water has been subjected to pollution an inevitable reality difficult to measure and control [2]. There is no chemically pure water in nature; only rain water is close to its standards, but the fall of the rain through the atmosphere and its contact with the rocks on which it flows charge it with dissolved mineral and organic substances [3]. Materials and Methods From the point of view of their chemical characteristics, waters are analysed from the perspective of the following characteristics: -water reaction; -oxygen regime indices (Dissolved oxygen - DO, oxygen biochemical consumption - OBC, chemical oxygen consumption - COC); -dissolved salts; -fixed residue; -water hardness; -organic substances; -nitrogen compounds (ammonia, nitrites, nitrates); -phosphorus compounds; -mineral substances (carbon, chloride, fluoride, iodine, sulphur, silica, calcium, magnesium, sodium and potassium, iron, manganese, aluminium, copper, lead and zinc; -gases (oxygen, carbon dioxide, sulphur hydrogen, methane, nitrogen. According to the Standards from February 16, 2006, concerning the classification of surface water quality in order to establish the ecological state of watercourses, they have established a number of five ecological states for natural rivers and lakes: very good (I), good (II), moderate (III), low (IV), and bad (V) on the ground of biological, hydro-morphological, chemical, and physico-chemical characteristics. For lakes, we need to also take into account the trophic degree; therefore, there are five degrees of trophism for the five ecological states: ultra-oligotrophic, oligotrophic, mesotrophic, eutrophic and hypertrophic. For artificial or irreversibly modified aquatic ecosystems we need to establish a very good (VG), good (G), and moderate (M) ecological potential. Below is a short analysis of the elements and standards of chemical and physico-chemical quality (general indices) for the water of the Crisul Alb river in

2 Results Obtained Table 1 Parameter Classification of the water of Crisul Alb depending on general indices in 2009 UM Nr. det. Minimal Statistic typical values Maximal B. Physico-chemical indices Standard deviation B.1. Physical indices, thermal regime and acidification Arithmetic mean Value River flow mc/s Water temperature ºC ph Suspension matter mg/l B.2. Oxygen regime Global quality class: II Dissolved oxygen mg O 2 /l I CBO5 mg O 2 /l II CCO-Mn mg O 2 /l I CCO-Cr mg O 2 /l I B.3. Nutrients Global quality class: I Ammonia (N-NH4) mg N/l I Nitrites (N-NO2) mg N/l II Nitrates (N-NO3) mg N/l I Kjeldahl nitrogen (N) mg N/l Organic nitrogen (N) mg N/l Total nitrogen (N) mg N/l I Class Orthophosphates (P- PO4) mg N/l I Total phosphorus (P) mg N/l I Chlorophyll a µg/l I B.4.Salinity Global quality class: I Conductivity µs/cm Filterable residue mg/l I 116

3 Chloride salts (Cl) mg/l Calcium (Ca) mg/l Magnesium (Mg) mg/l Natrium (Na) mg/l Alkalinity Dicarbonates (HCO3) mg/l B.5. Specific toxic pollutants Global quality class: II Copper (total con.) µg/l I Iron (total con.) mg/l II Manganese (total con.) mg/l III Zinc (total con.) µg/l I I. Thermal and acidification regime Temperature it is not standardised, it recorded in 2009 values ranging within 1-24ºC. ph it has standard values between 6.5 and 8.5, it recorded rather high values between 7.8 and 8.5. II. Oxygen regime Dissolved oxygen it has standard values between 9 and < 4 mg O 2 /l. Annual values ranged between mg O 2 /l. Annual values ranged within mg O 2 /l, i.e. in the 1 st quality class in CBO5 has standard values between 3 and > 20 mg O 2 /l. Annual values ranged between 1.7 and 5 mg O 2 /l. In 2007, the values of this index ranged within 2-5 mg O 2 /l, with arithmetic mean of 3.37 mg O 2 /l, i.e. in the 2 nd quality class. In 2008, the values of this index ranged between 1.7 and 3.8 mg O 2 /l, with an arithmetic mean of 2.57 mg O 2 /l, ranging in the 1 st quality class. In 2009, the values of this index ranged within mg O 2 /l, with an arithmetic mean of 3.5 mg O 2 /l, ranging in the 2 nd quality class. CCO-Mn has standard values between 5 and > 50 mg O 2 /l. Annual values ranged between 1 and 12.7 mg O 2 /l, i.e. in the 1 st quality class during the analysed period. CCO-Cr has standard values between 10 and > 125 mg O 2 /l. Annual values ranged between 5 and 43 mg O 2 /l. In 2007, the values of this index ranged between 5 and 43 mg O 2 /l, with an arithmetic mean of mg O 2 /l, i.e. in the 2 nd quality class. In 2008, the values of this index ranged between 5 and 13 mg O 2 /l, with an arithmetic mean of 7.83 mg O 2 /l, i.e. in the 1 st quality class. In 2009, the values of this index ranged between 5 and 19 mg O 2 /l, with an arithmetic mean of 8.83 mg O 2 /l, i.e. in the 1 st quality class. According to the values recorded in the index oxygen regime, between 2007 and 2009, the waters of the Crisul Alb River ranged in the 2 nd global quality class. 117

4 III. Nutrients Ammonia (N-NH4) has standard values between 0.4 and > 3.2 mg N/l. Annual values ranged between and mg N/l. Nitrites (N-NO2) has standard values between 0.01 and > 0.3 mg N/l. Annual values in 2007 ranged between and mg N/l, with an arithmetic mean of mg N/l, i.e. in the 2 nd quality class. In 2008, the values of this index ranged between , with an arithmetic mean of mg N/l, i.e. in the 1 st quality class. In 2009, the values of this index ranged between and 0.027, with an arithmetic mean of mg N/l, i.e. in the 2 nd quality class. Nitrates (N-NO3) has standard values between 1 and > 11.2 mg N/l. Annual values ranged between and mg N/l. Total nitrogen (N) has standard values between 1.5 and > 16 mg N/l. annual values ranged between and mg N/l. Orthophosphates (P-PO4) has standard values between 0.1 and > 0.9 mg P/l. Annual values ranged between and mg P/l. Total phosphorus (P) has standard values between 0.15 and > 1.2 mg P/l. Annual values ranged between and mg P/l. Chlorophyll a has standard values between 25 and > 250 µg/l. Annual values ranged between 0.50 and 8.50 µg/l. According to the values recorded in nutrients during the period , the waters of the Crisului Alb River ranged in the 1 st quality class. IV. Salinity Conductivity it is not standardised Filterable residue dried at 105ºC has standard values between 500 and > 1300 mg/l. Annual values ranged between 122 and 257 mg/l, i.e. in the 1 st quality class. According to the values recorded in salinity during the analysed period , the waters of the Crisului Alb River ranged in the 1 st quality class. V. Specific toxic pollutants Copper (total) has standard values between 20 and > 100 µg/l. Annual values ranged between 4.20 and µg/l, ranging in the 1 st quality class. Iron (total) has standard values between 0.3 and > 2 mg/l. Annual values measured in 2007 ranged between 0.04 and 1.74 mg/l, with an arithmetic mean of 0.46 mg/l, in the 2 nd quality class. In 2008, the values of this index ranged between 0.09 and 0.32, with an arithmetic mean of 0.17 mg/l, i.e. in the 1 st quality class. In 2009, the values of this index ranged between 0.12 and 0.58, with an arithmetic mean of 0.31 mg/l, i.e. in the 2 nd quality class. Manganese (total) has standard values between 0.05 and > 1 mg/l. Annual values measured in 2007 ranged between and mg/l, with an arithmetic mean of mg/l, i.e. in the 3 rd quality class. In 2008, the values of this index ranged between and 0.113, with an arithmetic mean of mg/l, i.e. in the 2 nd quality class. In 2009, the values of this index ranged between and 0.190, with an arithmetic mean of mg/l, i.e. in the 3 rd quality class. Zinc (total) has standard values between 100 and > 1000 µg/l. Annual values ranged between 5 and 26 µg/l, i.e. in the 1 st quality class. According to the values recorded in the index specific toxic pollutants in the year 2009, the waters of the Crisul Alb River ranged in the 2 nd global quality class. On May 24, 2010, we sampled 13 water samples in order to analyse them in the laboratory, as follows: -access of Crisului Alb River in the Gurahont Depression (Talagiului Gorges); -exit of the Crisului Alb River from the Gurahont Depression (Cociba-Loia Mare Gorges); -Valley of the Zimbrului River at the flowing point into the Crisul Alb River; -Valley of the Sighisoara River at the flowing point into the Crisul Alb River; -Valley of the Tacasele River at the flowing point into the Crisul Alb River; 118

5 Table 2 Nitrogen compounds Sample nr. Nitrate NO 3 (ppm) Nitrite NO 2 (ppm) Ammonia NH 4 (ppm) Standards Maximum admitted limits (MAL) according to the standards and minimal detection limit (MDL) for the analysed chemical parameters Parameters NO 3 (mg/l) NO 2 (mg/l) NH 4 (mg/l) Table 3 MAL for drinking water (mg/l) MAL for surface water (mg/l) MDL (mg/l) Valley of the Radestiului River at the flowing point into the Crisul Alb River; -the man-made pond in the village of Pescari; -the man-made pond in the village of Cil; -the channel dug in the old dumping site (nonecologised) of the commune of Gurahont; -new dumping site in Gurahont; -mill pond in Gurahont; -mine dump (non-ecologised) at the Zimbru mine; -drinking water well in the village of Dulcele. Laboratory analyses carried out on May 25, 2010, show the following: 119

6 Sample nr. Values of other indices (ph, Fe, Mn, Cl, P, Zn) ph Fe mg/l Mn µg/l Cl mg/l P mg/l Zn mg/l Table Sewage waters In the Gurahont Depression, only the commune of Gurahont has a sewage system. The sewage network of the commune of Gurahont is linked to two processing plants: the old plant operating since 1967 s managed by the Water- Canal Administration, with a maximum capacity of processing for 2,000 inhabitants, and the new plant still managed by the commune hall. Data collected from the S.C. Compania de Apa S.A. Arad show that sampling and analyzing water samples is done on a monthly basis. Below are the results of analysis charts carried out on February 23, 201, and April 30, 2010, at the old processing plant. As a result of the analysis of the indices presented previously, we could see that the values ranged within maximum admitted limits, except for ammonia whose maximum admitted limits were 4 times higher in the analysis carried out on April 30, In May 2020, we sampled water from the new processing plant, which we analysed on May 25, and that we present below. 120

7 Table 5 Analysis results of the sewage water samples analysed at the processing plant in Gurahont on February 23, 2010 Nr. Crt. Indices U.M. Value Analysis method Admitted limits according to the NTPA 002/ ph ph units 7.21 SR ISO10523/ Temperature ºC Total suspensions mg/l 80 STAS 6953/ CCO-Cr mg O 2 /l 159 SR ISO6060/ CBO5 mg O 2 /l 84 DIN Ammonia mg/l SR ISO 7150/ Total phosphorus mg/l 2.17 EN ISO 6878/ Detergents mg/l 1.89 SR EN 903/ Extractable substances mg/l 13<LQ SR 7587/ Filterable residue dried at 105ºC mg/l 890 STAS 9187/84 - Table 6 Analysis results of the sewage water samples analysed at the processing plant in Gurahont on April 30, 2010 Nr. Crt. Indices U.M. Value Analysis method Admitted limits according to the NTPA 002/ ph ph units 7.31 SR ISO10523/ Temperature ºC Total suspensions mg/l 140 STAS 6953/ CCO-Cr mgo2/l 289 SR ISO6060/ CBO5 mgo2/l 118 DIN Ammonia mg/l SR ISO 7150/ Total phosphorus mg/l 3.86 EN ISO 6878/ Detergents mg/l 1.59 SR EN 903/ Extractible substances mg/l 16 SR 7587/ Filterable residue dried at 105ºC mg/l 744 STAS 9187/84-121

8 Analysis of indices in the water from the new processing plant Table 7 Water sample nr. Nitrate NO 3 (ppm) Nitrite NO 2 (ppm) Ammonia NH 4 (ppm) Sample nr. ph Fe mg/l Mn µg/l Cl mg/l P mg/l Zn mg/l As a result of the analyses carried out we could see that they range within maximum admitted limits. Conclusions The values of the indices analysed in the surface waters in the Gurahont Depression point out the good quality of these waters, ranging in the 1 st and 2 nd quality categories. Some indices, such as the ph, which reaches the maximum admitted limit, or nitrites and manganese, show standard deviations. The quality of the water from the depth aquifer in the andesite volcanic agglomerates is, chemically, within exceptional drinking limits (STAS 1342/1991), with a few exceptions caused by some organic substances that are above these limits. References 1. Borza Iacob, G. Gabriel Arsene Ecologia Generala si Agricola, Timisoara 2. Rosu A Terra Geosistemul vietii, Ed. Stiintifica, Bucuresti 3. Normativ din 16 februarie -m2006- privind clasificarea calitatii apelor de suprafata in vederea stabilirii starii ecologice a corpurilor de apa., M.O. nr. 511 bis din 13 iunie