Tropentag, September 20 - 22, 2017 in Bonn
"Future Agriculture: Social-ecological transitions and bio-cultural shifts"
Study of Quality Water in Bypass Channel and the Sorbulak Lake (Almaty, Kazakhstan), Used for Irrigation of Agricultural Land
Nailya Ibragimova1, Oleg Esyrev2, Adiya Ibragim1
1German-Kazakh University (GKU), Fac. of Engineering and Economics, Kazakhstan
2Scientific Center of Anti-Infective Drugs, Laboratory of Pharmacology and Toxicology, Kazakhstan
This study undertakes analysis of sewage water quality indicators after purification; samples were taken in the bypass channel as well as in the lake-collector Sorbulak which water is used for agricultural irrigation.
Determination of phosphate, sulphates and nitrites showed that the level of these biogenous elements in Sorbulak lake has been twofold reduced in comparison with the channel water: 10.04±0.07 mg/ml / 22.7±0.2 mg/ml, 405.2±0.05 mg/ml/ 987.6±0.6 mg/ml and 22.5±0.08 mg/ml/ 34.6±0.05 mg/ml, respectively. NO3- - anion in channel water and in Sorbulak were lower than 23 mg/l, and the content of total nitrogen lies within 30-39 mg/ml.
Sorbulak lake showed a reduced concentration of phenol 2.02±0.08 mg/l, aluminum 0.12±0.01 mg/l, and lead 3.66±0.06 mg/l, compared to the bypass channel, but phenol and lead concentration were still higher than allowed. Moreover, reduction of surfactants (cation, anion) was observed in Lake Sorbulak, but the concentration of neon was practically the same in the channel as in the collector.
The comparative analysis of algological biodiversity identified that the bypass channel water contained more generic diversity (9 genus) as presented by Chlorophyta, and opposite to the Sorbulak lake contained also Chromophyta (7 genus ) and Cyanophycea. Increase of biodiversity of this last group of microalgae can be the reason of inorganic phosphorus and nitrogen absorption and as a result of biomass collection. That is why irrigation water containing these microalgae can stimulate growth of agricultural crops.
Thus, the channel for discharge of sewage water can be considered as an independent purification ecosystem, as the water passing through it continues to purify a a result of diverse form of lives in it. Finally, maximal purification is reached in the lake. However, Sorbulak lake water doesn't correspond to the quality levels for heavy metals and phenols.
Keywords: Algae, biogenous element, lake-collector Sorbulak, waste water
Contact Address: Nailya Ibragimova, German-Kazakh University (GKU), Fac. of Engineering and Economics, Pushkin Str. 111/113, KZ-050010 Almaty, Kazakhstan, e-mail: infodku.kz