Wyniki wyszukiwania - BazTech

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Treatment processes based on the molecular weight distribution of textile dyeing wastewater

Yaman F. B., Çakmakci M., Karadag D., Özkaya B., Bali V., Dora B.

Environment Protection Engineering

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2018

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Vol. 44, nr 2

147--158

EN

Rinsing wastewater from dyeing and bleaching processes in a cotton dyeing facility has been separately characterized to evaluate the suitable treatment processes and reuse options. Alternative treatment processes were proposed based on molecular weight distribution (MWD), ultraviolet absorbance of 254 nm (UV254) and specific ultraviolet absorbance (SUVA). Rinsing wastewater samples were sequentially filtrated to determine the MWD of 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), dissolved organic carbon (DOC), total Keldahl nitrogen (TKN) and ammonium (NH4+). Bleaching rinsing wastewater had higher organic and nitrogen contents than dyeing rinsing wastewater and concentrations of pollutants decreased after each membrane filtration step. During the sequential filtration, BOD5/COD ratio in bleaching rinsing wastewater slightly decreased while it significantly increased in dyeing rinsing wastewater. SUVA values indicated that organic matters in the rinsing wastewaters have hydrophilic characteristics in all conditions. The evaluation of all experimental data indicates that combination of anaerobic treatment and NF membrane filtration could provide high quality water for reuse within the facility and discharge into receiving environments.

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Removal of nitrates from wastewater using pond bottom soil

Erbanová E., Palarčík J., Slezák M., Mikulášek P.

Environment Protection Engineering

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2016

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Vol. 42, nr 2

145—154

EN

The possibility of the final treatment of mine water from chemical leaching has been investigated. Despite water purification, high nitrate levels remain in these waters and must be removed. The main requirements are the lowest economic, operating and staffing levels. These requirements are best achieved by the removal of nitrates using biological methods, in our case using the pond bottom soil. Experiments were carried out in a batch mode. The effect of the environment on the denitrification process, the influence of the type and amount of the organic substrate and basic parameters of the denitrification such as redox potential, pH and dissolved oxygen were studied.

3

Variability of Oxygen-Thermal Conditions in Selected Lakes in Poland

Ptak M., Nowak B.

Ecological Chemistry and Engineering. S

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2016

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Vol. 23, nr 4

639--650

EN

Dissolved oxygen in water (DO) is one of the primary parameters determining its quality. It remains in close relation to water temperature. The article presents results of DO and water temperature measurements performed for five stratified lakes in Poland in the years 2007-2014. The measurements were performed with monthly frequency in the summer half-year (May-October) in the deepest place of each of the lakes. The compared data show the complex character of the course of both of the parameters. The analysis of depth profiles revealed the prevalence of a decreasing tendency, or no tendency was recorded - both in the case of DO and water temperature. Due to the incoherent character of the water in the case of stratified lakes, a more detailed comparison was performed, referring to changes occurring in zones developed during summer stratification. It was determined that the temperature of the epilimnion was directly dependent on air temperature, and in all cases it showed an increasing tendency. Simultaneously, along with an increase in temperature, in the majority of cases, DO concentration in the zone decreased. In reference to the waters of the hypolimnion, increasing, decreasing, and no tendencies were recorded. The above distribution is determined by individual factors of the lakes - morphometry, trophic status, groundwater alimentation, etc. Several years of measurements of DO and water temperature in depth profiles of several lakes in Poland constitute valuable information on the current transformations of the environment of this part of Europe. In the future, the information can provide the basis for long-term analyses over the next decades, enriching global knowledge on those parameters of key importance for water ecosystems.