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1

Removal of textile dyes from water using cellulose aerogel

Liugė Monika, Paliulis Dainius, Kumpienė Jūratė, Paulauskienė Tatjana

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 1

49--62

EN

In this study, removal of textile dyes from artificially contaminated water was investigated using sorbent synthesised from cardboard waste. Aerogel - lightweight adsorbent - a material with a low density and large surface area. Aerogels obtained from cellulose, chitosan, lignin or pectin have good adsorption properties for removing organic pollutants from wastewater. The aim of this study was to determine the adsorption efficiency of naphthol green B, congo red, methylene blue and rhodamine B from artificially contaminated water using sorbent synthesised from cardboard waste. The mass of the cellulose aerogel (5 mas. %) adsorbents, that were used in the experiments varied from 1.6 g to 2.74 g. The optimal adsorption conditions were determined as pH = 6.0, concentration of dyes - 10 mg L–1 and 18.0 °C -19.0 °C temperature. Under the optimal conditions, the maximum removal efficiency of naphthol green B using aerogel was 16.45 %; congo red - 98.44 %; methylene blue 79.28 %; and rhodamine B - 52.44 %.

2

Evaluation of Zinc Accumulation in Moss (Pylaisia polyantha) Growing Near Intensive Traffic Street Based on Modelling and Experimental Data

Paliulis Dainius

Rocznik Ochrona Środowiska

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2021

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Tom 23

198--213

EN

Pylaisia polyantha moss growing near intensive traffic in Geležinis Vilkas street at Vingis Park (Vilnius) was selected as an indicator of environmental pollution. Two models were applied for the study: the Gaussian plume model – for zinc emission from automobiles calculation and mathematical model – for recalculating the zinc emission from transport to zinc concentration in moss. Moss samples were collected during spring, summer and autumn. There were no significant changes in Zn concentrations between these periods. Zn emission dispersion from pollution source was calculated only for one vehicle, in order to reach relationships between environmental conditions and dispersion of Zn emission from vehicle exhaust fumes pipe. It was detected that the concentration of Zn tends to decrease with the distance from the pollution source. It was observed that there was a strong relationship between wind speed and Zn concentration – the slower the wind speed, the higher concentration of zinc in moss.

3

Removal of lead(II) and zinc(II) from aqueous solutions applying fibber hemp (Cannabis sativa L.)

Paliulis Dainius

Ecological Chemistry and Engineering. S

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2021

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Vol. 28, nr 2

229--239

EN

Lead and zinc are heavy metals with toxic properties. These chemical elements are found in wastewater. The article deals with the removal of lead(II) and zinc(II) ions from polluted water using adsorption. As object of researches was selected natural polymer - fibber hemp (Cannabis sativa L.). Big quantities of fibber hemp are produced as waste in textile, agricultural industry, and therefore their usage could help to solve two problems - reducing quantity of fibber hemp as waste and reducing of water pollution by heavy metals. Pb(II) and Zn(II) ions adsorption with fibber hemp was investigated for contact time, pH, and heavy metal ions concentration impact. Pb(II) and Zn(II) ions biosorption rate was highest within the first hour, with optimal their biosorption recorded at pH = 5.0. Highest lead and zinc ions removal efficiency was recorded after 240-480 min and reached 60.5 and 61.7 % respectively. This study demonstrated the applicability and effectiveness of fibber hemp in lead and zinc ions removal, which could be applied for the sewage treatment plant in small scale.

4

Evaluation of total organic carbon quantity and emissions of CO2 from soil into the atmosphere near street

Pranskevicius Mantas, Paliulis Dainius

Ecological Chemistry and Engineering. S

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2021

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Vol. 28, nr 3

399--410

EN

Soil as an ecosystem is actively involved into climate formation process. Therefore, it is important to assess such soil quality indicators as total organic carbon (TOC) and CO2 emissions. Soil organic matter is considered to be its indicator of quality, which is one of the most important components of biosphere consistency and stability. Soil respiration shows carbon emission from soil into the atmosphere. This is a great indicator, illustrating soil biological activity. Impact of soil temperature, air humidity, time of day was evaluated on CO2 emission from the soil. The highest CO2 emission is observed in afternoon hours, up to 0.201 g CO2·m–2·h–1.

5

Experimental investigations of dynamic sorption of diesel from contaminated water

Paliulis Dainius

Archives of Environmental Protection

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2021

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Vol. 47, no. 4

30--39

EN

Surface wastewater pollution due to accidental runoff or release of oil or its products is a longstanding and common environmental problem. The aim of the study was to investigate the impact of concentrations of oil products (diesel) and suspended solids, the sorbent type, the water flow rate and the interfering factors (chlorides) on the dynamic sorption of diesel and to test regeneration of polypropylene after its use for sorption. The sorbents used for study included common wheat straw (Triticum aestivum), polypropylene and sorbents modified with hydrogen peroxide solution. Standard methods were used for the determination of the investigated parameters and an in-house procedure employing a gas chromatograph was used for the determination of diesel concentration. The following factors that impact the sorption of diesel were investigated during the study: diesel concentration, concentration of suspended solids; type of sorbent (common wheat straw (Triticum aestivum), wheat straw modified with hydrogen peroxide, and polypropylene), water flow rate; and influence of the interfering factors (chlorides). Filtration speed in the range of investigated speeds does not affect the efficiency of diesel removal. Removal efficiency does not depend on the concentration of diesel before the sorbent reaches its maximum sorption capacity. Filling containing 50% of polypropylene and 50% of wheat straw was used for the study. It was found that polypropylene and wheat straw do not remove chlorides and suspended solids from solution. The study found that the solution of hydrogen peroxide boosts the hydrophobic properties of common wheat straw, but does not affect the sorption of diesel. The recommended number of regenerations of polypropylene should be limited to two.

6

Investigation of lead removal from drinking water using different sorbents

Albrektienė Ramunė, Paliulis Dainius

Ecological Chemistry and Engineering. S

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2020

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Vol. 27, nr 1

67--82

EN

Lead is a heavy metal with strong toxic properties. This chemical element is found in wastewater and sometimes in drinking water. The article deals with the removal of lead(II) ions from polluted water using a sorption process to determine the most effective sorbent for the removal of lead(II) ions. Three sorbents were used in the research: clay, sapropel, and iron sludge. All three sorbents investigated reduce the concentration of lead(II) ions in water: clay efficiency was of 65.7-90 %, sapropel of 94.3-100 %, and iron sludge of 84.3-97 %, depending on sorbent type and contact duration. The research has shown that the most effective way to remove lead(II) ions from the test water is sapropel. Using different amounts of sapropel (1, 2, 3, 4, 5, 6 g/dm3 and 0.1, 0.2, 0.4, 0.5, 0.6, 0.8 g/dm3) and different duration of contact (30, 60, 90, 120 and 150 minutes), the concentration of lead(II) ions in the test water after purification did not exceed the permissible values for drinking water (10 mg/dm3), so that the lowest sapropel content of 0.1 g/dm3 can be used for sorption. Lead(II) ions are most effectively removed when contact time is 30 min.