Wyniki wyszukiwania - Biblioteka Nauki

1

The Potential Biosorption of Copper and Manganese by Bacterial Cellulose in the Environment

100%

Kroeksakul P. , Ngamniyom A. , Chongkolnee B.

Journal of Ecological Engineering

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2023

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tom Vol. 24, nr 11

190--196

EN

This study investigated the efficiency of copper and manganese adsorption by bacterial cellulose (BC) produced from Komagataeibacter intermedius BE073. BC was collected from production processes in a village in Nakhon Nayok province. BC had high moisture content of 91.15±3.68%, an average water absorption index (WAI) of 5.30±0.362, an average tensile strength of 99.1 ±6.18 MPa, average elongation at break of 6.41±0.67%, and an average Young modulus of 1445±177 MPa. Structural analysis of the BC material shows that it is a cellulose powder with a main group. Measurements show that the Mn content in BC rapidly decreased after soaking in solution, and that the highest Cu absorption efficiency of BC during a 120 minute period was 15469 mg kg-1. The results of this study show that BC may be successfully used to absorb various heavy metal residues from leachate, particularly Cu solutions. BC cannot absorb Mn from solution, so it cannot be used to absorb Mn from leachate. However, studies have shown that BC can release Mn into solution. Therefore, BC may be effective for use in agriculture, as Mn is a micronutrient for plants.

2

An Interactive Behavior of Soil Moisture Influences the Concentration of Arsenic in the Acidic Soil of the Plow Layer of the Central Region of Thailand

100%

Kroeksakul P. , Srisuwan P. , Uaesukpakdee T. , Panichpaisarn J.

Journal of Ecological Engineering

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2024

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tom Vol. 25, nr 8

168--178

EN

This article investigates trends in changing values of arsenic concentration in the plow layer under different conditions of soil moisture in the central region of Thailand. The study consists of two experiments: (1) examining the relationship between the vertical dynamics of As and soil moisture, and (2) exploring the effects of soil surface water evaporation on As speciation transformation and vertical dynamics. The experiments were conducted at the greenhouse facility of the Faculty of Environmental Culture and Ecotourism at Srinakharinwirot University. The evaporation rate of the greenhouse was measured to be 0.000104 mm/m2/h, and the soil permeability coefficient was 0.0014 cm/s. The effects of soil moisture on the vertical distribution of arsenic was found to be significant (p<0.05), particularly on day one, in the layer 0–10 cm. In layers 11–20, 21–30, and 31–40 soil with 40% moisture showed higher concentrations of arsenic than soil with moisture levels of 10% and 20% (p<0.05). The pattern of As available for vertical movement in the plow soil layer showed great variability, especially in the 11–20 cm, 21–30 cm, and 31–40 cm layers. The most notable increase was observed at a 40% moisture content. The principal component analysis (PCA) test found that PC1 was most influential on the soil layers 21–30 cm and 31–40 cm, while PC3 highlighted arsenic concentrations in layers 0–10 cm and 41–50 cm. The movement of arsenic through evaporation from below the plow showed great variability between layers with the most stable concentrations being observed on the 14th day. However, the research showed that arsenic moves vertically in acidic soil rather than evaporating to the soil surface.

3

Development and Characterization of Polyvinyl Alcohol/Bacterial Cellulose Composite for Environmentally Friendly Film

88%

Singhaboot P. , Kraisuwan W. , Chatkumpjunjalearn T. , Kroeksakul P. , Chongkolnee B.

Journal of Ecological Engineering

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2023

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tom Vol. 24, nr 6

226--238

EN

This research aimed to develop and characterize polyvinyl alcohol (PVA)/bacterial cellulose (BC) composite for environmentally friendly films. BC was produced from a high-performance strain of Komagataeibacter intermedius BE073 isolated from a bio-extract sample. The film was prepared by varying the ratio between PVA and BC content, and treatments consisted of 100:0, 90:10, 80:20, 70:30, and 60:40. The characterization of PVA/BC film in terms of mechanical properties, film structure, water and oxygen resistances, thermal stability, and biodegradation were investigated. Results revealed that PVA/BC film had properties superior to that of pure PVA film, and it has a high biodegradation rate. The mechanical properties changed little with the addition of BC, but the tensile strength and Young’s modulus increased with the addition of BC. Water absorption and moisture content were also reduced. However, adding BC improved oxygen transmission rates and thermal stability properties. Most importantly, the addition of BC helped the film to degrade. The higher the amount added, the higher the natural decomposition rate.

4

Evaluation of Pesticide and Heavy Metal Contamination on Soil Properties and Microbiota in Thailand’s Mountainous Region

75%

Kroeksakul P. , Ngamniyom A. , Silprasit K. , Sutthisaksopon P. , Sriyapai T. , Phowan N. , Singhaboot P.

Journal of Ecological Engineering

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2023

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tom Vol. 24, nr 7

331--344

EN

The article aims to investigate the state of soil elements in upland agriculture and the state of pesticide contamination in the environment of differing highland agricultural areas in Thailand. The number of heavy metals present was Fe > Mn > Zn > Pb > Ni > Cu > Cd, dominant pesticide contamination in the carbamate group is methomyl (0.11 mg/kg), and the organochlorine group is triazophos (0.02 mg/kg). Pesticide contamination was found to positively and significantly correlate with the soil’s total N and Fe content (p < 0.01). In the soil microbes, the dominant genera of Aquabacterium were found at the highland agriculture site H1, Massilia at H2, and Sphingomonas at H3.