The production of stable and mature compost often depends on the performance of microbes and their enzymatic activity. Environmental and nutritional conditions influence the characteristics of microbial communities and, therefore, the dynamics of major metabolic activities. Using three waste mixtures (textile waste mixed with either green, paper, or cardboard waste), the maturity of the compost produced was assessed by following the physico-chemical parameters and enzymatic activities provided by the microorganisms that were identified using next-generation sequencing (NGS). Among the three mixtures used, it was found that the two best mixtures showed C/N ratios of 16.30 and 16.96, total nitrogen of 1.37 and 1.39%, cellulase activities of 50.62 and 52.67 Ug−1, acid phosphatase activities of 38.81 and 68.77 Ug−1, and alkaline phosphatase activities of 51.12 and 56.86 Ug−1. In addition, several lignocellulosic species, together with those that are able to solubilize phosphate, were identified. Among those known for cellulase and acid/alkaline phosphatase activities, bacteria belonging to the Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes phyla were shown. The presence of species belonging to the Ascomycota and Basidiomycota phyla of Fungi, which are known for their ability to produce cellulase and acid/alkaline phosphatases, was demonstrated. These findings provide a basis for the production of stable and mature compost based on textile waste.

Composting is a promising source of mesophilic and thermophilic microorganisms directly involved in the decay of organic matter. However, there is a paucity of information related to bacterial and fungal diversity in compost and their enzymatic activities during the composting process. In this work, bacterial and fungal diversity during the mesophilic and thermophilic phases of textile waste composting was investigated as a way to explain the physical–chemical results obtained during the composting process. This was accomplished using a next-generation sequencing approach that targets either the 16S rRNA or ITS genomic regions of bacteria and fungi, respectively. It was observed that Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant bacterial phyla present at the mesophilic phase but not at the thermophilic one. Composting textile waste exhibits a sustained thermophilic profile (above 55 °C) that usually precludes fungal activity. Nonetheless, the presence of fungi at the thermophilic phase was observed. Rozellomycota, Basidiomycota, and Ascomycota were the most dominant phyla during both composting phases. Such thermophilic fungi with great ability to decay organic matter could be isolated as pure cultures and used for the bioaugmentation of textile waste composting to achieve an advanced maturity level of textile waste compost.

Dissolved organic carbon (DOC) interacts with dissolved trace metal affecting their mobility and bioavailability through the formation of DOC–metal complexes. Several types of biochar (BC) produced from slow pyrolysis of wood chips (WC), lignin (LG), and digested sewage sludge at 450 and 700 °C were tested for DOC leaching via batch and up-flow percolation test methods. Trace metal (Cd, Cu, and Pb) speciation modelling in BC eluates was carried out combining measured data (i.e., DOC, ph, temperature, and dissolved trace metal concentrations) with data reported in the literature regarding fractions of DOC that are inert or active (i.e., fulvic acids (FA) and humic acids (HA)) in metal binding. BC from LG (BCLG) and WC (BCWC) at 700 °C released lower cumulative amounts of DOC compared with BC at 450 °C in the range 0.02–0.07% and 0.06–0.09% of total carbon content, respectively. For both pyrolysis temperatures, BCWC exhibited a higher tendency to release DOC compared to BCLG. Speciation modelling results showed the predominance of FA and HA complexes of Cd, Cu, and Pb in all the eluates from BCWC and BCLG irrespective of the inert fractions of DOC or the different fractions of active FA and HA considered.

Benzene, toluene, ethylbenzene and xylene (BTEX) form an important group of volatile organic compounds (VOCs) affecting troposphere and posing risk to human health. The article examines the Mažeikiai area in the northern part of Lithuania where one of the largest Central European companies and the only oil refinery in the Baltic region (200,000 barrels/day) are close to the Baltic Sea. The research carried out mainly focuses on the following objectives: quantitative assessment of the amounts of BTEX occurring in the impact zone of the oil refinery and transport; estimation of background BTEX concentrations in the region; establishing the main sources of BTEX in the region researched and evaluation of impact of meteorological parameters on BTEX concentrations in different seasons. The passive measurement method was used for analysing VOCs (benzene (CH), toluene (CH), ethylbenzene (CH) and ortho-, meta- para-xylene (CH)). The research was carried out in 2010-2012. Its results showed that the average annual concentration of benzene was below the threshold value of 5 μg/m. Within the measurement period, the average concentration of benzene fluctuated from 1.2 to 2.4 μg/m, that of toluene varied from 1.3 to 3.5 μg/m, that of ethylbenzene varied from 0.3 to 0.7 μg/m and that of xylene (calculated as para-, meta- and ortho-xylene) varied from 1.0 to 2.4 μg/m. Compared to the established BTEX concentration, the actual background BTEX concentration in the urban area is two times higher. The seasonal analysis suggests that the highest values of benzene concentration are observed in the winter season.

During an extended period from 2010-2012 ambient air quality researches, concentration of nitrogen dioxide (NO 2 ) in the air was measured applying the passive method. In order to evaluate the spatial distribution of pollutants and the major sources, 12 sampling sites across the region were chosen. Additionally, the seasonal changes of this pollutant under different meteorological conditions (air temperature, humidity, wind speed and direction) were investigated. The long-term study showed 3.8 times higher NO 2 concentrations in the Mažeikiai urban area (24.2 μg m −3 ) as compared to other locations in the region (6.3 μg m −3 ). This confirms the assumption that the main source of NO 2 in this area is motor vehicle exhaust fumes. The analysis of the results obtained in different seasons showed a significant difference (p<0.05) in NO 2 concentrations under different meteorological conditions. The increase in NO 2 concentrations was recorded in the winter and late autumn seasons, due to reduced solar radiation and lower temperatures. Cluster analysis results showed that sampling sites can be grouped into different classes based on NO 2 main source, motor vehicles and traffic intensity.