The work is an attempt to assess piped water quality in four counties located in east central Poland. Piped water was analysed for three successive years in each county. Water samples were tested for the following physical and chemical parameters: turbidity, colour, conductivity, taste, odour, pH, nitrates (III), nitrates (V), iron and manganese. They were compared with the current standard values. Preliminary data analysis included an analysis of maximum and minimum values of physical and chemical parameters, and it revealed that turbidity, colour, iron and manganese contents exceeded the permissible standards in all the counties. Percentages of parameters exceedances and mean values of the exceedances were used to rank the counties in terms of water quality. The ranking was obtained by means of multidimensional comparative analysis. It was demonstrated that best quality water was supplied by Węgrów County water supply system which was followed by Mińsk Mazowiecki County. The third rank was assigned to Łosice County and the poorest quality water was found to be supplied by Siedlce County water supply system.

Wonji Shoa Sugar Estate (WSSE), located in the flood plain of the Awash River (Ethiopia), has been under long-term (>60 years) irrigation, industrial activities and agro-chemical usage. In this study, the hydrochemical properties of ground-water bodies available at WSSE have been characterized for quality compositions. Water samples were collected from groundwater monitoring piezometers distributed in the sugarcane plantation and then analysed for physico-chemical quality parameters (pH, EC,major cations and anions) following standard procedures. Other chemical indices (e.g., total dissolved solids (TDS),total hardness(TH),magnesium absorption ratio(MAR), base exchange (r1), meteoric genesis(r2)) were de-rived from the measured water quality parameters. The compositional variability and groundwater classification has been presented using the Box and Piper plots. The potential sources of minerals were suggested for each of the considered water sources based on their quality characteristics. Both trilinear Piper plot and meteoric genesis index revealed that groundwaterof the area is shallow meteoric water percolation type with a changing of hydrochemical facies and mixing trend. Ground-water of the area, is group 1 (Ca-Mg-HCO3) type, with no dominant cations and HCO3 are the dominant anions. Overall, the study result elucidates that the chemical composition of GW of the area showed spatial variability depending upon the variations in hydrochemical inputs from natural processes and/or anthropogenic activities within the region. The local an-thropogenic processes could be discharges from sugar factory, domestic sewage and agricultural activities.

This study presents the hydrochemical composition of groundwater under long-term irrigation of Wonji plain (Ethiopia) and its quality status for drinking purpose. Groundwater samples were collected from 30 groundwater monitoring tube wells installed at different parts of the sugarcane plantation and then analysed for the major physico-chemical quality parameters (pH, EC, major cations and anions) following standard test procedures. The status of groundwater for drinking was compared with WHO and other quality standards. Analytical analysis results indicated that majority of the considered quality parameters are rated above the prescribed tolerable limits for drinking set by WHO. About 97% of the water sample has water quality index in the range of very poor to unfit for drinking. The contamination index is in the ranges of low (–1.0) to high (3.6). In general, the groundwater of the area is unsuitable for human consumption without proper treatment such as boiling, chlorination, filtering, distillation, desalinaization, defluoridation, deionization, demineralization (ionexchange) and membrane processes. Since the TDS concentration is relatively small (<2000 ppm), demineralization process alone can be sufficient to bring the water to an acceptable level.

Quality assessment of shallow groundwater table is very important because it is the water that recharges deeper aquifers and constantly feeds the water levels of our surface streams and wetlands. Continuous monitoring of large number of quality parameters is essential for effective maintenance of water quality through appropriate control measures. However, it is very difficult and laborious task for regular monitoring of all the parameters even if adequate manpower and laboratory facilities are available. Therefore, this study presents the statistical analysis of physico- chemical parameters (pH, EC, TDS, Na, K, Ca, Mg, HCO3, Cl, CO3, SO4, TH, B, F) using correlation and Principal Component Analysis. The statistical analysis of the groundwater quality variables indicated that most of the variables are highly correlated. The strong correlation is an opportunity to develop a regression equation and monitor using few parameters. This provides an easy and rapid method of continuous groundwater quality monitoring. Moreover, groundwater of the area showed significant compositional variation. The compositional variability has implications for the source and origin of groundwater quality in the study area.

According to various sources, between approximately 8.5 and even 10 million tons of Russian coal entered Polish market in 2022, which was mainly used for heating purposes by heating companies and private households (especially in the northern regions of the country). A ban on the continuation of these imports requires the identification of other sources of fuel – these could be either imports from other countries or an increase in mining volumes by domestic mines. However, both of these alternatives require a certain amount of time to be realized. Finding new foreign suppliers entails new contracts, which can be all the more difficult as many other countries, like Poland, no longer want to buy Russian coal. And then there is the issue of negotiating appropriate prices.
A possible decision to increase domestic mining is linked to other problems. This requires, first and foremost, that new portions of the deposits that could be mined be made available and cut in advance, which often entails several years of underground roadworks and significant financial outlays for their implementation and for the appropriate technical equipment of the newly prepared mining faces. With appropriate financial support from the state, this may be possible but not in every mine as there are a number of other considerations that determine the volume of extraction that can be achieved, particularly if there is a desire to increase it.
The aim of this publication is to present, analyse and identify factors that directly influence the volume of hard coal production, taking into account the dynamically changing market environment.

Hard coal sludge is classified as group 01 waste or it is a by-product in the production of a hard coal with variable energy importance. Pulverized lignite is not waste but a final product of drying and the very fine pulverization of lignite with a high calorific value. The study comprised the basic material before granulation such as coal sludge (PG SILESIA) and pulverized lignite (LEAG) as well as their prepared blends after the granulation on a pipe vibration granulator designed at AGH. The pulverized lignite of the LEAG company shows a low sulfur contents. In the analyzed samples its average content (Stot d) is 0.61%. An average value of this parameter in the analyzed coal sludge samples is 0.55%. The addition of pulverized lignite does not have a significant impact on the total content of sulfur and of analyzed toxic elements (Hg, As, Cd, Cr, Co, Cu, Mn, Ni, Pb, Sb, Tl, and W) in the samples. The calorific value of coal sludge falls within the range of 11.0−12.4 MJ/kg (on a dry basis). For the coal sludge and pulverized lignite blends the calorific value clearly increases to values of 14.8−17.7 MJ/kg (on dry basis). The calorific value slightly decreases in the

The paper presents the correlation between the CRI (Coke Reactivity Index), CSR (Coke Strength after Reaction) and the remaining 36 quality parameters of coking coal from the Pniówek deposit (SW part of the USCB). The test results were obtained for a region of fundamental importance to the Polish reserves of coking coal, characterized by highly variable coalification and quality parameters. The tests related to the determination of relationships of the CRI and CSR indices to other parameters were based on 25 channel samples acquired from active workings. The characteristics of the variability of the CRI and CSR indices were analyzed using statistical methods. The dependencies between the CRI and CSR indices and the parameters having an impact on their values were determined using linear correlation. An attempt was also made to determine the correlations between the concerned parameters using the multiple correlation method. The obtained results have been presented and compared to the results of globally conducted experiments in the form of charts presented by (North et al. 2018b). No clear dependence of the CRI and CSR indices was exhibited in case of most of the analyzed quality parameters, which is supported by low correlation coefficients of r < 0.5. The statistical analysis exhibited only 9 cases of correlation between CRI and CSR with other quality parameters, where the correlation coefficient was r ≥ 0.5, that is: Ht a, Na2O, Al2O3 and SiO2, Mn3O4, da a and dr a. This confirms the different characteristics of coal from the studied area, exhibited multiple times, that should be related to the specific coalification process, especially the occurrence of thermal metamorphism.

The new legislative provisions, regulating the solid fuel trade in Poland, and the resolutions of

provincial assemblies assume, inter alia, a ban on the household use of lignite fuels and solid fuels

produced with its use; this also applies to coal sludge, coal flotation concentrates, and mixtures

produced with their use. These changes will force the producers of these materials to find new

ways and methods of their development, including their modification (mixing with other products

or waste) in order to increase their attractiveness for the commercial power industry. The presented

paper focuses on the analysis of coal sludge, classified as waste (codes 01 04 12 and 01 04 81)

or as a by-product in the production of coals of different types. A preliminary analysis aimed at

presenting changes in quality parameters and based on the mixtures of hard coal sludge (PG SILESIA)

with coal dusts from lignite (pulverized lignite) (LEAG) has been carried out. The analysis

of quality parameters of the discussed mixtures included the determination of the calorific value,

ash content, volatile matter content, moisture content, heavy metal content (Cd, Tl, Hg, Sb, As, Pb,

Cr, Co, Cu, Mn, Ni, and W), and sulfur content. The preliminary analysis has shown that mixing

coal sludge with coal dust from lignite and their granulation allows a product with the desired quality

and physical parameters to be obtained, which is attractive to the commercial power industry.

Compared to coal sludge, granulates made of coal sludge and coal dust from lignite with or without

ground dolomite have a higher sulfur content (in the range of 1–1.4%). However, this is still an

acceptable content for solid fuels in the commercial power industry. Compared to the basic coal

sludge sample, the observed increase in the content of individual toxic components in the mixture

samples is small and it therefore can be concluded that the addition of coal dust from lignite or carbonates

has no significant effect on the total content of the individual elements. The calorific value

is a key parameter determining the usefulness in the power industry. The size of this parameter for

coal sludge in an as received basis is in the range of 9.4–10.6 MJ/kg. In the case of the examined

mixtures of coal sludge with coal dust from lignite, the calorific value significantly increases to

the range of 14.0–14.5 MJ/kg (as received). The obtained values increase the usefulness in the

commercial power industry while, at the same time, the requirements for the combustion of solid

fuels are met to a greater extent. A slight decrease in the calorific value is observed in the case of

granulation with the addition of CaO or carbonates. Taking the analyzed parameters into account,

it can be concluded that the prepared mixtures can be used in the combustion in units with flue gas

desulfurization plants and a nominal thermal power not less than 1 MW. At this stage of work no

cost analysis was carried out.