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Reverse osmosis (RO) and nanofiltration (NF) are effective technologies for removing organic compounds from water. Most research focuses on the removal of organic compounds from water already treated. However, evaluating their removal from groundwater is necessary because coexisting ions affect treatment efficiency. In the case of inorganic compounds, the water's pH, concentration, and membrane charge are the main factors affecting the electrostatic repulsion between the ionic compounds and the charged membrane. This study aims to present the efficiency of removing the studied compounds with NF/RO from groundwater and the physicochemical and chemical processes involved in the removal. As a result of the research, it is found that the hydraulic performance of the membrane, especially for RO, is stable; the efficiency of benzene, ethylbenzene, toluene, and o-, m-, p-xylene removal throughout the research process is at 86% for RO and about 65% for NF. [ABSTRACT FROM AUTHOR]

We classify bisphenols as organic compounds from the group of phenols. Since bisphenols are carcinogenic and disrupt the human body's hormonal balance, removing these compounds from the aquatic environment is crucial. The production of creams and household plastics uses bisphenols. Such harmful compounds include bisphenol A and its derivatives (e.g., bisphenol B (BPB), bisphenol AP (BPAP), bisphenol M (BPM), bisphenol E (BPE), and bisphenol C (BPCl2)). Although bisphenol A is still the dominant bisphenol in the environment, the legal restrictions on its use lead to the use of other bisphenols. Biochemical processes remove 50%--90% of these compounds from wastewater. Introducing Fenton's reagent or UV radiation improves efficiency. However, these are still ineffective methods of their removal from sewage and water. The paper focuses on the possibility of removing bisphenols: bisphenol A, bisphenol E, bisphenol B, bisphenol G, bisphenol C, bisphenol AP, and bisphenol M from surface water using integrated nanofiltration--reverse osmosis membrane processes. The research is carried out at a small nanofiltration and reverse osmosis station. The process uses nanofiltration and the osmotic membrane of spiral aromatic polyamide membranes. Chemical determinations are made by chromatographic analysis developed for these compounds. The conducted studies showed the removal of the tested compounds with high effectiveness. The process parameters significantly influence the removal process, particularly the concentration of bisphenols in the feed and the transmembrane pressure. The impact of these processes should be further analyzed and explained. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the ability of the four porous materials: birch bark, cork, glass wool, and polyurethane foam to reduce the mineral oil index and the concentration of n-alkanes C7H16-C38H78 as well as to select the most efficient materials. Model solutions of gasoline, diesel oil, and distilled water with the following values of mineral oil index were prepared to tests: 52 μg/dm3, 68 μg/dm3 and 73 μg/dm3. Then, studies were carried out using a dynamic method, wherein the columns were filled with adsorbents tested, and in each of three testing series, 500 mL of the model solution at constant bed load of 1,0551 m3/m2h was filtered through the column. After filtration, the collected sample had volume of 250 mL. The collected samples were subject to determination of mineral oil index and concentrations of n-alkanes from C7H16 to C38H78. Studies have shown that the most effective materials to lower the mineral oil index and the concentrations of n-alkanes in water are birch bark and glass wool.

The prevalent occurrence and use of oil lead to an increasing environmental pollution by petroleum products. Petrochemical-based products penetrate the soil and then indirectly get to water along with the sewage and stormwaters that wash away the surface of streets and roads. The object of this work was to study the removal of oil from water. The study examined the use of test system: aeration–reverse osmosis (RO) in order to remove C7–C35petroleum compounds from aqueous solutions. Tests were conducted using the model water—distilled water with the addition of diesel oil and gasoline. The effectiveness of the integrated process was evaluated based on the degree of petroleum compounds removal from the water after various stages of the process, and after completion of water purification. Hydraulic performance of the membrane was also investigated. Six test series, starting from 2,997.87 to 96.5 mg/dm3concentration, were performed. The test water was aerated and then subjected to the RO process. Determination of petroleum hydrocarbons was made using a gas chromatograph according to Polish Norm PN-C-04643 and expressed as mineral oil index. [ABSTRACT FROM AUTHOR]

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Manganese salts in groundwater are among the most troublesome compounds and if these waters are to be used for municipal and industrial purposes, manganese must be removed to meet normative levels in accordance with the regulation of Minister of Health (20 April 2010) and the European Union Council Directive 98/83/EC. The aim of this study was therefore to select the most efficient filter beds to remove manganese from drinking water or water for economic purposes. The research included conducting the filtration process, in which seven different beds were used as the filter material: the Greensand, G-1, the Hydrocarbon, Zeolite, the Crystal Right, Ecomix A, and Ecomix C. All tested beds could be used for elimination of manganese. The authors showed a dependence of the concentrations obtained in the filtrate on the type and the nature of particular beds. It is recommended that the Greensand, the Crystal Right, and Ecomix C should be used in order to purify groundwater, where there is no additional contamination with organic compounds and water has increased hardness. For surface or infiltration water, where there is reduced concentration of manganese, the authors recommend that G-1, the Crystal Right, and Ecomix C should be used, whereas Zeolite, the Hydrocarbon, and Ecomix should not be used as stand-alone filters. [ABSTRACT FROM PUBLISHER]

Petroleum compounds appear in the surface and underground water in increasing concentrations. This is due to the emergence of new risks associated with the production, transport, use, and disposal of hazardous waste substances. These pollutants have a strong toxic impact on the organism, hence they should be removed using the most effective methods. This paper deals with the removal of petroleum compounds from water using a combination of classical and membrane methods. Coagulation and reverse osmosis were applied. The study used model water, i.e. distilled water enriched with a mixture of diesel fuel and gasoline. The aim of the study was to determine the possibility of petroleum removal during the hybrid process. The model water was subject to the coagulation process using Al2(SO4)3·18H2O, then filtered and subjected to the reverse osmosis process. Determination of petroleum hydrocarbons in the model water was made after coagulation and reverse osmosis. [ABSTRACT FROM PUBLISHER]

Depending on the system, in which the adsorption process is implemented, equations of kinetics, statics, and dynamics of adsorption can be applied for its mathematical description. The most general model used for description of adsorption process in the batch system is a model based on field equation of adsorbate concentration in the internal structure of the absorbent. Dynamics of adsorption examines the time-spatial distribution of adsorbate in the adsorbent bed. This publication presents an analysis and practical use of selected dynamics equations of the adsorption process for calculating the working time of sorbent deposits in a flow system. [ABSTRACT FROM PUBLISHER]

Agriculture products such as cereals, fruit, and vegetables are often found to be contaminated with residues of persistent pesticides and other toxic substances. The major source of entry of these compounds to food chain is the contaminated soil. Therefore, the status of the residue level of most persistent organochlorinated pesticides (OCP) in soil and agricultural crops should be monitored regularly. The frequency of occurrence and contamination levels of OCP residues in samples of soils, cereals, fruit and vegetables from different geographical regions such as Central Asia and East Europe were determined. The samples of soil, fruit (black currant), vegetables (beans, carrots, celery, cucumbers, lupine, parsley, and tomatoes) and cereals collected from Kazakhstan and Poland contained residues of different OCPs like aldrine, dieldrine, hexachlorocyclohexane isomers and dichlorodiphenyltrichloroethane (DDT) complex. Endosulfan and dicofol were also found in some samples in the concentration ranging from 0.008 to 0.8 mg/kg, particularly in samples of tomatoes from Kazakhstan. In the samples of the soil taken from Polish and Kazakhs farms, DDT and metabolites were detected. In the case of DDT complex, i.e. DDD, DDE, and DDT, the concentration ranged between 0.005 and 0.542 mg/kg and the pp′ isomers were more frequently encountered than their op′ counterparts. [ABSTRACT FROM PUBLISHER]

This article presents the influence of climatic conditions on surface water quality. The research methodology, including physicochemical analysis from the Gołdapa and Bludzia rivers, is presented. The research lasted for two years. The results of the physicochemical studies of the Gołdapa and Bludzia rivers in early spring, spring, and autumn show that each of these seasons impacts the quality of surface waters. Moreover, it was proven that all the parameters are strongly correlated with the air temperature, the sum of daily precipitation, and water levels. For detailed analysis, the obtained results of own research were compared with meteorological and hydrological data from the last 15 years (2005–2021) for the region of north-eastern Poland. It was proven that temperature changes contribute to increased surface water pollution in the north-eastern part of Poland. Waters from areas that humans have not developed are of better quality than those that drain the urban area, which is reflected in the case of the superior quality of the Bludzia river compared to the Gołdapa river. The upward trend in temperature in the Gołdap region indicates that global warming will continue. [ABSTRACT FROM AUTHOR]