Abstract: In this study, different types of magnetic biochar nanocomposites were synthesized using the co-precipitation method. Two biochar materials, namely, sewage sludge biochar and woodchips biochar, were prepared at two different temperatures, viz., 450 and 700 °C. These biochars were further modified with magnetic nanoparticles (Fe 3 O 4 ). The modified biochar nanocomposites were characterized using field emission–scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), SQUID analysis, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). The potential of prepared adsorbents was examined for the removal of hexavalent chromium (Cr(VI)) and Acid orange 7 (AO7) dye from water as a function of various parameters, namely, contact time, pH of solution, amount of adsorbents, and initial concentrations of adsorbates. Various kinetic and isotherm models were tested to discuss and interpret the adsorption mechanisms. The maximum adsorption capacities of modified biochars were found as 80.96 and 110.27 mg g -1 for Cr(VI) and AO7, respectively. Magnetic biochars showed high pollutant removal efficiency after 5 cycles of adsorption/desorption. The results of this study revealed that the prepared adsorbents can be successfully used for multiple cycles to remove Cr(VI) and AO7 from water.

Abstract: Extreme precipitation episodes are very common in Mediterranean area and can lead to serious and catastrophic environmental hazards. They have special incidence during autumn months, September, October and November (SON) with important impacts on society, leading frequently to significant economic losses and mortality. These events have special impact in mountainous areas where steep slopes enhance the effects of extreme precipitation. In mountainous areas rain gauge stations are sparse and normally in lower amount. Due to these reasons it is very important to map with higher accuracy the distribution of extreme precipitation. Also, in mountainous environments precipitation patterns can change in small distances that make the prediction more difficult, but also more important. A better prediction of areas with higher values of extreme precipitation will contribute to a better land use planning and avoid the effects of flash floods, land‐slides and soil erosion recognized as environmental problems. The aim of this paper is testing several well‐known interpolation methods, Inverse Distance Weight (IDW) with weighs of 1, 2, 3, 4 and 5, Local Polynomial (LP) with order 1 and 2, Radial Basis Methods (RBS), particularly Spline With Tension (SPT) and Thin Plate Spline (TPS), and Kriging techniques, Ordinary Kriging (OK) and Ordinary CoKriging (COK) in order to identify the less‐biased method to interpolate extreme precipitation calculated from the 95th percentile (P95) of SON precipitation in a mountainous area located in Portugal. The results show that extreme precipitation increases with the altitude and there are important differences between stations located at higher and lower altitudes. This relation is observed in the omni‐directional semi‐variograms calculated where we identified two major P95 areas coincident with higher elevations. The first one occurred at 12.19 km and the second at 23.57 km. The higher values of P95 are identified at Southeast and Northeast. In contrast, the lower P95 values are identified at Northwest due to lower altitudes and in the Northeast corner as a consequence of rain shadow effect. Prediction with precision of precipitation patterns in mountainous areas is difficult due to lack of data and the complex effect of topography in rainfall, however, it is of major importance in order to identify vulnerable areas. The findings observed in this study are a fundamental contribution to landscape planning and environmental management in areas with higher occurrence and vulnerability to extreme precipitation. Santrauka Gausūs krituliai, ypač būdingi Viduržemio jūros regionui, gali kelti rimtu pavoju aplinkai, lemti katastrofas. Krituliu poveikio zona ypač išsiplečia rudens laikotarpiu, t. y. rugsejo, spalio ir lapkričio (RSL) menesiais, neretai patiriama dideliu ekonominiu nuostoliu, žūsta ar kitaip nukenčia žmones. Statūs kalnu šlaitai sustiprina gausiu krituliu poveiki. Kalnuotose vietovese krituliu kiekio stebejimo stočiu nedaug, jos toli viena nuo kitos, todel labai aktualu tureti žemelapius, tiksliai nusakančius gausiu krituliu pasiskirstyma. Kalnuotose vietovese krituliu pobūdis skirtingu atstumu gali būti skirtingas, krituliu kieki numatyti sunkiau, tačiau tai itin svarbu. Tiksliau numatant vietoves, kur iškrinta daugiau krituliu, galima tikslingiau planuoti žemetvarka, išvengti staigiu potvyniu, nuošliaužu ir dirvožemio erozijos. Tyrimo tikslas buvo patikrinti kelis gerai žinomus interpoliacijos metodus – Inverse Distance Weight (IDW) su 1–5 svertinemis vertemis, Local Polynomial (LP), Radial Basis (RBS), ypač Spline With Tension (SPT), Thin Plate Spline (TPS), – bei Kriging technikas ir Ordinary Kriging (OK) bei Ordinary CoKriging (COK) metodus, siekiant parinkti tiksliausia, kuris leistu interpoliuoti gausius (95 %) kritulius RSL menesiais kalnuotoje Portugalijos teritorijoje. Nustatyta, kad krituliu kiekis dideja didejant altitudei. Reikšmingi krituliu skirtumai nustatyti stotyse, esančiose skirtinguose aukščiuose virš jūros lygio. Šis santykis pastebetas visomis kryptimis apskaičiuotose pusinese variogramose. Jose išsiskiria dvi teritorijos, kuriu P95 vertes didžiausios, ir akivaizdi sasaja su didelemis altitudemis. Pirmoji teritorija 12,19 km, o antroji 23,57 km aukštyje. Didžiausios P95 vertes pietryčiu ir šiaures rytu kryptimis, mažiausios – šiaures vakaru kryptimi, kur altitudes mažos, ir šiaures rytu teritorijos kampe del lietaus “šešelio” efekto. Tiksliai numatyti krituliu pobūdi kalnuotose teritori‐jose apsunkina duomenu trūkumas ir sudetinga topografijos itaka krituliams. Rezultatai ypač parankūs planuojant ir val‐dant dažniems ir gausiems krituliams jautrias teritorijas. Резюме Обильные осадки, особенно характерные для Средиземноморского региона, могут быть опасными для окружающей среды. Зона влияния осадков особенно увеличивается в осенний период – сентябре, октябре и ноябре. Осадки зачастую вызывают большие экономические убытки, гибнут или страдают люди. Влияние обильных осадков усиливают крутые горные склоны. В горных местностях станций наблюдения за количеством осадков немного и расположены они далеко друг от друга, поэтому необходимы карты, на которых было бы точно указано распределение обильных осадков. Характер осадков в горных местностях в зависимости от удаленности может значительно различаться, предвидеть количество осадков чрезвычайно сложно, однако это жизненно необходимо. Зная местности, на которых ожидается большее количество осадков, можно точнее планировать землеустройство, избежать внезапных наводнений, оползней и эрозии почв. Целью исследования было проверить несколько хорошо известных методов интерполяции – Inverse Distance Weight (IDW) с 1–5 значениями весомостей, Local Polynomial (LP), Radial Basis (RBS), особенно Spline With Tension (SPT), Thin Plate Spline (TPS), а также технику Kriging, методы Ordinary Kriging (OK) и Ordinary CoKriging (COK) с целью выявить наиболее точный, с помощью которого можно было бы интерполировать обильные (95%) осенние осадки в горных местностях Португалии. Установлено, что количество осадков увеличивается с увеличением амплитуды. Значительная разница в количестве осадков выявлена на станциях, находящихся на разной высоте от уровня моря. Это соотношение замечено на всех направлениях рассчитанных полувариограмм. На них выделяются две территории, на которых значения P95 наиболее велики и очевидна связь с большими амплитудами. Первая территория находится на высоте 12,19 км, вторая – 23,57 км. Наибольшие значения P95 отмечены в юго-восточном и северо-восточном, наименьшие – северо-западном направлениях, где амплитуды малы, и в углу северо-восточной территории из-за эффекта «тени» дождя. Точнее предвидеть характер осадков в горных местностях представляется затруднительным из-за недостатка данных и сложного влияния на осадки топографии. Результаты исследования окажутся особенно полезными при планировании и управлении территориями, подвергаемыми частым и обильным осадкам.

Abstract: 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.

Abstract: The investigation is focused on the uptake of heavy metals and macronutrients fluxes in Pinus sylvestris L. wood and soil under the sampled trees from contaminated and control sites. Soil pH, total organic carbon (TOC) and total and bioavailable heavy metals lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) and macronutrients, potassium (K) and magnesium (Mg) were compared on contaminated and control sites. Also, metal uptake of contaminated and control pine woods was determined. Concentrations of soil bioavailable Cd (0.009 mg kg−1), Pb (0.11 mg kg−1), Cu (0.076 mg kg−1), Zn (0.51 mg kg−1) and K (24.42 mg kg−1), Mg (8.44 mg kg−1) on the contaminated plot were significantly higher (p & lt; 0.001) than on the control plot 0.00004 mg kg−1for Cd, 0.007 mg kg−1 for Pb, 0.002 mg kg−1 for Cu, 0.22 mg kg−1 for Zn and 7.81 mg kg−1 for K, 2.40 mg kg−1for Mg. In addition, the percentage of bioavailable metals in contaminated soils was higher. Pb (34.49 mg kg−1), Cu (0.258 mg kg−1), Zn (1.36 mg kg−1) and K, Mg concentrations in wood were statistically higher than on the control site Pb (0.01 mg kg−1), Cu (0.172 mg kg−1), Zn (0.93 mg kg−1), at p & lt; 0.05 and p & lt; 0.001, respectively. Cd did not show any significant difference in concentration on the contaminated plot in comparison to the control site. Santrauka Pagrindinis tiriamojo darbo tikslas – nustatyti sunkiųjų metalų kiekį paprastosios pušies (Pinus sylvestris L.), augusios šalia buvusios Ekrano gamyklos Panevėžyje, medienoje bei palyginti su augusios kontrolinėje teritorijoje. Įvertinta ir palyginta abiejų teritorijų dirvožemis, nustatyta dirvožemio pH, bendrosios anglies kiekis (TOC), įvertintos suminė ir judriosios fazės sunkiųjų metalų – švino (Pb), kadmio (Cd), vario (Cu), cinko (Zn) bei makroelementų – kalio (K) ir magnio(Mg) koncentracijos. Nustatyta į pušų medieną užterštoje ir kontrolinėje teritorijose patekusių metalų kiekiai. Akivaizdu, kad judriosios fazės metalų koncentracijos užterštoje teritorijoje (Cd – 0,009 mg·kg–1, Pb – 0,11 mg·kg–1, Cu – 0,076 mg·kg–1, Zn – 0,51 mg·kg–1 ir K – 24,42 mg·kg–1, Mg – 8,44 mg·kg–1) yra didesnės (p & lt; 0,001) nei kontrolinėje(Cd – 0,000 04 mg·kg–1, Pb – 0,007 mg·kg–1, Cu – 0,000 2 mg·kg–1, Zn – 0,22 mg·kg–1 ir K – 7,81 mg·kg–1, Mg – 2,40 mg·kg–1). Pb (34,5 mg·kg–1), Cu (0,258 mg·kg–1), Zn (1,36 mg·kg–1) ir K bei Mg koncentracijos buvo statistiškaididesnės užterštoje teritorijoje (p & lt; 0,05) augusios pušies medienoje nei kontrolinės (p & lt; 0,001) – Pb – 0,01 mg kg–1, Cu – 0,172 mg·kg–1, Zn – 0,93 mg kg–1. Cd koncentracija užterštoje teritorijoje augusios pušies medienoje nedaug skyrėsi nuo kontrolinės. Резюме Главной целью научноисследовательской работы было определить количество тяжелых металлов в древесинесосны обыкновенной (Pinus sylvestris L.) на территории бывшего завода «Экранас» в Паневежисе и сравнить его сданными контрольной территории. В исследовательской работе оценены и сравнены почвы обеих территорий,определен показатель рН почвы, общее количество углерода (ОКУ), оценены общие и растворимые концентрации тяжелых металлов свинца (Pb), кадмия (Cd), меди (Cu), цинка (Zn), концентрации макроэлементов калия (K) имагния (Mg). Также оценено попадание металлов в древесину сосны в загрязненной и контрольной зонах. Замечена тенденция: концентрация растворимых металлов Cd (0,009 мг·кг–1), Pb (0,11 мг·кг–1), Cu (0,076 мг·кг–1), Zn (0,51 мг·кг–1) и K (24,42 мг·кг–1), Mg (8,44 мг·кг–1) в загрязненной зоне выше (p & lt; 0.001), чем в контрольной, соответственно Cd (0,00004 мг·кг–1), Pb (0,007 мг·кг–1), Cu (0,002 мг·кг–1), Zn (0,22 мг·кг–1) ir K (7,81 мг·кг–1), Mg (2,40 мг·кг–1). Концентрации Pb (34,49 мг·кг–1), Cu (0,258 мг·кг–1), Zn (1,36 мг·кг–1), K и Mg в древесине были статистически выше на загрязненной территории (p & lt; 0,05), чем на контрольной (p & lt; 0,001) – Pb (0,01 мг·кг–1), Cu (0,172 мг·кг–1), Zn (0,93 мг·кг–1). Концентрация Cd на загрязненной территории существенно не отличалась отконцентрации на контрольной территории.

Abstract: The present study evaluated short-time effect of steam modified biochar with rhamnolipid solution on the removal of different volatile organic and inorganic compounds (acetone, xylene, ammonia) in biofilter with capillary system. Modification of pine wood biochar with steam governed better treatment of pollar acetone and ammonia compounds from the air stream with removal efficiencies of 93% and 96%, respectively. It was related to biochar’s higher average capillary radius, moisture content and lower air velocity. However, removal of xylene was much lower and reached 72% in the case of modified biochar. It can be explained by its higher Henry’s constant, hydrophobicity and non-polarity.

Abstract: The size of sprayed droplets is a very important parameter that influences the operational efficiency of air-cleaning device charges. It is desirable for atomizers to spray droplets that are dispersed as much as technically and economically reasonable and possible. Fine dispersion spraying ensures effective moistening of the air-cleaning device charges, as well as an optimal consumption of water or other liquids. Three modifications of special atomizers were used for experimental analysis. The atomization of liquid and spraying in the special atomizer occurs when two frontal streams confront each other. Frontal streams are formed by an inner shield located in the special atomizer. The experiment was conducted using different spraying pressures, namely: 6 bar, 4 bar, 2 bar. The evaluation (performed using a microscope) of the size of sprayed droplets shows that the best (finest) spraying was by the special atomizer of modification 3. The depth of the channel of the inner shield is the parameter that has the biggest influence on the size of sprayed droplets. The special atomizer of modification 3 produces droplets with the following size distribution and rates: ≤0.05 mm—63.2 vol%; 0.2–0.6 mm—28.3 vol%; 0.6–1.0 mm—8.1 vol%; ≥1.0 mm—0.4 vol%.