Réka Dobozi, Zoltán Péter Jákói, Sándor Beszédes
et al.
In whey valorization, membrane separation stands out as a highly effective technique for purifying and isolating the various components of whey. The efficiency of whey ultrafiltration and diafiltration (UF/DF) largely depends on the balance between membrane selectivity, hydrodynamic conditions, and solute interactions at the membrane interface. In this study, sweet whey was fractioned using 10, 30 and 50 kDa polyether sulfone (PES) membranes under identical transmembrane pressure (TMP = 2.5 bar) with ultrafiltration and a subsequent 4-step constant volume diafiltration stages. The resulting compositional and dielectric changes were evaluated to identify optimal separation conditions and assess the applicability of dielectric parameter measurement as a rapid, non-destructive monitoring technique. Results showed that, regardless of the applied molecular weight cut-off (MWCO), using three DF cycles can wash out almost all the removable lactose from the retentates, and the dielectric assessment of both permeate and retentate fractions showed a strong, linear relationship between the change in dielectric behavior and the composition of each fraction. Analysis of the dielectric spectra confirmed that the ratio of the dielectric constant to the loss factor (<i>ε</i>′/<i>ε</i>″) exhibited a strong linear correlation (R<sup>2</sup> > 0.98, r > 0.99) with lactose concentration in the permeate fractions of all three MWCO membranes, as well as a similarly strong correlation (R<sup>2</sup> > 0.975, r > 0.98) with the total chemical oxygen demand (TCOD) measured in the retentate fractions.
Environmental technology. Sanitary engineering, Chemical technology
Recently, the potential of microalgae in wastewater treatment has attracted attention. The goal of this study is to find optimum conditions for microalgae growth and the concentration of cheese whey wastewater (CWW) to get the best treatment efficiency by using response surface methodology (RSM) and the decision tree algorithm for different pollutant parameters. The study used reactors with different amounts of CWW and Nannochloropsis sp. to find the best concentrations for each parameter. The best concentration of CWW was found to be 8000 mgCOD/L, and the best concentration of Nannochloropsis sp. microalgae was found to be 2200 mgVS/L. It was found that Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Total Kjeldahl Nitrogen (TKN), and Orthophosphorus (Ortho-P) could be removed at different ranges, 77–96 %, 95–98 %, 51–97 %, and 60–99 % of CWW, respectively, depending on the different combinations of microalgae and CWW concentrations. The desirability values in RSM for COD, TOC, TKN, and Ortho-P parameters to be 0.99, 0.94, 0.78, and 0.63, respectively. The study suggests the marine microalgae (Nannochloropsis sp.) could be an alternative way to treat saline CWW, to create a circular economy. The machine learning (ML) method validates that RSM predictions are consistent and accurate. The results show that it is possible to combine traditional optimization methods with more advanced ML methods to facilitate the design and the operation of the treatment plants.
Background: Phthalates are widely used plasticizers, which were identified as risk factors in the development of many human diseases. However, the effects of phthalates in the periodontitis are unknown. We aimed to investigated the relationship of periodontitis and phthalate exposure as well as the underlying mechanisms. Materials and methods: Univariate and multivariate logistic regressions were employed to evaluate the association between phthalate metabolites and periodontitis. The generalized additive model and piecewise logistic regression were conducted to investigate the dose-response relationship. Cell and animal models were used to explore the role and mechanism of DEHP in the development of periodontitis. Transcriptome sequencing, bioinformatics analysis, western blot, immunofluorescence and mice model of periodontitis were also employed. Results: MEHP (OR 1.14, 95% CI 1.05–1.24), MCPP (OR 1.08, 95% CI 1.00–1.17), MEHHP (OR 1.18, 95% CI 1.08–1.29), MEOHP (OR 1.18, 95% CI 1.07–1.29), MiBP (OR 1.15, 95% CI 1.04–1.28), and MECPP (OR 1.20, 95% CI 1.09–1.32) were independent risk factors. And MEHHP, the metabolite of DEHP, showed the relative most important effects on periodontitis with the highest weight (0.34) among all risk factors assessed. And the increase of inflammation and the activation of NFκB pathway in the periodontitis model mice and cells were observed. Conclusion: Exposure to multiple phthalates was positively associated with periodontitis in US adults between 30 and 80 years old. And DEHP aggravated inflammation in periodontitis by activating NFκB pathway.
Anne Bartlett, Jennifer Alix-García, Alejandro Abarca
et al.
Production bans are a common way for governments to address issues of social concern. However, when consumer demand for banned items is insensitive to price changes, cross-border trade may undermine these efforts. We examine the effects of Kenya’s 2018 moratorium on the extraction of wood products, including logs and charcoal, from public and community forests. The data show an immediate 36% increase in the domestic charcoal price in Kenya, where over 80% of consumers use it as their primary energy source. Subsequently, we document an increase of 133% percent in charcoal imports from Uganda to Kenya during the first 6 months of the ban. Further, we estimate that avoided deforestation in Kenya was likely displaced to Uganda such that net carbon emissions increased. These findings demonstrate the ineffectiveness of the ban as a mechanism to decrease greenhouse gas emissions and biodiversity loss from deforestation.
<p>SWAT (Soil and Water Assessment Tool) is a continuous-time, semi-distributed, river basin model widely used to evaluate the effects of alternative management decisions on water resources. This study examines the application of the SWAT model for streamflow simulation in an experimental basin with mixed-land-use characteristics (i.e., urban/peri-urban) using daily and hourly rainfall observations. The main objective of the present study was to investigate the influence of rainfall resolution on model performance to analyze the mechanisms governing surface runoff at the catchment scale. The model was calibrated for 2018 and validated for 2019 using the Sequential Uncertainty Fitting (SUFI-2) algorithm in the SWAT-CUP program. Daily surface runoff was estimated using the Curve Number method, and hourly surface runoff was estimated using the Green–Ampt and Mein–Larson method. A sensitivity analysis conducted in this study showed that the parameters related to groundwater flow were more sensitive for daily time intervals, and channel-routing parameters were more influential for hourly time intervals. Model performance statistics and graphical techniques indicated that the daily model performed better than the subdaily model (daily model, with NSE <span class="inline-formula">=</span> 0.86, <span class="inline-formula"><i>R</i><sup>2</sup></span> <span class="inline-formula">=</span> 0.87, and PBIAS <span class="inline-formula">=</span> 4.2 %; subdaily model with NSE <span class="inline-formula">=</span> 0.6, <span class="inline-formula"><i>R</i><sup>2</sup></span> <span class="inline-formula">=</span> 0.63, and PBIAS <span class="inline-formula">=</span> 11.7 %). The Curve Number method produced higher discharge peaks than the Green–Ampt and Mein–Larson method and better estimated the observed values. Overall, the general agreement between observations and simulations in both models suggests that the SWAT model appears to be a reliable tool to predict discharge in a mixed-land-use basin with high complexity and spatial distribution of input data.</p>
Water quality has become a significant concern in many river basins in China due to both point and non-point source pollution. The SWAT model assessed pollution reduction scenarios and their effects on Donghe River basin water quality in southwest China. The calibrated model evaluated existing point and non-point emissions. Three schemes reduced point sources by 30, 60, and 90% and non-point sources by 25, 50, and 75%, respectively. Simulations analyzed annual and monthly total phosphorus (TP) concentrations under the scenarios. Results showed that the scenarios effectively improved water quality, meeting Class IV TP standards annually. However, TP exceeded standards in dry months (January–April, December) under all scenarios. A certain degree of negative correlation (R = −0.52, P = 0.11) between TP and rainfall suggests rainfall that influences TP. Comprehensive measures are needed to achieve standards year-round. In summary, the study found that reducing emissions improved Donghe water quality overall but more work is required to meet standards during dry periods. Rainfall correlates with and may affect TP. The work emphasizes implementing comprehensive approaches for year-round water quality improvements in the basin.
HIGHLIGHTS
An appropriate SWAT model was established for the Donghe River Basin.;
Non-point source pollution in the Donghe River Basin accounts for more than half of the total phosphorus emissions.;
Rainfall is a critically important factor influencing the variation in total phosphorus concentration in the Donghe River Basin.;
The months of January to April and December each year constitute the most critical period for total phosphorus pollution in the Donghe River Basin.;
Zeinab Avarseji, Fakhtak Talie, Ebrahim GholamaAlipour Alamdari
et al.
Pendimethalin is a persistent herbicide. It is the third most widely used selective herbicide applied in soil that negatively affects humans and the environment. The current experiment assessed the ability of three bacterial species to degrade this herbicide. Pendimethalin was added to flasks in a 125 mg/L concentration and 107 CFU.mL-1 of Bacillus subtilis, Pseudomonas fluorescens, and Escherichia coli were added separately to the mineral salts medium media (MSM) and stored on a rotary shaker. The bacterial cell number, wet biomass, and chemical oxygen demand (COD) were determined after seven days. The concentration of pendimethalin residue was then determined using high-performance liquid chromatography (HPLC). A completely randomized design (CRD) with three replicates was used to arrange the experimental units, except for HPLC with only one replicate. The experimental results showed that all three bacterial growths rose after seven days post-inoculation in the pendimethalin modified media. A comparison of the growth kinetics of bacteria in the herbicide modified media and the control showed that the bacteria grew faster in the presence of the herbicide. The reduction in the COD parameter occurred in all the tested bacteria, but the highest COD removal efficiency (85%) was observed with B. subtilis. The highest biological degradation of pendimethalin compared to the control occurred in the B. subtilis inoculated media (78%), which also produce the most cell density. Based on the HPLC results, all three bacterial species were capable of biodegrading pendimethalin herbicide, with B. subtilis as the most effective bacterium, followed by E. coli and P. fluorescens.
Funmilola Oyebanji, Godson Ana, Opeyemi Tope-Ajayi
et al.
The focus of this study was to portray the spatial pattern of air quality across seasons in the eight sampled farm settlements using air quality indexes and assess the clusters of monitored air pollutants. The concentrations of air pollutants were determined using in-situ portable gas detectors and particulate counter. The AQI for each criteria pollutants (CO, O3, TSP, PM10, SO2, and PM2.5) was calculated using AQI formulae of the United States Environmental Protection Agency and mapped using the Inverse distance weighting (IDW) interpolation method in the Geographic information systems (GIS) environment. Principal component analysis (PCA) was used to group the parameters and estimate the interrelationships between the loadings of the parameters in each component. The AQI ranges of pollutants which deviated from the acceptable good status are CO (71.98 – 238 and 88.85 – 220.93), NO2 (10.14 – 107.07 and 10.84 – 72.88) and PM2.5 (12.90 – 70.85 and 12.56 – 54.02) for the dry and wet seasons, respectively. There were five and four PCs with eigenvalues > 1, accounting for 69.75% and 61.73% of the total variance during the wet and dry season, respectively. The parameters in each component are as follows; PC1 - TSP, PM10, PM2.5, Bacteria and fungi; PC2 - CO and Temperature; PC3 - relative humidity and O3; PC4 - CO2; PC5 - NO2 and SO2 for the wet season and PC1 - TSP, PM10, PM2.5, Bacteria and fungi; PC2 - NH3 and NO2; PC3 - CO2 and O3; PC4 - Temperature and relative humidity during the dry season. Biomass burning, engine exhausts and fine-particulate related activities are sources of air pollution and such may pose negative implication to human health and environment. Therefore, the use of alternative biomass disposal, regular servicing of processing engines and the wearing of protective wears against dust are recommended.
Andreas Bauwe, Petra Kahle, Bärbel Tiemeyer
et al.
In this study, 14 years of climate, stream flow, land management, nitrate-nitrogen (NO _3 ^– N) load and concentration data were analyzed to identify potential drivers for NO _3 ^– N losses at two tile-drained catchments under cropland use in northeastern Germany. Mean (±standard deviation) annual NO _3 ^– N concentrations were 9.7 ± 2.9 (drainage plot) and 6.8 ± 2.4 mg l ^−1 (ditch catchment), while mean annual NO _3 ^– N loads amounted to 22 ± 16 and 20 ± 16 kg ha ^−1 , respectively. Significant positive relationships between annual discharge and annual NO _3 ^– N losses underlined the importance of hydrologic conditions on NO _3 ^– N export mechanisms. No direct relationships were found between N soil surface surpluses and NO _3 ^– N losses. Any possible impact of N soil surface surpluses on NO _3 ^– N export rates was overridden by the hydro-meteorological conditions in the catchment. Positive correlations between the climatic water balance and NO _3 ^– N losses suggest that agricultural catchments with similar characteristics as ours may face—without countermeasures—increased N losses in the future as regional climate projections predict wetter winters in the coming decades. Our analysis has further shown that effects of land management strategies aiming at reducing N losses into surface waters might only become visible with a delay of years or even decades.
Liner merupakan komponen terpenting dalam fasilitas tempat pengolahan akhir (TPA) sampah untuk mencegah lindi mencemari tanah. Bahan yang sering digunakan sebagai liner adalah tanah lempung yang memiliki permeabilitas rendah. Salah satu tanah lempung alami yang dapat digunakan sebagai liner TPA adalah bentonit. Bentonit memiliki permeabilitas yang sangat rendah, namun stabilitas gesernya tidak begitu kuat sehingga berpotensi mengalami keruntuhan apabila digunakan di daerah lereng.Di sisi lain, limbah bangunan yang berupa pecahan batu bata, campuran pasir dan semen, serta beton memiliki kuat geser yang tinggi dan berpotensi sebagai campuran bentonit. Pada penelitian ini, limbah bangunan sebanyak 5%, 10%, dan 15% ditambahkan pada bentonit untuk meningkatkan kekuatan geser bentonit sehingga didapatkan campuran bahan semi kedap dengan stabilitas yang lebih tinggi dan permeabilitas rendah. Hasil uji stabilitas geser yang dilakukan pada tegangan normal 50 kPa , 100 kPa, dan 200 kPa menunjukkan bahwa semakin meningkatnya konsentrasi campuran bahan bangunan, maka semakin meningkat pula nilai tegangan geser yang dihasilkan
Urban material resource requirements are significant at the global level and these are expected to expand with future urban population growth. However, there are no global scale studies on the future material consumption of urban areas. This paper provides estimates of global urban domestic material consumption (DMC) in 2050 using three approaches based on: current gross statistics; a regression model; and a transition theoretic logistic model. All methods use UN urban population projections and assume a simple ‘business-as-usual’ scenario wherein historical aggregate trends in income and material flow continue into the future. A collation of data for 152 cities provided a year 2000 world average DMC/capita estimate, 12 tons/person/year (±22%), which we combined with UN population projections to produce a first-order estimation of urban DMC at 2050 of ~73 billion tons/year (±22%). Urban DMC/capita was found to be significantly correlated ( R ^2 > 0.9) to urban GDP/capita and area per person through a power law relation used to obtain a second estimate of 106 billion tons (±33%) in 2050. The inelastic exponent of the power law indicates a global tendency for relative decoupling of direct urban material consumption with increasing income. These estimates are global and influenced by the current proportion of developed-world cities in the global population of cities (and in our sample data). A third method employed a logistic model of transitions in urban DMC/capita with regional resolution. This method estimated global urban DMC to rise from approximately 40 billion tons/year in 2010 to ~90 billion tons/year in 2050 (modelled range: 66–111 billion tons/year). DMC/capita across different regions was estimated to converge from a range of 5–27 tons/person/year in the year 2000 to around 8–17 tons/person/year in 2050. The urban population does not increase proportionally during this period and thus the global average DMC/capita increases from ~12 to ~14 tons/person/year, challenging resource decoupling targets.
Assessing the factors that have an impact on potential evapotranspiration (PET)
sensitivity to changes in different climate variables is critical to
understanding the possible implications of climatic changes on the catchment
water balance. Using a global sensitivity analysis, this study assessed the
implications of baseline climate conditions on the sensitivity of PET to a
large range of plausible changes in temperature (<i>T</i>), relative humidity (RH), solar radiation (<i>R</i><sub>s</sub>) and wind speed (<i>u</i><sub><i>z</i></sub>). The analysis was conducted at 30 Australian locations representing different climatic zones, using the Penman–Monteith and Priestley–Taylor PET models. Results from both
models suggest that the baseline climate can have a substantial impact on
overall PET sensitivity. In particular, approximately 2-fold greater
changes in PET were observed in cool-climate energy-limited locations
compared to other locations in Australia, indicating the potential for
elevated water loss as a result of increasing actual evapotranspiration (AET)
in these locations. The two PET models consistently indicated
temperature to be the most important variable for PET, but showed large
differences in the relative importance of the remaining climate variables.
In particular for the Penman–Monteith model, wind and relative humidity were the second-most important variables for dry and humid catchments,
respectively, whereas for the Priestley–Taylor model solar radiation was the second-most important variable, with the greatest influence in warmer
catchments. This information can be useful to inform the selection of
suitable PET models to estimate future PET for different climate conditions,
providing evidence on both the structural plausibility and input uncertainty
for the alternative models.
Raw and modified bentonite has been used to develop effective sorbents to remove phosphate from aqueous solution. Acid thermoactivation, Rewoquate, Irasoft, calcium, Fe and Al were employed to treat the bentonite. Results show that samples adsorption capacity for phosphate is in the order of, unmodified bentonite = acid thermoactivation < Rewoquate < calcium ≅ Irasoft < Fe < Al ≅ Fe-Al. The phosphate adsorption with Fe-Al-bentonite (FAB) modification was more than 99% and the phosphate removal reached the peak value in the initial 30 min. The phosphate adsorption of FAB was pH independent in the range of 2–10. The common coexisting ions in wastewater have no effect on the phosphate adsorption. The phosphate adsorption results were very well fitted in the Freundlich and Langmuir isotherm model and the maximum adsorption capacity was 8.33 mg P/g at pH 6.5 for 1 hour, which was better than similar modified bentonite with low time and Fe-Al consumption. FAB was characterized by scanning electron microscopy, X-ray diffraction, X-ray fluorescence and Fourier transform infrared. Therefore, the results confirm that FAB is a selective phosphate sorbent and environmentally friendly for its potential application for phosphate removal from wastewater.
Internal
standing waves (seiches) in the South Aral Sea are studied for the first
time. The study, based on numerical simulations and field data, focuses on
two different campaigns: the first in autumn 2006, when the stratification
was weak and there was a mild prevailing northeasterly wind, and the second
in autumn 2013, when the stratification was strong and there was a mild
easterly wind. Between these two campaigns, the sea surface level decreased
by 3.2 m. The periods of the fundamental modes were identified as 36 and
14 h, respectively. In both years, either second or third vertical
modes were found. In general, the vertical modes in 2013 were higher because of the
broad and strong pycnocline. For both years, it was found that the deep
quasi-homogeneous mixed upper layer could sustain internal waves under
mild wind conditions. The observed first and second vertical modes in 2006
are the first and second horizontal modes and the second and third vertical modes
in 2013 are the second and third horizontal modes. The results suggest that, due
to sea level variations, the neck connecting the Chernyshev Bay to the main
body of the lake can become a critical location for the development of a
nodal line for all principal oscillation modes. Rotation effects on waves
were not analyzed in this study.
In this study, MCM-41 was prepared via hydrothermal method in presence of ethanol as a co-solvent and co-surfactant in alkaline media. Inorganic sorbent ZnCl2-MCM-41 was synthesized via covalent grafting method by dispersion of samples into pure toluene for solid state interaction between silanol groups of MCM-41 surface and ZnCl2 particles. Samples were characterized by nitrogen adsorption analysis, XRD, BET surface area, and FTIR spectrometry. MCM-41 BET surface area measured was 1099 m2/g, which was later reduced to 602 m2/g after incorporation of ZnCl2 particles onto MCM-41 surface. Effect of different experimental conditions such as solution temperature, pH, contact time, and initial concentration of Ni(II) ions were investigated on the amount of nickel adsorption. For experimental data, the Langmuir isotherm showed a better fit than Freundlich isotherm, which indicates that nickel adsorption onto inorganic sorbent was homogeneous and monolayer. At optimum conditions, maximum adsorption capacity of Ni(II) by sorbent obtained was 303 mg/g according to Langmuir isotherm. Pseudo-second order model predicted kinetic of nickel adsorption onto synthesized sorbent better than other models. Free energy was 9.8 kJ/mol determined by Dubinin-Radushkevich model, which confirms chemical nature of nickel adsorption onto synthesized sorbent.
Environmental sciences, Water supply for domestic and industrial purposes
W pracy przedstawiono wyniki badań wpływu zbrojenia rozproszonego na wytrzymałość na ściskanie popiołu lotnego pochodzącego z Elektrowni „Skawina” w Skawinie stabilizowanego 3% dodatkiem wapna hydratyzowanego lub cementu portlandzkiego. Jako zbrojenie zastosowano paski folii o wymiarach 5 × 10, 10 × 10, 20 × 10 oraz 20 × 20 mm oraz syntetyczne mikrowłókna Fibrofor High Grade. Uzyskane wyni-
ki pozwoliły stwierdzić, że wytrzymałość na ściskanie popiołu ze zbrojeniem włóknami Fibrofor High Grade była dwukrotnie większa niż w przypadku badań z paskami folii.
Wytrzymałość na ściskanie popiołu lotnego z dodatkiem cementu portlandzkiego była wyraźnie wyższa niż przy dodatku wapna hydratyzowanego
Fernando Paz-Pellat, Ma. Isabel Marín-Sosa, Mario Martínez-Menez
Modelar la relación precipitación-escurrimiento (P-Q) en parcelas o cuencas hidrográficas cobra especial importancia cuando se tienen fines de planeación y manejo de los recursos hídricos. En la actualidad existen diferentes modelos de tipo hidrológico que permiten aproximar esta relación; sin embargo, se dificulta su aplicación, dado que requieren datos de una gran cantidad de parámetros. Un esquema más simple y atractivo para este tipo de modelación es el método del número de curva (CN), que depende de un solo parámetro; sin embargo, se requiere conocer la dinámica de la cobertura de la vegetación, y la respuesta del suelo y su cobertura (residuos agrícolas, entre otros) para poder aplicarlo, ya que
estos factores influyen en la respuesta hidráulica del sistema. Un esquema similar (en simplicidad) al del CN es el modelo introducido por Paz (2009), este último considera que el patrón que aproxima la relación P-Q está compuesto por dos fases: una exponencial y una lineal. En el presente trabajo se revisó el modelo expo-lineal a partir de datos de precipitación y escurrimiento tomados durante un periodo de seis años (1996-2001) sobre lotes de escurrimiento con cultivo de maíz (diferentes sistemas de manejo del suelo). El modelo del CN se empleó, en este caso, como esquema de ordenación de los patrones hidrológicos presentados con los diferentes tratamientos. A partir de los patrones observados, se decidió utilizar sólo la fase lineal del modelo expo-lineal para aproximar la relación P-Q. Los resultados mostraron que los valores de Q estimados presentan alta correlación con los valores de Q medidos (R2 =0.99 en todos los sistemas de manejo), por lo que se concluye que el modelo puede utilizarse de manera confiable como un esquema simplificado de modelación de la relación P-Q. Los resultados empíricos obtenidos definen un camino de modelación simple, a partir de aproximar la estimación de los parámetros del modelo expo-lineal.
Hydraulic engineering, Water supply for domestic and industrial purposes
This paper analyses the morphological effects of extreme floods (recurrence interval >100 years) and examines which parameters best describe the width changes due to erosion based on 5 affected alpine gravel bed rivers in Austria. The research was based on vertical aerial photos of the rivers before and after extreme floods, hydrodynamic numerical models and cross sectional measurements supported by LiDAR data of the rivers. Average width ratios (width after/before the flood) were calculated and correlated with different hydraulic parameters (specific stream power, shear stress, flow area, specific discharge). Depending on the geomorphological boundary conditions of the different rivers, a mean width ratio between 1.12 (Lech River) and 3.45 (Trisanna River) was determined on the reach scale. The specific stream power (SSP) best predicted the mean width ratios of the rivers especially on the reach scale and sub reach scale. On the local scale more parameters have to be considered to define the "minimum morphological spatial demand of rivers", which is a crucial parameter for addressing and managing flood hazards and should be used in hazard zone plans and spatial planning.