Abstract: The usage of zeolites in wastewater treatment has been extended in the two recent decades. This review investigates recent developments on the zeolite usage in the removal of heavy metals from polluted solutions. Various databases were used to search, evaluate, combine and analyze. The number of specific publications based on keywords linked with zeolite usage used in searching engines was more than 1000. However, about 200 publications passed the criteria set. The synthesis methodology for the production of zeolitic adsorbents, the modification of natural zeolites and their effect on the removal of heavy metals are described. Furthermore, the capacity of adsorbents to remediate polluted solutions and identify optimum conditions are reported and compared. The maximum adsorption capacity among heavy metals was for Pb(II) for all types of zeolite adsorbents (27.70 mg/g for chloride-modified zeolite, 113 mg/g for Fe-modified zeolite, 653 mg/g for surfactant modified zeolite, 808 mg/g for synthesized zeolites and 909.09 mg/g for nanozeolite). Cr(IV), Cu(II), Ni(II), Zn(II) and Co(II) were other heavy metals having good adsorption capacities on synthesized zeolites. According to the literature review, the adsorption of heavy metals by synthesized and nanozeolites is the most efficient.

Abstract: Precise estimation and forecast of reference evapotranspiration (ET0) stand crucial for developing an efficient irrigation scheduling that helps better utilization of scanty water resources. One of the tools to predict ET0 is to employ machine learning algorithms that predict near future ET0 values based on past values from the ET0 timeseries. The aim of this research is to provide one-step ahead predictions of ET0 with different deep and machine learning methods using calculated past values of ET0. In this context, daily values of ET0 were computed via the FAO-56 Penman-Monteith approach that employ five climatic variables. For predicting one-step ahead ET0, this study evaluates the prediction accuracy and estimation capability of deep learning algorithms, i.e., a Long-Short Term Memory (LSTM) and a bi-directional LSTM (Bi-LSTM) network. The prediction performances of the LSTM and Bi-LSTM were compared with those of a Sequence-to-Sequence Regression LSTM network (SSR-LSTM) and an Adaptive Neuro Fuzzy Inference System (ANFIS). According to the findings, all four methods produced one-step ahead ET0 amounts in satisfactory precision and error levels with Correlation Coefficient, Index of Agreement, and a20-index ranging from 0.698 to 0.999, 0.833 to 0.999, and 0.624 to 1.0, respectively. Results further revealed the superiority of Bi-LSTM followed by SSR-LSTM, ANFIS and LSTM models identified by the ranking values computed using Shannon’s Entropy. The overall results indicate that the Bi-LSTM model could be successfully employed to predict one-step ahead ET0 values quite precisely.

Abstract: Hydro-agrological research considers the reference evapotranspiration (ETo), driven by meteorological variables, crucial for achieving precise irrigation in precision agriculture. ETo modelling based on a single meteorological parameter would be beneficial in places where the collection of climatic parameters is challenging. The aim of this research is to develop a deep neural network (DNN) architecture that predicts daily ETo with a single input parameter selected based on the feature importance (FI) score generated by the machine learning techniques, random forest (RF), and extreme gradient boosting (XGBoost). This study also investigated the potential of SHapley Additive exPlanations to interpret and validate the outcomes of the feature selection methods by assessing the contributions of each feature to the ETo prediction. These methods recommended solar radiation as a significant parameter in the datasets of three California Irrigation Management System (CIMIS) weather stations located in distinct ETo zones. Three ETo models (DNN-Ret, XGB-Ret, and RF-Ret) were built using solar radiation as the sole input, and CIMIS ETo as the output. The performance evaluation of the developed models proved that DNN-Ret outperformed XGB-Ret and RF-Ret regardless of the dataset, with coefficients of determination (R2) ranging from 0.914 to 0.954 in the local scenario, with an average decrease of 8–9.5% in mean absolute error and root mean squared error, and an improvement of 2.6–2.9% in Nash–Sutcliffe efficiency and 1.7–2% increase in R2. The overall result analysis highlighted the efficiency of DNN-Ret in the single input parameter based ETo modelling in diverse climatic zones.

Abstract: A reasonable assessment of the value of ecosystem services is an effective measure to maintain the normal operation of the ecosystem and adjust the balance between economic development and the ecological environment. With the help of the related concepts of ecosystem services, this paper establishes an evaluation framework system and adopts the widely used and comprehensive evaluation method of equivalent factors, which is a rapid accounting tool used for the evaluation of ecosystem services. The value of agricultural ecosystem services was estimated from 2008 to 2017 in a typical arid-semiarid region, and nine ecosystem service functions were analyzed. Our research showed that from 2008 to 2017 the value of agricultural ecological services in Gansu Province increased annually, and the annual growth rate in 2012 was the highest (15%). The results showed that the selection of appropriate methods could quickly and effectively evaluate the value of agricultural ecosystem services. In-depth research on the function and value of agroecological services could better promote the sustainable development of agroecosystems and maintain the balance and integrity of ecological service functions. Evaluation of the balance and integrity of agricultural ecosystem ecological service functions in arid semi-arid regions will provide recommendations for land use and sustainable development and ecological environment protection in these regions. • Agricultural ecosystem services have changed in an arid and semiarid region of China in recent decades. • We reflect the results of China's ecological progress. • This study provides advice on agricultural development of other developing countries.

Abstract: This paper aims to develop, in a case of multiple water sources, an optimal operational strategy that can be used in arid/semiarid regions by water decision-makers to schedule the use of each source over time, to control the artificial recharge to aquifers, to improve the energy efficiency related to the water supply system, to determine the optimal amount of water each source should supply over a period, and to minimise the water costs. In this regard, a novel, cost effective, and advanced optimal controller to operate a water supply system in arid/semiarid regions has been developed. This model is designed as a multi-constraint non-linear programming model that meets the demand for an ever-growing population, and considers in its formulation multiple surface water sources, aquifers, desalination plants, recycled water plants, the seasonal availability of surface water and groundwater, the monthly rainfall variability, and the seasonal energy price. To verify the effectiveness of the developed model, a real case study was conducted. The results obtained showed a 3% reduction in the water supply cost and sustainable improvement in groundwater management, demonstrating the model’s capacity to manage aquifer recharge efficiently, to optimally schedule the use of water sources. Adopting this strategy improves water security and the energy security in an urban region as it decreases the use of energy-intensive water sources during seasons with high electricity demand.

Abstract: The study examined the spatiotemporal variability of land use/land cover changes (LULC), land surface temperature (LST), and heat island (HI) in northwestern Bangladesh. Landsat images were used for evaluating LULC, LST, and HI for the years 1990, 2002, 2014, and 2018. Unsupervised and index-based classification approaches were used for mapping LULC. The mono-window algorithm was employed to identify the spatiotemporal variability of LST and HI. The analysis suggested that water bodies, forests, and bare land dwindled during these 28 years with an average of about 40%, 70%, and 45%, respectively. Agricultural land had been expanded from 1990 to 2002 and gradually stabilized in recent decades. Settlement areas increased alarmingly from 1990 to 2018. The water bodies, forests and bare lands were reduced due to the widening of agricultural land and rapid growth of urban area. The extents of the HI were found to be spreading out and became most extensive in 2018. LST had risen by around 5.5 °C from 1990 to 2018. The lower temperature zones prevailed in the water bodies, forests and agricultural lands whereas higher temperature zones were visible in the river sand bars and highly urbanized areas. The method used in this study is very successful in sparse built-up areas. The outputs of the study will be a great input in the city masterplan for landscape optimization and urban ecological balance in the study area and provide baseline information for future researches looking for inspecting the impacts of LULC change on a regional scale in plainland regions. Highlights • Spatiotemporal dynamics of LULC were evaluated in the northwest region of Bangladesh • Heat islands were delineated successfully indicating the rapid growth of urbanization • Enlargement of the urban area is the main cause for the increasing LST phenomenon • The rate of HI expansion validated by the changing thematic areas of LULC • Trends of urbanization and HI growth are alarming within the district town areas.

Abstract: Lake water quality issue related to algal blooms is a serious problem in basins with abundant agricultural lands, causing harmful effects to freshwater ecosystems and decreasing water quality for human uses. Remote sensing methods have been used to monitor water quality of large lakes and coastal areas; however, few studies have been conducted to understand spectral properties of small lakes. This research explores applicability of Sentinel-2 satellite in understanding spatiotemporal patterns of water quality of two small-sized reservoirs, Lake Bloomington and Evergreen Lake, Central Illinois. We tested the feasibility of Sentinel-2 satellite data for monitoring algal blooms by comparing and calibrating multiple satellite algorithms (e.g., Bottom-of-Atmosphere (BOA) reflectance, Maximum Chlorophyll Index (MCI), and band ratios) against lake water quality indicator variables (e.g., chlorophyll-a, turbidity, secchi depth) obtained from water sample analysis in the laboratory or field measurements. The regression models performed better for Evergreen Lake than Lake Bloomington. Comparison of chlorophyll-a and turbidity with satellite reflectance values showed that suspended sediments contribute to the turbidity in the case of Lake Bloomington, while the algae contribute to the turbidity in Evergreen Lake. Using regression models, water quality indicator maps were created, showing the spatial pattern of algae in the lakes, generally, showing heterogeneous chlorophyll-a distribution, lower in downstream and higher in upstream areas. The study confirmed suitability of Sentinel-2 data for monitoring water quality of less turbid small-sized lake.

Abstract: In this study, projection of droughts was performed using monthly precipitation and temperature data in the Balochistan and Sindh provinces of Pakistan. Rainfall is the main source of water in the study area. The Reconnaissance Drought Index was used to explore drought events from the selected sites of the regions. The index-flood procedure was used to perform the drought analysis in the study area. Two statistical methods were used to select Generalized Pareto distribution as the most acceptable distribution for drought risk assessment. The distribution was estimated through the L-moments approach for both regions. Three problems were addressed in this study. Regional analysis was performed for regional quantiles covering a large area and on-site analysis for each site’s drought projections. The Monte Carlo simulations procedure was utilized for reliability assessment of estimated quantiles that proved likeness at lower return periods and uncertainty at higher return periods. Lastly, quadratic regression was performed between drought means and site characteristics for drought quantiles at ungauged sites. According to the results, there are chances of more drought in the future if the recent climatic conditions continue in the study area. The study results will help stakeholders, government, and water resource managers in preparing plans about drought and water availability in the area.

Abstract: This study investigated seasonal variability of sources and fluorescence characteristics of dissolved organic matter (DOM) in the Ganges River using three-dimensional excitation-emission matrix (3DEEM) spectroscopy and parallel factor analysis (PARAFAC). 3DEEM and PARAFAC identified five fluorophores (Peak: A, C, M, T, W) and four fluorescent components, i.e., detergent, fulvic acid (M-type), fulvic acid (C-type), and protein-like, respectively, showing high fluorescence characteristics in the pre-monsoon (March-June) and monsoon (July-October) compared to the post-monsoon (November-February) period. Dissolved organic carbon (DOC) and Specific ultraviolet absorbance (SUVA254) were in the range 1.85-4.7 mg/L and 1.23-5.51 L/mg-m, respectively. DOM components were both fresh and microbial-derived throughout the year. Local hydrological and physicochemical conditions supported the autochthonous and aromatic DOM production in post-monsoon, and richness of terrestrial-derived natural and anthropogenic DOM in the pre-monsoon and monsoon periods. The molecular weight of DOM decreased from the mid of pre-monsoon and continued till monsoon with the increase of terrestrial-derived DOM and photo-irradiation as well as microbial activity. Tryptophan-like fluorescence (TLF) showed high intensity throughout the peak-flow pre-monsoon and monsoon periods, demonstrating a high to intermediate risk of microbial contamination of the Ganges River. The seasonal variability of DOM characteristics suggests that the source and biogeochemistry of DOM in the Ganges Rivers might be sensitive to local hydrology and climate. • DOC concentrations and DOM fluorescence intensity attained their highest values at the beginning of monsoon and showed high seasonal variability. • The compositions of DOM carried by the Ganges River varied at different times of the year, and fresh, autochthonous and less aromatic DOM dominated in the late pre-monsoon and monsoon. • PARAFAC model identified four fluorescent DOM components (detergent-, fulvic- (M like), fulvic- (C like) and protein-like) which showed high seasonal variability with rainfall and river discharge.

Abstract: Recently, a great attention has been given on applying low-cost and effective adsorbents as a promising approach to treat wastewater The main goal of this work was to investigate the performance and mechanisms of mercapto-functionalized magnetic graphene quantum dot (Fe2O3-GQDs-SH, FGM) for Cd2+ adsorption from wastewater The obtained adsorbent was characterized by using energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and vibrating sample magnetometry (VSM) techniques The Cd2+ adsorption data of the adsorbent were fitted to the Langmuir isotherm model At the optimum conditions, ie, an incubation time of 30 min, a pH of 7, and an adsorbent dosage of 002 g, a maximum Cd2+ adsorption capacity of 12821 mg g− 1 was obtained In addition, after five consecutive sorption–regeneration cycles, the FGM still exhibited 9101 % of the original Cd2+ sorption capacity when 01 mol L− 1 HNO3 was used as the desorbing agent These results clearly indicate that the FGM is a high-stability adsorbent with promising applications as an effective adsorbent for removing toxic metal ions from wastewater

Abstract: Drastic measures such as lockdown imposed in the countries worldwide to control the extent of COVID-19 have influenced environmental parameters substantially. The aim of the present study was to investigate the impact of lockdown on the air quality in Hyderabad city by comparing the pollutants concentration during lockdown and pre-lockdown periods. A comparative study was also made on the pollutant concentrations observed during the pre-lockdown (1st February – 23rd March 2020) and lockdown period (24th March - 30th April 2020) to those of the pollutants in the previous years (2018 and 2019). The Pearson correlation coefficient was employed to correlate the ozone (O3) concentration with other pollutants. Carbon monoxide (CO), nitrogen oxides (NOX) and O3 were monitored along with meteorological parameters like temperature, relative humidity and solar radiation. It was observed that the O3 concentration increased from 26 ppb (by volume) to 56.4 ppb during pre-lockdown and lockdown period, respectively, due to the decrease in CO and NOX concentration. The concentration of NO2, NO and CO were also reduced during the lockdown period by 33.7%, 53.8% and 27.25%, respectively. To identify the statistical significance of the parameters, analysis of variance (ANOVA) was used. The present study provides new insights on the ambient air pollution in terms of the aforesaid parameters and could pave the way for regulatory authorities to implement control measures to curb the air pollution. Highlights • COVID-19 lockdown improved the air quality by the reduction in air pollutants leading to increased ozone concentration. • Pearson model was used to correlate the ozone (O3) with oxides of nitrogen (NOX), CO and other meteorological parameters. • NOX and carbon monoxide (CO) concentrations were reduced by 33.7 % and 27.25 %, respectively, due to COVID lockdown.

Abstract: This paper studies the shoreline alterations occurring along the Al Batinah region in the Sultanate of Oman and the impacts of Cyclone Kyarr on its shoreline. The methods used in this research employed Sentinel images and the Digital Shoreline Analysis System within the GIS environment to measure changes of the shoreline and explore Kyarr’s impacts from 2017 to 2020. The results showed that from 2017 to 2020, the Al Batinah coast experienced erosion at a rate of 9 m/year. In addition, the Shoreline Change Envelop showed that the maximum shoreline change was reported from 2018 to 2019, with a 1145 m advancement that coincided with Kyarr in 2019. Further, data from the period between 2017 and 2018 showed that 73 % of the coastline was dominated by soil deposition at an average rate of 10 m/year, while the period between 2018 and 2019 showed erosion at an average rate of -40 m/year. The results of this study will be of interest to decision-makers involved in monitoring shoreline changes and would also be of immence importance in ensuring sustainable coastal zone management and development, especially in areas prone to extreme events such as tropical cyclones.

Abstract: An evaluation of the Sacramento Soil Moisture Accounting (SAC-SMA) model was conducted to be used in flood event simulations with datasets at a time step up to one hour. The SAC-SMA model is a complex conceptual model which integrates two soil zones, the upper and lower zone, in order to provide current soil moisture conditions and generated streamflow. However, in flood events, where time intervals are small, the generated flood hydrograph is usually the product of only the upper soil layer runoff generation mechanism while the lower zone and baseflow have little impact. In this context, a modified version of the original SAC-SMA model was introduced, where only the upper zone processes are kept in order to reduce the parameter count and the overall model uncertainty involved, and a comparison was made against the original model output. The two models were calibrated and validated for a series of flood events occurred at the Karitaina basin of the Alfeios river, located in southern Greece. The results show that both model versions were able to reproduce the observed runoff with success. The simplified model showed high consistency with the original model in all cases, which is an obvious improvement to the original model, since it provided results of equal quality, while lowering significantly the total parameter count and the computing time. This contributes against the overall model generated uncertainty which is crucial for real-time data processing applications and flood forecasting systems. • Presentation of the SAC-SMA model concept, variables, parameters and flowchart. • Introduction of a modified – simplified version of the original SAC-SMA model to be used for event-based rainfall runoff applications. • Calibration and validation of the SAC-SMA using fine temporal scale datasets in a mountainous basin in Greece.

Abstract: This study aims to determine the differences in hydrochemistry, the factors influencing these differences, and their relationship with karst aquifer development in Jonggrangan Karst, Java Island, Indonesia. The discharges were measured in three springs and the slow-flow percentage was separated. Furthermore, Principal Component Analysis (PCA) was conducted to determine the factors affecting hydrochemical conditions, while the karst aquifer development level was analyzed using the Master Recession Curve (MRC) method. The three springs showed variations in hydrochemistry due to different discharge fluctuations controlled by the karst aquifer nature in releasing its groundwater storage. Anjani Spring showed most fluctuations, while Kiskendo and Mudal Springs were relatively stable. The results also revealed that the hydrochemical conditions were influenced by the same main principal factors. When slow-flow is dominant during the dry season, carbonate mineral dissolution-precipitation is the primary process, whereas when quick-flow is dominant during flood events, dilution by precipitation causes carbonate mineral dissolution. Meanwhile, mixing with rainwater, water infiltration from the unsaturated zone, and interaction with clastic rock were secondary principal factors. Based on MRC analysis, the Anjani Spring had the most developed aquifer with a value of 8, while the Kiskendo and Mudal Springs had a value of 5.5. The higher value of karst aquifer development at the Anjani Springs led to the development of more diverse and large voids (conduits), which allowed water to be transported with more variable velocity and residence time. Therefore, the hydrochemical conditions of this spring fluctuated the most compared to the other springs.

Abstract: The aim of this study is two-fold. First, an extension of the original GasifEq model developed in our laboratory takes place. The new model, called as modified GasifEq, deals with the thermodynamic analysis of the gasification process and is able to predict the concentrations of the main gaseous products of the process, e.g., carbon monoxide, hydrogen, methane, water, carbon dioxide and nitrogen, as well as the concentrations of some minor components present in the final gas produced such as hydrochloric acid, hydrogen sulfide and chlorine. The results of the modified GasifEq, are compared against experimental data taken from the literature showing very good agreement. Second, the modified GasifEq is applied in a case study, concerning a plasma gasification plant in Greece that treats 750 tonnes per day (TPD) of municipal solid waste (MSW). Sensitivity analysis of the operational parameters of the plasma gasification process is performed, aiming to maximize the net energy produced and minimize the costs of the plant. For the calculation of the capital, operational and maintenance costs of the process, correlations from the literature as well as market data, when available, were used. It is shown that the cost of the plasma gasification process is comparable to that of the widely used incineration process.

Abstract: The particulate collection potential of tree species in a control and five experimental sites of an urban area in India were studied. Tree species selection was based on their commonness to all the sites, proximity to each location and their abundance in Indian subcontinent. A total of 45 leaf samples for all species in each site were analysed following standard protocols in three seasons (monsoon, post-monsoon and pre-monsoon) during 2015–2016. Out of the twenty one selected trees, eight were deciduous and thirteen evergreen. Particulate collection potential of deciduous trees was 22.6% more than that of evergreen trees. The leaf area showed direct relations, whereas petiole length and internodal distance showed antagonistic relations with particulate accumulation. The average particulate deposit on the leaves of trees of experimental sites (0.500 mg/cm2) was significantly more than that of the control site (0.358 mg/cm2). 80.95% of the species showed higher accumulation in the experimental sites against 19.04% of species in the control site. Distinct seasonality (p < 0.05) was noticed in respect of both parameters. Among the trees, Butea monosperma (1.156 mg/cm2), Tectona grandis (0.995 mg/cm2) and Diospyros melanoxylon (0.766 mg/cm2) had a high particulate deposit capacity with capturing efficiency of 48.44, 41.71 and 32.09%, respectively. On the basis of the study, it is advocated that tree species like B. monosperma, T. grandis and D. melanoxylon should be given top priority to function as barriers of particulate matter.

Abstract: The present study is an attempt to implement several spatial interpolation methods for the distribution of groundwater level in a wider area with multiple aquifers having variable hydraulic characteristics. Moreover, the goal of this study is to compare the results of these methods and check their accuracy and reliability, considering mainly the physical meaning of the outcome. Finally, we try to figure out which of these methods manage to identify hydrogeological features like groundwater divides, hydraulic conductivity barriers and no flow boundaries, and to highlight the hydraulic relationship between aquifers. Exploratory Spatial Data Analysis proved to be a necessary step prior to the implementation of spatial interpolation methods, since normalization of datasets, removal of general trends and data declustering was necessary for the proper implementation of geostatistical methods and reduction of the uncertainty of the results. Inverse Distance Weight, Radial basis functions, simple Kriging and Cokriging methods were implemented. None of the implemented methods produced results that were totally unreliable or erroneous and each method added pieces of information that were useful for the deeper understanding of the hydrogeological processes in the study area. The most appropriate spatial interpolation method for generating a groundwater level distribution surface, in an area with multiple aquifers and significant heterogeneity in hydraulic properties proved to be the Ordinary Cokriging method with altitude as a second parameter, which was highly correlated to groundwater level values in the study area. Cokriging method succeeds to accurately represent both the local variations within the individual aquifers and also to highlight the hydraulic relationships between them. Highlights • All spatial interpolation methods produced realistic surfaces. • Geostatistical methods produced smoother surfaces and lower hydraulic gradients. • Applying block declustering to sample data significantly reduces prediction uncertainty. • The most appropriate method for groundwater level distribution is Ordinary Cokriging.

Abstract: The effectiveness of the process of ultrasonication (US), electrocoagulation (EC) and hybrid sono-electrocoagulation (US+EC) on landfill leachate wastewater treatment was evaluated based on the removal efficiency of % color and % Chemical Oxygen Demand (COD) along with power consumption The experimental results showed that the hybrid US+EC had a high color (100%) and COD (94%) removal efficiency with a lower power consumption of 450 kWh/m3 compared to the individual EC and US processes In this hybrid US+EC process, the effects of various operating parameters were investigated and optimized using Design-Expert (12) based on the central composite design approach The optimization results indicated a maximum COD removal efficiency of 7105% with a minimum power consumption of 233 kWh/m3 at the following optimal experimental conditions: electrolyte concentration (X1) = 076 g/L, current density (X2) = 275 A/dm2, COD concentration (X3) = 391950 mg/L, sonication power (X4) = 100 W and treatment time (X5) = 3605 min The synergistic effect was calculated using the US, EC and US+EC process based on the % COD removal efficiency and has a positive effect of 2051% The % COD and % color removal efficiency were analyzed using a closed reflux method and UV-VIS spectrophotometer Thus, the hybrid US+EC process, significantly enhances the efficiency of pollutants removal from landfill leachate wastewater

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are a type of persistent toxic organic pollutants with potential carcinogenicity and mutagenicity, therefore, dangerous for the safety of human and animal health. The present study investigated the biodegradation of phenanthrene (PHE) and pyrene (PYR) in in-vitro and in-vivo conditions, by the white rot fungus Podoscypha elegans strain FTG4, isolated from an old rotten wood log through the lignin enrichment method. The ligninolytic enzyme production was periodically checked during PHE and PYR degradation under the influence of different physical parameters viz. pH, temperature, and salinity. PHE and PYR degradation by P. elegans were estimated by HPLC and produced degradation metabolites were identified by GC-MS. Structural changes in PHE and PYR during its degradation were observed by FTIR. The assessment of PHE and PYR removal in in-vivo condition was analyzed in the soil system and phytotoxicity evaluation of degradation metabolites was tested on Vigna radiata by the seed germination method. It was found that in in-vitro condition, P. elegans strain FTG4 removed about 99% of PHE and 98.9% of PYR from the degradation medium (20 mg/L concentration individually), although in the in-vivo condition, it reached up to 50.6% of PHE and 48% of PYR (50 mg/kg concentration individually). The metabolites produced during the degradation were the result of oxidation, dehydrogenation, and ring cleavage reactions, confirming the ligninolytic enzyme activity of P. elegans. Phytotoxicity results indicated that P. elegans strain FTG4 mediated PHE and PYR degradation enhanced the germination index, which ultimately reduced the phytotoxicity. Highlights • We report on the biodegradation of PAHs by ligninolytic fungus Podoscypha elegans • In-vitro P. elegans removed 99% of PHE and 98.9% of PYR from degradation medium • In-vivo P. elegans shows promising results for PHE and PYR degradation • PHE and PYR were degraded by oxidation, dehydrogenation, and ring cleavage reactions • P. elegans mediated PHE and PYR degradation shows reduction in phytotoxicity. Graphical abstract

Abstract: Recalcitrant wastewaters are hardly biodegradable. Therefore, these wastewaters must be treated prior to their disposal into water bodies. Advanced oxidation processes (AOP) represent promising alternative treatments since they are capable of improving their biodegradability. However, AOP treatments may be expensive and demand high energy consumption, especially when a complete mineralization of organic pollutants is expected. For this reason, AOP are often associated with other treatment methods. The microalgae-based wastewater treatment is a remarkable environmentally friendly technology since, in addition to the wastewater remediation, it can provide microalgae biomass to be used as feedstock for biofuel production. This review summarizes the current knowledge regarding the use of combined AOP and microalgae treatment aiming at both wastewater remediation and algal biomass production. Additionally, an integrated flowsheet of remediation of recalcitrant wastewater (using AOP and microalgae) and exploitation of microalgal biomass is proposed as an additional contribution of this paper. Scientific publications from 2009 to 2019 available in the Web of Science databases were reviewed. 1255 papers were selected, 328 papers were reviewed after screening, and 76 were actually included. The number of studies that encompass combinations of AOP and microalgae treatment are very scarce. The ozonation is the pretreatment most often utilized for pollutant oxidation and disinfection of recalcitrant wastewaters. The review of these articles shows that the harvested microalgae biomass from recalcitrant wastewaters pretreated by AOP has potential to be used as feedstock for biofuel production. Highlights • Remediation of recalcitrant wastewater by AOP and microalgae combined treatment. • Biomass from recalcitrant wastewaters pretreated by AOP can produce biofuels. • There are few studies about AOP and microalgae combined treatment. • A layout for recalcitrant effluent remediation and biomass exploitation is proposed.

Abstract: The availability of water resources in a reservoir for electricity generation is strongly linked to climate and weather conditions. Also, the use of these water resources is influenced by the population size as well as anthropogenic activities. This research attempts to assess the combined effects of (i) climate change (CC), (ii) land use/land cover change (LULCC), and (iii) development (Dev) conditions on water resources and hydropower generation (HPGen) using Regional Climate Models (RCMs) from Coordinated Regional Downscaling Experiment (CORDEX) under the Representative Concentrated Pathways (RCP): RCP4.5 and RCP8.5. The RCMs considered are: CanRCM, CCLM, and WRF being drived by CanESM2, CNRM-CERFACS, and NorESM1, respectively. The Water Evaluation and Planning model (WEAP) tool is used to simulate the water availability and HPGen in the Mono basin under present and future conditions. The ensemble mean of the three-climate dataset analysis reveals that the temperature is projected to increase significantly while the precipitation change is uncertain under both RCPs in the near (2020–2050) and the far (2070–2090) futures. These changes in climate variables consequently affected simulated water availability for different water consumption sectors especially the HPGen in the near and far futures. Moreover, the Dev was found to exacerbate the burden that constitutes the CC for water availability and HPGen. Nevertheless, LULCC associated with either CC or both CC and Dev were projected by all the RCMs and their ensemble mean to reduce this burden. However, its side effects namely reservoir siltation and sedimentation need to be deeply investigated.

Abstract: Microporous erionite-activated carbon (E-AC) composite was synthesized by activating oil palm ash followed by reacting with aluminum oxide (Al2O3) under alkaline conditions using hydrothermal method. The Al2O3 was added to the activated palm ash to balance the excess silica dioxide (SiO2) to obtain the erionite type of zeolite. The E-AC composite was employed to remove a potent pharmaceutical water pollutant, doxycycline antibiotic under batch adsorption. The effect of solution pH (3–13), doxycycline initial concentration, and temperature were screened in the batch study. The E-AC composite revealed appreciable surface area and average pore size of 467.23 m2/g and 2.765 nm, respectively, with abundant chemical surface hydroxyl (-OH) and amine (N-H) adsorptive sites. The textural and surface chemistry greatly contributed to a high monolayer adsorption capacity of 353.81 mg/g at 50 °C. Also, the Langmuir isotherm with a high R2 of 0.99 for doxycycline adsorption on E-AC sufficiently described the equilibrium data. High monolayer adsorption capacity of E-AC compared to other adsorbents in the literature suggests the efficiency of this study. Novel composite synthesis was aimed to enhance the surface area and to increase the doxycycline removal capacity. These encouraging results show that the E-AC composite could pave the way for more low-cost composites to be used as adsorbents for pharmaceutical and other pollutant removals from wastewater.

Abstract: Cassava (Manihot esculenta) peels are residues of cassava processing obtained in large quantities in tropical west Africa. This work was geared towards developing thermodynamic models to study the potential in valorising the biomass via pyrolysis and in-line steam reforming processes. The flowsheets for energy recovery were developed successfully without errors and the results were validated with experimental findings. The yield, product composition and product selectivity of both processes were critically examined with respect to the process factors. The pyrolysis results revealed 53.65 wt% oil, 21.43 wt% char and 24.92 wt% gas at 525 °C. Results obtained for optimal process factors are reforming temperature of 600 °C, pressure of 1 atm and steam to carbon molar ratio (S/C) of 10. The synthesis gas obtained at optimal conditions had a hydrogen content of 70.2 mol%, carbon dioxide content of 27.9 mol%, carbon monoxide content of 1.9 mol% and only trace quantities of methane. The effects of process factors on the product composition in the steam reforming of cassava peel waste were confirmed. Cassava peel waste has great potential for valorisation by these thermochemical processes.

Abstract: Nutrient deficiency in soil suppresses crop growth, yield and nutritional value of the products. Textile effluent, a rich source of several essential minerals (including Ca, Mg, Cu, Fe, Zn, Mn) required for plant growth, could be a viable option to supplement the nutrient availability of soil. Although presence of some toxic metals and organic compounds restrict its use as irrigation water, its controlled use as fertilizer was not studied so far. This study was undertaken to assess the utilization of textile industry effluent for its suitability and potentiality as nutrient supplement by applying it onto chilli (Capsicum annum L.) cropping system. The effects of textile effluent fertilization was assessed by the wet cotton method at room temperature for germination, and in pot experiment in field conditions for growth and biochemical analysis using four effluent dilution rates (i.e., 10%, 20%, 40% and 60% v/v). The results of the experiment showed no inhibitory effect of textile effluent on seed germination, while its fertilization as soil drench worked as nutrient supplement for growth in chilli cultivars. The fertilization with textile effluent enhanced the plant biomass by 110.9% and 124.5%, and the leaf area by 21.5% and 2.6% in chilli cultivar GVC-121 and GVC-101, respectively. The total carbohydrate and foliar protein were also favoured by fertilization with the effluent. Moreover, least proline accumulation under lower dose suggested reduced stress due to textile effluent fertilization. The study concluded that the lower dose of textile effluent fertilization can function as nutrient supplement for chilli cultivars and 20% (v/v) effluent dilution provides the most favourable results.

Abstract: The efficacy of a biosorption-based approach using living cells of Deinococcus radiodurans for recovery of Eu3+ from aquatic systems has been investigated. The effects of four variables including pH, culture media constituents, inoculum age and initial Eu3+ concentration were evaluated. Among five different media compositions tested, the combination of tryptone, glucose, yeast extract (TGY), cystine and NaCl showed highest removal of Eu3+ by the Deinococcus species. Similarly, maximum biosorption of Eu3+ was achieved at pH 6. Further, at the optimized condition of pH 6 and inoculum age of 45 h with TGY + cystine+NaCl culture media, 81% of Eu+3 was removed within 3 h at an initial Eu+3 concentration of 150 mg L−1. The appearance of EuPO4 peak in the XRD analysis of the D. radiodurans culture further indicated that biosorption of Eu3+occurred onto the PO4 functional group of the microbial cell wall. The high Eu+3 biosorption efficiency by D. radiodurans may constitute an effective and eco-friendly alternative strategy to recover Eu+3 from contaminated environment. Highlights • First report on Eu+3 biosorption by Deinococcus radiodurans. • Almost 80% Eu+3 biosorption occurs even at high initial concentration of 150 mg L−1. • PO4 functional group present on the cell plays a vital role on Eu3+ biosorption.

Abstract: This paper aims to find the possible relationships between winter precipitation (December, January, February; DJF) in Iran with three oceanic sources through the correlation wavelet analysis by applying the continuous wavelet transform (CWT), the cross–wavelet transform (XWT), and the wavelet transform coherence (WTC). The sources in the North Atlantic Ocean (30°W-70°W, 10°N-30°N), the South Pacific Ocean (80°W-120°W, 20°S-40°S) and the Indian Ocean (50°E-100°E, 10°S-40°S) were selected using Pearson correlation coefficient (PCC > 0.5) that can represent the possible relationships between Iran’s winter precipitations with the oceanic sea surface temperature (SST) anomaly. The monthly gridded precipitation and SST data with a 2.5° × 2.5° resolution were evaluated from 1984 to 2019 to achieve this goal. The XWT results of precipitation and SST anomaly showed that the 8–16 months period is the most effective and predominant period between the South Pacific Ocean and 81% of all the precipitation zones. WTC results for the North Atlantic Ocean and 72% of all the precipitation zones showed periods of 4–8 (36%) and 16–32 (36%) months as the dominant duration. Despite the proximity of the Indian Ocean to the precipitation zones, there is no significant causal relationship between them, based on the XWT results. However, due to Madden–Julian oscillation (MJO), the 4–8 months period (45%) was seen between the Indian Ocean and some precipitation zones, based on WTC results.

Abstract: Employing inclined dense jets is a common way for the disposal of brine from coastal desalination plants. Reaching an optimal design to minimize the negative impacts of brine on marine ecosystems has been a popular environmental-related line of research over the last decades. This paper numerically analyzes the mixing and geometrical properties of 30° and 45° inclined dense jets when they discharge close to the bed. For this purpose, two series of numerical simulations were developed. In the first series, the nozzle was placed far enough from the lower boundary to act as a free jet. Meanwhile, in the second series, the distance between the nozzle tip and seabed was substantially reduced. By comparing these two series, the effect of proximity to bed on the behavior of dense jets has been investigated. The governing equations were solved by modifying a solver within the CFD package of OpenFOAM. The numerical results were presented in comparative figures and were compared to previous works. Comparisons indicated that the numerical model predicts the geometrical characteristics of dense jets in good agreement with the past experimental studies. However, the dilution predictions are conservative. It has been observed that proximity to the bed has almost no appreciable effects on the behavior of 45° jets. However, for 30° jets, when the bed proximity parameter (y0/LM) falls below 0.14, the normalized values of horizontal and vertical locations of centerline peak and return point dilution are slightly reduced while the terminal rise height remains untouched. • The properties of free and boundary-affected dense jets were numerically analyzed. • Some characteristics of 30° jets were found to be influenced by the lower boundary. • The 45° dense jets were insensitive to variations of the bed proximity parameter. • The model predicted the geometric characteristics with reasonable accuracy. • The dilution predictions were found to be conservative.

Abstract: The removal of aqueous methylene blue (MB) dye using organically modified natural Na-kaolinite was optimized Organo-kaolinite was synthesized by replacing exchangeable Na+ ions in Na-kaolinite with cetyltrimethylammonium bromide (CTAB), and the adsorption behaviour was systematically explored as an efficient adsorbent for the removal of dyes Furthermore, the properties of the obtained samples were characterized by FTIR spectrophotometric analysis, which confirmed that CTAB cations had modified the kaolinite to possess a new functional group Batch mode experiments were conducted to test the performance of the modified kaolinite in removing MB dye to optimize the following experimental conditions: adsorbent quantity, initial concentration, mixing speed, contact time and initial pH The findings indicated that the MB adsorbent efficiency could reach up to 100% when the above conditions were set at 03 g/100 mL, 50 mg/L, 200 rpm, 60 min and pH = 12, respectively The adsorption isotherms and kinetics of the organic-modified kaolinite for MB concurred with Freundlich adsorption equation and the pseudo-second-order kinetics, respectively In accordance with the principles of environmental preservation and reuse of waste, granulated glass waste was used to optimize the adsorption efficiency of kaolinite Furthermore, two tested reactive systems were used in two-dimensional (2D) domain experiments by mixing a 1:1 ratio of modified kaolinite:granulated glass waste The COMSOL Multiphysics 35a software was utilized to determine the spread of MB within the permeable reactive barrier (PRB) for the 2D domain at equilibrium conditions • Kaolinite was modified by cetyltrimethylammonium bromide to remove methylene blue • Organo-kaolinite was used in a two-dimensional permeable reactive barrier • The COMSOL Multiphysics model was used to simulate the permeable reactive barrier

Abstract: Due to the impact of drought on crop yield, the aim of this research is the susceptibility assessment of winter wheat, barley and rapeseed species to drought using Generalized Estimating Equations (GEE) and Cross-Correlation Function (CCF). For this objective, the climatic data of 10 synoptic stations in Iran from 1968 to 2017 (i.e., 50 years) were used. Then, the AquaCrop model was adopted to simulate annual yield (Ay) of the above-mentioned species. Also, the standardized precipitation evapotranspiration index (SPEI) was applied to assess drought conditions in selected constant and progressively increasing reference time periods, including 1-month, 3-month, 6-month and 12-month time scales (27 reference time periods) starting in October. For evaluating the accuracy of the GEE model, the correlation coefficients (CC) between simulated and predicted annual yields in selected species through the AquaCrop model and GEE model were used, respectively. The accuracy test of the GEE model showed that the CC between simulated and predicted annual yield of barley almost in all stations and all-time scales were significant at 0.01 level. Only in Birjand and Kerman stations the CC between simulated and predicted annual yield were significant at 0.05 level in 3.7% and 66.67% of time scales, respectively. Based on the GEE and CCF models in all stations, the susceptibility of rapeseed to drought was more than that of wheat, and the susceptibility of wheat was more than that of barley.