Zainab Khan, Ateeque Ahmad, Syed Kausar Shamim
et al.
Abstract Lakes, as essential lentic ecosystems, undergo dynamic changes influenced by exogenic factors. The delicate balance of lakes is prone to disruption due to various factors. Therefore, it is of paramount significance that these crucial ecosystems are studied thoroughly. The present study delves into the physicochemical properties-temperature, pH, dissolved oxygen, conductivity, total dissolved solids, and transparency- along with diversity indices such as Shannon-Wiener diversity, Pielou’s evenness, and species richness, based on phytoplankton, in three candidate lakes of the Kumaun region i.e., Nainital, Bhimtal, and Sadiyatal. A comparative analysis was done for littoral and limnetic zones for the ecological indices by utilizing PCA to unveil potential similarities among the lakes. Results highlight distinct dissimilarities, rooted in geography, and altitude. Unexpectedly high temperatures and low dissolved oxygen is observed in Nainital while Bhimtal represents resilience due to its relatively large size and better transparency. Sadiyatal is observed thriving with highest species richness possibly due minimal human interventions. Littoral zones exhibited higher species diversity, driven by nutrient availability and macrophyte interactions, whereas the limnetic zone was dominated by planktonic species adapted to open-water conditions. This study presents novel insights into the intricate interactions between physicochemical attributes and phytoplankton dynamics, significantly advancing the understanding of these lake ecosystems.
Water supply for domestic and industrial purposes, Environmental sciences
Abstract The widespread presence of microplastics (MPs) in water has become an environmental concern due to their adverse effects on human health and aquatic ecosystems. To address this issue, metal–organic framework/graphene oxide composites have recently emerged as a promising solution for wastewater treatment due to their unique properties such as high loading capacity and enhanced stability. In this research, the uptake mechanisms of two types of MPs, including Polyamide 66 (PA66) and Polyurethane (PU) based on the metal–organic framework Cu-BTC/graphene oxide (Cu-BTC/GO) composite, are evaluated by molecular dynamics (MD) simulation. By increasing the number of adsorption sites through the incorporation of GO onto Cu-BTC, the designed composite demonstrates higher efficiency in removing MPs compared to the pristine MOF. The removal percentage of PA66 and PU increases from 25% and 0.75% in the MP-single Cu-BTC systems to 100% upon adsorption in the Cu-BTC/GO composite, respectively. The adsorption capacity of Cu-BTC/GO composite for MPs is enhanced through π–π stacking, C–H⋯ π interactions, hydrogen-bonding network, and electrostatic attractions, with a predominant hydrophobic nature. Furthermore, the results of density functional theory (DFT) calculations confirm the findings from the MD study. This research provides detailed atomistic insights into the mechanisms of microplastics removal by the metal–organic framework composite with graphene oxide from wastewater.
Samaneh Ghanbarlou, Davood Kahforoushan, Hossein Abdollahi
et al.
Emissions of greenhouse gases, including carbon dioxide, harm the environment. Therefore, many international researchers are concerned about the use of fossil fuels. So, to prevent further irreversible climate change, it is necessary to reduce the temperature and CO2 emissions by 2050. For this purpose, agricultural wastes are very effective and economical sources as one of the methods of CO2 capture. The main objective of this research was to investigate the role of agricultural wastes in carbon dioxide capture and the factors affecting their performance with the aim of protecting the environment. The present research is of the type of applied research and analytical-descriptive in terms of research method. The findings showed that agricultural wastes (biomass) like bamboo wastes, olive stones, peanut shells, walnut shells, sugarcane bagasse, cottonwood, rice straw, and coffee grounds are effective in CO2 capturing. they are also inexpensive and non-toxic, and show an adsorption capacity of up to 21 mmol/g and a surface area of up to 3900 m2/g. while petroleum or coal-based adsorbents have an adsorption capacity of about 160-900 mg/g and a surface area between 850-3800 m2/g.
Environmental sciences, Water supply for domestic and industrial purposes
Athare Khakshour, Masoud Shakarami, Mohammad Nazeri Tahroudi
et al.
This study aims to (1) evaluate the Crop Water Productivity (CWP) and gray Water Footprint (WFGray) for key agricultural systems in Lorestan province, Iran, to identify hotspots of inefficiency and pollution, and (2) develop and compare Machine Learning (ML) models for predicting these metrics to aid in management and forecasting. We calculated CWP and WFGray for major crops (including forage corn, wheat, beans, potatoes and vegetables) across multiple meteorological stations in Lorestan province. Furthermore, we employed two ML algorithms including Random Forest (RF) and Support Vector Machine (SVM) to model and predict these indices. Model performance was evaluated using the Mean Absolute Error (MAE). The assessment revealed significant regional and crop-specific disparities. Forage corn was the most efficient and sustainable system (CWP: 2.173 kg/m³, WFGray: 0.05 m³/kg), whereas bean production was the least efficient (CWP: 0.064 kg/m³). Spatially, stations like Azna (potato) demonstrated best practices, while Kuhdasht was identified as a critical area of concern due to low efficiency and high fertilizer pollution. In modeling, the optimal algorithm was target-dependent: RF was superior for predicting CWP (MAE: 0.236), while SVM performed relatively better for the more complex WFGray. This study concludes that addressing water security and agricultural pollution in the region requires tailored, crop-specific interventions and improved farm management practices. Furthermore, while ML model (particularly RF) proves to be a powerful tool for forecasting water productivity, accurately modeling the environmental impact (WFGray) remains a challenge, highlighting the need for more robust data and further research in this domain.
Abstract To address the problems of low efficacy and low microbial activity in low-temperature municipal wastewater treatment, this study utilized an air-lift micro-pressure internal circulation integrated reactor (AMICIR). Through controlling the amount of aeration and dissolved oxygen (DO) in the reactor, AMICIR creates alternating aerobic and anaerobic environments, explores the enrichment conditions of aerobic denitrifying bacteria, examines the changes in pollutant removal efficiency and the characteristics of bacterial colony structure during the process of enrichment of aerobic denitrifying bacteria in the system, and reveals the mechanism of nitrogen removal by aerobic denitrifying bacteria cooperating with anaerobic denitrifying bacteria in the low-temperature municipal wastewater treatment system. Experimental results showed average removal rates of NH4 +-N, chemical oxygen demand (COD), total phosphorus (TP), and total nitrogen (TN) reaching 93.85%, 89.30%, 92.75%, and 75.4%, respectively. The microorganisms secreted large amounts of proteins and polysaccharides, forming zoogloea and anaerobic microenvironments conducive to traditional denitrification reactions. IlluminaMiSeq sequencing analysis revealed the presence of anaerobic phyla. The system was enriched with a large number of microorganisms, and aerobic denitrifying bacteria (Flavobacterium, Rhodoferax, and Pseudomonas) were successfully cultured. Flavobacterium emerged as the dominant species, with relative abundance ranging from 18.56% to 22.60%. Functional gene prediction indicated high abundance of aerobic denitrification genes, such as napA. Aerobic denitrifying bacteria were successfully enriched in the system to improve nitrogen removal from municipal wastewater at low temperatures.
As online TV delivery disrupts conventional TV broadcasting and unbundles TV cable channels, allowing consumers to choose programs and TV brands more directly, hit content is “king” more than ever before. This dissertation offers a new analysis of Canadian English-language TV drama content’s failure to mature into a popular genre or robust economic sector since its introduction in the 1960s, and suggests ways that the Canadian English-language TV drama value chain might be strategically adjusted in response to global market disruption, by strengthening the development phase. The problem is approached with two methodologies: value chain analysis and qualitative field research. Findings identify weak links in the value chain and propose that the Canadian English-language TV drama content model is structurally flawed and has inhibited maturation of the sector. The study theorizes a TV drama value chain composed of 3 functional segments (develop, produce, distribute) and identifies the root of the Canadian drama problem as the creation phase, known in TV as development, analogous to the R&D phase in other industries. The theorization explains why decades of policy attention and subsidies targeted to the production phase have not substantially improved domestic or global market performance of Canadian English-language TV drama. Moreover, the reframing reveals that development and distribution are functionally linked, while the production phase is the most separate. Theorization and field research concur that a strong imperative for financial returns is essential for successful creative results, from the earliest moments of development. Conversely, a weak link to monetization negatively impacts asset creation, impairing the development phase and, in the case of Canadian English-language TV drama, inhibits its capability to compete effectively in a 21st-century drama attention economy that increasingly rewards creative excellence. Interviews with stakeholders occupying elite development positions in the Canadian and Hollywood TV drama industry confirm an urgency to upgrade development to foster transformation of Canada’s TV drama model, from one purposed for domestic supply to one driven by global demand, and in so doing, future-proof Canadian TV drama for the digital age. Against the backdrop of Canada’s unique geo-cultural position vis a vis the U.S., characterized by brain drain of high-performing Canadian TV drama creators to Hollywood and attempts by Canadian English-language TV drama to compete with Hollywood hits, this research contributes to debates on cluster upgrading, local-global linkages, and economic diasporas that focus on value capture of highly skilled professionals who seek career acceleration in global escalator regions. Findings are applicable to any nation upgrading domestic creative industries which, like TV drama, are characterized by an imperative for innovation excellence in R&D-intensive global value chains.
As online TV delivery disrupts conventional TV broadcasting and unbundles TV cable channels, allowing consumers to choose programs and TV brands more directly, hit content is “king” more than ever before. This dissertation offers a new analysis of Canadian English-language TV drama content’s failure to mature into a popular genre or robust economic sector since its introduction in the 1960s, and suggests ways that the Canadian English-language TV drama value chain might be strategically adjusted in response to global market disruption, by strengthening the development phase. The problem is approached with two methodologies: value chain analysis and qualitative field research. Findings identify weak links in the value chain and propose that the Canadian English-language TV drama content model is structurally flawed and has inhibited maturation of the sector. The study theorizes a TV drama value chain composed of 3 functional segments (develop, produce, distribute) and identifies the root of the Canadian drama problem as the creation phase, known in TV as development, analogous to the R&D phase in other industries. The theorization explains why decades of policy attention and subsidies targeted to the production phase have not substantially improved domestic or global market performance of Canadian English-language TV drama. Moreover, the reframing reveals that development and distribution are functionally linked, while the production phase is the most separate. Theorization and field research concur that a strong imperative for financial returns is essential for successful creative results, from the earliest moments of development. Conversely, a weak link to monetization negatively impacts asset creation, impairing the development phase and, in the case of Canadian English-language TV drama, inhibits its capability to compete effectively in a 21st-century drama attention economy that increasingly rewards creative excellence. Interviews with stakeholders occupying elite development positions in the Canadian and Hollywood TV drama industry confirm an urgency to upgrade development to foster transformation of Canada’s TV drama model, from one purposed for domestic supply to one driven by global demand, and in so doing, future-proof Canadian TV drama for the digital age. Against the backdrop of Canada’s unique geo-cultural position vis a vis the U.S., characterized by brain drain of high-performing Canadian TV drama creators to Hollywood and attempts by Canadian English-language TV drama to compete with Hollywood hits, this research contributes to debates on cluster upgrading, local-global linkages, and economic diasporas that focus on value capture of highly skilled professionals who seek career acceleration in global escalator regions. Findings are applicable to any nation upgrading domestic creative industries which, like TV drama, are characterized by an imperative for innovation excellence in R&D-intensive global value chains.
Abstract The tannery industry inevitably generates toxic and catastrophic wastewater, which results in a huge threat to public health and water resources. Therefore, this work aimed to synthesize parthenium hysterophorus-based biochar–Fe3O4 composite for removal of Cr(VI) from tannery wastewater under 34 full factorial experimental designs of the Box–Behnken, which was analyzed using response surface methodology under four independent factors of pH (3, 6, and 9), initial Cr(VI) concentrations (40, 70, and 100 mg/L), contact times (30, 60, and 90 min), and adsorbent doses (20, 60, and 100 mg/100 mL). This composite adsorbent was described by a high BET surface area of 237.4 m2/g, XRD prominent peaks, SEM morphology corroborate and FTIR multifunctionalities of O–H at 3296 cm−1, the vibration of ketone C–OH at 1240 cm−1, and the vibration of C–O–C at 1147 cm−1 and Fe–O stretching at 542 cm−1. The maximum Cr(IV) removal efficiency of 91.8% was recorded at an initial Cr(VI) concentration of 40 mg/L, pH of 3, adsorbent dose of 100 mg/100 mL, and a contact time of 90 min, whereas the minimum Cr(VI) removal of 17.3% was observed at an initial Cr(VI) concentration of 100 mg/L, 20 mg/100 mL of adsorbent dose, pH of 9, and contact time of 30 min. The concentration of Cr(VI) in real wastewater was determined to be 85.13 mg/L and its remediation was found to be 81.8%. Langmuir’s model was the best fit with experimental data at R 2 0.99 and qmax 400 mg/g, showing that the adsorption process was homogenous and monolayer. In conclusion, the adsorption results were encouraging, and biochar–Fe3O4 appears to be a potential candidate for Cr removal from wastewater.
Magda A. Akl, Abdelrahman S. El-Zeny, Mohamed Ismail
et al.
Abstract In recent years, facing the problem of improving environmental quality, cellulose and cellulose-based (nano) composites have received great attention as adsorbents. In this work, we report the modification and functionalization of cellulose by nitrogen- and sulfur-containing moieties through a three-steps process; native cellulose is first oxidized by potassium periodate (KIO4) to form dialdehyde cellulose (DAC), which then condenses with aminoguanidine and react with phenyl isothiocyanate to form 4-phenyl guanyl thiosemicarbazide dialdehyde cellulose (DAC@GuTSC). The prepared DAC@GuTSC is characterized by a number of techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental analysis (EA), Brunauer–Emmett–Teller (BET) and thermogravimetric analysis (TGA). The prepared DAC@GuTSC adsorbent was used to remove Cu2+ Hg2+ and Pb2+ from aqueous solution and environmental water samples. The influence of various factors on the adsorption efficiency including pH, initial metal concentration, contact time, adsorbent dosage, temperature, and ions interfering with adsorption was investigated. Under optimal adsorption conditions, the adsorption capacity of Cu2+, Hg2+ and Pb2+ was 50, 94 and 55 mg g−1, respectively. The adsorption process is well described by the Langmuir model, and it was found to follow the pseudo-second-order kinetics model. The spontaneous and endothermic adsorption of Cu2+, Hg2+ and Pb2+ was confirmed by the calculated thermodynamic functions. The prepared DAC@GuTSC composite has been successfully applied to remove Cu2+, Hg2+ and Pb2+ from real water samples with recovery greater than 90% and relative standard deviation (RSD) less than 3%. The reasonable Cu2+, Hg2+ and Pb2+adsorption mechanism on the prepared DAC@GuTSC composite has been elucidated.
I Gusti Lanang Made Parwita, I G B Sila Dharma, Mawiti Infantri Yekti
et al.
The need for clean water is generally divided into two groups, namely domestic water needs and non-domestic water needs. Non-domestic water needs are water needs other than for household purposes such as for education, industry, tourism, social and others. In general, the determination of non-domestic water demand is estimated to be around 20-25% of the total domestic water demand. Badung Regency has characteristics as the main tourist area in Bali as evidenced by the existence of 33 tourist destinations, both cultural tourism, natural tourism, artificial tourism and youth tourism. With these characteristics, this study emphasizes the analysis of non-domestic water needs in the tourism sector. The research was conducted by analyzing various factors related to the need for clean water in the tourism sector such as hotel accommodation, tourism support facilities and the number of tourism objects available. The results of this analysis are compared with domestic water needs according to the existing population. The analysis shows that non-domestic water demand for tourism accommodation (hotels, villas and condominium hotels) is 186.76 liters / second, for tourism objects is 7.64 liters / second, restaurants and bars is 24.21 liters / second.
Jahangir Abedi-Koupai, Mohammad-Mahdi Dorafshan, Ali Javadi
et al.
Abstract The potential evapotranspiration is considered as an important element of the hydrological cycle, which plays an important role in agricultural studies, management plans of irrigation and drainage networks, and hydraulic structures. Estimating the potential evapotranspiration reference of particular climatic regions at different time scales, which is one of the most important atmospheric parameters, is of a particular importance in the optimal use of resources. The time series analysis method, GARCH model, is applied in order to investigate changes and estimate the potential evapotranspiration. In the present study, the efficiency of GARCH series model related to processes of modeling and estimating potential evapotranspiration, which is estimated by FAO Penman–Monteith and Hargreaves methods, was investigated. Also, future values of potential evapotranspiration are modelled and estimated at the synoptic station of Tabriz. Results showed that Time Series is considered as a precise tool to estimate evapotranspiration values. It was found that GARCH (1.1) time series has better results for FAO Penman–Monteith and Hargreaves methods compared to other models; also, it simulates the process of time series changes with less error. Observed and predicted evapotranspiration charts of both methods indicated that observational evapotranspiration was highly close to the lower limit of estimated evapotranspiration. Therefore, applying lower limit estimation as a prediction value was suggested.
Abubakari Zarouk Imoro, Raymond Asante Owiredu, Osayomwanbo Osarenotor
et al.
Abstract In the developing world, most animal farmhouses dispose of their wastewater without treatment and that creates conditions for the spread of diseases. To discourage this practice, there is the need to provide relatively simpler wastewater treatment options. Thus, this research work sought to optimise the chemical oxygen demand (COD) removal efficiency of a simple anaerobic digester by determining the optimum concentrations of rhamnolipid biosurfactant and potassium phosphate buffer needed to make the anaerobic digester remove COD efficiently. The central composite design was used for the optimization study. In the one factor at a time experiment, increasing the concentration of the potassium phosphate buffer from 1.07 g/l K2HPO4 + 0.53 g/l KH2PO4 to 1.37 g/l K2HPO4 + 0.83 g/l KH2PO4 increased the COD removal efficiency of the anaerobic digester from 19.3 to 24.7%. Also, increasing the concentration of rhamnolipid from 80 to 320 mg/l increased the efficiency of the digester from 24.2 to 26%. The percentage COD removal was highly improved (> 85%) in the optimisation study when both rhamnolipid and buffer were combined at high levels (+ 1). The model built from the central composite design reflected a good fit of the data obtained with R 2 of 82.5% and a p value of 0.000. This study therefore demonstrated that a simple anaerobic digester can be used to remove COD in wastewater by optimising the concentrations of rhamnolipid and potassium phosphate buffers in the treatment system.
Mohammad Hossein Jahangir, Maryam Jahanpanah, Mahnaz Abolghasemi
In this study, in order to simulate the current climate (1970-2016) for calculating the drought index in Fars Province, the data used include daily rainfall, minimum temperature, maximum temperature, and sunny hours at Shiraz station in a period of 46 years (1970-2016) as the entry for the LARS-WG statistical model. To simulate the climatic parameters at the Shiraz station basin, the data of HADCM3 model were downscaled using WG-LARS model under two scenarios A2 and A1B. The results showed that the average annual rainfall will increase under A2 scenario by about 1.5% and under A1B scenario by about 5.5%. Moreover, sunshine hours in the study period will be reduced under both scenarios. With high precision, the model could simulate maximum temperature, minimum temperature, and radiation parameters, but more error in simulating was presented in the precipitation parameter than other parameters. The highest increase, with about 80%, was due in September under scenario A2, which occurred in the upcoming period of the study period. Based on the SPI drought index, the most severe droughts occurred in 2008 in Shiraz station showing an index value of -2.89. Moreover, SPI shows that the most precipitation was recorded in 1995 with an index value of 1.91.
Environmental sciences, Water supply for domestic and industrial purposes
Amin Mahdavi-Meymand, Mohammad Zounemat-Kermani, Kourosh Qaderi
Hydro-suction is an appropriate and economical method for dredging deposited sediment at reservoirs. In this study, a physical model was made and some experiments were designed to analyze the ranges of blockage depth in different hydraulic conditions. In the model, 80 tests were conducted using three diameters (d), three water heads (H) and different diving depths of pipe inlet (Z) from the sediment level to the blockage depth. In general, the results indicated that the more increase in the diving depth, the higher hydro-suction efficiency. In some of the experiments, a vortex flow was observed under the pipe inlet. The results indicated that the formed vortex flow have a positive effect on the hydro-suction efficiency. The results associated to the blockage depth approved that hydro-suction systems with larger pipe diameter and more water head have a greater blockage depth (Zb). The Froude number (Fr) analysis indicated that an increase in Fr would cause increment efficiency and blockage depth of hydro-suction system. Subject to a constant pipe diameter, the results revealed that increasing the H/d ratio equal to 66.66 and 133.33%, would enhance the Zb/d ratio equal to 58.89 and 112.22%, respectively.
Environmental sciences, Water supply for domestic and industrial purposes
Two laboratory-scale single-stage submerged membrane bioreactors (MBRs) were operated in parallel to examine the effect of different flux conditions and several fouling mitigation methods. After control operation (filtration only), three fouling control methods (relaxation, standard backwash and chemical backwash) at 27 litres per m2 per hour (LMH) flux and four different flux conditions (54, 36, 27 and 18 LMH) with standard backwash were applied. Physical performance of MBRs was evaluated based on the operational duration to reach maximum transmembrane pressure and the volume of permeate produced during the operational duration. Then relative cost–benefit analysis was carried out. Results showed that the combination of chemical backwash and standard backwash was the most effective for fouling mitigation in terms of physical improvement of MBR performance. However, the combination proved less economical (400% + α relative cost) than standard backwash alone (343% relative cost), because of the additional cost for pumps and chemicals. It also showed that lower flux (18 LMH) is desirable as it showed better physical performance (1,770% improvement as compared to the highest flux, 54 LMH) and proved more economical than higher flux configuration. Therefore, it is concluded that the operation with standard backwash at the lowest possible flux is the best combination to improve MBR performance as well as long-term cost–benefit. HIGHLIGHTS
Many studies focus mainly on high-cost, high-performance techniques without economic justification. But this research focused on the interpretation of performance improvement made by several fouling control methods in terms of relative cost as well as physical performance.;
Chemical backwash supported by standard backwash showed the best physical performance among the other operations with different fouling control methods. However, the best operation in physical performance was proven to be less economical than standard backwash operation, because it showed higher long-term cost than that of standard backwash operation.;
Therefore this study suggested one of useful tools to justify any fouling control methods in MBR research field not only by physical performance but also by cost-benefit.;
Abstract Water is the wonder of nature which is an essential source of nutrient for all forms of life. It helps in proper digestion, energy metabolism, transport of nutrients and metabolites, cellular functions, and excretion of waste materials from our body and animals. Furthermore, water plays a vital role in body thermoregulatory and electrolyte health, and performance the fluidity and cushioning environment for the developing fetus in the human and animals. The quality of water determines the health and productivity of milk and their quality, as it causes bioaccumulation of water solutes in the milk and body tissues. Therefore, its quality has to be good for optimum health, and performance of dairy cattle. The high-altitude environments have limited surface and groundwater resources and more dependent on snow precipitations, very deep bore well groundwater, and mountain river. Recently, quality of high-altitude water resources has become questionable due to more environmental pollution, climate change, and high anthropogenic activities at high altitude. Therefore, there is a continuous requirement to monitor water quality, dairy product quality, and cattle health for prevention and control of waterborne diseases. This review reveals the water quality and the probable effects on the health performance of dairy cattle with a particular emphasis on high-altitude regions. From this review, it can be concluded that global warming and an increase in tourists at high-altitude regions have caused deterioration of water quality, which may affect the health, reproduction, and production of quality dairy products. This may lead to bioaccumulation of some toxic molecules and metals into higher food chain and affecting public health.
Water sludge management is one of the main problems facing water and wastewater companies. Disposal of conditioned sludge by chemical polymers is restricted due to the health and environmental effects. Recently, the use of natural polymers has been investigated to reduce the side effects of chemical polymers. In this study, the effectiveness of Moringa Pergerina seed as a natural polymer in the conditioning of water treatment sludge has been studied. In this study, sludge samples from the Tehranpars Water Treatment Plant were taken daily from the sedimentation tank. Sampled sludge conditioning was performed using jar test by Moringa pergerina powder dissolved in salt water (1N NaCl). Optimization of three important factors in the jar test, including mixing speed, mixing time and optimum dosage using the Box-Behnken Design, Response Surface Design Method (RSM), was performed in Design Expert software. Results: The minimum capillary suction time (CST) and specific resistance filtration (SRF) was obtained at 30.294 and 6.19×1012 m / kg respectively under optimal conditions. The results were obtained in terms of speed and time of mixing 50 rpm and 3 min, 250 rpm and 100 s with an optimal dosage of 5040 mg/L of Moringa Peegerina dissolved in salt water and a desirability index of 1.000. The best effectiveness of Moringa Pergerina for sludge conditioning was obtained in acidic media. Under optimal operating conditions, SRF and CST relative to the initial conditions of the sludge was reduced by 75% and 42%, respectively.
Technology, Water supply for domestic and industrial purposes
Abstract The marine microalga Nannochloropsis oculata was investigated for its biosorption capacity for the removal of Cd(II) ions from aqueous solution using batch mode experiments. pH (2–5), biomass dosage (0.0191 g/50 mL and 0.392 g/50 mL) and temperature (293–323 K) being the experimental parameters affecting the biosorption process were observed. To describe the experimental equilibrium data, Langmuir and Freundlich isotherms models were applied. The biosorption potential of N. oculata biomass for Cd(II) ions was found to be 232.55 mg/g. The calculated thermodynamic parameters (∆G°, ∆H° and ∆S°) showed that the biosorption of Cd(II) ions onto N. oculata was feasible, spontaneous and exothermic at 298–323 K. Evaluation of experimental data in terms of biosorption kinetics showed that the biosorption of Cd(II) by N. oculata well followed pseudo-second-order kinetics. The FTIR spectra indicated that the functional groups predominantly involved in the biosorption were –OH, COO–, –CH and phosphate groups. The XRD pattern of the biosorbent showed a change in crystallinity of N. oculata biomass after the biosorption. It was concluded that N. oculata can be used as an effective, low-cost and environmentally friendly biosorbent for the removal of Cd(II) from aqueous solution.