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Due to increasing problems of freshwater availability and wastewater treatment and management, there is a dire need to control water pollution. A major portion of wastewater is produced through dye contamination from textile industries. In this study, efforts were made to evaluate the renewable, environment-friendly, and biomass-based adsorbent for the effective removal of dyes from aqueous solution. Pine sawdust biomass samples were subjected to adsorption under different parametric studies to optimize the adsorption process efficiency. The maximum adsorption efficiency was observed around 50-60 % under different working conditions. This study demonstrates that the non-linear versions of the PSO and IPD kinetic models were better than the linear forms from the perspective of the dye adsorption mechanism. Comparably, the nonlinear fitting of the Freundlich model yielded lower χ² values and higher R² values than the linear fitting. Positive Gibbs free energy values imply that the adsorption is non-spontaneous and thermodynamically unfavorable at the investigated temperatures. The thermodynamic study shows that the adsorption of BBY onto the PSD adsorbent is an exothermic process. [ABSTRACT FROM AUTHOR]

Tobacco stalk biomass (TSB) is explored for reactive black 5 (RB5) dye treatment in batch reactor. TSB displayed RB5 adsorption efficiency of 93.5% at 120 min. The RB5 data were fitted to linear and non-linear isotherms and kinetic models. Error functions were determined to have a holistic view on optimum parameters and to validate prediction of models. Harkin-Jura exhibited better fit than that of Freundlich and Langmuir isotherms suggesting multilayer adsorption of RB5 onto TSB on the basis of R2 and chi-square (X2) error values. Adsorption kinetics was best explained by intraparticle diffusion model (IPD) at increasing initial concentration of RB5. Among the error functions evaluated, the X2 values for the IPD model were found to be smaller than those for PSO. This suggests that kinetics of RB5 dye is better controlled by IPD phenomenon. Fourier transform infrared spectroscopy confirms the physical adherence of dye to the adsorbent. Values of Gibbs free energy were found to be -19.55 -21.41, -23.40 and -25.33 kJ/mol which shows spontaneous adsorption. Moreover, it is found that TSB adsorbent could be utilized as the effective and economically viable adsorbent for RB5 dye from aqueous solution. [ABSTRACT FROM AUTHOR]

Reliable prediction of precipitation by numerical weather prediction (NWP) models depends on the appropriate representation of cloud microphysical processes and accurate initial conditions of observations of atmospheric variables. Therefore, to retrieve reasonable cloud distributions, a 1-D variational Ice Cloud Microphysics Data Assimilation System (IMDAS) is developed to improve the predictability of NWP models. The general framework of IMDAS includes the Lin ice cloud microphysics scheme as a model operator, a four-stream fast microwave radiative transfer model in the atmosphere as an observation operator, and a global minimization method that is known as the shuffled complex evolution. IMDAS assimilates the satellite microwave radiometer data set of the Advanced Microwave Scanning Radio- meter for the Earth Observing System (AMSR-E) and retrieves integrated water vapor and integrated cloud liquid water content. This new method successfully introduces heterogeneity into the initial state of the atmosphere, and the modeled microwave brightness temperatures agree well with the observations of the Wakasa Bay Experiment 2003 in Japan. It has significantly improved the performance of the cloud microphysics scheme by the intrusion of heterogeneity into the external global reanalysis data, which resultantly improved atmospheric initial conditions. [ABSTRACT FROM AUTHOR]

Heavy metal contamination impacts plant growth and productivity by causing damage at all levels of plant organization, making it one of the most significant abiotic stressors. This study evaluated the uptake and distribution of cadmium (Cd) and copper (Cu) in Solanum lycopersicum L. and identified the antioxidant enzyme activity and tolerance capacity. In Hoagland's nutrient solution, plants were exposed to Cd and Cu for 21 days. Fresh biomass of roots and shoots, root length, Cd and Cu accumulation and antioxidants were determined. Fresh biomass of roots and shoots was maximum in control treatment. A decline of 87 and 69% in root and shoot fresh weight was observed, respectively, at 100 µM of Cd as compared to the control. While a decline of 62 and 84% in root and shoot fresh weight was observed, respectively, at 20 µM of Cu as compared to control. Root growth decreased due to Cd and Cu stress as no root growth was measured at 20 µM of Cu, and the lowest root increment of 0.12 cm was observed at 100 µM of Cd. Maximum accumulation was found at 75 µM of Cd and 20 µM of Cu where roots accumulated greater as compared to shoots. In the leaves, the CAT, APX, and SOD activities increased at almost all levels of Cd and Cu. S. lycopersicum showed significant reduction in biomass and is not tolerant or accumulator of Cd and Cu. Chelators or soil conditioners need to be used to reduce the anticipated metal toxicity. [ABSTRACT FROM AUTHOR]

Herein, 3D flower-like δ-MnO 2 , MXene and δ-MnO 2 /MXene in-situ hybrid (IH) composites were prepared (via hydrothermal and solution treatment methods) for the effective removal of Cr (VI) from the contaminated water. The effect of various experimental parameters including contact time, pH levels and initial Cr (VI) ions concentration was determined and compared under static conditions. The kinetics of Cr (VI) adsorption onto δ-MnO 2 , MXene, and IH confirmed the existence of a pseudo-second-order model. The obtained results reveal that the removal of Cr (VI) largely depends on the pH of the solution. The adsorption isotherm data fits best for Freundlich model, illustrating a multi-site adsorption mechanism of Cr (VI) ion on these adsorbents. The maximum Cr (VI) adsorption capacities onto δ-MnO 2 , MXene and IH are 235.65 mg g−1, 273.1 mg g−1 and 353.87 mg g−1, respectively. The study reveals that hetero-engineered approach of synthesizing transition metal oxides with MXenes provides abundant opportunities to remove contaminants from water with better efficiency due to reduction and electrostatic interaction. [ABSTRACT FROM AUTHOR]

Environmental matrices are polluted with the plethora of contaminants, and among these, the concerns related to heavy metals (HMs) are also included. Due to the low cost in a long-term application and environmental friendliness, the use of biological remediation has gained significant attention in recent decades. The use of ornamental plants (OPs) in the field of phytoremediation is scarcely reported, and the impacts of HMs on OPs have also not been investigated in great depth. The OPs mediated HMs remediation can simultaneously remove contaminants and bring improvement in aesthetics of the site. The biomass of OPs produced after such activities can be used and sold as pot plants, cut flowers, essential oils, perfumes, air fresheners production, metal phytomining, and feedstock in silk production. The OPs also present a lower risk of HMs bioaccumulation compared to crop plants. This review focuses on the current knowledge of HMs toxicity to OPs, their applicability advantages, methods to improve the tolerance of OPs with incremented HMs uptake, challenges in the field, and future application perspectives. The case studies realted to practical application of OPs, from China, Iran, India, Oman, Pakistan, and Turkey, were also discussed. This work fetches the inter-disciplinary features and understanding for the sustainable treatment of HMs in a new novel way, to which no previous review has focused. [Display omitted] [ABSTRACT FROM AUTHOR]

Waste wood biomass as precursor for manufacturing activated carbon (AC) can provide a solution to ever increasing global water quality concerns. In our current work, Melia azedarach derived phosphoric acid-treated AC (MA-AC400) was manufactured at a laboratory scale. This novel MA-AC400 was tested for RO16 dye removal performance as a function of contact time, adsorbent dosage, pH, temperature and initial dye concentration in a batch scale arrangement. MA-AC400 was characterized via scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering (DLS) and fluorescence spectroscopy. MA-AC400 is characterized as mesoporous with BET surface area of 293.13 m2 g−1 and average pore width of 20.33 Å. pHPZC and Boehm titration confirm the acidic surface charges with dominance of phenolic functional groups. The average DLS particle size of MA-AC400 was found in the narrow range of 0.12 to 0.30 µm and this polydispersity was confirmed with multiple excitation fluorescence wavelengths. MA-AC400 showed equilibrium adsorption efficiency of 97.8% for RO16 dye at its initial concentration of 30 mg L−1 and adsorbent dose of 1 g L−1. Thermodynamic study endorsed the spontaneous, favorable, irreversible and exothermic process for RO16 adsorption onto MA-AC400. Equilibrium adsorption data was better explained by Langmuir with high goodness of fit (R2, 0.9964) and this fitness was endorsed with lower error functions. The kinetics data was found well fitted to pseudo-second order (PSO), and intra-particle diffusion kinetic models. Increasing diffusion constant values confirm the intraparticle diffusion at higher RO16 initial concentration and reverse was true for PSO chemisorption kinetics. MA-AC400 exhibited low desorption with studied eluents and its cost was calculated to be $8.36/kg. [ABSTRACT FROM AUTHOR]

Retrieval of land surface variables and atmospheric variables over land from passive microwave remote-sensing data sets has been a challenge for many years. A lot of progress has been made in these quests such as using cloud-resolving models and data assimilation. Data assimilation allows the integration of observations (including observation errors) into imperfect models, thereby yielding more improved model forecasts. In this work, a coupled data assimilation framework (CDAF) is proposed and applied to predict the evolution of land surface and atmospheric conditions. CDAF comprises a coupling of two data assimilation schemes, namely a land data assimilation scheme (LDAS) and an ice microphysics data assimilation scheme (IMDAS). This system has been developed and evaluated using data for the Tibetan Plateau. In this framework, both low-frequency and high-frequency passive microwave brightness temperatures (T Bs) are assimilated. Low-frequency T Bs are assimilated in the LDAS subsystem and used to obtain land surface conditions, which are subsequently used as improved initial conditions together with high-frequency T Bs and assimilated in the IMDAS subsystem to obtain atmospheric conditions. The retrieved land surface variables and integrated atmospheric variables are demonstrated to show good agreement with observed land and atmosphere conditions such as those derived from point measurements of temperature and soil moisture (using the Soil Moisture and Temperature Measurement System (SMTMS)), sonde, Advanced Infrared Sounder (AIRS) and Global Precipitation Climatology Project (GPCP) products. The distribution of integrated cloud liquid water and cloud ice is shown to follow the observed cloud distribution over the study area. It is shown that by using IMDAS with modifications to account for precipitation and a good description of land surface emission, it is possible to obtain precipitation information of high fidelity over the land surface. Retrieved integrated water vapour using IMDAS shows correspondence with ‘corrected’ AIRS total precipitable water product. It is also shown that the relative humidity profile obtained from IMDAS agrees with the corresponding sonde profile. From the simulations, it is clear that by using the CDAF, there is marked improvement in the forecast conditions compared with the non-assimilation scenario for all of the variables considered. Comparisons with observed land surface conditions and inferences of atmosphere state from the Geostationally Operational Environmental Satellite Series 9 (GOES-9) InfraRed Channel 1 (IR1) brightness temperatures and the GCPC's cumulative daily precipitation indicate that the CDAF is able to generate reliable forecasts that agree with observation-derived products. [ABSTRACT FROM AUTHOR]