Sludge granulation and e ciency of phase separator in UASB reactor treating combined industrial e uent

Sludge granulation and the effect of gas-liquid-solid separator （GLSS） design on the efficiency of upflow anaerobic sludge blanket （UASB） and upflow anaerobic sludge filter （UASF） reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age （from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor）. X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease （82%-69%） in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved （14%-20%） the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient.     

To duckweeds (Landoltia punctata), nanoparticulate copper oxide is more inhibitory than the soluble copper in the bulk solution

CuO nanoparticles (CuO-NP) were synthesized in a hydrogen diffusion flame. Particle size and morphology were characterized using scanning mobility particle sizing, Brunauer-Emmett-Teller analysis, dynamic light scattering, and transmission electron microscopy. The solubility of CuO-NP varied with both pH and presence of other ions. CuO-NP and comparable doses of soluble Cu were applied to duckweeds, Landoltia punctata. Growth was inhibited 50% by either 0.6 mg L⁻¹ soluble copper or by 1.0 mg L⁻¹ CuO-NP that released only 0.16 mg L⁻¹ soluble Cu into growth medium. A significant decrease of chlorophyll was observed in plants stressed by 1.0 mg L⁻¹ CuO-NP, but not in the comparable 0.2 mg L⁻¹ soluble Cu treatment. The Cu content of fronds exposed to CuO-NP is four times higher than in fronds exposed to an equivalent dose of soluble copper, and this is enough to explain the inhibitory effects on growth and chlorophyll content.     

Novel Pretreatment Performance Evaluation for Cellulose Nanofibrils Extraction from Ficus natalensis Barkcloth

Recently, nanosized cellulose materials extraction is extensively interesting from the sources of sustainable materials. Cellulose nanofibrils (CNF) extraction through green bio-based materials featured as promising interest in the field of science. In this study, dimethyl sulfoxide (DMSO) was applied to examine its effectiveness in pretreating the Ficus natalensis barkcloth cellulose (FNBC) for CNF production before 2,2,6,6,-tetramethylpiperidine-1-oxyl (TEMPO) oxidation. The pretreatment performance of DMSO was evaluated based on the structural and morphological changes. DMSO pretreated FNBC attained the most dramatic morphological changes as compared to untreated cellulose samples. The results of the scanning electron microscope (SEM) and transmission electron microscope (TEM) shows that there is an extensive structural disruption of FNBC during the pretreatment process, which could be because of outstanding ability to eliminate non-cellulosic materials and amorphous regions from the FNBC, confirmed by the X-ray diffractometry (XRD) showing higher crystallinity values, as well as higher thermal stabilities values of pretreated FNBC samples, were also noted. Overall, this study revealed a tremendously effective and pioneer pretreatment method for fractionating FNBC, to stimulate the successive extraction of cellulose nanofibrils. Furthermore, based on the cellulose and CNF characterizations, this study showed that F. natalensis barkcloth could be considered as an alternative source of cellulose for potential value-added industrial applications such as the food industry, paper making, and biomedicines.

Graphic Abstract

     

Clean and sustainable transportation through electric vehicles — a user survey of three-wheeler vehicles in Pakistan

Environmental Science and Pollution Research - Transportation sector is one of the major contributors to GHG emissions, and it is essential to investigate the role of electric vehicles in economic...