Statistical Interpretation and Profiling the Leaching Characteristic of Chromium in the Basic Chrome Sulphate (BCS) Sludge Dumping at Village Khanchandpur-Rania, District Kanpur Dehat, Uttar Pradesh (India)

Without immobilized hazardous waste contaminates soil and groundwater, which can further bio-accumulates and poses serious negative health impact on flora as well as fauna. The present investigation has been conducted to study of leaching behavior of chromium species in immobilized hazardous waste containing Basic Chrome Sulphate (BCS) dumped at dumping site Khanchandpur Kharanja, Rania, Kanpur Dehat district of Uttar Pradesh, India. Results indicated that the pH of sludge ranged from 10.16–11.90 while EC ranged from 840-16160 dSm-1 in a different layer of the dumpsite and significantly varies on increasing depth. A similar trend was also observed in TDS contents which strongly justified the leaching of salts in lower depth. Total Cr concentration (25029.94 mg kg-1) was observed in the top layer which was significantly increased on increasing depth i.e., 36102.0 mg kg-1 and 42811.77 mg kg-1 while TCLP based concentration ( 216.44 mg kg-1 in top layer) was significantly increased on increasing depth i.e., 406.25 mg kg-1 and 517.60 mg kg-1. A similar trend was also observed in total and TCLP hexavalent and trivalent (Cr6+ and Cr3+) chromium concentration. Hierarchical Cluster Analysis is separated all sample based on depth into three different cluster based on dissimilarity. A significant correlation was observed with TCLP Cr6+ in TCLP Cr3+, EC, and TDS at 0.01 levels while EC, TDS, total Cr6+, and TCLP Cr were significant correlated with TCLP Cr3+. The leaching behavior of Cr species was higher as well as increasing of depth in the dumping site.

Biosorption of chromium by dry algae Chlorella kessleri

Decontamination of environment according to traditional methods is not only economically inaccessible but also often highly environmentally harmful. It is necessary to apply methods that are environmentally friendly as possible. These methods include bioremediation, which uses organisms able to fight with high concentrations of pollutants to decontaminate the environment. In this study, we observed the biosorption of chromium from the aquatic environment using dried algae Chlorella kessleri. The results of the specific sorption at pH = 4.00 in the chromium model sample had a value of q = 5.9 mg / g, which represented a decrease in the chromium concentration by 74%. The specific sorption in the case of the native chromium sample q after 24 hours reached the highest value (q = 2.74 mg / g) at pH = 4.00. During the experiment, we observed a constant change in the content of photosynthetic pigments in the prepared solutions where it was shown that after 24 h exposure the yield of chlorophyll a was decrease by 95.91% compare to control. In the case of chlorophyll b, the same trend was demonstrated where 91.92% decrease of its content after 24 hours was observed. This type of dried alga has been shown to be a rapid biosorbent, in relatively short time intervals. The results of the study show that in the process of decontamination there was not only the binding of chromium to the cell surface but also its penetration through the cell wall.

The Danubian cryptic invader Theodoxus fluviatilis (Gastropoda: Neritidae) in the River Rhine: a potential indicator for metal pollution?

Metal pollution poses a major threat to aquatic systems especially in anthropogenic influenced areas, in as much as metals are persistent in the environment. The freshwater snail Theodoxus fluviatilis has often been used as an indicator species for the ecological status in river monitoring. In the River Rhine, the native Northern-European form of T. fluviatilis is nowadays extinct, whilst the Danubian form is spreading along the river. The aim of our study was to investigate if the cryptic invader is affected by metal exposure present in the River Rhine and to discuss its potential as an indicator for metal pollution. Several environmental abiotic (14 water environmental variables plus five common metal concentrations in water and biofilm) and biotic parameters (biofilm mass) were measured across 23 sites along the River Rhine. Five population and six histopathological parameters were evaluated on snails collected at all 23 sites. Aqueous chromium concentration was positively correlated to the damage of male reproductive organs of T. fluviatilis, and higher ammonium concentration was correlated to a decrease in snail size and an increase in the proportion of juveniles. None of the analysed snail parameters was negatively correlated to concentrations of other metals measured, like copper and zinc. Therefore, based on the parameters evaluated, our results indicate that the Danubian form of T. fluviatilis is only restrictedly suitable as an indicator for metal pollution in the River Rhine system. Further field and laboratory investigations including other stressors are necessary to evaluate the indicator potential of the cryptic invader holistically.

Effect of chromium substitution on the dielectric, ferroelectric and piezoelectric properties of PLNZNT ceramics (P=Pb2+, L=La3+, N=Nd3+, Z=Zr4+, N=Nb5+, T=Ti4+)

Piezoelectricity is one of the renewable and clean electrical energy sources, as it is generated from materials specially manufactured for this purpose in proportions and scales called piezoelectric materials, that is, electricity resulting from mechanical work that produces the electric field, and this is known as the direct piezoelectric effect. An inverse mechanical effect can also be observed when an electric field is applied to the same piezoelectric material that deforms and returns to its original shape after the electric field is removed. In order to contribute to improving the properties of these materials that have been prepared from insulating ceramic materials having an equivalent formula: Pb0.975 La0.015 Nd0.01 [(Zr 0,524 Ti 0,476) 0.9875 -3/4 z Nb0.005 Crz]O3 abbreviated PLNZCNT (z = 0%, 0.5%, 0.75%, 1%, 1.25%, 1,5% and 2%). The formation of pure single-phase perovskite compounds of tetragonal symmetry for all samples was confirmed by X-ray diffraction (XRD) analyzes. The scanning electron micrographs show that the grains have melted, most of the separating walls have disappeared, and the average grain size has increased. Information about the effects of chromium concentration on the measured properties was obtained based on temperature and frequency measurements of the dielectric properties of PLNZNT ceramics, represented by an increase in Curie temperature with increasing Cr3+ concentration. The ferroelectric properties of materials are characterized by the presence of a polarization hysteresis cycle as a function of the applied electric field (P-E). To measure the piezoelectric and electromechanical properties at room temperature, was used by the standard resonance and anti-resonance method. It was found that the sample E2 (0.75%) sintered at 1200°C achieves excellent dielectric, ferroelectric and piezoelectric properties (𝜺r=24394.51, tan δ =0.072 and Tc = 378K). The values of saturated electric polarization (Ps=29.61 µC/cm²), remnant electric polarization (Pr=24.63 µC/cm²) and coercive electric field (Ec=0.905kV/mm), as well as piezoelectric charge coefficient (d33 = 435 pC/N) for sample E2 (0.75%).

Investigating the hexavalent chromium removal from aqueous solution applying bee carcasses and corpses modified with Polyaniline

There are currently heavy metals in most industrial effluents which are among the most significant environmental pollutants. Hexavalent chromium is one of the most significant heavy metals. In this research for the first time, eliminating the hexavalent chromium from the aqueous medium/aquedia applying bee carcasses and corpses modified with polyethylene was examined. Adsorption experiments were conducted discontinuously on laboratory solutions, including hexavalent chromium. The optimal adsorption conditions such as different pH factors, contact time, initial chromium concentration, and adsorbent value on the adsorption rate were examined at different levels, and adsorption isotherms were plotted. Some adsorbent properties were examined using Field Emission Scanning Electron Microscopy, XRD analysis, Fourier Transform Infrared Spectroscopy, and BET test to study the properties of the synthesized adsorbent. This study indicated that the highest percentage of removal related to polyethylene composite and bee carcasses in the presence of polyethylene glycol was 50.56% among the bee carcasses composites. The parameters effective on the adsorption process for polyethylene composite and bee carcasses and losses in the presence of polyethylene glycol suggested that the adsorption percentage increased for this composite by decreasing the pH, increasing the contact time, and increasing the adsorbent. The highest percentage of adsorption was obtained when the pH was 2, the contact time was 120 min and the adsorbent value was 8 g/L and the initial concentration of chromium was 100 ppm. The most optimal removal percentage was achieved at the pH = 2, the contact time was 30 min, and the adsorbent value was 2 g/L, and the initial chromium concentration was 100 ppm. The results of drawing adsorption isotherms also indicated that higher R2 had a better fit than Langmuir for polyethylene composite and bee carcasses in the polyethylene glycol Freundlich equation.

A study on chromium accumulation in Labeo rohita in the river Yamuna ecosystem in Mathura-Agra region in Uttar Pradesh, India

The present study revealed the chromium toxicity and its health measures in L. rohita from the Yamuna river at Mathura- Agra region. Samples were taken in triplicate from both sites i.e. Vrindavan (Bihar ghat) and Agra (Renuka Ghat). The study was carried out on Four different organs (i.e. gills, muscles, liver, and kidney) of the fish sample. The sampling was done from Oct 2018 to January 2020. Chromium concentration in different organs of the fish was analyzed by Atomic absorption spectrophotometer(AAS). The average Cr concentration in gills was highest (9.64 mg/l) at the Mathura site followed byAgra sites (7.78 mg/l) for the month of April 2019. The concentration of Cr was highest in samples taken in the month of April 2019 and it was lowest in October 2018. The significantly high Cr concentration values were observed in the Mathura region than the Agra region for both seasons. In all samples, Cr concentration was above the standards stated by WHO except in the Kidney. In the present study, the bioaccumulation factor showed the chromium concentration in the tissues followed the order of gill > liver > muscle > kidney. HPI, MQI, and Pearson’s correlation coefficient analysis were also done in which HPI was observed very high and there was a positive correlation between all the samples. Keywords: Chromium, BCF, HPI, MQI, AAS, Fish Organs

Biosorption of Hexavalent Chromium Metal Ions by Lentinula Edodes Biomass: Kinetic, Isothermal, and Thermodynamic Parameters

Lentinula edodes was investigated as a biosorbent for hexavalent chromium biosorption in this study. To examine the optimum conditions of biosorption, the pH of the hexavalent chromium solution, biosorbent dosage, temperature, contact time, and initial hexavalent chromium concentration were identified. Further, to clarify the biosorption mechanism process, the isothermal, kinetic, and thermodynamic parameters were determined. The functional groups and surface morphology of the biosorbent were identified using Fourier transform infrared spectrometry and scanning electron microscopy in the absence and presence of hexavalent chromium, respectively. Based on the results, the maximum biosorption capacity was determined as 194.57 mg g–1 under acidic conditions at 45 °C. From the kinetics studies, the biosorption process was observed to follow the Freundlich isotherm and pseudo-second-order kinetic models well. Thus, L. edodes as a biosorbent has potential usage for wastewater treatment owing to its effective biosorption capacity.