Comparison of Adsorption Performance of Biochar Derived from Urban Biowaste Materials for Removal of Heavy Metals

This study investigated the adsorption performance of biochar produced from different types of urban biowaste material viz., sugarcane bagasse (SB), brinjal stem (BS), and citrus peel (CP) for removal of heavy metal ions (Pb, Cu, Cr, and Cd) from aqueous solution. The effects of biowaste material, dosage of biochar, solution pH, and initial concentration of heavy metal ions and isotherm models were performed to understand the possible adsorption mechanisms. The results showed that the biochar derived from BS and SB removes Cu (99.94%), Cr (99.57%), and Cd (99.77%) whereas biochar derived from CP removes Pb (99.59%) and Cu (99.90%) more efficiently from the aqueous solution. Biochar derived from BS showed maximum adsorption capacity for Cu (246.31 mg g-1), Pb (183.15 mg g-1), and Cr (71.89 mg g-1) while the biochar derived from CP showed highest for Cd (15.46 mg g-1). Moreover, biochar derived from BS and SB has more polar functional groups and less hydrophobicity than the biochar derived from CP. This study reveals that solution pH and biochar doses play a major role in removal of heavy metal ions from aqueous solution. The results of Langmuir model fitted well for Pb and Cu while the Freundlich model for Cr and Cd. Our study concludes that the biochar derived from different biowaste materials adsorbs heavy metal ions majorly through surface complexation and precipitation processes. The results of this study will be very useful in selecting the effective urban biowaste material for making biochar for heavy metal removal from the aqueous environment.

A new low temperature solid modification in 1-isothiocyanato-4-(trans‑4-propylcyclohexyl)benzene (3CHBT) probed by Raman spectroscopy and quantum chemical calculations

Raman spectra of 1-isothiocyanato-4-(trans 4-propylcyclohexyl)benzene (3CHBT) were studied in the region, 1450-2300cm^-1 at twenty two different temperatures in the range, 83-293K in cooling and heating cycles. All bands in this region were critically evaluated in term of linewidth, peak position and relative intensity. Raman bands at ~2085cm^-1 and ~2120cm^-1 shows clear evidence of a solid modification through anomaly in temperature dependence peak positions and linewidths variation in the temperature range 173-203K. A detailed analysis of the variation of the linewidth and peak position of the two component bands leads to the conclusion that the molecular/dimer arrangement in crystalline packing changed between 173K and 203K. This solid modification was also analyzed at the molecular level. The ~2085cm^-1 and ~2120cm^-1 bands were corresponded as parallel and anti-parallel dimers of 3CHBT, which are identified as dimer I (D₁) and dimer II (D₂), respectively. The structures of both the dimers have been optimized by quantum chemical calculations employing density functional theoretic (DFT) methods.

Beneficiary level factors influencing Janani Suraksha Yojana utilization in urban slum population of trans-Yamuna area of Delhi

BACKGROUND & OBJECTIVES

Janani Suraksha Yojana (JSY), a conditional cash transfer scheme introduced to improve the institutional delivery rates and thereby reduce the maternal and infant mortality was implemented in all States and Union Territories of India from 2007. The present study was carried out to identify the beneficiary level factors of utilization of JSY scheme in urban slums and resettlement colonies of trans-Yamuna area of Delhi.

METHODS

A cross-sectional community based survey was done of mothers of infants in the selected areas of the two districts by stratified random sampling on a population proportionate basis. Socio-demographic factors, antenatal services availed and distance of nearest health facility were studied. Outcome variable, a beneficiary, was a woman who had ever interacted with the ASHA of her area during the antenatal period of previous pregnancy and had child birth in an institution. Descriptive tables were drawn; univariate analysis followed by multiple logistic regression was applied for identifying the predictors for availing the benefits.

RESULTS

Of the 469 mothers interviewed, 333 (71%) had institutional delivery, 128 (27.3%) had benefited from JSY scheme and 68 (14.5%) had received cash benefits of JSY. Belonging to Hindu religion and having had more than 6 antenatal check ups were the significant predictors of availing the benefits of JSY.

CONCLUSION

There is a need to improve the awareness among urban slum population about the utilization of JSY scheme. Targeting difficult to access areas with special measures and encouraging more antenatal visits were essential, prerequisites to improve the impact of JSY.

Low temperature Raman study of a liquid crystalline system 4-decyloxy benzoic acid (4DBA)

The Raman spectra of a liquid crystalline system, 4-Decyloxy benzoic acid (4DBA) have been recorded at different temperatures within the interval 300-78 K in order to identify the structural changes in crystalline state of a nematogen and to understand the molecular alignment therein. The earlier predicted dimer structure of 4DBA was optimized with DFT method and the theoretical Raman spectra of dimer as well as monomer have been calculated for comparison with the experimental spectra. The mode specific quartic coupling coefficient; A(i,ω) and phonon frequency; ωi have been calculated using temperature dependent anharmonic perturbation theory. The precise band shape analysis of Raman bands at ~807, ~881, ~1255, ~1282, ~1436, ~1576, ~1604, ~2881 and ~3081cm(-1) gives signature of temperature induced slow crystal modification. The structural changes leading to crystal modification have been discussed.

Temperature dependent Raman study of S(B)-->S(C) transition in liquid crystalline compound N-(4-n-pentyloxybenzylidene)-4'-heptylaniline (5O.7)

Temperature dependent Raman study of C-H in-plane bending mode ( approximately 1163cm(-1) and approximately 1190cm(-1)) and C-C stretching mode of phenyl ring ( approximately 1571cm(-1) and approximately 1594cm(-1)) of N-(4-n-pentyloxybenzylidene)-4'-heptylaniline (5O.7) has been done. Vibrational assignment and potential energy distribution (PED) of individual modes have been calculated employing density functional theory (DFT) for the first time. The S(B)-->S(C) transition is nicely depicted in the variation of the linewidth of the approximately 1163cm(-1) band and the peak position of approximately 1594cm(-1) band with temperature. Because of a small amount of charge density transfer from the core part to the alkyl chain region, the approximately 1163cm(-1) band shifts towards lower wavenumber side whereas the approximately 1190cm(-1) band towards higher wavenumber side at S(B)-->S(C) transition. The approximately 1571cm(-1) and approximately 1594cm(-1) bands are assigned as 8a and 8b modes, whose relative intensity variation with temperature gives the evidence of increased possibility of C-H bending motion of the linking group and the C-C stretching of the alkyl chain in S(C) phase.

Temperature-dependent Raman study of the smectic to nematic phase transition and vibrational analysis using density functional theory of the liquid crystalline system 4-decyloxy benzoic acid

Room-temperature Raman spectra of the thermotropic liquid crystalline system, 4-decyloxy benzoic acid (4DBA) have been recorded and the experimentally observed bands are assigned by density functional theory (DFT) for the first time. The C-O and C-C stretching and C-H in-plane bending modes of the phenyl ring and C=O stretching modes of the -COOH group are the marker bands for the smectic (S) --> nematic (N) and nematic (N) --> isotropic (I) transitions for this system. The temperature-dependent Raman spectra for these bands in the heating cycle clearly characterize the S-->N and the N-->I transition over a range <1 degree C, which is much better than the earlier range of 23 degrees C for S-->N and 26 degrees C for the N-->I transition. The approximately 773, approximately 807, approximately 881, and approximately 1146 cm(-1) bands disappear, whereas a band at approximately 830 cm(-1) appears at the S-->N transition. The relative intensity of the approximately 1257 and approximately 1280 cm(-1) bands distinguishes the three phases, namely smectic, nematic, and isotropic, in 4DBA. The variation of line width and peak wavenumber of the approximately 1128 and approximately 1168 cm(-1) bands also clearly shows the two transitions. The molecular reorientation at the transition and the effect of local fields present in the liquid crystalline mesophases are also briefly discussed on the basis of changes in intensity, linewidth and peak wavenumber with temperature.