COMPARATIVE ADSORPTION STUDY ON RICE HUSK AND RICE HUSK ASH BY USING AMARANTHUS GANGETICUS PIGMENTS AS DYE

Low cost adsorbents such as Rice Husk (RH) and Rice Husk Ash (RHA) were used for removing dyes from aqueous medium and later Linear, Langmuir and Freundlich adsorption isotherms have been verified by using adsorption data. RH was activated by treating with nitric acid and RHA was prepared from RH by dolomite process. Natural dyes were extracted from the vegetable Amaranthus gangeticus by using a standard method. The removal efficiency of adsorbents was measured for the variation of parameters pH, contact time and adsorbents concentration. It has been noted that after changing time for same amount of adsorbent (1g/100ml) and dyes (10 ml) RH gave no efficiency trend but increased to 43.91% whereas for RHA efficiency was gradually increased to 59.62%. A reverse trend was noted when adsorption amounts were changed and others were put constant where RHA efficiency gradually increased to 99.30% but RH gave no trend with highest efficiency was close to 61.85%. The RH removal efficiency was good for pH 11 close to 62.86% and it was continuous from 3.95% at pH 2. Alternately, RHA gave 80.21% at pH 2 and later was decreased to 1.5% at pH 9 and again increased from pH 11. It is noted that RHA removal efficiency is better than RH and adsorptions are well fitted with isotherms

COMPARATIVE ADSORPTION STUDY ON RICE HUSK AND RICE HUSK ASH BY USING AMARANTHUS GANGETICUS PIGMENTS AS DYE

Low cost adsorbents such as Rice Husk (RH) and Rice Husk Ash (RHA) were used for removing dyes from aqueous medium and later Linear, Langmuir and Freundlich adsorption isotherms have been verified by using adsorption data. RH was activated by treating with nitric acid and RHA was prepared from RH by dolomite process. Natural dyes were extracted from the vegetable Amaranthus gangeticus by using a standard method. The removal efficiency of adsorbents was measured for the variation of parameters pH, contact time and adsorbents concentration. It has been noted that after changing time for same amount of adsorbent (1g/100ml) and dyes (10 ml) RH gave no efficiency trend but increased to 43.91% whereas for RHA efficiency was gradually increased to 59.62%. A reverse trend was noted when adsorption amounts were changed and others were put constant where RHA efficiency gradually increased to 99.30% but RH gave no trend with highest efficiency was close to 61.85%. The RH removal efficiency was good for pH 11 close to 62.86% and it was continuous from 3.95% at pH 2. Alternately, RHA gave 80.21% at pH 2 and later was decreased to 1.5% at pH 9 and again increased from pH 11. It is noted that RHA removal efficiency is better than RH and adsorptions are well fitted with isotherms

Surface and Ground Water Pollution in Bangladesh: A Review

Environmental analysis does not become properly meaningful unless follow the standard procedure in sampling, preserving and also in analysis. This study investigates different studies on surface and groundwater pollution and discusses their findings along with impacts on environment, human health and aquatic ecosystem demolition. Fresh water is a vital need for drinking, household, agricultural and industrial use. Fresh water availability is shrinking worldwide due to imprudent use. Abound availability of fresh water in Bangladesh is now polluting due to unwise dumping of industrial, household, agricultural and municipal wastes. Water body in urban arena is severely polluted rather than rural part. The over concentration of DO, BOD, COD, EC, TDS, Cr, Cd, Pb was observed in Dhaka region. The highest arsenic concentration was found in the ground water of Lakshimpur. The main sources of pollution in industrial cities are anthropogenic sources like untreated industrial effluent and municipal wastes whereas in rural part the main sources of pollution are agricultural and naturogenic. Transboundary impact also intensifies some river water pollution. Government approved the policies, ordinance, acts and laws however, due to lack of proper implementation and monitoring water pollution problem increasing day by day

(Quinolin-8-yl) Tin Synthons in Transmetalation Reactions with Transition Metals Yield Multimetallic Organometallic Molecules and Clusters

Transition metal (Hg, Ag, Pd, Ni, Sn, Cu) complexes and clusters form from the reaction of metal salts and QSnX (Q = quinolin-8-yl; X = Q or Cl) synthons. Our original intent was the use of Q2Hg, Q2Sn, or QSnCl as an ambiphilic ligand; however, we observed an apparent redox-trans metalation reaction in most of the cases. Bimetallic Hg-Ag complexes were prepared using Q2Hg as an ambiphilic ligand. Heterobimetallic (Ni-Sn and Pd-Sn) complexes were obtained from the reaction of NiCl2 (or PdCl2) with in situ generated QSnCl. Geometry and electronic configuration of the complexes were investigated using DFT methods. The NBO analysis predicts a two-fold interaction between Ni-Sn and Pd-Sn that includes an attractive covalent bonding component and a repulsive electrostatic component. Mayer Bond Order calculation suggests a low degree of covalent bonding between Ni-Sn and Pd-Sn bonds. This establishes that the QSn ligand may be acting as an ambiphilic ligand in the Ni-Sn and Pd-Sn complexes. Copper and palladium clusters were formed from redox transmetallation reactions using in situ generated Q2Sn, or Me2SnQ2 and Ph2SnQ2 ligands. An unusual structural motif, a low-valent, coordinatively unsaturated, M-m-Sn-M (M = Cu or Pd) atom was observed in clusters Q4Cu6Sn2, Q3Cu3Sn4, and Q4Cl2Pd4Sn2. X-ray studies prompted us to investigate their electronic structures using computational methods. QTAIM, MBO analysis, and CM5 charge models were calculated for the respective clusters. The atomic charge on this unusual tin atom was calculated in the range (-0.39) – (+0.08). This work demonstrates a new approach to synthesizing bimetallic clusters and molecules using QSnX