Adsorption potentialites of bio-sorbents derived from prosopis cineraria and hibiscus rosa-sinensis in the removal of methyl orange dye from polluted waters.

Leaves, stems and their ashes of Prosopis cineraria and Hibiscus rosa-sinensis have been explored for their surface sorption abilities towards Methyl Orange Dye using simulated waters. Various physicochemical parameters such as pH, time of equilibration and sorbent concentrations are optimized for evoking the sorption potentialities of the plant materials for the maximum extraction of the Methyl Orange Dye from waters. The surface sorption nature is found to pH sensitive and % of removal is maximum near pH: 3. % removal of the Dye is more with ashes than respective bio-materials. Co-anions, in fivefold excess, are found to be interfering in the order: trivalent anion>divalent > monovalent while co-cations have shown relatively less interference on the extraction of the Dye at optimum conditions of extraction. The adoptability of the methodologies developed is tested with some real industrial effluents.

Extraction of methylene blue dye from polluted waters using some bio-adsorbents.

Sorbents derived from roots of Tephrosia purpurea, leaves and stems of Terminalia Arjuna and Bivalve snail shells have been explored for their sorption abilities towards Methylene Blue using synthetically prepared simulated waste waters. It is found that at high pHs, these bio-materials have shown strong affinity towards Methylene Blue. The physicochemical properties such as pH, sorbent concentration and time of equilibration have been optimized for the maximum removal of Methylene Blue from waste waters. Methodologies have been developed to extract good quantities of the dye. The roots powder of Tephrosia Purpurea has been proved to very effective even at 1.0 gm/500 ml of the sorption concentration at pH :8 or 10. More than 95.0% of extraction of Methylene Blue has been found with the bark powders of Terminalia Arjuna at all pH of study viz., 2-10. Interference of Fivefold excess of common anions and cations present in natural waters, have been studied. Anions have not interfered while Cation like Ca2+, Mg2+ and Cu2+ have shown some interference but Fe2+ and Zn2+ have synergistically maintained the maximum extraction of the dye. The procedures developed have been successfully applied to some industrial effluent.

New bio-sorbents in the control of chromium (VI) pollution in waste waters.

The sorption abilities of leaves powders of Bhringraj , Aerva lanata, Trianthema portulacastrum L for extracting Chromium (VI) from polluted waters have been studied with respect to various physicochemical parameters such as pH, sorption dosage and equilibrium time. The conditions for maximum removal of Chromium (VI) have been optimized. Ten fold excess of common cation ions present in natural waters, viz., Ca2+, Mg2+ , Cu2+, Zn2+, Ni2+ and Fe2+ have synergistic effect in increasing the % removal of Chromate. SO4 2—and Phosphates are found to be interfering with the extractability of Chromates but NO3 - , Chloride, Fluoride and Carbonate have marginal interference. However, the extraction has never come down below 72.0%. Maximum extractions to an extent of 96.0%, 92.0%, and 84.0% from synthetic waters are observed with the leaves powders of Bhringraj , Aerva lanata, Trianthema portulacastrum L respectively at pH:2 and at optimum equilibration time and sorbent concentrations. The methodologies developed are applied to diverse waste water samples collected from industrial effluents and polluted lakes. The procedures are found to be remarkably successful in removing the Chromiume(VI) from waste waters.

Stems and their ashes of some herbal plants as adsorbents in the removal of chromium (VI) from waste waters.

A thorough investigation is made to explore the surface sorption abilities of powders of stems and their ashes of some herbal plants in controlling the Chromium (VI) pollution in waste waters. It is found that the powders of stems and their ashes of Achyranthes aspera, Mentha, Emblica officinalis, Hybiscus roja sinensis, Ocimum sanctum and Psidium guajava have strong affinity towards Chromate at low pH values. % of removal of Chromate is found to be pH sensitive and also depends on sorption concentration and time of equilibration. The conditions for the maximum extraction of Chromate at minimum dosage of sorbent and equilibration time have been optimized. More than 90.0% of removal of Chromate is found. Sorbent concentrations and time needed for the maximum removal of Chromate is less for the ashes of stems than with the raw stem powders. The presence of ten fold excesses of Cations : Ca2+, Mg2+ , Cu2, Zn2+ and Ni2 + and anions like NO3 - ,Chloride, Fluoride and Carbonate have marginally effected the % removal of Chromium (VI) while Sulphate and Phosphate showed some interference with some sorbents but even with them, the % of extractability never comes down to 71.0%. The adoptability of the methodologies developed in this work are tested with respect to diverse waste water samples collected from industrial effluents and in natural lakes and found to be remarkably successful.

Removal of phosphates from polluted waters using bio-adsosrbents.

Increasing interest is being envisaged by environmental researchers in controlling the phosphates pollution in natural waters by evoking the surface sorption characteristics of bio-waste materials of flora origin. In the present work, a thorough investigation has been made to find powders of leaves or their ashes of different classes of plants, having the affinity towards phosphate ions. 10 plant leaves and their ashes have been found to have sensitivity towards Phosphate ion. Investigations have been made in optimizing the various physico-chemical parameters such as equilibration time, pH and sorption dosage for the maximum removal of phosphates. The % of removal is found to be increasing with the increase in pH and equilibration time. The ashes of leaves shows more sorption towards phosphates than powders of leaves.79% to 90% removal of phosphate from polluted waters are found at optimum conditions with the sorbents investigated in this work. The interference of foreign ions on the % of extraction of phosphate reveals that some divalent cations are found be synergizing the extraction and thereby % of removal of Phosphate is increased even in the presence of 500 ppm of the said ions.

Fluoride pollution in ground waters of Kandukur revenue Sub-Division of Prakasam district in A.P., India and batch mode defluoridation using active carbons of some plant byproducts as adsorbents.

Fluoride is an acute toxin and is deemed to be slightly more dangerous than even lead. 48 water samples collected from hand pumps and bore wells belonging to 24 gram panchayats (villages) of Kanduku revenue sub division of Prakasam district in Andhra Pradesh, were chemically analyzed for fluoride ion concentrations. High and low fluoride containing regions were identified on the basis of fluoride levels in the water samples and also on the prevalence rate of dental and skeletal fluorosis of the study area. Further, water samples containing high fluoride levels were tried for defluoridation by employing Active Carbons of abundantly available low-cost plant byproducts. These materials under optimum conditions of adsorbent dosage, time of equilibration and pH, were found to be successfully decreasing the fluoride ion concentration below permissible limits without disturbing drinking water quality standards.