Source identification study of heavy metal contamination in the industrial hub of Unnao, India.

India's Unnao region is home to many leather-treatment facilities and related industries. Industrial and agricultural waste leads to heavy metal contamination that infiltrates groundwater and leads to human health hazards. This work measured the amount of heavy metal in groundwater at specific sites near the industrial facilities in Unnao and identified potential sources of contamination as anthropogenic or lithogenic. Groundwater samples were taken from 10 bore well sites chosen for depth and proximity to industry. Data obtained from sample sites was interpreted using a multivariate statistical analytical approach, i.e., principal component analysis, clustering analysis, and correlation analysis. The results of the multivariate analysis showed that cadmium, copper, manganese, nickel, lead, and zinc were correlated with anthropogenic sources, while iron and chromium were associated with lithogenic sources. These findings provide information on the possible sources of heavy metal contamination and could be a model for assessing and monitoring heavy metal pollution in groundwater in other locales. This study analyzed a selection of heavy metals chosen on the basis of industries located in the study area, which might not provide a complete range of information about the sources and availability of all heavy metals. Therefore, an extended investigation on heavy metal fractions will be developed in further studies.

Biosorption of arsenic from aqueous solution using dye waste.

The purpose of this study is to examine on removal of arsenic from water by biosorption through potential application of herbal dye wastes. Four different flower dye residues (after extraction of natural dye) viz. Hibiscus rosasinensis, Rosa rosa, Tagetes erecta, and Canna indica were utilized successfully for the removal of arsenic from aqueous solution. Batch studies were carried out for various parameters viz. pH, sorbent dose, contact time, initial metal ion concentration, and temperature. Data were utilized for isothermal, kinetic, and thermodynamic studies. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDAX), and Fourier transform infrared (FTIR) analyses of biomass were performed. The results showed that 1 g/100 ml for 5.0-5.5 h contact time at pH 6.0-7.5 with agitation rate 150 rpm provided 98, 96, 92, and 85 % maximum absorption of arsenic by R. rosa, H. rosasinensis, T. erecta, and C. indica, respectively, at initial concentration of 500 ppb. Data followed Langmuir isotherm showing sorption to be monolayer on heterogeneous surface of biosorbent. Negative values of ΔG° indicated spontaneous nature, whereas ΔH° indicates exothermic nature of system followed by pseudo-first-order adsorption kinetics. FTIR results showed apparent changes in functional group regions after metal chelation. SEM and EDAX analyses showed the changes in surface morphology of all test biosorbents. Herbal dye wastes, used as biosorbent, exhibited significant (85-98 %) removal of arsenic from aqueous solution. Hence, these biosorbents are cost-effective, easily available, eco-friendly, and comparatively more effective than other biosorbents already in use. These may be used to remove arsenic and other toxic metals from water.

Biosorption of arsenic in drinking water by submerged plant: Hydrilla verticilata.

To evaluate the biosorption efficacy of submerged aquatic plant Hydrilla verticilata for arsenic uptake from drinking water. H. verticillata, a submerged aquatic plant was utilized successfully for arsenic uptake from aqueous solution. Batch studies with various parameters viz. pH, sorbent dose, contact time, initial metal ion concentration, and temperature were carried out. Data were utilized to plot Lagergren graph along with pseudo-second-order graphs for kinetic studies to estimate the removal efficacy and to determine the nature of reaction. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) have been performed for characterization of metals on biomass. The study showed 96.35 % maximum absorption of arsenic by H. verticilata at initial concentration of 100 ppb with 0.5 g of biomass/100 ml for 5 h contact time at pH 6.0 with 150 rpm agitation rate. Data followed Langmuir isotherm showing sorption to be monolayer on homogeneous surface of biosorbent. The negative values of ΔG° indicated spontaneous nature; whereas ΔH° indicates exothermic nature of system and negative value of ∆S° entropy change correspond to a decrease in the degree of freedom to the adsorbed species followed by pseudo-second-order adsorption kinetics. FTIR and SEM results showed apparent changes in functional group regions after metal chelation and the changes in surface morphology of biosorbent. This is a comparatively more effective, economic, easily available, and environmentally safe source for arsenic uptake from solution due to its high biosorption efficacy than other biosorbents already used.

Efficient biosorption of chromium(VI) ion by dry Araucaria leaves.

BACKGROUND: In this paper, batch removal of hexavalent chromium from aqueous solutions by Araucaria heterophylla leaves was investigated. The batch experiments were conducted to study the adsorption of metal species and effect of different pH, contact time, metal concentration, biosorbent concentration, and adsorption capacity. METHOD: Freundlich and Langmuir's isotherm model were used to describe the adsorption behavior, and the experimental results fitted Freundlich model well. RESULTS: The adsorption efficiency observed for all chromium concentrations, i.e., 1, 3, 5, and 10 mg/L was 100% and the equilibrium was achieved in 30 min for 1 and 3 mg/L, whereas for 5 and 10 mg/L, it was less than 60 min. FTIR spectra was taken to identify functional groups involved in the biosorption. CONCLUSION: Thus, Araucaria leaves can be considered as one of the cheap and efficient biosorbent for toxic hexavalent chromium removal from natural or wastewaters.

Canna indica flower: New source of anthocyanins.

In this study the red flowers of Canna indica (Cannaceae) were extracted by using sonicator and isolation of anthocyanins have been carried out. Four anthocyanin pigments have been isolated apart from quercetin and lycopene. They are Cyanidin-3-O-(6''-O-α-rhamnopyranosyl)-ß-glucopyranoside (1), Cyanidin-3-O-(6''-O-α-rhamnopyranosyl)-ß-galactopyranoside (2), Cyanidin-3-O-ß-glucopyranoside (3) and Cyanidin-O-ß-galactopyranoside (4). These compounds were isolated by using HPLC and their structures were subsequently determined on the basis of spectroscopic analyses, i.e., (1)H NMR, (13)C NMR, HMQC, HMBC, ESI-MS, FTIR, UV-Visible etc. The isolated compounds showed good antioxidant activity thus makes it suitable for use in food coloration and as a nutraceutical. Thus it is a promising pigment source for food applications.

Methylated anthocyanidin glycosides from flowers of Canna indica.

Methylated anthocyanin glycosides were isolated from red Canna indica flower and identified as malvidin 3-O-(6-O-acetyl-beta-d-glucopyranoside)-5-O-beta-d-glucopyranoside (1), malvidin 3,5-O-beta-d-diglucopyranoside (2), cyanidin-3-O-(6''-O-alpha-rhamnopyranosyl-beta-glucopyranoside (3), cyanidin-3-O-(6''-O-alpha-rhamnopyranosyl)-beta-galactopyranoside (4), cyanidin-3-O-beta-glucopyranoside (5) and cyanidin-O-beta-galactopyranoside (6) by HPLC-PDA. Their structures were subsequently determined on the basis of spectroscopic analyses, that is, (1)H NMR, (13)C NMR, HMQC, HMBC, ESI-MS, and UV-vis. Compounds (1-4) were found to be in major quantity while compounds (5-6) were in minor quantity.

Preparation of gold nanoparticles from Mirabilis jalapa flowers.

Biosynthesis of gold nanoparticles has emerged as an important area in nanotechnology and biotechnology due to growing need to develop environmentally benign technologies. Generally, nanoparticles are prepared by a variety of chemical methods which are not environmentally friendly. In the present study, we report a rapid and convenient method to reductively prepare gold nanoparticles from auric chloride using aqueous extract of Mirabilis jalapa flowers. The flower extract acts as a reducing agent and encapsulating cage for the gold nanoparticles. The production of gold nanoparticles has been done by the controlled reduction of the Au3+ ion to Au0. The formation of gold nanoparticles has been established by FT-IR and UV-Vis spectroscopy, as well as by TEM, XRD, EDAX and AFM. The study suggests that M. jalapa flowers can be a cheap source as a reductant for the production of gold nanoparticles.

Sulphates for skin preservation--a novel approach to reduce tannery effluent salinity hazards.

In tanneries microorganisms are able to find environment suitable for their growth. Raw hide of buffalo and other animals like goat that are economically important, are an ideal source of nutrients for bacterial and fungal growth. In the past, preservatives like sodium chloride provided effective protection to fresh hides however the ill effect of their excessive use was not evaluated. But recently concern over potential ecological hazards has become more deliberate and sodium chloride features lot of disadvantages in agriculture as most of the tannery effluent is flown in agricultural fields in India. After rigorous laboratory experimentation on moisture content, SEM of hide, pure sodium sulphate as well as sodium sulphate in addition with sodium chloride (i.e. 10% w/w and 20% w/w) proved as most preferable option for curing of buffalo hide which gives effective preservation. Pollution load studies put forward sodium sulphate as an effective curing agent for buffalo hide to apply at industrial scale also.