V. Sivasankar

Fluoride removal from water using activated and MnO2-coated Tamarind Fruit (Tamarindus indica) shell: batch and column studies.

The present work is concerned with the defluoridation capacities of activated (ATFS) and MnO(2)-coated Tamarind Fruit Shell (MTFS), using batch and column sorption techniques. In the batch technique, the dynamics of fluoride sorption, with respect to pH, [F](o) and sorbent dose, was studied. The applicability of pseudo-first order for ATFS and Ritchie-second order for MTFS was observed. The kinetics data were found to fit well with Temkin isotherm for ATFS and Langmuir for MTFS. The interaction of co-ions in the defluoridation capacity of the sorbent was studied. Column experiments were carried out under a constant fluoride concentration of 2mg/l, flow rate and different bed depths. The capacities of the breakthrough and exhaustion points increased with increase in the bed depth for ATFS unlike MTFS. The Thomson model was applied to the column experimental results. The characterization of the sorbents, ATFS and MTFS, was done using the FTIR, SEM and XRD techniques.

Tamarind (Tamarindus indica) fruit shell carbon: A calcium-rich promising adsorbent for fluoride removal from groundwater.

Tamarindus indica fruit shells (TIFSs) are naturally calcium rich compounds. They were impregnated with ammonium carbonate and then carbonized, leading to ammonium carbonate activated ACA-TIFS carbon. The resulting materials and carbon arising from virgin fruit shells V-TIFS were characterized and assayed as adsorbent for the removal of fluoride anions from groundwater. The fluoride scavenging ability of TIFS carbons was due to naturally dispersed calcium compounds. X-ray diffraction (XRD) showed that TIFS carbon contained a mixture of calcium oxalate and calcium carbonate. Batch studies on the fluoride removal efficiency of TIFS carbons with respect to contact time, pH, initial fluoride concentration, and co-ion interference were conducted. Applicability of various kinetic models (viz., pseudo-first-order, pseudo-second-order, intra-particle diffusion and Elovich) and sorption isotherms were tested for batch techniques. The fluoride removal capacity of TIFS carbons was found to be 91% and 83% at a pH of 7.05 for V-TIFS and ACA-TIFS carbons, respectively. The practical applicability of TIFS carbons using groundwater samples was approved. The fluoride removal was greater in groundwater without hydrogen carbonate ions than those containing these ions. The characterizations of fluoride unloaded and loaded TIFS carbons were done by SEM and XRD studies.

An investigation on the pollution status of holy aquifers of Rameswaram, Tamil Nadu, India

The Study area is the sacred Ramanathasamy temple and selected for the characterization of physico-chemical parameters viz., pH, EC, TDS, Salinity, TA, TH, Ca + 2, Mg + 2, Chloride and Fluoride for 22 groundwater samples and the impact of pre- and post-monsoon on the groundwater quality was also studied. The study area is well known for the chronic fresh water shortage and the locals depend mostly on springs for their fresh water needs. The Water Quality Index (WQI) computed shows the transfer of samples under unacceptable quality to acceptable quality. The Langelier Saturation Index (LSI) reflected that majority of the samples have the tendency to form scale. The Karl Pearson correlation matrix has approved the maximum relationship of calcium and chloride with respect to the total dissolved solids (TDS). It is interesting to conclude that the groundwater in the study area has very hard nature, especially of non-carbonate type.

Solid waste, its health impairments and role of rag pickers in Tiruchirappalli City, Tamil Nadu, Southern India.

In India, the significant increase in the generation of municipal solid waste (MSW) during the last few decades is due to the rapid population and economic development. Though the appropriate attempts are made through the 3-‘R’ principles, waste management still needs to be envisaged seriously by everybody for a cleaner and greener environment. Rag-pickers, who contribute to solid waste management to some extent, are the people who rummage through garbage bins to pick out ‘rags’ for their livelihood. These rag-pickers usually collect the materials that have good re-sale value as these materials are mostly recycled or reused. In the present study, the collection and the management of solid waste and the level of microbial pollution generated through air, soil and solid waste were studied. A questionnaire survey based on age, sex, educational status, socio-economic status, habits and health effects was conducted from 65 randomly selected rag-pickers from various places of Tiruchirappalli city The results revealed that they can be properly educated and trained to protect themselves from unhygienic practices and addiction. Either the Government or non-governmental organizations (NGOs) should devise a suitable proposal to monitor and make use of these unorganized rag-pickers who are indispensable to the society.

The seasonal status of chemical parameters in shallow coastal aquifers of Rameswaram Island, India

The study area Rameswaram, a holy island, is famous for the sacred Ramanathaswamy temple, which cements people of the country regardless of their place, residence, or their religion or creed. This coastal tract is experiencing a chronic fresh water shortage, despite a few spring sources. The study area is selected for the characterization of physico-chemical parameters viz., pH, EC, TDS, salinity, TA, TH, CH, MH, chloride, and fluoride for 150 groundwater samples and the impact of pre- and post-monsoons on the groundwater quality is studied. The water quality index advocates the transfer of groundwater quality from unacceptable status in the pre-monsoon into an acceptable status in the post-monsoon. The Langelier saturation index reflects the scaling tendency of groundwater in the study area. The Karl Pearson correlation matrix has approved the maximum influence of calcium and chloride on the total dissolved solids. It is interesting to conclude that the groundwater in the study area has very had nature, especially of non-carbonate type.

Fluoride in Groundwater and Dental Fluorosis in Rameswaram Area, Tamil Nadu, Southern India

The fluoride content in 419 groundwater samples from different sources in Rameswaram area, Southern India was determined in addition to the other physico-chemical parameters. From the results, it was evaluated that about 15% of the groundwater samples were found to contain the F content greater than the WHO recommended limit of 1.5 mg/l. The dental fluorosis survey among the school children also revealed that the percentage of boy victims was greater than the girl victims. The correlation values between Total Alkalinity (TA) and Fluoride (F) is evident for the leaching of Fluoride into the groundwater of the study area.

A Probe on the Status of Microorganisms in the Air, Soil and Solid Waste Samples of Ariyamangalam Dumping Site at Tiruchirappalli District, South India

This research contribution is concerned with the microbial occurrence in air, groundwater, soil and solid wastes around a dumping site with an area of about 48 acres located at Ariyamangalam of Tiruchirappalli District, South India. The groundwater and soil samples were collected within a radius of 2 and 0.5 kms respectively. Severe microbial dominance in the groundwater samples was inferred from the MPN per 100 ml of total coliforms. The Karl Pearson correlation was carried out for the total coli forms with the physico-chemical properties of the water samples. The correlation study ascertained the influence of nitrogen and its oxy anions on the growth of microorganisms in operating the biogeochemical cycle. The aero-microbial study conducted at the dumping site registered the survival of six genera each of bacterial and fungal organisms which alleviate the possibility of hazards to the environment and residents’ health. Various harmful and infectious diseases that spread through the microorganisms originated from the dumping site are also discussed in this chapter.

Groundwater fluoride removal using modified mesoporous dung carbon and the impact of hydrogen-carbonate in borehole samples

There have been many research reports pertained to the interference of co - ions including hydrogen carbonate against the removal of fluoride from water. In this context, the present research explores the fluoride removal efficiency of ammonium carbonate modified dung derived carbon (DDC500) in the absence and presence of hydrogen carbonate using synthetically made fluoride solutions and groundwater samples. The adsorbent DDC500 was found to achieve the highest removal of 80% of fluoride at pH 6.95 than the washed carbon (DDC500W) and dung ash (DA) of 48% and 23% respectively. In DDC500, the carbon base in concert with inorganic residues actively functioned in the fluoride removal process and chosen for synthetic fluoride solutions (2-5 mg L-1) and 16 groundwater samples (2.1-3.6 mg L-1) from 10 locations of Usilampatti Taluk in Madurai District, South India. After the removal of hydrogen carbonate in groundwater, the percentage of samples was increased in accordance with the safe limits of World Health Organization (WHO) and Bureau of Indian Standard (BIS). Langmuir isotherm model (R2 = 0.9379) was in concordance with the adsorption of fluoride from groundwater free from hydrogen carbonate. The dynamics of other groundwater quality parameters at conditions and the independency between F-/HCO3- ratio and DE were illustrated by scatter plots. Characterization studies for the dried dung (CD110), derived carbons (DDC500 and DDC500W) and ashes (CD110A, DDC500A and DDC500WA) using FE-SEM, XRD, FTIR, Raman and TGA - EGA were done to understand the nature and behavior of materials.