Molluscicidal effect of biogenic silica and botanical pesticides for the control of Achatina fulica (giant African land snail) and Laevicaulis alte (garden slug)

The molluscicidal effect of silica synthesized from rice husk ash (RHA) on snails (Achatina fulica Bowdich) and slugs (Laevicaulis alte Férussac) was assessed under laboratory conditions. The silica particles derived from RHA were also coated with leaf extracts (botanical pesticides): Azadirachta indica A. Juss, Pongamia pinnata (L.), Nicotiana tabacum (L.), and Calotropis procera (L.). The silica coated with plant extracts and the uncoated silica were applied to the molluscs in dust or slurry form. Inactivation, mortality, and body fluid loss in A. fulica and L. alte were observed over 24 h and recorded. The body fluid losses were 25%–42% for snails and 37%–62% for slugs that had been dusted with silica. During the experiment it was also noted that as the concentration of silica increased (0.15, 0.20, and 0.25 g), the time required for inactivation and mortality was reduced. The dust application was more effective than the slurry. The lower concentration of silica in the slurry (0.05 and 0.10 g) did not have any significant effect on A. fulica or L. alte. For A. fulica the biopesticide-coated silica particles were more effective when coated with neem, followed by tobacco and karanj; for L. alte, the particles were most effective when coated with tobacco, followed by neem and karanj. The plant extract (liquid as well as dry powder) without silica showed no molluscicidal effect on A. fulica and L. alte, except for some temporary inactivation, particularly with tobacco extract. The application of common salt, a practice often used by farmers, was also tested. It was observed that the effects of common salt on A. fulica and L. alte were less significant than those of silica coated with botanical pesticides.

Thermally processed biochar: preparation, characterisation and their application for cadmium removal from surface and groundwater

The thermally modified Parthenium biochar was used as an efficient adsorbent for removal of Cd from water. Parthenium biochar (PBC) prepared at 500°C was thermally activated by re-heating it at 700°C. PBC and thermally modified biochar (TMPBC) was characterised by FTIR, SEM-EDS, BET-surface area and XRD. The surface area of TMPBC (3.44 m2g−1) was higher than PBC (1.89 m2g−1). The optimum conditions for Cd adsorption was found to be pH, 5.0; biochar dose, 2.5 (g L−1); time, 30 min; temperature 25°C; initial Cd concentration, 100 mg L−1. Cadmium removal parameters were assessed using kinetic (pseudo first and second order) and adsorption models (Langmuir, Freundlich, and Redlich-Peterson). Cd removal followed pseudo second order kinetic model. The Cd removal capacity of TMPBC (129.2 mg g−1) was significantly higher than PBC (59.3 mg g−1). Cd removal by TMPBC (97–99%) was also demonstrated for a surface and underground waters. FTIR, XRD and SEM-EDS analysis confirmed the ion exchange and otavite precipitation mechanisms of Cd removal by biochar. The thermal modification technique could be an alternative for commercially available activated carbons; however this needs to be explored with different biomasses and other elements

Health status of communities living around Jharia coalfield area

87-92<span style="font-size:9.0pt;font-family:Times-Roman;mso-bidi-font-family:Times-Roman; mso-bidi-language:HI">Coal is one of the most abundant and important energy resource of the world. It plays an imperative role in defining economy of a nation. It dominates the energy matrix in India, contributing over 50% of the total primary energy production and is expected to continue as a crucial future energy source. Each step of the coal utilization: mining, transportation, washing, combustion, and disposing of post combustion ashes has impacts on human health. Various human diseases associated with coal mining mainly results from inhalation of particulate matter during the mining process. High levels of coal production were associated with worse health status and with higher rates of cardiopulmonary (heart/lung) disease, hypertension, lung disease, and kidney disease. Coal Worker's Pneumoconiosis is characterized by coal dust-induced lesions in the gas exchange regions of the lung. The connection between potential environmental problems with human health is a fairly new field and requires the cooperation of both the geoscience and medical disciplines. The miners as well as the inhabitant's vicinity to the mining areas are generally susceptible to the respiratory disorders due to constant exposure to the coalmine dust for a prolonged period. Health survey was conducted in the close proximity of the 18 different spots where the dust samples were collected with epidemiological questionnaires. Peoples were interacted to give respond about the diseases symptoms they have due to the exposure of environmental contaminants. Each subject was interviewed to assess the accurate medical history like symptoms related with cough, sputum production, and other symptoms related with eyes, nose, throat, chest, etc. Results are presented as percentage of those affected in each site, for a particular characteristic. The extent to which there was a difference between coal mine and control communities was estimated by odds ratio (OR). Statistical significance was evaluated by chi-square test using software (SYSTAT-12). Among the males, the severity of disease symptom in residential site could be arranged as joint discomfort, eye irritation, general weakness, dizziness etc. In case of commercial site the severity is dry cough, eye irritation, general weakness etc. Whereas for female the severity was higher for hip pain followed by eye irritation, general weakness and dizziness. In general, female are more vulnerable to general weakness. </span

Assessment of environmental soil quality around Sonepur Bazari mine of Raniganj coalfield, India

Assessment of soil quality is one of the key parameters for evaluation of environmental contamination in the mining ecosystem. To investigate the effect of coal mining on soil quality, opencast and underground mining sites were selected in the Raniganj coalfield area, India. The physical, chemical, and biological parameters of the soils, and trace metals and PAHs (polycyclic aromatic hydrocarbons) in the soils were evaluated. Soil dehydrogenase (+79 %) and fluorescein (+32 %) activities were significantly higher in underground mine (UGM) soil, whereas peroxidase activity (+57 %) was higher in opencast mine (OCM) soil. Content of As, Be, Co, Cr, Cu, Mn, Ni, and Pb was significantly higher in OCM soil, whereas Cd was higher in UGM. In general, the PAHs contents were higher in UGM soils, probably due to the natural coal burning at these sites. The observed values for the above properties were converted into a unitless score (0–1.00) and the scores were integrated into an environmental soil quality index (ESQI). In the unscreened index (ESQI-1) all the soil parameters were included and the results showed that the quality of the soil was better for UGM (0.539) than the OCM (0.511) soils. Principal component analysis was employed to derive ESQI-2 and accordingly, total PAHs, loss on ignition, bulk density, Be, Co, Cr, Ni, Pb, and microbial quotient (respiration: microbial biomass ratio) were found to be the most critical properties. The ESQI-2 was also higher for soils near UGM (+10.1 %). The observed indicators and the ESQI results revealed that soil quality assessment for these coal mining soils is largely depended on soil PAHs and potentially toxic trace metals. The proposed ESQI may be further refined by incorporating specific parameters related to human exposure risks and exposure pathways

Reclamation of wasteland for cultivation of cotton crop through application of pond ash and its leachate

7-18Reclamation of a vast area of wasteland available in India is a challenge for making it suitable for agriculture and forestry purposes through application of appropriate technology for its fast growing population. Huge amount of fly ash is being generated from combustion of coal in 145 existing thermal power plants, which contributes to 70% of the total energy requirement of the country. Present production of fly ash is 184 million tons per annum, which is projected to exceed 440 million tons per annum by 2030. This gargantuan quantity of fly ash not only poses environmental problems but occupies large areas of land for its disposal, which needs urgent and appropriate measures for its safe disposal and gainful utilization on sustainable basis. The study carried out by Central Institute of Mining and Fuel Research, Dhanbad on the bulk utilization of fly ash in agriculture and forestry sectors under different agro-climatic conditions and soil types for last two decades, indicates that pond ash is superior to soil in respect of plant nutrients and other physico- chemical properties. Keeping this in view, field scale study has been carried out in pond ash amended wasteland of farmer at Bhusawal (Maharashtra) followed by its irrigation with percolating water of ash pond for cultivation of cotton crops. The enhanced yield and quality of crop, improved soil condition and its residual effect on successive crops for longer period shows its potential for reclamation of waste/degraded land

Removal of phosphorus from aqueous solution using lignite fly ash

183-187Phosphorus (P) is an important element in making a major contribution to agriculture and industrial development. However, its release to surface waters leads to serious pollution. The development of technology for P removal offers the opportunity for abatement of environmental hazards and recycling. Fly ash is widely available and a cheap adsorbent and its alkaline properties make it interesting for use in waste water treatment through precipitation of phosphates. An attempt was made to study the P removal ability of lignite fly ash from Neyveli Lignite Corporation (Tamil Nadu). In order to determine the phosphate removal capacity of fly ash and the effect of adsorbent quantity (5 and 10g per 100mL), temperature (28 and 50°C), retention time (5 and 30 min) on P removal, sorption studies were conducted using phosphate solutions containing 20, 50, 100, 150 and 200 mg/L P. The results showed that the LFA was able to remove even 100% of 20 mg/L at 10g adsorbent with 30 min retention time at 28°C. The P removal capacity decreased with increase in P concentration, the removal was 86.51% at 200 mg/L P. The adsorbent quantity significantly influenced the P removal; the average removal was 94.81% at 5g and 97.5% at 10g. The data was also fitted into Langmuir and Freundlich adsorption equation. The Langmuir adsorption maximum was the highest for 5g fly ash-30 min equilibrium at 28°C (40.98 mg/kg). The adsorption maxima decreased with increase in temperature, however, the factor related to bonding energy has increased at 50°C. Altogether the study revealed that the LFA could be successfully used for instantaneous P removal at ambient condition, however other parameters like solid-liquid ratio, maximum carrying capacity, etc. need to be yet optimized

Reclamation of low land/barren land through fly ash amendment

30-37Considering huge generation of fly ash (185 million tons/annum) from 132 thermal power plants (TPPs) in the country and its insufficient utilization (up to 60%), there is urgent need for the development of an eco-friendly technology capable of utilizing it on bulk scale on sustainable basis. Keeping view fly ash as a useful ameliorant that may improve the physical, chemical and biological properties of problematic soils and as a source of plant nutrients (macro and micro), field demonstration trials were carried out on 8.4 acre of unutilized and undulating low lying area at Kali Mela, Jamadoba, Dhanbad filled with Tata Steel's FBC ash (up to a depth of 4 m) to reclaim it using biological amendments such as top soil layer (4 cm), cow dung manure, coco peat, vermi-compost, bio-fertilizer and NPK fertilizers (suitable proportions), selection and plantation of adaptable plant species (forestry, fruit bearing and oil yielding) . The planted species were monitored in respect of growth and biometric parameters at different growth stages followed by physicochemical and biological characterization of ash filled low land. The obtained results evinced that among the physicochemical properties, textural composition, bulk density, water holding capacity, porosity, and major/secondary and micro-nutrient levels of ash filled low land significantly improved with the progressive growth of planted species apart from considerable improvement in growth/biometric parameters and physiological behavior of the planted species. The different biological parameters (ectomycorrhiza, N-fixing bacteria, P-solubilizing bacteria, and dehydrogenase activity) were found to have increased at successive stages of the plantation. The beneficial uses of fly ash in agro-forestry applications were popularized periodically among the local farmers/inhabitants. As such the low lying area could be sustainably reclaimed using fly ash in bulk scale through biological means, which can be further extended in the vicinity of other power plants in the country

Torrefaction of agro-wastes (palmyra palm shell and redgram stalk): characterization of the physicochemical properties and mechanical strength of binderless pellets

To increase the utilization of agro-waste as solid fuel, torrefaction is an important process to improve the fuel properties. In the present investigation, palmyra palm shell (PPS) and redgram stalk (RS) were torrefied in a specially designed stainless-steel tubular reactor with varying temperatures (230 °C, 260 °C, and 300 °C) under a nitrogen atmosphere at two residence times of 30 and 60 min. The influence of torrefaction temperature and residence time on mechanical properties and moisture reabsorption tendency of the binderless pellets were investigated. With increasing the torrefaction temperature up to 300 °C (60-min residence), the mass and energy yield decreased, and the fixed carbon, high heating value, and energy density increased. The fuel ratio (FR) increased from 0.25 or 0.23 to 1.35 and 0.52 for PPS and RS, respectively. The combustibility index increased up to a certain temperature (260 °C); however, at 300 °C, it decreased. Grindability of the torrefied biomass increased; about 99.89% and 95.28% of the smallest particles’ fraction pass through a < 75-µm sieve for PPS and RS, respectively, at 300 °C and 60 min as compared to the raw agro-wastes. The moisture reabsorption tendency of untorrefied and torrefied PPS and RS pellets was measured under the controlled environment of 60% RH at 40 °C. FTIR study supported the hydrophobicity of the torrefied material than the raw biomass. This study demonstrated that the torrefied PPS and RS have fuel properties comparable with India lignite, and this renewable fuel could be sustainably used for power generation and domestic applications

Rare Earth Elements in Soils of Jharia Coal Field

There are many sources trough which the soil get enriched and contaminated with REEs. The determination of REEs in environmental samples has been limited because of the lack of sensitive analytical techniques. Soil samples were collected from four sites including open cast coal mine, natural coal burning, coal washery and control in the coal field located in Dhanbad, India. Total concentrations of rare earth elements (REEs) were determined using the inductively coupled plasma atomic absorption spectrometry in order to assess enrichment status in the coal field. Results showed that the mean concentrations of La, Pr, Eu, Tb, Ho, and Tm in open cast mine and natural coal burning sites were elevated compared to the reference concentrations, while Ce, Nd, Sm, and Gd were elevated in coal washery site. When compared to reference soil, heavy REEs (HREEs) were enriched in open cast mines and natural coal burning affected soils, however, the HREEs were depleted in the coal washery sites. But, the Chondrite-normalization diagram showed significant enrichment for light REEs (LREEs) in all the soils. High concentration of Pr, Eu, Tb, Ho, Tm, and Lu in coal mining and coal burning sites may pose human health risks. Factor analysis showed that distribution and relative abundance of REEs of the coal washery site is comparable with the control. Eventually washing or cleaning of coal could significantly decrease the emission of REEs from coal into the environment