Removal of lead (II) from synthetic and batteries wastewater using agricultural residues in batch/column mode     

J. Singh  A. Ali  V. Prakash 《International Journal of Environmental Science and Technology》2014,11(6):1759-1770

The present article explores the ability of five different combinations of two adsorbents (Arachis hypogea shell powder and Eucalyptus cameldulensis saw dust) to remove Pb(II) from synthetic and lead acid batteries wastewater through batch and column mode. The effects of solution pH, adsorbent dose, initial Pb(II) concentration and contact time were investigated with synthetic solutions in batch mode. The Fourier transform infrared spectroscopy study revealed that carboxyl and hydroxyl functional groups were mostly responsible for the removal of Pb(II) ions from test solutions. The kinetic data were found to follow pseudo-second-order model with correlation coefficient of 0.99. Among Freundlich and Langmuir adsorption models, the Langmuir model provided the best fit to the equilibrium data with maximum adsorption capacity of 270.2 mg g^?1. Column studies were carried out using lead battery wastewater at different flow rates and bed depths. Two kinetic models, viz. Thomas and Bed depth service time model, were applied to predict the breakthrough curves and breakthrough service time. The Pb(II) uptake capacity (q _e = 540.41 mg g^?1) was obtained using bed depth of 35 cm and a flow rate of 1.0 mL min^?1 at 6.0 pH. The results from this study showed that adsorption capacity of agricultural residues in different combinations is much better than reported by other authors, authenticating that the prepared biosorbents have potential in remediation of Pb-contaminated waters.  相似文献   

Spectral element analysis to evaluate the stability of long and steep slopes   总被引：1，自引：1，他引：0  

Ram Chandra Tiwari  Netra Prakash Bhandary  Ryuichi Yatabe 《Acta Geotechnica》2014,9(5):753-770

This paper evaluates the stability of long and steep slopes examining the effect of the critical length/depth ratio, L/H, and critical slope angle, β _cr, by comparing the results of infinite slope equation with the spectral element method. In addition, the influence of uphill and downhill boundaries on stability of long and steep slopes is also evaluated in theoretical domains. As an example, this paper presents a stability analysis of long and steep vegetated and barren slopes in saturated and seismic conditions, and also evaluates the effectiveness of the infinite slope equation for those slopes. In the vegetated slopes, the root zone may not extend to the whole depth of slope, which may lead to overestimating the factor of safety by infinite slope equation. This paper examines the applicability of the infinite slope equation for infinitely long, steep, and shallow slope model by comparing the results of the spectral element method.  相似文献   

Geochemical characterization and heavy metal contamination of groundwater in Satluj River Basin   总被引：1，自引：0，他引：1  

Chander Kumar Singh  Kumari Rina  Ravi Prakash Singh  Saumitra Mukherjee 《Environmental Earth Sciences》2014,71(1):201-216

Groundwater, a renewable and finite natural resource, vital for man’s life, social and economic development and a valuable component of the ecosystem, is vulnerable to natural and human impacts. The aim of present study is to evaluate hydrogeochemical parameters and heavy metals in groundwater and to study their spatial distribution in the Rupnagar District of Punjab. The spatial distribution of physico-chemical parameters were studied using Arc GIS 9.2. It was observed that the concentration of parameters, such as NO₃, Cd, Cr, Mn and Pb was above permissible limit (World Health Organization, WHO) in southern part of the study area. The heavy metal pollution index (HPI) was calculated for all sampling locations and it was found much above the critical limit of pollution. Geochemical reaction models of selected water groups were constructed using Phreeqc. Geochemical modeling suggests that sodium has source other than halite-albite and calcium has alternate source other than gypsum-carbonate or silicates. It also suggests that evaporites, ion exchange, dissolution along with anthropogenic activities are controlling the hydro-geochemistry of groundwater in the region. Various indices, such as heavy metal pollution index, permeability index, sodium adsorption ratio, were studied to verify suitability of groundwater for drinking and irrigation.  相似文献   

Hydrogeological processes controlling the release of arsenic in parts of 24 Parganas district,West Bengal     

Neha Singh  Ravi Prakash Singh  Saumitra Mukherjee  Kyle McDonald  K. J. Reddy 《Environmental Earth Sciences》2014,72(1):111-118

A study was conducted to understand the hydrogeological processes dominating in the North 24 Parganas and South 24 Parganas based on representative 39 groundwater samples collected from selected area. The abundance of major ions was in the order of Ca²⁺ > Na⁺ > Mg²⁺ > K⁺ > Fe²⁺ for cations and HCO₃ ^? > PO₄ ^3? > Cl^? > SO₄ ^2? > NO₃ ^? for anions. Piper trilinear diagram was plotted to understand the hydrochemical facies. Most of the samples are of Ca-HCO₃ type. Based on conventional graphical plots for (Ca + Mg) vs. (SO₄ + HCO₃) and (Na + K) vs. Cl, it is interpreted that silicate weathering and ion exchange are the dominant processes within the study area. Previous studies have reported quartz, feldspar, illite, and chlorite clay minerals as the major mineral components obtained by the XRD analysis of sediments. Mineralogical investigations by SEM and EDX of aquifer materials have shown the occurrence of arsenic as coating on mineral grains in the silty clay as well as in the sandy layers. Excessive withdrawal of groundwater for irrigation and drinking purposes is responsible for fluctuation of the water table in the West Bengal. Aeration beneath the ground surface caused by fluctuation of the water table may lead to the formation of carbonic acid. Carbonic acid is responsible for the weathering of silicate minerals, and due to the formation of clay as a product of weathering, ion exchange also dominates in the area. These hydrogeological processes may be responsible for the release of arsenic into the groundwater of the study area, which is a part of North 24 Parganas and South 24 Parganas.  相似文献   

New finding of sillmanite in sapphirine-bearing granulites from Pedapalli,NE part of the Eastern Dharwar Craton,India     

D. Prakash  P. Chandra Singh 《Journal of the Geological Society of India》2014,84(1):29-34

We report the occurrence of sillimanite in sapphirine-bearing granulites near Pedapalli town in the north eastern part of the Eastern Dharwar Craton (EDC). The sapphirine-bearing granulites of the Pedapalli area display evidence of metamorphic reactions involved in the formation of diverse mineral assemblages documented in different types of reaction textures. The common stable assemblage contains sapphirine-spinel-orthopyroxene-cordieriteplagioclage-corundum-sillimanite. The P-T evolution of these sapphirine granulites has been constrained by using the TWEEQU program. Temperature of formation of sapphirine-spinel assemblages is high, around 800 °C, and pressure ca. 8 kbar. The assemblage reported in this study has important bearing on the high-temperature metamorphism and exhumation history of the EDC.  相似文献   

Modeling storm surges associated with super typhoon durian in South China Sea   总被引：1，自引：0，他引：1  

Kak Choon Loy  Prakash Chandra Sinha  Juneng Liew  Fredolin Tangang  Mohd Lokman Husain 《Natural Hazards》2014,70(1):23-37

Super typhoon Durian struck the central Philippines on November 30, 2006 and southern coast of Vietnam on December 5, 2006. The reported maximum wind exceeded 250 km/h, and the central pressure was 904 hPa during the peak of the system. The typhoon brought colossal damage, both in terms of lives and in terms of properties to the Philippines and Vietnam while Thailand and Malaysia were slightly affected. The energy from the high-velocity wind and central pressure drop resulted in the generation of storm surges along the coastal region of the Philippines including its surrounding islands as well as parts of southern Vietnam. In this paper, a numerical 2D model is used to study the oceanic response to the atmospheric forcing by 2006 super typhoon Durian in the coastal regions of the Philippines and Vietnam. The initial study of this model aims to provide some useful insights before it could be used as a coastal disaster prediction system in the region of South China Sea (SCS). The atmospheric forcing for the 2D model, which includes the pressure gradient and the wind field, is generated by an empirical asymmetrical storm model. The simulated results of storm surges due to typhoon Durian at two locations lie in the range of observed data/estimates published by the Joint Typhoon Warning Centre (JTWC).  相似文献   

Dynamic Subsidence Characteristics in Jharia Coalfield,India   总被引：1，自引：0，他引：1  

Amar Prakash  Ajay Kumar  Kalendra Bahadur Singh 《Geotechnical and Geological Engineering》2014,32(3):627-635

Surface ground movements are usually described by a number of characteristic indices such as vertical displacement, horizontal strain and slope, which are an inevitable consequence of underground mining. Every point at the surface over a panel is subjected to strain and slope during mining and its investigation is essential to assess the safety of surface structures. Therefore, the behaviour of dynamic active and residual subsidence was studied for a few panels of Jharia coalfield. The subsidence and slope were linearly related to time. Compressive and tensile strains showed typical fluctuating characteristic behaviour. The rate of mining being a key and controlling parameter for rate of subsidence their inter-relationship was developed, which showed a rational trend. Compressive and tensile strains and slope showed poor correlation with rate of face advance.  相似文献   

Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations     

R. Pandiyan  S. V. Subbarao  T. Nagamani  Chaitra Rao  N. Hari Prasad Rao  Harish Joglekar  Naresh Kumar  Surya Ratna Prakash Dumpa  Anshu Chauhan  B. P. Dakshayani 《Journal of Astrophysics and Astronomy》2017,38(2):35

On 28th September 2015, India launched its first astronomical space observatory AstroSat, successfully. AstroSat carried five astronomy payloads, namely, (i) Cadmium Zinc Telluride Imager (CZTI), (ii) Large Area X-ray Proportional Counter (LAXPC), (iii) Soft X-ray Telescope (SXT), (iv) Ultra Violet Imaging Telescope (UVIT) and (v) Scanning Sky Monitor (SSM) and therefore, has the capability to observe celestial objects in multi-wavelength. Four of the payloads are co-aligned along the positive roll axis of the spacecraft and the remaining one is placed along the positive yaw axis direction. All the payloads are sensitive to bright objects and specifically, require avoiding bright Sun within a safe zone of their bore axes in orbit. Further, there are other operational constraints both from spacecraft side and payloads side which are to be strictly enforced during operations. Even on-orbit spacecraft manoeuvres are constrained to about two of the axes in order to avoid bright Sun within this safe zone and a special constrained manoeuvre is exercised during manoeuvres. The planning and scheduling of the payloads during the Performance Verification (PV) phase was carried out in semi-autonomous/manual mode and a complete automation is exercised for normal phase/Guaranteed Time Observation (GuTO) operations. The process is found to be labour intensive and several operational software tools, encompassing spacecraft sub-systems, on-orbit, domain and environmental constraints, were built-in and interacted with the scheduling tool for appropriate decision-making and science scheduling. The procedural details of the complex scheduling of a multi-wavelength astronomy space observatory and their working in PV phase and in normal/GuTO phases are presented in this paper.  相似文献   

Effect of Interplanetary Turbulences Causing High/low Amplitude Anisotropic Wave Trains in Cr Intensity     

Kumar  Santosh  Chauhan  M. L.  Dubey  S. K. 《Solar physics》1997,176(2):403-415

The high/low-amplitude anisotropic wave train events (HAE/LAE) in CR intensity have been investigated during the period 1981–1990, using the neutron monitoring data for different latitudes. In all, 21 HAE and 15 LAE cases have been studied. It has been observed that the phase of the diurnal anisotropy remains in the same co-rotational direction for the majority of the HAE/LAE cases. However, it has also been observed that the phase of the diurnal anisotropy changes to later hours in some of the HAE cases, whereas it changes to early hours in some of the LAE cases. Further, the amplitude of the semi-diurnal anisotropy for HAE/LAE cases remains statistically the same; however, the phase of the semi-diurnal anisotropy for HAE has been found to shift to later hours for all events. Furthermore, the HAE occur dominantly during the declining phase of solar activity, whereas LAE occur dominantly during the minimum solar activity period. The geomagnetic activity index-A_p has been observed to remain low during the period of each HAE/LAE. The possible phenomenon to cause the enhanced/low-amplitude daily variation has been proposed to appear on the back side of the Sun.  相似文献   

Assessing the state of homogeneity,variability and trends in the rainfall time series from 1969 to 2017 and its significance for groundwater in north-east India     

Borah  Parashmoni  Hazarika  Suhasini  Prakash  Amit 《Natural Hazards》2022,111(1):585-617

Natural Hazards - Rainfall is the key climatic variable, on which water availability, food security and livelihood depend, especially in an agrarian society like the northeast region of India. It...  相似文献