Browsing by Author "Singhal, Anupam"

Now showing 1 - 20 of 51

Analyzing environment sustainability enablers using fuzzy DEMATEL for an Indian steel manufacturing company
(Emerald, 2019-03-20) Singhal, Anupam; Routroy, Srikanta
The purpose of this paper is to analyze the Environmental Sustainability Enablers (ESEs) for an Indian steel manufacturing company to select the appropriate set of ESEs for implementing and enhancing environmental sustainability.
Analyzing the effects of pickling sludge and fly ash valorized cement sand bricks
(Springer Nature, 2025-07) Routroy, Srikanta; Singhal, Anupam
The disposal of Stainless-Steel Pickling Sludge (SSPS) in landfills remains an important issue. Utilizing SSPS as construction material mitigates the negative environmental effects associated with its disposal, providing a sustainable solution. This study investigates co-utilization of SSPS and fly ash as partial substitution of river sand on cement sand bricks properties. Nine cement sand bricks compositions, including control mix, were prepared with varying composition of SSPS, fly ash and river sand. Four compositions were developed with SSPS varied from 2.5 to 10% with fixed fly ash content of 50%. Four additional compositions with varying fly ash content from 40 to 47.5% and varying SSPS 2.5–10% content as partial substitution of river sand were prepared. The developed bricks demonstrated that gradual increment of SSPS (2.5–10%) and reduction of fly ash (47.5–40%) proved incremental to the compressive strength up to 28 MPa. In addition, the morphological analysis using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) were conducted for the compositions. The microstructure analysis showed that with inclusion of fly ash, Mix 2 (M2) compositions revealed a dense microstructure validating the sorptivity results as compared to Mix 1 (M1) compositions. Finally, the cost estimation of the waste valorized bricks as compared to the control bricks was observed to be significantly low. The experiment outcomes concluded adoption of SSPS-fly ash waste valorized bricks as a greener alternative to disposal.
Application of ANN for Water Quality Index
(IJMLC, 2019-10) Singhal, Anupam; Gupta, Rajiv
Attempt has been made to create a Water Quality Index (WQI) based on artificial neural network (ANN) and globally accepted parameters. Several methods to measure WQI are available in the research and ambiguity problems exist where all the sub-indices of WQI are acceptable but overall index is not acceptable. In this study, we have tried to develop the WQI based on the WHO (world Health Organization) parameters (Dissolved Oxygen, pH, Turbidity, E. Coli and Electric Conductivity). The results also reveal changes in ANN based result from various input neural network model and its parameters. Even within same model, changes occur with variation in parameter. Based on the statistical parameter of regression value, the parameter and network model would be selected. With the dataset created for this study have shown the Cascade network is best for predicting the WQI.
Assessment and monitoring of groundwater quality in semi –arid region
(Elsiever, 2020-10) Singhal, Anupam; Gupta, Rajiv
The depletion of groundwater resources threatens water security around the world and it is of prime concern. Minimization of the impact of unhealthy drinking water requires monitoring of contaminants and awareness to all stake holders. The work is aimed at developing a Water Quality Index (WQI) to assess and report water quality to policy makers and stake holders for comprehensive planning. This new WQI method assigns individual weights to each sample point under consideration, along with wholesome weights, to account for the relative risk of each contaminant. Water quality is determined for pre and post monsoon seasons. Spatial distribution of water quality is used to estimate the probable impact on affected population. A case study was carried out to validate the method. For this purpose, a total of 163 wells (covering an area of 30,623 square km.) were sampled in a semi-arid region in North India, during pre and post monsoon seasons. Sixteen physico-chemical parameters were measured and six parameters were deemed highly critical due to their coverage and associated health risk. Against the general belief, a rise in the number of wells with permissible limits of Chloride, Nitrite, Fluoride and TDS is observed after the monsoon. The WQI determined by the procedure indicates that only 47% and 59% of the local populace has access to groundwater of acceptable quality during pre and post monsoon seasons respectively.
Assessment of Groundwater Quality Using GIS and Various Water Quality Indices: A Case Study of the Shekhawati Region of Rajasthan, Northwest India
(EJSC, 2016) Singhal, Anupam; Gupta, Rajiv
Assessment of Groundwater quality using Water Quality Index (WQI) and Geographic Information System (GIS) was carried out in the Shekhawati region of Rajasthan. The results of 15 physico-chemical parameters were used for the calculation of WQI. The results indicated that WQI values range from 0 to 1304 and 0-11,701 for two different approaches used and thus indicates very poor groundwater quality status in the region. The Fuzzy method as a third approach was also used to generate a WQI and resulted in only 2 values. The geographical information system using the Inverse Distance Weighted method (IDW) delineated groundwater quality zones into good to very poor potential areas. The hierarchal cluster analysis identified anthropogenic contamination, natural mineralization, reverse cation exchange as the major processes controlling groundwater chemistry. From the correlation matrix, it could be said that Turbidity, Total Hardness as CaCO3, Ca hardness as CaCO3, Mg hardness as CaCO3, Chlorides as Cl-, Fluorides as F- and TDS are responsible for high WQI values in the region.
An Assessment of Qualitative and Quantitative Municipal Solid Waste City Compost by Indexing Method
(Springer, 2023-09) Khare, Srishti; Singhal, Anupam
Globally, the disposal of municipal solid waste (MSW) is a significant environmental challenge. The production of MSW is continuous in megacities, small cities, and large villages, and if wastes are not managed properly, they can have a detrimental effect on both the environment and human health. Processes such as incineration, anaerobic digestion, and composting are widely adopted. The MSW city compost (MSWCC) generated poses significant challenges due to the presence of a high amount of residual metal toxicity. Therefore, the researcher examined the material's physical and chemical properties, as well as its heavy metal content and spectral characteristics were investigated to assess the applicability of its use for different purposes generated from MSW dump yards. For this purpose, spectral characterization including mineralogical analysis with X-ray diffraction (XRD) was used to determine the presence of heavy metals; topographical imaging and elemental mapping with a scanning electron microscope and energy dispersive X-ray analysis were carried out (FESEM-EDX). Current investigation shows that (i) XRD, SEM–EDX confirms the evidence of HMs in MSWC; (ii) In terms of Zn, Cu, Cd, Pb, and Ni, MSW compost did not meet the quality control guidelines of ‘The Fertilizer (Control) Order 1985.’ (iii) Using the Indexing method, the Fertilizing Index (FI) of compost was found to be 4.4, which means it has a high potential to fertilize. The Clean Index (CI) of compost, on the other hand, was found to be 1.7, which means it has a high potential to pollute with heavy metals; (iv) The compost sample belongs to RU-3 (Restricted Use category 3) class and, hence, has been found unsuitable for any kind of use.
Bio-chelate assisted leaching for enhanced heavy metal remediation in municipal solid waste compost
(2024-06) Singhal, Anupam; Srinivas, Rallapalli
Municipal solid waste compost, the circular economy's closed-loop product often contains excessive amounts of toxic heavy metals, leading to market rejection and disposal as waste material. To address this issue, the study develops a novel approach based on: (i) utilizing plant-based biodegradable chelating agent, l-glutamic acid, N,N-diacetic acid (GLDA) to remediate heavy metals from contaminated MSW compost, (ii) comparative assessment of GLDA removal efficiency at optimal conditions with conventional nonbiodegradable chelator EDTA, and (iii) enhanced pre- and post-leaching to evaluate the mobility, toxicity, and bioavailability of heavy metals. The impact of treatment variables, such as GLDA concentration, pH, and retention time, on the removal of heavy metals was investigated. The process was optimized using response surface methodology to achieve the highest removal effectiveness. The findings indicated that under optimal conditions (GLDA concentration of 150 mM, pH of 2.9, retention time for 120 min), the maximum removal efficiencies were as follows: Cd-90.32%, Cu-81.96%, Pb-91.62%, and Zn-80.34%. This process followed a pseudo-second-order kinetic equation. Following GLDA-assisted leaching, the geochemical fractions were studied and the distribution highlighted Cd, Cu, and Pb's potential remobilization in exchangeable fractions, while Zn displayed integration with the compost matrix. GLDA-assisted leaching and subsequent fractions illustrated transformation and stability. Therefore, this process could be a sustainable alternative for industrial applications (agricultural fertilizers and bioenergy) and social benefits (waste reduction, urban landscaping, and carbon sequestration) as it has controlled environmental footprints. Hence, the proposed remediation strategy, chemically assisted leaching, could be a practical option for extracting heavy metals from MSW compost, thereby boosting circular economy.
Bio-chelation for sustainable heavy metal remediation in municipal solid waste compost: a critical review of chelation technologies
(Springer, 2025-04) Singhal, Anupam; Srinivas, Rallapalli
Municipal solid waste (MSW) compost is a promising solution for sustainable urban waste management, widely used as a soil amendment and for carbon sequestration. However, heavy metals in MSW compost pose risks to ecosystems, food safety and human health. This review critically examines three decades of research (1994–2024) on heavy metal contamination in MSW compost and household hazardous waste (HHW), identifying gaps in managing these pollutants, particularly regarding hazardous waste co-disposal. It evaluates existing remediation strategies for heavy metal removal, with a focus on chemical-assisted leaching using chelating agents. Key treatment parameters—such as chelating agent concentration, pH, contact time, liquid/solid ratio, temperature and flow rate—are analysed in both batch and continuous modes. The study advocates for biodegradable chelating agents as an effective approach to enhancing MSW compost quality, with applications in landfill reclamation and agriculture. Emphasizing the need for eco-friendly heavy metal mitigation, the review underscores the importance of safe urban composting practices. The findings contribute to the circular economy and Sustainable Development Goals by promoting sustainable and safe MSW compost applications, fostering environmental protection and public health and guiding research and industry toward scalable, marketable remediation solutions.
Characterization of stainless steel pickling bath sludge and its solidification/stabilization
(Elsiever, 2008-06) Singhal, Anupam
X-ray diffractometer analysis of stainless steel sulfuric acid pickling bath sludge shows that it contains FeCr2O4, NiCr2O4, NiCrO4, and Cr2O3, which do not dissolve in the acids. X-ray fluorescent spectroscopy (XRF) study reveals that chromium concentration in the sludge is as high as in stainless steel, whereas nickel concentration is on lower side and iron is the major constituent of the sludge. Cement-sludge sand mortar cubes have been prepared in the laboratory. Compressive strength of these cubes decreases linearly with increase in sludge content. As per US EPA TCLP test, heavy metal (Cr and Ni) concentrations are negligible in leachate of cement-sludge sand mortar cubes at 28 days of curing. Hence, cement-sludge sand mortar cubes can be made for safe disposal of sludge.
Characterization of stainless steel pickling bath sludge and its solidification/stabilization
(Elsevier, 2008-06) Singhal, Anupam
X-ray diffractometer analysis of stainless steel sulfuric acid pickling bath sludge shows that it contains FeCr2O4, NiCr2O4, NiCrO4, and Cr2O3, which do not dissolve in the acids. X-ray fluorescent spectroscopy (XRF) study reveals that chromium concentration in the sludge is as high as in stainless steel, whereas nickel concentration is on lower side and iron is the major constituent of the sludge. Cement-sludge sand mortar cubes have been prepared in the laboratory. Compressive strength of these cubes decreases linearly with increase in sludge content. As per US EPA TCLP test, heavy metal (Cr and Ni) concentrations are negligible in leachate of cement-sludge sand mortar cubes at 28 days of curing. Hence, cement-sludge sand mortar cubes can be made for safe disposal of sludge.
Compounded fuzzy entropy-based derivation of uncertain critical factors causing corrosion in buried concrete sewer pipeline
(Springer Nature, 2025-05) Rallapalli, Srinivas; Singhal, Anupam
Corrosion in buried concrete sewer pipelines remains a critical challenge for infrastructure sustainability, driven by the complex interplay of environmental, material, operational, pipe-related, and physical factors with inherent uncertainty and interdependency, aspects often overlooked previously. This study introduces a novel compounded fuzzy entropy-based approach to systematically prioritize critical corrosion-inducing factors, integrating environmental (H₂S, pH, humidity, temperature, O₂), material (cement content, alkalinity, w/c ratio, porosity, permeability), pipe-related (age, length, diameter, depth, slope), operational (flow velocity, water pressure, hydraulic energy loss, sewage residence time, sewer type), and physical (soil type, corrosivity, moisture, groundwater level, external load) factors. Results identify H₂S (0.2073), pH (0.2055), humidity (0.2031), pipe age (0.2039), length (0.2019), cement content (0.2026), alkalinity (0.2015), water pressure (0.2073), flow velocity (0.2043), soil type (0.2042), and soil corrosivity (0.2025) as the most influential contributors, enabling targeted corrosion mitigation strategies and enhancing infrastructure resilience.
Delineation of agricultural fields in arid regions from Worldview-2 datasets based on image textural properties
(Springer, 2023-04) Singhal, Anupam
Barren lands are being transformed into agricultural fields with the growing demand for agriculture-based products. Hence, monitoring these regions for better planning and management is crucial. Surveying with high-resolution RS (remote sensing) satellites like Worldview-2 provides a faster and cheaper solution than conventional surveys. In the study, the arid region comprising cropland and barrenlands are efficiently and autonomously delineated using its spectral and textural properties using state-of-the-art random forest (RF) ensemble classifiers. The textural information window size is optimized and at a GLCM (gray-level co-occurrence matrix) window size of 13, a stable trend in classification accuracy was observed. A further rise in window sizes did not improve the classification accuracy; beyond GLCM 19, a decline in accuracy was observed. Comparing GLCM-13 RF with the no-GLCM RF classifier, the GLCM-based classifiers performed better; thus, the textural information assisted in removing isolated crop-classified outputs that are falsely predicted pixel groups. Still, it also obscured information about barren lands present within croplands. Delineation accuracy was 93.8 % for the no-GLCM RF classifier, whereas, for the GLCM-13 RF classifier, an accuracy of 97.3 % was observed. Thus, overall, a 3.5 % improvement in accuracy was observed while using the GLCM RF classifier with window size 13. The textural information with proper calibration over high-spatial resolution datasets improves crop delineation in the present study. Henceforth, a more accurate cropland identification will provide a better estimate of the actual cropland area in such an arid region, which will assist in formulating a better resource management policy.
Development of a low cost potato gel system for nitrate removal from water
(RJCE, 2016-09) Shukla, Paritosh; Gupta, Rajiv; Singhal, Anupam
This paper proposes to utilize the commonly available natural resource in form of tuber i.e. potato to treat the water for nitrate. The gel derived from potato (Solanum tuberosum) is employed for the removal of contaminant present in the water. The chosen system has shown overall 92 % reduction in nitrate concentration. Batch study was carried out to optimize the parameters (time of reaction, adsorbent weight and adsorbate concentration) followed by 144 h run of column to determine capability of adsorbent with artificial samples. Our studies showed that the batch study followed the Langmuir isotherm more closely than the Freundlich isotherm. Column data fit the Thomas model and kinetic constant is determined using Thomas equation. The maximum sorption capacity determined for adsorbent is 0.2484 mg/g. FTIR analysis of adsorbent (potato gel) at two different conditions shows changes in transmittance indicating the presence of active sites in adsorbent responsible for nitrate reduction.
Economical Treatment Method for Waste Pickling Liquor for Micro, Small and Medium Scale Enterprises
(Tech Journal, 2014) Singhal, Anupam; Gupta, Rajiv; Verma, Sanjay Kumar
Waste pickling liquor is pertinent to hazardous waste. Various types of recovery and regeneration methods are used to recover and regenerate the acid and metals from waste pickling liquor. But these methods are sumptuous and not amenable for small scale industries. In a developing country like India, where lots of micro, small and medium scale industries exist, only precipitation is a pecuniary treatment method but it generates lots of sludge. There are severe problems in its disposal to lined sites (landfills). This study has been undertaken to minimize the generation of the pickling sludge by different neutralizing agents and their combinations with economic valuation and also sludge characterization has been done. The results show that the treatment of pickling effluent with lime only is the economical solution but the quantity of sludge generation is on a higher side. However, the authors recommend 20% calcium hydroxide and 80% sodium hydroxide for the treatment because sludge reduction is appreciable and lower sludge generation will result in lower cost of sludge handling, i.e., sludge collection, transportation and disposal arrangement. The sludge characterization results show that the sludge generated by the treatment of WPL requires further treatment before using it as a building material.
EFFECT OF SAND REPLACEMENT BY MILL SCALE ON THE PROPERTIES OF CONCRETE
(International Journal of Engineering Technology Science and Research, 2015-03) Bhunia, Dipendu; Singhal, Anupam
Concrete is the most widely used construction material in the world. This popularity of concrete carries with it an immense environmental cost. Billions of tons of natural materials are mined and processed each year to be used in concrete, which leaves a substantial mark on the environment. Efforts to use suitable recycled materials as substitutes for concrete aggregate are gaining in importance, such as recycled concrete aggregate, post-consumer glass, tires, etc. But one waste material which has not been extensively tested yet is mill scale. Mill scale is a flaky hazardous solid waste formed on the steel’s surface during the steel manufacturing processes. This work aims to evaluate the use of mill scale in Portland cement concrete, as a replacement for natural fine aggregates. Cement mortars with mix proportioning 1:3 were prepared varying the mill scale content of fine aggregate form 0% to 100%, for determination of compressive and tensile strength. The water/cement ratio used was 0.5 for all mix proportions. The compressive strength at different proportions did not give a general trend and two peaks were obtained at 60% replacement and 100% replacement. Maximum tensile strength was observed at 60% replacement of standard sand. A mix design was also done for M35 grade of concrete by the IS method. OPC of 43 grade was selected and sand replacement was done with mill scale varying from 0% to 80% with a suitable water cement ratio of 0.40. The compressive strength was measured after 28 days of completion of curing. Maximum strength was obtained for 40% sand replacement. Moreover, concrete with mill scale has demanded greater water content to maintain the workability.
Effect of urbanization on the urban lake water quality by using water quality index (WQI)
(Elsevier, 2023-07) Srinivas, Rallapalli; Singhal, Anupam
Lake water serves an efficient source of drinking, irrigation, agriculture, industry, construction, domestic and recreation use for the urban and rural population of developing countries. The paper focuses on the assessment of water quality on the selected lakes which is affected by the speedy development of the city under the sprawl of urbanization and concretization by applying Water Quality Index (WQI) tool. Four lakes, namely Hebbal, Ulsoor, Allasandra and Mahadevapura are selected in the silicon city, Bengaluru for water quality assessment. A total of 10 parameters were taken into consideration, such as pH, turbidity, total alkalinity, total acidity, total phosphorus, COD, BOD, DO, nitrates and total nitrogen from 2 sampling sites depending upon the source of wastewater or sewage discharges. Water samples were collected and prepared for composite samples. These composite samples were examined for their different chemical and physical properties and the results were compared with standard permissible values. The results of WQI of Hebbal Lake (70.89–72.74), Ulsoor Lake (83.44–83.3), Allasandra Lake (54.47–51.84) and Mahadevapura Lake (159.41–155.81) showed that the lakes fall under poor, very poor and unsuitable categories. The results pointed out the anthropogenic activities and entry of untreated sewage into the lake. This confirms the urgent need for regular monitoring of lakes and setting up of certain policies for lake water management.
Fired clay bricks synergistically valorizing hazardous nickel chrome-plating sludge and fly ash: Performance assessment
(Elsevier, 2024-04) Singhal, Anupam; Routroy, Srikanta; Bhunia, Dipendu; Lahoti, Mukund
Nickel Chrome Plating Sludge (NCPS) is a hazardous waste containing 25%-30% nickel and chromium. Previous attempts to immobilize NCPS into fired clay bricks resulted in weakened strength due to porosity and microstructure deterioration. This study introduces co-valorization of NCPS and fly ash in fired clay bricks to address these issues. Factory-scale firing of green bricks, alongside conventional clay bricks, assessed the commercialization potential. The optimal proportion of NCPS, fly ash, and clay was found to be as 12.5:37.5:50.0, respectively. Fly ash addition significantly improved brick properties, causing compressive strength to increase from 3.2 MPa to 11.6 MPa for a NCPS content of 12.5%. Microstructural analysis highlighted fluxing oxides in NCPS, amorphous silica-alumina in fly ash, synergistic ceramic bond formation, enhanced sintering and pore filling during vitrification. The study also demonstrated substantial fuel savings of 40%-50% due to NCPS's high heat of combustion causing internal firing of green bricks. The developed bricks exhibited almost double linear attenuation coefficients, indicating enhanced gamma radiation shielding. Leaching tests confirmed successful heavy metal immobilization. This co-valorization approach not only overcomes previous drawbacks but also offers significant environmental and economic benefits in utilizing NCPS in brick production.
Heavy metal remediation using chelator-enhanced washing of municipal solid waste compost based on spectroscopic characterization
(Springer, 2023-04) Singhal, Anupam; Srinivas, Rallapalli
Due to high metal toxicity, mixed municipal solid waste (MSW) compost is difficult to use. This study detected the presence of heavy metals (Cd, Cu, Pb, Ni, and Zn) in MSW compost through mineralogical analysis using X-ray diffraction (XRD) and performed topographical imaging and elemental mapping using a scanning electron microscope and energy dispersive X-ray analysis (SEM–EDX). Ethylenediaminetetraacetic acid (EDTA), a typical chelator, is tested to remove heavy metals from Indian MSW compost (New Delhi and Mumbai). It deals with two novel aspects, viz., (i) investigating the influence of EDTA-washing conditions, molarity, dosage, MSW compost-sample size, speed, and contact time, on their metal removal efficiencies, and (ii) maximizing the percentage removal of heavy metals by determining the optimal process control process parameters. These parameters were optimized in a batch reactor utilizing Taguchi orthogonal (L25) array. The optimization showed that the removal efficiencies were 96.71%, 47.37%, and 49.94% for Cd, Pb, and Zn in Delhi samples, whereas 45.55%, 79.52%, 59.63%, 82.31%, and 88.40% for Cd, Cu, Pb, Ni, and Zn in Mumbai samples. Results indicate that the removal efficiency of heavy metals was greatly influenced by EDTA-molarity. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of hydroxyl group, which aids heavy metal chelation. The results reveal the possibility of EDTA to reduce the hazardous properties of MSW compost.
Hydro-chemical profiling and contaminant source identification in agricultural canals using data driven clustering approaches
(Springer Nature, 2025) Singhal, Anupam; Rallapalli, Srinivas
Canal networks are vital for irrigated agriculture in semi-arid regions, yet their water quality is increasingly endangered by diffuse agro-chemical runoff and unregulated effluent discharges. Despite this growing risk, long-term, high-resolution assessments that simultaneously capture spatial patterns and seasonal dynamics remain scarce—leaving practitioners with limited evidence for targeted interventions. Addressing this gap, the study sampled ten canal sites monthly for 11 months across Charkhi Dadri District (Haryana, India) and analysed sixteen physicochemical parameters, including heavy metals and irrigation-relevant ions. A suite of multivariate techniques—R- and Q-mode hierarchical clustering, principal-component analysis (PCA), correlation matrices and one-way ANOVA—was employed to disentangle pollution drivers, while the Irrigation Water Quality Index (IWQI) translated complex chemistry into management-ready scores. Two principal components explained 72.6% of variance, with aluminium, iron and copper emerging as dominant contributors; ANOVA revealed significant seasonal shifts (p < 0.05) in these metals. Cluster analysis pinpointed contamination hotspots, and IWQI values of 67.3–85.5 classified canal water as “good” to “very good” for irrigation. By integrating granular spatiotemporal monitoring with advanced multivariate statistics, the study delivers a scalable framework for managing irrigation canals in data-limited, semi-arid landscapes.
The impact of construction of hill roads on the environment, assessed using the multi-criteria approach
(Taylor & Francis, 2021-03-30) Singhal, Anupam; Singh, Ajit Pratap; Mittal, Ravi Kant
The environmental impact assessment (EIA) in regard to road widening of a 26 km stretch in Reasi District of Jammu and Kashmir (Union Territory) has been studied. Impact on the environment included temperature, deforestation, rainfall, landslides, blasting, surface and groundwater, air and soil pollution, habitat change, historical and socio-environmental factors. The study indicates that buses are the highest emitters of Hartridge Smoke Unit (HSU) followed by light commercial vehicles, heavy commercial trucks and cars, and three-wheelers in that order. The study also established that the make and age of the vehicle had negligible impact on the observed values of HSU and the light absorption coefficient (k). With the help of multi-criteria tools, the EIA has been quantified for four alternatives of a road stretch using fourteen criteria. The results show that the impact of the construction of two-lane highways on the environment is high, but that it can also be mitigated effectively.