Department of Civil Engineering

Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1927

Browse

Author: search.filters.author.Singhal, Anupam

Search Results

Now showing 1 - 10 of 27
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Sustainable ceramic bricks for toxic industrial waste inertization: factory scale development and characterization
    (Springer, 2025-07) Singhal, Anupam; Routroy, Srikanta; Bhunia, Dipendu
    This work reports factory-scale development of cleaner ceramic bricks with the incorporation of hazardous nickel chromium electroplating sludge (NCS) obtained during chrome-plated steel production. The NCS is particularly rich in chromium and nickel, the two metals used for chrome plating. Earlier attempts to incorporate NCS in ceramic bricks faced substantial strength reduction due to heavy metals’ presence. We engineered a high-volume incorporation of pulverised coal fuel ash (PFA) along with NCS and tested 20 compositions with varying proportion of the three ingredients. The optimum composition was obtained with 37.5% PFA, 12.5% NCS, and remaining clay soil. The optimum composition bricks witnessed substantially enhanced density and compressive strength, reduced water absorption and efflorescence. XRD analysis indicated formation of spinel structure and mullite leading to strength enhancement. SEM analysis indicated increased pore filling in brick matrix with PFA cenospheres. XRF analysis revealed appreciable presence of fluxing oxides in NCS which facilitated the sintering process. Additionally, higher amount of reactive silica and alumina in PFA led to formation of stronger ceramic bonds. Leaching tests by Toxicity Characteristic Leaching Procedure indicated negligible release of heavy metals, indicating successful immobilization of heavy metals. The developed methodology provides the relevant stakeholders an eco-friendly, economical, readily deployable scheme for eliminating the mounting NCS accumulation.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Synergic valorization of nickel-chrome plating sludge via alkali activation of steel slag and fly ash: performance analysis
    (Springer, 2024-09) Lahoti, Mukund; Singhal, Anupam; Routroy, Srikanta; Bhunia, Dipendu
    Nickel–chromium plating sludge (NCPS) is a hazardous waste due to high concentration (~ 25%–30%) of chromium and nickel. Electric arc furnace slag (EAFS) is a by-product of secondary steel manufacturing through the electric arc furnace route. In this work, we valorized NCPS in an innovative ambiently cured alkali-activated NCPS-Fly ash-EAFS mortar (ANFEM). NCPS substituted the binder from 0 to 25% (by weight) in the step size of 5%. The binder composition had EAFS/fly-ash = 1.0, activator/binder = 0.45, silicate/hydroxide = 2.5. Incorporation of NCPS in ANFEM resulted in several benefits such as successful NCPS immobilization, improving the flash setting and flowability issues of alkali-activated EAFS and minimal degradation in mechanical properties. Microstructural investigation by XRD, FTIR, SEM offered insights on the underlying mechanisms of NCPS valorization and corroborated the observed results of compressive strength, water absorption, bulk density, acid resistance, and surface porosity test. At 10 wt% substitution of NCPS, ANFEM produced optimum results, such as compressive strength of 40 MPa; Wabs enhancement by 4.2%; bulk density reduction by 1.1%; and the least acid-induced deterioration. Extensive leaching tests determined leachate’s heavy metals concentration to be well-within the permissible limits. Factory scale deployment of developed methodology produced paver blocks well-satisfying Indian Standard Code 15,658: 2006.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.