Analysis of emerging contaminants: A case study of the underground and drinking water samples in Chandigarh, India

The present report deals with the analysis of emerging contaminants and the quality of drinking and underground water supply in Chandigarh, India. A water sampling monitoring and analysis was conducted by collecting a total of 54 samples of underground & drinking water of Chandigarh to analyse the health risk associated with the spread of emerging contaminants in the water sources. The quality of water samples was also assessed by measuring the colour, odour, temperature, pH, electrical conductivity (EC), biological oxygen demand (BOD), dissolved oxygen (DO), total dissolved solids/ salts (TDS) and hardness. For the estimation of the emerging contaminants (Endosulphan (ES) and Hexachlorohexane (HCH)) in the water samples, an extraction procedure was carried out by dispersive liquid-liquid extraction method followed by analysis using gas chromatography-mass spectrometry (GC-MS). The levels of ES and HCH obtained were compared with the drinking water standards of the Bureau of Indian Standards (IS: 10500). The levels of HCH and ES in all the water samples tested were found to be below the detection limit. It cannot be denied that the industrial discharge and other agencies seems to be complying with the regulations. The Initiatives by the Central and State Govt of India seems to have created sensitivity and awareness among the public specifically among the farmers. The limit of detection (LOD) were 1.0 × 10−3 and 2.4 × 10−3 ppm for ES and, HCH respectively. However, some water pollution indicators such as TDS, EC, DO and total hardness were found to exceed the limits specified by the Bureau of Indian Standards (BIS)

Enhanced Wastewater Remediation Using Mesoporous Activated Wheat Straw Biochars: A Dye Removal Perspective

The escalating contamination of water bodies by synthetic dyes necessitates innovative and ecoconscious strategies for wastewater treatment. In this study, activated biochars BC-800 (1:0.25), BC-800 (1:0.5), and BC-800 (1:1) from wheat straw were synthesized. Here, ratios denote the mass relationship between wheat straw and potassium hydroxide; “800” represents the pyrolysis temperature. These activated biochars were rigorously characterized revealing the most efficient material, BC-800 (1:1), presenting a surface area of 2578.82 m2/g and average pore diameter of 5.51 nm. Across parallel batch experiments, it effectively extracted synthetic dyes (rhodamine B (RhB), methylene blue (MB), and methyl orange (MO)) from wastewater within 15–20 min, primarily through chemisorption pathways. Increased surface area and porosity resulted in a greater dispersion of adsorption sites including C═C linkages (π–π interactions) and H-bonding via surface carbonyl groups (C═O). To understand the adsorption mechanism, Langmuir, Freundlich, and Temkin isotherm models were employed to investigate the equilibrium adsorption behavior. Results show that BC-800 (1:1) followed the Freundlich isotherm (R2: 0.9659 for RhB, 0.9927 for MB, and 0.9979 for MO, respectively), showing dye molecules form multilayers on the surface of the biochar (π-stacking). Biochar recycling through chemical regeneration demonstrated sustained dye removal efficiency >90% for BC-800 (1:1) over multiple cycles

Isothiocyanates: Promising Chemical Substance for Environmental Remediation

The lack of proper waste management as well as enforcement policies in many countries of the world have resulted in environmental pollution problems including the discharge of pollutants into water from many sources, including agriculture, tannery industries, micro-plastics, industrial and domestic waste. Wastewater effluents are significant contributors to a number of water and soil pollution problems. Scientific and technological advancements have benefited society, however, , the environmental pollution resulting from the discharge of contaminants, especially from industrial and agricultural sources is a major concern for the environment and society, creating the need for new and effective research in wastewater treatment, industrial discharge management, water and soil remediation technologies and management. Among the water availability problems faced globally, obtaining safe and clean water is a problem that needs the urgent attention of the scientific and research communities. This chapter summarizes the potential applications of isothiocyanates as promising materials for water and soil clean-up. The exploitation of isothiocyanates as chemical substances to eliminate pathogens in water and soil due to their good antimicrobial action is also highlighted. Isothiocyanates have versatile applications such as elimination of toxic metal ions from water and soil, metal nanoparticles (Nps) from aqueous medium, extraction of gold from electronic waste, adsorption of organic pollutants such as dyes, and antimicrobial action against pathogens in water and soil

Biosynthesis of silver nanospheres, kinetic profiling and their application in the optical sensing of mercury and chlorite ions in aqueous solutions

Pollution of water linked to microbial decontamination and extensive use of sodium chlorite (NaClO2 ) as a disinfectant, especially in the face of the current COVID-19 situation, is a serious water pollution issue that needs to be addressed. In this context, an environmentally friendly and cost-effective method has been developed for the biomimetic synthesis of Ag nanospheres (Ag NSs) using aqueous extract of Piper nigrum for the detection of chlorite (ClO2- ) and mercury (Hg2+ ) ions. The strong antioxidant properties of the biomolecules present in the Piper nigrum extract reduce silver ions (Ag+ ) to Ag0 . After optimization of the formulation parameters, it was observed that 1 mL of piper nigrum extract was sufficient to reduce and stabilize 100 mL of 1.5 mM of Ag+ in 2.5 h at 30 °C. X-ray diffraction (XRD) pattern of Ag NSs revealed their crystalline nature and the characteristic Bragg's diffraction peaks confirmed their face cubic crystal (FCC) lattice. The characteristic reddish-brown color and absorption surface plasmon resonance (SPR) band at 435 nm confirmed the successful fabrication of Ag NSs. Kinetic analysis revealed a three-phase growth pattern involving nucleation, growth and stabilization. Transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM) micrograms, showed spherical NSs with narrow polydispersity with particle size ranging from 10 to 30 nm. The synthesized NSs were exposed to various metal ions and anions. The absorption intensity of Ag NSs quenched in the presence of mercury ions (Hg2+) among the cations and Chlorite ions (ClO2- ) among the anions. The limit of detection (LOD) of 7.47 μM and 1.11 μM was evaluated from the calibration curve for Hg2+ and ClO2- , respectively. Based on these promising results, it is suggested that the method reported is a low-cost and one step biogenic protocol for the synthesis of Ag NSs and their employment for the detection of Hg2+ and ClO2- ions.

Enhanced Wastewater Remediation Using Mesoporous Activated Wheat Straw Biochars: A Dye Removal Perspective

The escalating contamination of water bodies by synthetic dyes necessitates innovative and ecoconscious strategies for wastewater treatment. In this study, activated biochars BC-800 (1:0.25), BC-800 (1:0.5), and BC-800 (1:1) from wheat straw were synthesized. Here, ratios denote the mass relationship between wheat straw and potassium hydroxide; “800” represents the pyrolysis temperature. These activated biochars were rigorously characterized revealing the most efficient material, BC-800 (1:1), presenting a surface area of 2578.82 m2/g and average pore diameter of 5.51 nm. Across parallel batch experiments, it effectively extracted synthetic dyes (rhodamine B (RhB), methylene blue (MB), and methyl orange (MO)) from wastewater within 15–20 min, primarily through chemisorption pathways. Increased surface area and porosity resulted in a greater dispersion of adsorption sites including CC linkages (π–π interactions) and H-bonding via surface carbonyl groups (CO). To understand the adsorption mechanism, Langmuir, Freundlich, and Temkin isotherm models were employed to investigate the equilibrium adsorption behavior. Results show that BC-800 (1:1) followed the Freundlich isotherm (R2: 0.9659 for RhB, 0.9927 for MB, and 0.9979 for MO, respectively), showing dye molecules form multilayers on the surface of the biochar (π-stacking). Biochar recycling through chemical regeneration demonstrated sustained dye removal efficiency >90% for BC-800 (1:1) over multiple cycles