Sustainable and Cleaner Technologies for Environmental Remediation

For a decade, nanotechnology research has been one of the most attractive field of wastewater treatment. In the present study, green route synthesized noble metallic nanoparticles of silver and platinum catalytic activity were assessed for degradation of 4-Nitrophenol as a model by UV−visible spectroscopy. Then, catalytic activity of typical organic dyes of Alizarin red S and Brilliant blue G were also performed and monitored by UV−visible spectroscopy. The efficiency of silver and platinum nanoparticles in reducing the 4-Nitrophenol and dyes were compared. The catalytic activities of both nanoparticles were also quantified by analyzing the sodium Borohydride reduction of 4-Nitrophenol. As a result, it has been observed that the silver nanoparticles show more reducing ability than platinum nanoparticles.

Heavy metal resistant bacteria were identified from tannery effluent wastewater in and around Ezar Tanneries in Vaniyambadi, Vellore district, South India. In the first step, eleven bacterial isolates were collected from tannery effluent wastewater and tested on Luria Bertani (LB) agar plates enriched with 5 mg/l concentrations of five distinct heavy metal ions, including Cr, Cu, Ni, Pb, and Zn. Heavy metal resistance was a primary factor in choosing these two isolates. Staphylococcus aureus was determined to be the causative agent based on morphological and biochemical characteristics of the isolates. All of the detected isolates showed resistance to both copper and lead. Maximum growth of Staphylococcus aureus, a sewage isolate, occurred at 30 °C and pH 6.5. Bioremediation of heavy metal-tainted sewage and wastewater may benefit from the use of the discovered Staphylococcus aureus strain that is resistant to the metals in question.

Chlorpyrifos is chemically known as O,O- diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate belongs to organophosphorous pesticide. Usage of pesticide is still problematic and cause drastic changes in the ecosystem due to its moderate toxicity. The soil contaminated with chlorpyrifos was used to isolate CP degrading bacteria by standard pure culture technique. After isolation, the identified isolates were P. aeruginosa and P. flourescens and their pure cultures stored for further degradation studies. In nutrient broth and MSM medium, the growth of bacteria was observed by turbidometric measurements with different concentration of pesticides. The cultures of chlorpyrifos degrading bacteria were centrifuged for 20 min at 5000 rpm and the supernatants were collected. The collected supernatants subjected to analysis of UV-Vis spectrophotometer at 300 nm to find out the maximum absorption spectra. The control was used as a blank. P. aeruginosa and P. flourescens has the range of different values at different concentration of pesticides when absorbed at the maximum spectra of 300 nm. In P. aeruginosa, the chlorpyrifos residue was recorded in the 0.5c followed by 1.0c, 1.5c, 2.0c and 2.5c. The highest chlorpyrifos residue was obtained in 0.5c and 1.0c. In P. flourescens, the highest chlorpyrifos was recorded in the 0.5c, followed by 1.03c, 1.5c, 2.0c and 2.5c. The highest chlorpyrifos residue was obtained in 0.5c and 1.0c. After the degradation studies by UV-Vis spectrophotometer analysis, comparatively P. aeruginosa have shown the higher degradation of chlorpyrifos. The compound present in the treated sample after degradation of chlorpyrifos was separated and identified by GC-MS analysis. The chlorpyrifos was detected at Retention Time (RT) of 11.27 and the compound was identified as Thienol-3,5 Pyridine. This compound confirmed the degradation of chlorpyrifos by Pseudomonas sp.

The efficacy of metribuzine, a selective herbicide recommended for comprehensive weed control in rice, was investigated on Phormidium and Chroococcus species, common species of cyanobacteria obtained from the National Marine Cyanobacterial Facility (NFMC). A comparative study of the effects of metribuzine on both species of cyanobacteria measures their chlorophyll-a content and biochemical levels such as carbohydrate, protein, amino acid and lipid levels over 18 days of time- and dose-dependent exposure. was evaluated under laboratory conditions by Results showed that the herbicide exerted pleiotropic effects on both cyanobacterial species over the concentration range tested (2–10 μg). Chlorophyll a was more adversely affected by metribuzine at the highest concentration (10 μg) on day 18. On day 12, more than 50% inhibition of cyanobacterial growth was observed when 10 μg of metribuzine was applied. Carbohydrate, protein, amino acid, and lipid levels were reduced with herbicide, but by day 18, effects were noticeable at the highest concentrations for both cyanobacteria. Metribuzine concentrations in the 2 µg range also affected chlorophyll a and biochemical content in both cyanobacteria. Phormidium species were more affected by metribuzine than Chroococcus species. Since, Phormidium and Chroococcus species are abundant in paddy fields and can be used as inoculum for rice biofertilizer programs, protecting them from the potential residual effects of herbicides is critical to correctly managing local soil fertility.

The soil microbiome performs a wide range of crucial functions; however, we have a limited understanding of its biodiversity. Extracting microbes from polluted sites could reveal potential microbes that could be used to mitigate pollution better than conventional microbes. Soil DNA may be extracted directly, amplified using polymerase chain reaction, and profiled to reveal more about the soil microbiome’s taxonomy and function than ever before. Current procedures frequently combine DNA sequencing with other methods like denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), single-strand conformation polymorphism (SSCP), terminal restriction fragment length polymorphism (TRFLP), amplified rDNA restriction analysis (ARDRA), amplified ribosomal intergenic spacer analysis (ARISA), and cloning. The advantages and disadvantages of these methods are discussed, and new developments that have relevance as an appliance shedding light on the soil microbial ecology are also included. Soil diversity cannot be assessed using just one approach; therefore, picking the right one and using newly discovered information can significantly improve our understanding of soil microbes for their specific applications in mitigating.

The present study is alternative for removal of synthetic dyes particularly reactive red 120 and reactive black 5 dyes by Aspergillus niger and Pleurotus ostreatus by shake flask system for 7 days. The efficiency of decoloration of reactive red and reactive black, at room temperature (28 ± 2 °C), by Aspergillus niger are 78% and 66% respectively. Similarly, Pleurotus ostreatus shows 64 and 77% of decoloration for reactive red 120 and reactive black 5 respectively. The optimization of the decolorization efficiency was then carried out for the fungal colonies. The various physical parameters such as pH (3, 4, 5 and 6), temperature (30, 37 and 45 °C) and C:N ratio (1:2, 1:1, 2:1) were optimized to obtain maximum decolorization of the commercial reactive dyes by Aspergillus niger and Pleurotus ostreatus.

For life to exist, water is essential. Several conventional methods and combinatorial approaches are in practice to clean wastewater, which needs to be maintained. Additionally, wasted water must be treated and used for various purposes. Domestic wastewater is defined as water used for activities such as dish washing, laundry, and house cleaning. Different kind of ways to treat household wastewater. It can be purified using various techniques, including physical, chemical, biological, and natural processes. Physical methods require expert or qualified personnel for maintenance and control, along with the best equipment for use. Each tactic uses various techniques. The chemicals used in chemical wastewater treatment methods can cause harm to people. However, biological treatment requires both aerobic and anaerobic systems. Mentha aquatica was used in this study as a natural source for treating domestic wastewater. The chemical oxygen demand (COD), biological oxygen demand (BOD), and turbidity measurements were used to evaluate the water quality. It was noted that the chemical oxygen demand and biological oxygen demand readings had significantly decreased on days 11 and 21 of treatment. Thus, the observed data confirm M. aquatica as a potential replacement for current wastewater treatment methods.

Hedychium flavum, a medicinal, edible, and ornamental plant, is widely cultivated in India. Essential oils from the plant are used for various medical purposes and the leftover plant residue after oil extraction is discarded as a waste. An attempt was made to explore the used of this waste to remove heavy metals from wastewater was analysed. Result shows that the waste powder can be used effectively for metal removal. Hedychium flavum sequence was submitted to the NCBI database to procure accession numbers MN988619.

Acinetobacter baumanni was isolated from polluted soil. An attempt to study the A. baumannii to degrade dye was explored. It was found effective against azo dye and was able to completely degrade the dye under 48 h in a shake flask. Molecular analysis on the isolate A. baumanni was performed together with Hedychium flavum, and the sequence was submitted to the NCBI database to procure accession number MT192652.1. Response surface Methodology-Box-Behnken design (RSM-BBD) was used to optimize the condition and achieve 98–99% dye decolorization.

The photocatalytic degradation approach for industrial dyes in the presence of appropriate nanocatalyst offers a possible way for the complete removal of various pollutants from the aqueous environment. Therefore, in this study, we have made an attempt on use of bio-synthesized copper oxide (CuO) nanoparticles harnessed by neem extract for the degradation of reactive orange M2R (RO-M2R). The significant catalytic degradation of dye was found to be pH10, catalytic dosage at 10 ppm, and dye concentration at 3 gL⁻¹ and irradiation time at 5 h through one factor at a time (OFAT). Further, Box Behnken design was applied to optimize and investigate the interaction between these four variables for the degradation of dye. It was predicted that maximum degradation was 84.04% under optimum conditions of pH at 11.84, catalytic dosage at 2.20 gL⁻¹, dye concentration at 7.49 ppm and irradiation time of 4 h. The validity of the optimal level predicted under the RSM was established by an independent experiment.

Societal waste materials from the landfill are considered as one of the major contributors affecting the ecosystem and environment. Composting and vermicomposting are the commonly used methodologies to treat and convert these waste materials into the useful manure by the collective action of earthworms and other beneficial microbes. Waste management is considered as an integral part of a sustainable society, thereby necessitating the conversion of these biowastes into alternative management processes such as vermicomposting. Vermicompost produced by the activity of earthworms is rich in nutritive organic macro and micronutrients, vitamins, growth hormones, beneficial soil microbes and enzymes such as proteases, amylases, lipase, cellulase and chitinase etc. Such microbes and enzymes continue to disintegrate organic matter even after they have been excreted from the earthworms. In this review, we have summarized the importance of vermicomposting, effect of process-enhancing supplements, the detoxification process of industrial wastes by earthworms and the role of vermicompost in plant growth and development. Further, the recent advancements in innovative vermicomposting technologies employed for small- and large-scale production are highlighted. Collectively, it highlights vermicompost as a powerful crop nutrient in sustainable agriculture.

A large number of waste printed circuit boards are produced annually, which looms large as a serious threat to our environment. When discarded in a landfill, printed circuit boards (PCB) contain poisonous and dangerous metallic and non-metallic fractions (NMF). This study illustrates the viability of using NMF recycled from waste PCB as one of the constituent materials in the manufacture of building goods like fly ash bricks and paver blocks as a possible route to environmentally friendly construction. The raw materials were combined with NMF in a variety of ratios ranging from 5 to 25%. In comparison to conventional products, NMF-incorporated fly ash bricks and paver blocks shown an improvement in compressive strength. Fly ash bricks made with NMF showed no efflorescence. In comparison to conventional products, NMF-incorporated products were observed to absorb less water. When compared to the control specimens, the NMF blended paver block specimens showed a significant resistance to water penetration.

Municipal solid waste (MSW) management is a pressing issue in developing nations across the globe. Organic fraction makes up a major fraction of the waste composition. Owing to its high organic matter, high abundance and low concentrations of pollutants, MSW is suitable for bioconversion. Old age-established concepts like composting and vermicomposting offer rearrangement and recycling of the organic components of waste through the cyclic pathways in the natural environment lowering the quantity of waste and upcycling it to value-added organic manure. Food production owing to the green revolution has proved to be unsustainable in the longer run. Sustainable agriculture embraces judicious ecosystem management and discourages the use of synthetic inputs. Fortified quality organic manures can be directed for sustainable agricultural practices achieving natural circularity, safe quality food production and upliftment of the physicochemical and biological quality of soil and crops. Engaging the other hidden half of nature- the human world of intents and thoughts, positive-divine thought-based bioelectromagnetic energy generated by meditation during the farming process- Sustainable Yogic Agriculture (SYA) has experimentally shown enhanced levels of agroecosystem health, microbial activity and crop production. The present work reviews the bioconversion of locally available organic waste to manures for nutrient management of agricultural soil and crop production and their quality enhancement by incorporating a transdisciplinary SYA approach. Nature has multidisciplinary intricate linkages and is highly receptive to human emotions. Transdisciplinary practical solutions can become potential solutions to realize the vision of a sustainable nation.

Micronized biomass silica (MBS) is an agricultural waste obtained by burning and grinding rice husk in a controlled atmosphere to nano scale. The present chapter focuses primarily on the performance assessment of MBS as an ingredient in production of Fly ash brick and paver blocks. The research was carried in two stages. Casting and compressive strength tests of mortar mixtures with variable MBS content in the range of 0, 5, 10, 15, and 20% by weight of cement were conducted in the first step. The optimum percentage of MBS substitution in mortar was found to be 15% and the microstructural properties of hydrated cement mortar mixes using SEM and EDAX shows that the addition of MBS to the hydrated cement mortar mixes resulted in the formation of CSH gels and CaCO₃ crystals, which may be credited to improved strength. In second stage, fly ash bricks and paver blocks were casted by replacing fly ash and cement respectively with varying percentage of MBS (0, 10, 20, 30, 40 & 50%). From the compressive strength test it was found out that optimum replacement of MBS was 15% for fly ash bricks and paver blocks. Efflorescence was not observed in fly ash bricks at all proportions of MBS. When compared to control specimens, MBS blended fly ash brick and paver block specimens showed a significant resistance to water penetration. The present study indicates the feasibility of utilizing MBS as a raw material in production of sustainable building materials and products.