Water Pollution: Effects, Prevention, and Climatic Impact

The stress on our water environment as a result of increased industrialization, which aids urbanization, is becoming very high thus reducing the availability of clean water. Polluted water is of great concern to the aquatic organism, plants, humans, and climate and indeed alters the ecosystem. The preservation of our water environment, which is embedded in sustainable development, must be well driven by all sectors. While effective wastewater treatment has the tendency of salvaging the water environment, integration of environmental policies into the actor firms core objectives coupled with continuous periodical enlightenment on the present and future consequences of environmental/water pollution will greatly assist in conserving the water environment

Effect of operational parameters, characterization and antibacterial studies of green synthesis of silver nanoparticles using Tithonia diversifolia

Background There is a growing interest in the green synthesis of silver nanoparticles (AgNPs) using plant extract because the technique is cost effective, eco-friendly and environmentally benign. This is phasing out the use of toxic and hazardous chemical earlier reported. Tithonia diversifolia is a wild sunflower that grows widely in the western part of Nigeria with a proven medicinal benefit. However, several studies carried out have left doubts on the basic operational parameters needed for the green synthesis of AgNPs. The objective of this work was to carry out green synthesis of AgNPs using T. diversifolia extract via an eco-friendly route through optimization of various operational parameters, characterization, and antimicrobial studies. Method Green synthesis of TD-AgNPs was done via bottom-up approach through wet chemistry technique using environmentally benign T. diversifolia plant extract as both reducing and stabilizing agent. Phytochemical Screening of the TD plant extract was carried out. Experimental optimization of various operational parameters—reaction time, concentration, volume ratio, and temperature was investigated. TD-AgNPs were characterized by UV–Vis spectroscopy, FTIR Spectroscopy, SEM/energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Antimicrobial studies against multi drug resistant microorganisms (MDRM) were studied using the agar well diffusion method. Results This study reveals the importance of various operational parameters in the synthesis of TD-AgNPs. Excellent surface plasmon resonance peaks (SPR) were obtained at optimum experimental factors of 90 min reaction time under room temperature at 0.001M concentration with the volume ratio of 1:9 (TD extract:Ag ion solution). The synthesis was monitored using UV–Vis and maximum wavelength obtained at 430 nm was due to SPR. The morphology and elemental constituents obtained by TEM, SEM, and EDX results revealed a spherical shape of AgNPs with prominent peak of Ag at 3.0 kV in EDX spectrum. The crystallinity nature was confirmed by XRD studies. FTIR analysis proved presence of biomolecules functioning as reducing, stabilizing, and capping agents. These biomolecules were confirmed to be flavonoid, triterpenes, and saponin from phytochemical screening. The antimicrobial studies of TD-AgNPs were tested against MDRM—Escherichia coli, Salmonella typhi, Salmonella enterica, and Bacillus subtilis. Discussion The variation of reaction time, temperature, concentration, and volume ratio played substantive and fundamental roles in the synthesis of TD-AgNPs. A good dispersion of small spherical size between 10 and 26 nm was confirmed by TEM and SEM. A dual action mechanism of anti-microbial effects was provided by TD-AgNPs which are bactericidal and membrane-disruption. Based on the antimicrobial activity, the synthesized TD-AgNPs could find good application in medicine, pharmaceutical, biotechnology, and food science

Low cost adsorbent prepared from Vigna subterranean waste: Physicochemical, morphological and surface chemistry data set

Expensive commercial activated carbon has led to the continuous search for alternate suitable materials of low cost. Crop residues possess certain characteristics that makes them suitable alternate to commercial activated carbon. Some crop residues with such excellent characteristics and suitability for uptake of pollutants have been neglected hence the aim of this work. Here, we exposed the physicochemical characteristic such as surface pH, pHpzc, elemental composition, the Brunauer-Emmett-Teller (BET) surface area of a neglected African crop residue, Babara Nut Chaff (BNC). The surface chemistry via the Fourier Transformed Infrared (FTIR) spectroscopic studies as well as the surface morphology as obtained by the Scanning electron microscopic (SEM) studies are detailed herein. Hetero atom carrying functional groups such as single bondOH, Cdouble bondO and Csingle bondN would be suitable sites for metal ion uptake. Pores, gullies and crevices shown on BNC surface will also serve as a medium of pollutant trapping

Antibiotics threats on vegetables and the perils of low income nations practices

Loose control on antibiotics usage, improper waste disposal, the use of reclaimed water in crop production, and other poor practices can enhance the antibiotic contamination of soil, water and the environment. These then threaten food safety and human health. Highly susceptible crops such as vegetables easily accumulate antibiotics and can be a viable route for the spread of antibiotics resistant bacteria and the induction of antibiotics resistant genes. This paper discusses common usages and negative impacts of antibiotics, and the extent of their contamination in various environmental components viz-a-viz their impact on vegetables. Peculiar challenges and practices related to low income nations (LINs) as well as their consequential effects are also discussed. Areas of future research that needs attention in LINs are succinctly presented. This review therefore will serve as tool to increase the awareness of consumers, food producers, environmentalists and policy makers on the impact of antibiotics and inadequate practices on vegetable production

The removal of pharmaceutical pollutants from aqueous solution by Agro-waste

Pharmaceuticals are a unique class of emerging contaminants owing to their intrinsic ability to induce physiological effects on man and animals at low concentrations. Pharmaceuticals are released into the environment via diverse routes; human and animal wastes are the major sources. The persistence and mode of action of pharmaceuticals in the environment make them a major concern. Among methods available for wastewater treatment, the adsorption technique is found to be effective and easy to operate. The expensive nature of commercial activated carbons, however, created a limitation to the adsorption technique; hence the exploration for low-cost and sustainable adsorbents for the removal of different categories of water contaminants. Agricultural wastes offer such advantages as low-cost, abundance and eco-friendly materials in adsorbent preparation. Herein presented are the category and classes of pharmaceuticals cum the risks associated with pharmaceuticals released into the environment. The chemistry of activated carbon/agro wastes viz-a-viz suitability and potency in adsorption of different pharmaceutical waste removal were reviewed; the benefits associated with agricultural wastes usage in pharmaceutical removal have also been presented. Various challenges, gaps cum research prospects in the current field of discussion are herein presented. This work will serve as a tool for public education and enlightenment, help environmentalists make plans for envisaged threats and serve as a guide for policy makers

Threats from antibiotics : a serious environmental concern

Antibiotics are bioactive substances, used as human and animal medicines for illness prevention, disease treatment and growth promotion. They are considered to be pseudo persistent given their continuous input in the environment. Antibiotics enter agro ecosystems through several routes such as wastewater irrigation, soil application, animal manures or bio-solids which are mostly biologically active thus creating potential risks to the environment. They are present in different environmental matrices at low concentrations as residues. Antibiotic residues enter the environment primarily via urine, feces and manure from humans and animals after they have taken the medication, as well as from manufacturing wastewater. These residues contaminate the soil, surface water, and groundwater by leaching or runoff and ultimately breed antibiotic-resistant bacteria (ARB) and genes (ARG). These triune threat viz antibiotics, ARB and ARG have not been effectively removed by various treatment in wastewater treatment plants. Here, we put together existing knowledge and aim at providing in-depth knowledge to the extent to which a wide range of treatment processes determine the ultimate fate of antibiotic-bred threats (ARB and ARG) in conventional and advanced wastewater treatment. The use of antibiotics is inevitable, hence studies focusing on minimizing their discharge into the environment viz-a-viz support future regulatory measures are of great importance

Novel plantain peel activated carbon–supported zinc oxide nanocomposites (PPAC-ZnO-NC) for adsorption of chloroquine synthetic pharmaceutical used for COVID-19 treatment

Chloroquine has been reported as an effective drug for the treatment of COVID-19 and with the rise in its administration and continued use, metabolites of chloroquine invariably find their way into the environment. There are many concerns recently on the presence of pharmaceuticals in the aquatic environment, hence the need for environmental remediation via effective adsorbent. Plantain peel activated carbon-supported zinc oxide (PPAC-ZnO) nanocomposite was prepared and characterized using physicochemical and spectroscopic techniques. The rate of uptake of chloroquine by PPAC-ZnO nanocomposite was investigated by batch technique under different operational parameters. PPAC-ZnO nanocomposite was characterized by various physicochemical techniques by SBET = 606.07 m2g−1, pH(pzc) = 4.98 surface area by Saer’s method = 273.4 m2g−1. The carboxylic, phenols, lactone, and basic sites were determined by the Boehm method. Chloroquine uptake was confirmed by FTIR and SEM before and after adsorption. Change in morphology after adsorption was revealed by scanning electron microscopy (SEM). X-ray diffraction (XRD) showed the crystallinity of PPAC-ZnO nanocomposite. The batch adsorption experiment results showed that adsorption capacity increased with an increase in temperature. The maximum chloroquine sorption was 78.89% at a concentration of 10 ppm and a temperature of 313 K. Equilibrium sorption fitted well to Langmuir and Temkin isotherms with a high correlation coefficient (R2) of 0.99. Pseudo-second-order best described the kinetic data and adsorption mechanism was pore diffusion dependent. Thermodynamics parameters (ΔG =  − 25.65 to − 28.79 kJmol−1; ΔH = 22.06 kJmol−1 and ΔS = 157.69 Jmol−1) demonstrated feasibility, spontaneity, and endothermic behavior of the process with degrees of randomness. The activation energy for adsorption was less than 40 kJmol−1 suggesting a physisorption mechanism. This study results revealed that PPAC-ZnO nanocomposites are a sustainable and effective adsorbent for the removal of pharmaceutical waste

Trapping Rhodamine B dye using functionalized mango ( Mangifera indica ) pod

The use of acid-modified mango pod (AMMP) sorbent for removing Rhodamine B (Rh-B) dye from aqueous media was investigated. Raw mango pod (RMP) and AMMP sorbents were characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), powdered X-ray diffractogram (PXRD), Fourier transform infrared (FTIR), point of zero charge pH (pHpzc), and Boehm titration (BT) techniques. Batch adsorption was employed to examine the influence of operational factors. Sorption kinetic parameters were calculated using pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The pseudo-second-order model best fitted the adsorption kinetic data most with maximum correlation coefficient (R2 > 0.99). The process of the adsorption was controlled by both boundary layer and intraparticle diffusion mechanisms. Four isotherm models (Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin) were utilized to analyze the equilibrium data at various temperatures. Freundlich model gave the best fit with the maximum regression (0.99), while the Langmuir isotherm model established a maximum monolayer adsorption capacity of 500 mg g−1. Thermodynamic parameters studied revealed that the interaction is spontaneous and endothermic in nature. The cost analysis of the current study provides convincing proof that AMMP is efficient for removing Rh-B dye from solution by providing a saving of 225.2 USD/kg, which is eight times cheaper than commercial activated carbon. Consequently, the study revealed that AMMP is a viable, effective, and sustainable sorbent for Rhodamine B dye removal

Preparation and characterization of rice husk activated carbon-supported zinc oxide nanocomposite (RHAC-ZnO-NC)

Indiscriminate waste discharge into water bodies has increased the level of water pollution via anthropogenic activities. Hence the need for the development of sustainable and environmentally benign nanomaterials has the potential for wastewater treatment. Rice husk activated carbon (RHAC) prepared by orthophosphoric acid activation was successfully loaded with freshly prepared ZnO nanoparticles by a bottom-up approach via precipitation method resulting in the RHAC-ZnO-NC. RHAC-ZnO-NC's mineralogy with 72% zincite was determined by XRD, morphology by SEM, and the functional group by FTIR. The physicochemical parameters showed surface area 615.2 m2 g-1, pH (pzc) (6.62), pH (6.53), bulk density (0.88 g/cm3), ash content (18.45%), and volatile matter (58.08%). The porosity was determined by iodine number. Boehm titration was carried out for oxygen-bearing functional group determination. The study substantiated RHAC-ZnO-NC as a promising material for adsorption and photocatalytic degradation