Cross Talk Between Zinc-Solubilizing Bacteria and Plants: A Short Tale of Bacterial-Assisted Zinc Biofortification

A contemporary approach to bacterially mediated zinc (Zn) biofortification offers a new dimension in the crop improvement program with better Zn uptake in plants to curb Zn malnutrition. The implication of Zn solubilizing bacteria (ZSB) represents an inexpensive and optional strategy for Zn biofortification, with an ultimate green solution to enlivening sustainable agriculture. ZSB dwelling in the rhizospheric hub or internal plant tissues shows their competence to solubilize Zn via a variety of strategies. The admirable method is the deposition of organic acids (OAs), which acidify the surrounding soil environment. The secretion of siderophores as a metal chelating molecule, chelating ligands, and the manifestation of an oxidative–reductive system on the bacterial cell membrane are further tactics of bacterially mediated Zn solubilization. The inoculation of plants with ZSB is probably a more effective tactic for enhanced Zn translocation in various comestible plant parts. ZSB with plant growth-enhancing properties can be used as bioelicitors for sustainable plant growth via the different approaches that are crucial for plant health and its productivity. This article provides an overview of the functional properties of ZSB-mediated Zn localization in the edible portions of food crops and provides an impetus to explore such plant probiotics as natural biofortification agents.

Ultrasensitive Room-Temperature Acetone Gas Sensors Employing Green-Solvent-Processed Aligned InNdO Nanofiber Field-Effect Transistors

The development of a high-performance acetone gas sensor for detecting low concentrations of acetone gas is still a key issue. Here, we propose the green-solution-processed electrospinning technique to construct Nd-doped...

High-Quality and Easy-to-Regenerate Personal Filter

Proper respiratory tract protection is the key factor to limiting the rate of COVID-19 spread and providing a safe environment for health care workers. Traditional N95 (FFP2) respirators are not easy to regenerate and thus create certain financial and ecological burdens; moreover, their quality may vary significantly. A solution that would overcome these disadvantages is desirable. In this study a commercially available knit polyester fleece fabric was selected as the filter material, and a total of 25 filters of different areas and thicknesses were prepared. Then, the size-resolved filtration efficiency (40-400 nm) and pressure drop were evaluated at a volumetric flow rate of 95 L/min. We showed the excellent synergistic effect of expanding the filtration area and increasing the number of filtering layers on the filtration efficiency; a filter cartridge with 8 layers of knit polyester fabric with a surface area of 900 cm2 and sized 25 x 14 x 8 cm achieved filtration efficiencies of 98 % at 95 L/min and 99.5 % at 30 L/min. The assembled filter kit consists of a filter cartridge (14 Pa) carried in a small backpack connected to a half mask with a total pressure drop of 84 Pa at 95 L/min. In addition, it is reusable, and the filter material can be regenerated at least ten times by simple methods, such as boiling. We have demonstrated a novel approach for creating high-quality and easy-to-breathe-through respiratory protective equipment that reduces operating costs and is a green solution because it is easy to regenerate.

Use of Chlorella sorokiniana (Chlorellaceae, Chlorellales) microalgae for purification of waste water from the brewing industry

The paper presents some environmental problems of the brewing industry. The literature data on the methods of water purification using microalgae have been studied. The composition of wastewater from the brewing industry is shown to consist of few biogenic elements, namely: nitrogen, phosphorus and potassium, which are necessary for microalgae biomass cultivation. Therefore, the wastewater from the brewing industry can be used as a basis for making a nutrient medium to cultivate microalgae. In the experimental part, the effect of various dilutions of a suspension of microalgae Chlorella sorokiniana (C) grown on a nutrient medium with untreated wastewater (UWW) from the brewing industry was studied. Various percentage ratios of wastewater to microalga suspension were studied, namely: UWW/C = 70:30, 50:50, and 30:70 for the ability to absorb nitrogen, organic and inorganic carbon from dry matter, and to change the pH value. The dependences of the growth rate of microalgae at various percentage additives of the wastewater from the brewing industry are presented. It was shown that at a UWW:C = 30:70, this dependence is characteristic of the standard growth curve of a microorganism culture. A lag phase, phases of exponential growth and withering away are observed. At a 70:30 ratio, the harmful effect of effluents on the growth of microalgae is obvious, on the 3rd day their death occurs, the green solution acquiring a brown color to confirm the death of microalgae cells. It has been shown that the optimal UWW:C ratio is 30:70, with no loss of biomass, it grows well using pollutants for its nutrition. The color of the solution after cultivation was bright green, which corresponded to the color of healthy cells. At UWW:C = 30:70, the wastewater is purified up to 70% and 90% for total nitrogen and organic carbon, respectively. The pH value changes from acidic to neutral. Keywords: Chlorella sorokiniana, wastewater treatment, brewing industry

Phytoremediation of Toxic Metals: A Sustainable Green Solution for Clean Environment

Contamination of aquatic ecosystems by various sources has become a major worry all over the world. Pollutants can enter the human body through the food chain from aquatic and soil habitats. These pollutants can cause various chronic diseases in humans and mortality if they collect in the body over an extended period. Although the phytoremediation technique cannot completely remove harmful materials, it is an environmentally benign, cost-effective, and natural process that has no negative effects on the environment. The main types of phytoremediation, their mechanisms, and strategies to raise the remediation rate and the use of genetically altered plants, phytoremediation plant prospects, economics, and usable plants are reviewed in this review. Several factors influence the phytoremediation process, including types of contaminants, pollutant characteristics, and plant species selection, climate considerations, flooding and aging, the effect of salt, soil parameters, and redox potential. Phytoremediation’s environmental and economic efficiency, use, and relevance are depicted in our work. Multiple recent breakthroughs in phytoremediation technologies are also mentioned in this review.

Is the Sharing Economy Green? Evidence from Cross-Country Data

Using cross-sectional data from 165 countries, this study takes a fresh look at whether or not the sharing economy is a green solution for countries. This study relies on the Timbro sharing economy index and uses both carbon emission and environmental performance index as proxies for the greenhouse gas effect and overall environment, respectively. Due to limited sample size and non-normal distribution of the sample, this paper applies the Bayesian regression model, which is based on posterior distribution. The findings suggest the following: (1) a high sharing economy level has a negative relationship to carbon emissions but a positive relationship to overall environmental performance; (2) the joint variables show that a high sharing economy level together with high broadband access, urbanization, and high education level reduces carbon emissions; and (3) for manufacturing countries, a high sharing economy level together with high urbanization is associated with comparatively low carbon emissions and high environmental performance. In general, these findings allow us to conclude in favor of the contribution made by a high sharing economy level to sustainability.

Review of Active and Passive Daylighting Technologies for Sustainable Building

According to the International Energy Agency, nearly 20% of worldwide electricity is used up by lighting. This is equal to the total electricity nuclear power generates. Thus, it is needy to explore new technologies for direct use of sunlight via integrating daylight system to the building, which is cost-saving, environment-friendly, and a green solution rather than indirect conversion of electricity to lighting even from renewable sources. In this paper, we present a review on the existing technologies of daylighting systems up to date and how they can provide lighting in a building interior via collection and distribution of sunlight. Our review is a comprehensive study to embrace both passive daylighting system with stationary design and active daylighting system equipped with sun tracking. The economic feasibility, general challenges, and prospects of daylighting systems are also discussed to understand the existing problems that hinder the extensive deployment of daylighting systems. In conclusion, more research works are needed in improving the technological development of a daylighting system so that it is more affordable, environment-friendly, less energy-intensive, and easy to install and gives uniform illumination for the effective application in both commercial building and residential houses.

CURRENT DEVELOPMENT OF SORBENTS DERIVED FROM PLANT AND ANIMAL WASTE AS GREEN SOLUTION FOR TREATING POLLUTED AQUEOUS MEDIA

In this review article, the recent development of organic sorbents derived from plant and animal waste for treating polluted aqueous media is presented. The application of biomass has been recognized reliable to adsorb hazardous pollutants contained in wastewater generated by emerging industries. This paper also discusses other existing technologies for removing pollutants including heavy metals, dyes, oil and grease, antibiotic and phenolic compounds from polluted aqueous media. Furthermore, several prominent examples of plant and animal wastes such as eucalyptus bark, pine bark, rice husk, various fruit peels, and animal bones are also properly reviewed. The effects of modification techniques on sorbent performance such as carbonization, pyrolysis, and chemical impregnation using acid or alkaline chemicals are considerably included. Some gaps in current literature are also discussed including the tendency of certain targeted pollutants, the use of simulated aqueous media, the scale of research projects, and the prominent modification procedures. Eventually, based on the relevant literature, clear conclusion has been drawn that these natural disposals have great potentiality as environmentally friendly sorbent alternative to other commercial expensive sorbents, and their reuse has been part of green solutions supporting a circular economy system.

Internet of Things-based Smart Street System

Enormous amount of electrical energy is consumed in urban areas by means of street lights. Currently, the street lights are turned on and off manually which will lead to wastage of electrical energy. Due to inadequate dimming and low efficiency of lights, current is being wasted. The main aim of this smart LED system is to create a street light which will behave according to its surrounding. This LED will turn on automatically during dark time and off during bright time with the help of LDR. It will remain dim when there is no one near the light and turns on bright when people pass by it. By doing this, huge amount of energy is being saved. Though solar energy is efficient, it can’t work during rainy season. Thus, piezoelectric sensor is a good replacement of it. It converts the pressure that applied on it to electrical energy. This sensor is fixed in the road which will convert the pressure applied to it by the vehicles to electrical energy which can be utilized by the LEDs. Finally, this system aims to present an overview of a profitable and green solution to the energy consumption problem imposed by street lighting.