نشریه کاربرد شیمی در محیط زیست
پیاپی 44 (پاییز 1399)

Hydrogels are 3-Dimensional (3-D) polymers that are water-insoluble. The functional groups in Hydrogels lead to water absorption and swell. In the Interpenetrating polymer network (I.P.N), polyvinyl sulfonic acid P(VSA) is imprisoned in the cross-linked polyvinyl pyrrolidone (PVP) because of the higher Maxwell energy of PVP rather than P(VSA).In this work, we prepared co-hydrogels by free radical polymerization method using the two monomers PVP and PVSA. The azobisisobutyronitrile (AIBN) as an initiator and N,N-methylen-e-bisacrylamide as a cross-linker agent was used at 65ċ for five hours and 45 minutes. We prepared co-hydrogels in 1:1,1:0.5,and 1:0.25 mole ratios on feed composition. Therefore, we obtained amphiphilic hydrogels to study the complexation behavior between the two cationic and anionic monomers. Uv-Spectrometry was performed. For the first time, the structural properties were identified by FT-IR. We investigated the swelling properties of synthesized co-hydrogels (Amphiphilite hydrogels) at different temperatures. The optimum temperature for the synthesized co-hydrogels was obtained.

The amount of waste has been steadily increasing due to the increasing human population and urbanization. Waste materials are generated from manufacturing processes, industries and municipal solid wastes (MSW). A large number of components in MSW create health and environmental problems. Health impacts include exposure to toxic chemicals through air, water and soil media; exposure to infection and biological contaminants. The environmental impacts can be pollution and global warming, photochemical oxidant creation, abiotic resource depletion, acidification, eutrophication, and eco toxicity to water. The communities, industries, and individuals have, therefore, found several ways to reduce and better manage Municipal Solid Waste through a combination of practices not only to extract reusable components but to generate energy in the form of heat or electricity. These practices include source reduction, recycling, and processing/disposal through different technologies such as composting, combustion/incineration, gasification, anaerobic digestion, landfill and so on. The increasing awareness about the environment has tremendously contributed to the concerns related with disposal of the generated wastes. This paper presents a detailed review about waste and waste management options, and research published on the effect of waste materials on environment.

Recently, due to the increasing resistance of microorganisms to common antibiotics, the use of phenolic and antimicrobial compounds in medicinal plants has received special attention.

The extract of mountain nester plants was extracted by maceration method and their phenolic compounds were identified by HPLC, the antimicrobial effect of the extract was investigated in concentrations (25, 50 and 100 µg/ml). These bacteria included common microbes and fungi, including Streptococcus mutans, Streptococcus sanguinis, Streptococcus salivaris, Streptococcus subrinus, Escherichia coli, Icnella cordens, Pseudomonas aeruginosa and Klebsiella pneumoniae. Disc diffusion and MIC methods were used to investigate the antimicrobial activity of the extracts.

In the investigation of the effect of each extract on bacteria, it was found that the medicinal plant of mountain nester has the least inhibitory effect against Klebsiella pneumoniae bacteria and the most inhibitory effect on Candida glabrata fungus. The results of the MIC test also confirm these effects

According to the phytochemical results obtained from the extract of this research, it can be stated that the studied medicinal plant has antibacterial phenolic compounds. Therefore, the results of the research showed that the medicinal plant extract of mountain nasturtium has appropriate antimicrobial properties against bacteria that cause oral and dental infections, so this herbal medicine can be used as an alternative to standard chlorhexidine drugs. And Nystatin said.

Lavender with the scientific name Lavadul angustifelia belongs to the mint family, and the extract and essence of this plant are widely used in traditional medicine. This study was conducted with the aim of investigating the antibacterial effects of alcoholic and aqueous extracts of lavender on some pathogenic bacteria. First, alcoholic and aqueous extracts of lavender were prepared by Soxhlet method, and then concentrations of 100 to 0.39% of this extract were prepared and their effect on standard strains of bacteria Bacillus subtilis, Streptococcus mutans, Listeria monocytogenes, Yersinia enterocolitica and Salmonella enteritidis determined by well diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts on the studied bacteria were measured by the micro-titer plate method with the reduction of resazurin dye. The results showed that the alcoholic and aqueous extracts of Lavander have a significant inhibitory effect on all five tested bacteria. By increasing the concentration of the extracts, their effect on the studied bacteria increased. Also, both extracts (aqueous and alcoholic) had a greater effect on gram-positive bacteria, so that both Lavender extracts showed the greatest effect on Bacillus subtilis and the least effect on Salmonella enteritidis. The inhibitory and lethality effects of the alcoholic extract was higher than that of the aqueous extract. Alcoholic and aqueous extracts of Lavandula angustifalia have significant inhibitory effects on the growth of pathogenic bacteria, especially gram-positive bacteria, so they can be used to against diseases caused by these bacteria.

This article deals with the role of mathematical chemistry in environmental studies. The aim of the article is to highlight the role of mathematical chemistry as a mathematical thinking in environmental studies. Mathematical thinking governing mathematical chemistry characterizes modeling strategies in environmental studies. The research background of environmental studies show that mathematical chemistry has been effective in solving many environmental problems. In this article, by presenting research examples and without entering into the specialized formulation of mathematical chemistry, the interaction between mathematical chemistry and the environment has been explored from its various dimensions so that the interaction of mathematical chemistry with environmental studies has been explored. The result of this research confirms that environmental problems are the driving engine of mathematical chemistry and mathematical thinking hidden in mathematical chemistry is the key to solving environmental problems. In Iran's universities, today the door to constructive interaction between mathematical chemistry and the environment has been opened in the form of intergroup scientific activities, and the country is on the verge of entering the era of mathematical thinking.

The gradual drying up of Urmia Lake has created the environment for environmental, social and economic crises in the northwestern region of the country. Human activities are one of the main threats to these ecosystems.

This article is a review article in which related documents were searched using Google Scholar and Jihad University and Normexa data. In this period of time, more than 20 documents were reviewed and extracted according to the relevant criteria.

Surveys showed that human factors play the most important role. Among the human factors, we can mention the construction of structures such as dams in the watershed of the lake, as well as the construction of a highway on the lake, and among the climatic factors, we can mention the recent droughts that cause a decrease in rainfall and an increase in evaporation. And the influential factors have been the agriculture and tourism sectors.

among the causes of the crisis, dam building, changing the pattern of rainfed to irrigated agriculture, drilling unauthorized wells, excessive water extraction from surface and underground sources, and climate factors such as recent droughts that cause a decrease in rainfall and an increase in evaporation. They are involved that these factors have caused the drying up of Urmia lake and this drying has affected the vegetation of the region, the economic and social conditions of the residents of the region, which should be considered in the formulation and implementation of long-term plans.