Production Of Resins Research Articles

Bibliometric Review of State-of-the-art Research on Microbial Oils’ Use for Biobased Epoxy

Abstract Epoxy resins are widely used polymers from which a variety of products are derived and applied in many industries. Most epoxy resins are still obtained from mainly fossil feedstocks, such as epichlorohydrin and bisphenol A, which are also highly toxic. Additionally, fossil derived epoxy resin products are forming non-biodegradable waste at their end of life. Recently the number of studies aiming to find solutions and other raw materials for the replacement of fossil derived epoxy resins has increased, showing that bio-based epoxy resins are a promising alternative. An interesting alternative raw material for bio-based epoxy resins is epoxides derived from microorganisms, such as epoxidized microbial oil. This review article explores and compares the latest solutions for the use of microbial oils in the production of bio-based epoxides, outlines the prospects for their future use and points out the shortcomings of these solutions.

Threat to the Sustainable Production of Natural Resins: A Case of Rangeeni Strain of Kerria lacca (Kerr) in Eastern Plateau & Hills Region of South East Asia

The study conducted to examine the trends, growth and instability in the production of an insect-based natural resin in India. Study is designed with sampling and Focused Group Discussions (FGDs) based primary data as well as secondary data. District-level time-series data of Jharkhand state for 50 years from 1970-71 to 2019-20 was used. Time series analysis revealed the variation in lac production levels in different levels of geo coordinates. Compound Annual Growth Rate (CAGR) was worked out by fitting the exponential function. The instability indices worked out by using the method suggested by Cuddy and Dell. The growth in lac production and export of lac-based value-added products has decelerated in the post-liberalization period, while yield growth has accelerated. The overall decline in the production level of rangeeni crop ranged from -5.54% in Western Plateau Sub Zone V to -6.98% in South Eastern Plateau Sub Zone VI. Utilization of the existing natural endowment of Butea monosperma in major rangeeni lac-producing districts in Western Plateau Sub Zone V could be a promising strategy to minimize the variation in the production of rangeeni crop. A paradigm shifts from rangeeni lac cultivation during previous decades coupled with climate change issues may be another possible reason for the regional disparity in the level of rangeeni lac production.
 The overall scenario in Jharkhand state depicts the alarming situation for katki crop (Rainy season rangeeni crop) having the highest instability index (49.69), particularly with significant negative growth rates from 2000 to 2020. The magnitude of decline for katki crop was found highest and most significant during the 2001-2010 period. Although, the production of rangeeni strain was affected adversely in Jharkhand (-21.60%) during the Ninth Five Year Plan coupled with shifting from rangeeni to kusmi lac cultivation due to boosting through capacity building and skill development programs which influenced the awareness and knowledge level of the stakeholders. However, COVID-19 could break the momentum, and functionaries including the institutions and facilitators shifted to manage the disrupted supply chains during 2019-20 and 2020-21. Post COVID-19 scenario, emerged with new ICT-enabled interventions with greater scope for extension and awareness programs. However, there is a huge technological gap in the existing lac industry with poor automation and dependency on local labor. Policy interventions including market initiatives like Minimum Support Prices (MSP), Van Dhan Vikas Kendras (VDVKs); and Institutional initiatives like FPOs, SHGs, JLGs, etc. may play a key role in strengthening the sector. New host plants like Flemingia semialata may be promoted to reduce instability indices in the long run.

Potential Effects of Bisphenol A on the Heart and Coronary Artery of Adult Male Rats and the Possible Role of L-Carnitine.

Bisphenol A (BPA) is an environmental toxin utilized for the production of polycarbonate plastics and epoxy resins. Due to BPA's extensive production and environmental contamination, human exposure is unavoidable. The effects of low-dose of BPA on various body tissues and organs remain controversial. Our study investigated the potential of BPA to induce biochemical, histopathological, and immunohistochemical changes in the coronary artery and myocardium and the potential protective role of L-carnitine (LC). 24 adult Wistar albino male rats were divided equally into a control group, a BPA-treated group (40 mg/kg/d, by gavage for 4 weeks), and a BPA plus LC-treated group (received 40 mg/kg/d of BPA and 300 mg/kg/d of LC, by gavage for 4 weeks). BPA-exposed rats demonstrated structural anomalies in the coronary artery tissue including vacuolation of cells in the media and detachment of the endothelium of the intima. Congestion of blood vessels and infiltration by polynuclear cells were observed in the myocardium. There was an enhanced collagen deposition in both tissues indicating fibrosis. Immunohistochemical changes included enhanced eNOS and caspase-3 expression in the coronary artery and myocardium indicating vascular disease and apoptosis, respectively. Oxidative damage was evident in the coronary artery and the myocardium of BPA-treated rats, which was indicated by the reduced level of glutathione (GSH) and elevated malondydehyde (MDA) levels. The coadministration of LC significantly improved BPA-induced structural alterations and oxidative stress. In conclusion, BPA could potentially cause pathologic changes and oxidative damage in the coronary artery and myocardium, which could be improved by LC coadministration.

Formulation of Drying and Non Drying Oil Alkyd Resin from Palm Oil (Elaesis guineensis jacq.) and Tuna Fish Oil (Thunnus sp.) toward Acid Number Value and Non Volatile Content as Surface Coating Resin

Resin is a polymer chemical substance that is made up of monomers from carbon and nitrogen. Alkyd resin, a surface coating resin, produced by polycondensation reaction between polybasic and polyhydric alcohols, modified with monobasic acids or their anhydrides, and drying oil at controlled temperatures. Alkyd resin is widely used in the paint and surface coating industries. The advantages of this resin are its strong chemical and thermal resistance, quick drying power, and inexpensive cost. Alkyd resins can be produced from natural oil (palm and tuna fish oil). Oil derived from palm and tuna fish is known as natural oil. Tuna fish oil includes 40.04 % oleic acid. The oleic content is suitable for use in the alcoholysis process in the production of alkyd resins. The major ingredients in this study were tuna fish oil and palm oil. The aim of this research is to determine the influence of a combination of palm oil:tuna fish oil ratio, amount of pthalic anhydride, and temperature of alcoholysis process on the value of acid number and non-volatile content of alkyd resin was investigated using a Completely Randomized Design (CRD).

Susceptibility of male reproductive system to bisphenol A, an endocrine disruptor: Updates from epidemiological and experimental evidence.

Bisphenol A (BPA) is an omnipresent environmental pollutant. Despite being restrictions in-force for its utilization, it is widely being used in the production of polycarbonate plastics and epoxy resins. Direct, low-dose, and long-term exposure to BPA is expected when they are used in the packaging of food products and are used as containers for food consumption. Occupationally, workers are typically exposed to BPA at higher levels and for longer periods during the manufacturing process. BPA is a known endocrine disruptor chemical (EDC), that causes male infertility, which has a negative impact on human life from emotional, physical, and societal standpoints. To minimize the use of BPA in numerous consumer products, efforts and regulations are being made. Despite legislative limits in numerous nations, BPA is still found in consumer products. This paper examines BPA's overall male reproductive toxicity, including its impact on the hypothalamic-pituitary-testicular (HPT) axis, hormonal homeostasis, testicular steroidogenesis, sperm parameters, reproductive organs, and antioxidant defense system. Furthermore, this paper highlighted the role of non-monotonic dose-response (NMDR) in BPA exposure, which will help to improve the overall understanding of the harmful effects of BPA on the male reproductive system.

NMR metabolomics analysis ofEscherichia colicells treated with Turkish propolis water extract reveals nucleic acid metabolism as the major target

Propolis is a resinous bee product containing several hundred biologically active compounds. Although the antibacterial activity of propolis has been demonstrated in many in vitro studies, less is known about its mode of action. In this study, we aimed to shed some light on the antibacterial mechanism of action of propolis against Escherichia coli BW25113 using a nuclear magnetic resonance (NMR) based metabolomics approach. E. coli BW25113 cells were subjected to different sub-lethal concentrations (0, 2, 4, and 6mg/mL) of Turkish propolis water extract (PWE). The 500-MHz 1H NMR spectroscopy was then employed to ascertain the metabolic profiles of E. coli extracts. A total of 52 metabolites were identified from the NMR spectra, belonging to 17 main classes, such as amino acids and peptides, purines, and fatty acids. Twelve out of these 52 metabolites displayed remarkable changes at all tested PWE concentrations when compared to control conditions (P<.05). Levels of 28 more metabolites were significantly altered in at least one of the three PWE treatments. The results of partial least squares discriminant analysis showed that there was a clear separation between control and propolis-treated cells and that putrescine, adenine, adenosine, guanosine, glucose, N6-acetyllysine, and acetamide had the highest effect on group differentiation. Finally, quantitative pathway analysis revealed that purine metabolism was significantly affected by PWE treatments. Our results suggest that PWE inhibits the growth of E. coli BW25113 by affecting nucleic acid metabolism to a great extent. To the best of our knowledge, this is the first study to evaluate the global metabolic response of a bacterium to propolis.

Perfluorinated Sulfonate Resins as Reusable Heterogeneous Catalysts for the One‐Pot Synthesis of DiPhenolic Esters (DPEs)

AbstractLevulinic acid, easily obtained from cellulose, represents a fundamental chemical platform for a number of valuable building blocks. Among them, diphenolic acid and its esters (DPA and DPE) are valid candidates to replace Bisphenol A in polycarbonate and epoxy resin production processes. In this study, we report a one‐pot synthesis of alkyl DPEs in the presence of a heterogenous acid catalyst starting from levulinic acid, an alcohol and phenol as solvent‐reagent. The most interesting member of the DPE family, the ethyl 4,4‐bis(4‐hydroxyphenyl)pentanoate, is selectively obtained in a good yield in the presence of a commercially available heterogeneous acid catalyst, the Aquivion, which can be reused for at least six times without any noticeable loss in activity.

Synthesis of Alkyd Resin Through Alcoholysis – Polyesterification Process from Used Cooking Oil Pretreatment Using Alkaline Activated Natural Bayah Zeolite

Waste cooking oil can be treated by an adsorption process using Bayah natural zeolite as raw material for alkyd resin synthesis. This study aimed to determine the optimum conditions for the equivalent ratio of OH:COOH and the temperature of the alkyd resin synthesis. The research was carried out by preparing used cooking oil and Bayah natural zeolite (BNZ), adsorption process, and alkyd resin synthesis through the alcoholysis-polyesterification process. The optimum addition of Bayah natural zeolite-activated NaOH 0.75 N in pretreatment waste cooking oil is 30% weight in terms of color, density, viscosity, and functional group characteristics of the resulting alkyd resin. The characteristics of the alkyd resin product at optimum conditions obtained light brown color with an OH: COOH equivalent ratio of 1.4, and the alcoholysis and esterification temperature at 190 oC with a density value is 1.112 g/cm3, FFA value is 0.1528%, viscosity value is 4808 cP. The ester functional group at wavelengths 1267 cm-1 and 1722 cm-1, the 1H NMR spectrum of the ester group at the peak of 3.5 ppm, and a functional group of 7.6 ppm.

Guayule as an alternative crop for natural rubber production grown in B- and Se-laden soil in Central California

The potential of growing guayule ( Parthenium argentatum A. Gray) as an alternative crop for saline, boron- and selenium-laden soils in the Westside of central California was evaluated in both greenhouse and drainage sediment field experiments. In the greenhouse experiment, salt and boron (B) tolerance and selenium (Se) accumulation were evaluated in guayule accessions AZ-1 thru AZ-6 grown in saline soil and irrigated with simulated saline drainage water. The guayule accessions AZ1, AZ5, and AZ6 tolerated salinity and B levels better than the others. Consequently, AZ1, AZ5, and AZ6 were then planted in field sediment plots with slight salinity and moderate B levels. In both greenhouse and field studies, concentrations of Se, B, and Na in the leaves were as high as 0.6–8 mg/kg dry weight (DW), 2000 mg/kg DW, and 17,500 mg/kg DW, respectively, in both experiments. In both experiments, concentrations of rubber and resin ranged from 4 to 14 w/w% in the stems, and applied salinity increased rubber and resin production in some accessions. This two-phase study provides additional evidence for guayule accessions (AZ1–6) as a promising rubber-producing crop that tolerates saline irrigation water in poor quality soils. In addition, guayule may be useful in the gentle phytoremediation of Se in poor quality soils or in soils irrigated with Se-laden drainage water. • Guayule AZ accessions grown under saline, B- and S- laden conditions were evaluated. • Guayule’s tolerance to salinity, B, and Se in soil and irrigation varies by accession. • Boron, Se, and Na accumulation mostly takes place in leaf tissue. • Natural rubber and resin were not negatively affected by slight to moderate salinity. • Accession AZ5 was best suited for salinity and B.

Recycling of carbon fiber reinforced polymers in a subcritical acetic acid solution

A novel single-stage solvolysis process is demonstrated for recycling carbon fibers from an epoxy-based composite material using 50 wt% acetic acid solution under subcritical conditions. The process yields 100% fiber recovery efficiency in less than 30 min at 300 °C. Qualitative SEM/EDS analysis of the fibers reveals that the recovered fibers are entirely free of resin, and the carbon fiber surfaces were not damaged. SEM images and gravimetric measurements of the composites treated at lower temperatures and short residence times show an initial increase in mass of the CFRP samples, suggesting a two-step process consisting of initial composite swelling due to uptake of solvent, followed by depolymerization and chemical decomposition of the polymer. FTIR and GC-MS analyses confirm resin decomposition and production of aromatic and aliphatic compounds.

Diversity of agarwood-inducing fungi from Gyrinops versteegii tree

Gyrinops versteegii is a tropical tree of the Thymelaeaceae family. Under special conditions, G. versteegii tree can produce agarwood (Gaharu), a high economic commodity in the world yielding aromatic resin. Agarwood can be used for incense, perfume, addition to herbal medicine, food ingredients, and ornamental functions. It also contains phenolic compounds and feruly glycerides, which exhibit anti-cancer activity. It is apparently an induced resinous product due to subsequent infection by facultative fungal pathogens. In this study, we aim to investigate the diversity of agarwood-inducing fungi by isolating fungi from the infected trunk of G. versteegii. The pure fungi isolates were identified microscopically and then reconfirmed by molecular techniques. The identification method included genomic DNA isolation, DNA amplification of Internal Transcribed Spacer (ITS) genes by a specific primer, direct ITS gene sequencing and molecular analysis of fungi species. The investigated fungi that resulted from this research are Fusarium sp. Gv1, Aspergillus sp. Gv2 and Fusarium sp. Gv3. Three different fungi found in the same infection site show that the diversity of agarwood-inducing fungi from the G. versteegii tree is relatively high.

Research on advanced treatment of phenolic chemical wastewater and carbon replacement by the multi-layer biological activated carbon filter

After a series of biochemical processes, the wastewater engendered by the production of phenolic resin is ultimately left with a majority of difficult degradation organic matter. Most of these organic compounds are harmful to the water environment and require further advanced treatment before discharge. In this study, the original simple biological activated carbon (BAC) filter column device was improved. The new multi-layer BAC filter does not require backwash after improvement. The treatment efficiency of the multi-layer BAC filter was studied through long-term operation, and the variation of pollutants in the wastewater was analyzed. The results indicated that the multi-layer BAC filter could effectively remove hardly biodegradable organic matter, ammonium‑nitrogen (NH4+-N), and total nitrogen (TN), and its mechanism was mainly that hardly biodegradable organic matter and TN were removed by adsorption and biodegradation, while NH4+-N was only removed by microbial degradation. The pore-size distribution characteristics on the BAC surface were analyzed, and it was found that the adsorption and biodegradation reactions mainly occurred in the microporous region. The experiment on carbon replacement indicated that the service time of the BAC system could be prolonged by choosing the correct time of carbon replacement and adding the appropriate amount of microorganisms. Based on high-throughput sequencing, it was found that the microbial communities on BAC at the same height were significantly different before and after carbon replacement. The results of this paper are of some relevance for the upgrading of advanced treatment processes for chemical wastewater in practical engineering.

Simulation of Dry Reforming of Methane Catalyzed by Iron Hexagonal Mesoporous Silicates (Fe-HMS) Using Aspen HYSYS

This paper deals with the theoretical study of mesoporous silicates applied to the dry reforming of methane. In order to enhance natural gas and reduce the concentration of carbon dioxide, which is a greenhouse gas in the atmosphere in the same way as methane, the catalytic properties of silicate of the Fe-HMS-n type were used in the simulation of the methane dry reforming reaction on HYSYS. The dry reforming of methane aims to produce syngas, which is an important raw material in the production of fertilizers and resins. Among the Fe-HMS-n silicates used, Fe-HMS-15 provided good catalytic performance for methane dry reforming. A study of the influence of the quantity of iron incorporated in the silicates on the activity was carried out. This led to the conclusion that increasing the iron content improves the catalytic performance of silicates. On the other hand, this performance decreases for high porous volumes. By varying the relative quantity of reactants, the results proved that a molar ratio value greater than unity favors a majority production of dihydrogen due to the decomposition of methane. Conversely, the excess of carbon dioxide leads to the formation of carbon monoxide in a preponderant manner.

Life Cycle Assessment of Selected Single-Use Plastic Products towards Evidence-Based Policy Recommendations in Sri Lanka

The global demand for plastic is expected to double in the next 20 years. The increasing demand for Single-Use Plastic Products (SUPPs) has become one of the main environmental problems in many developing countries, including Sri Lanka, through direct and indirect means, in the way of excessive consumption and the pollution of the environment through waste generation. In this way, there is a pressing need to accelerate the sustainability evaluation, comparison, impact mitigation and policy recommendation of SUPPs to address the environmental impacts and sustainable development. Therefore, this study aims to quantify and compare the environmental impacts of SUPPs for policy decision making in Sri Lanka using life cycle assessment (LCA) techniques. Accordingly, the most popular and widely used single-use plastic products, which are under consideration for regulation in Sri Lanka, and their possible alternatives, are considered for this LCA study. The results reveal that SUPPs produced using polystyrene (PS), polypropylene (PP), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polyethylene terephthalate (PET) have a significant contribution in all life cycle stages, in terms of global warming potential (GWP) and endpoint impact categories. However, the outcomes of the study reveal that the net GWP impact of SUPPs that have recycling practice at the end of life shows better performance compared to incineration and landfill. In addition, the polylactic acid- (PLA)-based products also show a significant impact on mid- and end-point GWP impact categories. Remarkably, the midpoint analysis of PLA-based products and their alternatives emphasized that PLA production was the most impactful for most of the midpoint impact categories due to PLA resin production, which contributes significantly to all impact categories. In particular, for the pesticide bottles with the preferred end-of-life option of incineration, the HDPE indicates a 7.6% lower GWP compared to PET. For reusable steel cutlery, the largest GWP-associated life cycle stage is the user phase (97.5%), which includes cleaning the cutlery. However, the overall reduction in GWP in the use of steel, considering the best (PS with recycling) and worst (PS with incineration) case scenarios, with single-use items are 0.01 and 0.05 kg CO2 (eq), respectively. In the case of pesticide bottles, with the preferred end-of-life option being incineration, the HDPE indicates a 7.6% lower GWP compared to PET. the study reveals that conducting LCA will facilitate scientific decision making for policy interventions related to SUPPs and their processes. Notably, the study shows that, at present, the capability of conducting LCA studies to evaluate the sustainability performance of SUPPs in Sri Lanka is limited due to the lack of life cycle inventory (LCI) data availability on SUPPs and relevant waste management practices in Sri Lanka.

Tekanan Kapitalis dan Jatuhbangunnya Wanatani Krui di Sumatra

We present a brief description of the processes that have led to changes in Krui's damar agroforests. To explain these changes, we use the idea of a 'capitalist squeeze', where factors of reproduction and economy - drought, inheritance patterns, and local trade relations - combine with state and agribusiness pressure. We integrate remote sensing data at the historical level of damar agroforestry with deforestation data and small oil palm plantations throughout Krui. In January 2016, we carried out a two-week quick assessment at Krui agroforestry to assess the yield of damar per hectare and the arrival of sawmills paying high prices for resin wood. Participant observation, interviews (n=12), and focus group discussions (n=3) established that previous collaborative efforts had failed to protect the Krui damar forests from extensive felling, mostly by smallholders taking advantage of high prices of damar timber and oil palm. Attention to the capitalist squeeze bring a focus to the need to create social relations that are just, inclusive, and egalitarian in the production of resin itself.

The Cytotoxicity and Anticancer Effects of Propolis against the Oral Squamous Cell Carcinoma: In Vitro Study

Background and aim: A wide range of therapeutic properties, including anti-cancer properties, are attributed to propolis, a resinous product obtained from several plants that possess a variety of medicinal properties. A study on honeybee-produced propolis showed that in mice, it showed a significant reduction in the progression of squamous cell carcinoma in the head and neck, but in humans, its role in HNSCC remains unclear.&#x0D; Method and materials: Propolis was sampled from two types of Iranian. Extraction was done using ethanolic extracts of propolis. The cll viability was evaluated by MTT assay. Cancer cell lines were assessed for gene expression, such as mmp-2, mmp-9, bax, and bcl-2.&#x0D; Results: Increased sample concentrations reduced cell viability but did not cause significant cytotoxicity. A RT-PCR indicated that the Khalkhal sample produced more effects among the two samples, and the level of bax mRNA gene expression in the Khalkhal sample was increased. With an increasing concentration of Khalkhal samples, the expression increased. Increasing Khalkhal sample concentration also reduced mRNA levels of bcl-2, mmp-2, and mmp-9.&#x0D; Conclusion: Khalkhal’s propolis can be considered a suitable sample for the study of antiapoptotic and proapoptotic gene expression. Additionally, it can be used as a potential candidate for inhibiting the proliferation and spread of oral cancer cells.

Current progress in treatment technologies for plastic waste (bisphenol A) in aquatic environment: Occurrence, toxicity and remediation mechanisms

Bisphenol-A (BPA) is a type of endocrine disrupting compound (EDC) that is being widely used in the production of polycarbonate and epoxy resins. In the last few years, human exposure to BPA has been extensively high due to the continuous increment in the Annual Growth Rate (AGR) of the BPA global market. The presence and transportation of BPA in the environment could cause serious damage to aquatic life and human health. This paper reviewed the literature on the exposure and toxicity mechanisms of BPA and advanced analytical techniques for the detection of BPA in the environment and human beings. The study indicated that BPA can cause damaging effects on numerous tissues and organs, including the reproductive system, metabolic dysfunction, respiratory system, immune system and central nervous system. On the basis of reported studies on animals, it appears that the exposure of BPA can be carcinogenic and responsible for causing a variety of cancers like ovarian cancer, uterine cancer, prostate cancer, testicular cancer, and liver cancer. This review paper focused mainly on the current progress in BPA removal technologies within last ten years (2012–2022). This paper presents a comprehensive overview of individual removal technologies, including adsorption, photocatalysis/photodegradation, ozonation/advance oxidation, photo-fenton, membranes/nanofilters, and biodegradation, along with removal mechanisms. The extensive literature study shows that each technology has its own removal mechanism and their respective limitations in BPA treatment. In adsorption and membrane separation process, most of BPA has been treated by electrostatic interaction, hydrogen boning and π-π interations mechanism. Whereas in the degradation mechanism, O* and OH* species have played a major role in BPA removal. Some factors could alter the removal potential and efficiency of BPA removal. This review paper will provide a useful guide in providing directions for future investigation to address the problem of BPA-containing wastewater treatment.

Kontribusi Penyadapan Getah Pinus (Pinus Merkusii) terhadap Tingkat Pendapatan di PT. Inhutani I Kabupaten Gowa, Sulawesi Selatan

Income is a person's source of income to meet daily needs which are very important for survival. The income of pine sap tappers who live in rural areas generally does not come from one source, but comes from two or more sources of income. The relatively low level of income requires household members who are potential farmers to work harder. This study was to determine the contribution of tapping pine sap to the income level of the tapping community at PT. Inhutani I, Gowa Regency, South Sulawesi. This research was conducted from April to May 2022. The method used was the census method. The number of samples consisted of 20 heads of families with pine sap tappers status. This study uses primary data and secondary data. Collecting data through field surveys and data collection techniques using observation, interviews and questionnaires. The data analysis used in this research is qualitative and quantitative analysis. The results showed that the average income of pine resin tappers in the pine forest area. Pine sap income Rp. 2.030.000/month, other sector income Rp. 1.365.000/month, and the total income of the tappers is Rp. 3.395.000/month. Then the total income of pine resin tappers is Rp. 3.395.000/month, the contribution of pine resin tappers is 59.79%/month. With pine resin income of Rp. 2.030.000/month, people in pine forest area. And the income contribution of tappers is Rp. 1.745.000/month, or 59.79% with a total income of Rp. 3.395.000/month, and the components needed for tappers are Rp. 1.650.000/month. The need for direction and guidance from PT. Inhutani I Gowa to the community to be enthusiastic and participate in increasing the production of pine resin in order to meet the set targets, and this is useful for the company because the production of sap increases, the income of the community also increases.

Pretreatment Hydrolysis Acidification/Two-Stage AO Combination Process to Treat High-Concentration Resin Production Wastewater

The rapid development of the resin industry has led to a large amount of high-concentration resin production wastewater, which has created serious water pollution problems while limiting the development of related enterprises. In this study, a combined pretreatment hydrolysis acidification/two-stage anaerobic oxic (AO) process for high-concentration resin production wastewater was constructed, and the effect of operation time on the treatment efficiency of the hydrolysis acidification and the two-stage AO unit was investigated using chemical oxygen demand (COD), total nitrogen (TN), and NH3-H (ammonia nitrogen) as indicators. The effect of operation time on the treatment efficiency of the hydrolysis acidification and the two-stage AO unit was investigated. Results showed that the pretreatment of “alkaline digestion + ozone oxidation” could effectively remove volatile phenols and phenolic organic pollutants from the wastewater. The average removal rates of COD, TN, and NH3-H (ammonia nitrogen) of resin production were 91.96%, 85.35%, and 85.67%, respectively. The average concentrations of final biochemical effluent were 404.7, 21.4, and 11.4 mg/L, respectively.

Effect of microwave and ultrasound‐assisted extraction methods on phytochemical extraction of bee propolis of Indian origin and its antibacterial activity

SummaryThe propolis is a natural resinous product of bee hive and its composition majorly depends on the flora and geographical region. This study evaluated the propolis extracts collected from two different phytogeographical regions of India: Jammu &amp; Kashmir (JKP) and Rajasthan (RP) obtained through maceration, ultrasound‐assisted extraction (UAE) and microwave‐assisted extraction (MAE). Phytochemical composition and antibacterial effect of bee propolis against Staphylococcus aureus and Escherichia coli bacteria by the minimum inhibitory concentration assay were performed. The best results were obtained for JKP propolis and UAE was more efficient provided the highest extraction yield (46.76–62.44 g), phenols (137.17–355.58 GAE per g propolis), flavonoids (20.66–60.23 Q per g propolis) and antioxidant activity (76.04–64.24%) for both samples. The JKP and RP samples exhibited maximum inhibitory effect on gram – positive bacteria S. aureus with MIC value of 5 mg mL−1 compared to gram – negative bacteria E. coli.