Optimum pH Level Research Articles

Effects of dietary mannan oligosaccharides and coated calcium butyrate on performance, carcass parameters, blood biochemistry and meat quality of growing Japanese quails

Aim of study: Despite previous research into mannan oligosaccharides (MOS) and calcium butyrate coated with palm oil (CCB) in poultry, there is a notable gap in the literature regarding the effects of these feed additives, either individually or in combination, on the growth performance, carcass values, blood biochemistry, immune response, and meat quality of growing Japanese quails. Area of study: Türkiye Material and methods: A total of 168 mixed-sex one-day-old quails were randomly allocated to one of four treatment groups, with each group containing 7 birds per cage. The control group was fed a basal diet, while the treatment groups received the following additives: 1 g/kg of CCB, 2 g/kg of MOS, and a combination of MOS+CCB added to the basal diet, respectively. Main results: None of the treatments had a significant impact on performance, relative organ weights, total protein, albumin, globulin, total cholesterol, high-density lipoprotein cholesterol, and lipoprotein lipase concentrations in blood serum, or humoral immunity on day 28. However, the inclusion of MOS and CCB in the diet, either individually or in combination, increased carcass yield and reduced low-density lipoprotein cholesterol and triglyceride levels in the blood serum. Additionally, these additives helped maintain optimal pH levels and lower malondialdehyde concentrations in the breast meat. Moreover, the combination of MOS + CCB significantly improved water holding capacity and antibody titers against the Newcastle Disease vaccine on day 42 in Japanese quails. Research highlights: The natural feed additives CCB and MOS contribute to enhanced carcass yield, improved meat quality, and strengthened humoral immunity, while simultaneously lowering lipid values in the bloodstream.

Enhanced photocatalytic activity of CeO2 and magnetic biochar-CeO2 nanocomposite prepared from Murraya koenigii stem for degradation of methyl orange under UV light

This paper discusses the synthesis and characterization of CeO2 nanoparticles (NPs), magnetic biochar-CeO2 (MBC-CeO2) nanocomposites (NCs), and their photocatalytic analysis in methyl orange (MO) degradation. MBC-CeO2 material is synthesized on the basis of carbonization of iron oxide precursor treated with Murraya koenigii (curry leaf) stem powder. CeO2 with crystallite size 7.78 nm and MBC-CeO2 with crystallite size 14 nm are identified from XRD, with band gap energies 3.16 and 2.84 eV respectively. XPS, SEM, TEM, BET, UV–visible, FTIR, and PL characterizations are conducted to study the morphology, oxygen vacancy concentration in the samples. The removal efficiency of Methyl Orange (MO) is studied by changing both pH and concentration of MO solution. The decolorization of MO is observed at an optimum level of pH 4, with a catalyst dosage of 50 mg, which obeys pseudo-first-order kinetic theory. Under 16 min UV irradiation treatment, the decolorization efficiency of the as-prepared MBC-CeO2 is 96.7 % and total organic carbon (TOC) is ∼94 %, and for the as-prepared CeO2 it is 87.5 % and ∼ 81 % respectively. The plausible degradation pathway of MO is analyzed through LC-MS method. Regression studies are conducted to assess the suitability of all models towards photocatalytic degradation. The recycling experiment showed that both MBC-CeO2 and CeO2 are excellent stable catalysts for the activation of MO.

Investigation of Reactive Red 198 Dye Removal by Chitosan from Aqueous Solution

This study used chitosan, a biopolymer with high adsorption capacity obtained from shrimp shells, to remove Reactive Red 198 dye from water. The effects of pH, temperature, dye concentration, and particle size on adsorption were investigated. The optimum pH level for the adsorption was determined as 5. The effect of the temperature was found to be adverse, and it was observed that the adsorption capacity of chitosan decreases as the temperature increases. Considering the effect of the initial dye concentration, the adsorption values of under-size chitosan (passed through a 150-mesh sieve) and over-size chitosan (retained on a 150-mesh sieve) at 200 mg/L dye concentration were 197.38 and 196.22 mg/g, respectively. At 100 mg/L dye concentration, these values were 97.41 and 96.10 mg/g, respectively. Adhesion of the Reactive Red 198 was easier because the adsorption surface area expanded with the reduction of the particle size of the chitosan. According to the results of the study, it was seen that the isotherm model of adsorption is a suitable monolayer for the Langmuir isotherm model. Langmuir isotherm’s maximum adsorption capacity (Qmax) was calculated as 500 mg/g. The kinetic model was in line with the pseudo-second-order kinetic model. The FTIR spectra of the chitosan before and after adsorption showed that the adsorption is indeed chemical. Furthermore, SEM results demonstrated that the adsorption was more efficient due to the fibrous and porous structure of the chitosan.

Synthesis of metal doped nano-ferrites Co0.5Zn0.25M0.25Fe2O4 by co-precipitation method and application as adsorbent and photocatalyst for removal of direct orange-108 acid dye: equilibrium, kinetic and thermodynamic studies

In this study, metal-doped quaternary nano ferrites (Co0.5Zn0.25M0.25Fe2O4, M = Ba, Cu, Mn, Ni and Sr) were synthesized and evaluated for their efficiency in removing Direct Orange-108 Acid Dye from aqueous solutions. The adsorption performance of these materials was systematically investigated under various conditions. Optimal pH levels for dye removal were found to be pH 2 (41.45 mg/g), pH 2 (36.37 mg/g mg/g), pH 4 (31.13 mg/g), pH 4 (44.75 mg/g), and pH and 3 (39.62 mg/g) at optimal dosage of 0.05 g/50 mL and at an initial concentration of at 75 ppm and 50 ppm for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. Additionally, the study revealed that an optimum temperature of 40 °C enhanced the adsorption efficiency, resulting in adsorption capacities of 41.92 mg/g, 40.56 mg/g, 33.22 mg/g, 48.00 mg/g, and 43.71 mg/g for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. The shaking time with optimal results were obtained at 45 and 60 min. Similarly, as a photocatalyst have optimal pH at 2, 3 and 4, optimum dose 0.05 g/50 mL, initial concentration of dye was 50 and 75 ppm with contact time of 45 and 60 minutes at 40 °C as optimum temperature. The pseudo second order adsorption kinetic model and Langmuir adsorption equilibrium isotherm displayed strong fitting for experimental data. While degradation kinetic follow BMG and second kinetic model. NH4OH solution showed maximum desorption The thermodynamic study demonstrated the exothermic character. The adsorption study of real textile effluents was also conducted that yielded valuable information.

Investigating the Impact of pH Levels on Water Quality: An Experimental Approach

Abstract: Water quality is a critical aspect of environmental health and human well-being. pH, as a fundamental parameter, plays a significant role in determining the chemical characteristics of water. This experimental study aims to investigate the impact of pH levels on water quality. The research involved collecting water samples from various sources and subjecting them to controlled pH variations in a laboratory setting. Multiple parameters, including dissolved oxygen, nutrient availability, microbial activity, heavy metal contamination, algal blooms, turbidity, and ecological health, were assessed to evaluate the effects of pH on water quality. The results revealed that pH fluctuations had a substantial influence on these parameters, indicating a direct relationship between pH levels and water quality. The study findings contribute to the understanding of the complex interactions between pH and water quality, providing valuable insights for water resource management and environmental conservation efforts. Further research is warranted to explore additional factors that may influence the relationship between pH and water quality and to develop sustainable strategies for maintaining optimal pH levels to ensure safe and healthy water resources. I have mainly focus in this research paper the effect of pH and TDS in deferent temperature of deferent water sample.

DEVELOPMENT OF THE TECHNOLOGY OF DEEP CULTIVATION OF A TRANSFORMED B. SUBTILIS STRAIN

Deep cultivation of recombinant cultures in bioreactors makes it possible to accumulate a large number of specific antigens used in the production of immunobiological preparations and diagnostic test systems in a short period of time, taking into account stimulating and limiting growth factors. The main purpose of the research was to determine the influence of the factors of seed concentration, pH level and the level of dissolved oxygen on deep cultivation, with the control of accumulation kinetics by turbidimetry. During the research, it was found that the most optimal inoculation concentration is 1 million cells/cm3 with a maximum final concentration of B. subtilis 4x106 cells/cm3, the most optimal pH level is a dynamic mode from 8.0 to 6.0 with a maximum final concentration of 5x106 cells/cm3, the most optimal level of dissolved oxygen is stationary mode with a minimum oxygen level of 25%, with a maximum final concentration of 4x106 cells/cm3.Bacteriological, technological and biochemical methods were used in the work to develop the modes of deep cultivation of the transformed B. subtilis strain with control of pH parameters and the level of dissolved oxygen.The scientific significance of the research is based on the development of deep cultivation, with an assessment of external growth factors and their influence on the kinetics of accumulation of the transformed B. subtilis strain, which will provide effective conditions for the growth and production of microorganisms. The practical significance of the research is based on the possibility of optimizing the biotechnological stages of the cultivation of the transformed B. subtilis strain, which will positively affect the efficiency of submerged cultivation as the main method for the accumulation of specific antigens.

Using Detached Industrial Hemp Leaf Inoculation Assays to Screen for Varietal Susceptibility and Product Efficacy on Botrytis cinerea.

In greenhouse production, grey mould caused by Botrytis cinerea Pers. is one of the most widespread and damaging diseases affecting medicinal cannabis (MC). Fungicide options to control this disease are extremely limited due to the regulations surrounding fungicides and chemical residues as the product end users are medical patients, often with compromised immune systems. Screening for alternative disease control options, such as biological and organic products, can be time-consuming and costly. Here, we optimise and validate a detached leaf assay as a quick and non-destructive method to evaluate interactions between plants and pathogens, allowing the assessment of potential pathogens' infectivity and product efficacy. We tested eight industrial hemp varieties for susceptibility to B. cinerea infection. Using detached leaves from a susceptible variety, we screened a variety of chemical or organic products for efficacy in controlling the lesion development caused by B. cinerea. A consistent reduction in lesion growth was observed using treatments containing Tau-fluvalinate and Myclobutanil, as well as the softer chemical alternatives containing potassium salts. The performance of treatments was pH-dependent, emphasizing the importance of applying them at optimal pH levels to maximise their effectiveness. The detached leaf assay differentiated varietal susceptibility and was an effective method for screening treatment options for diseases caused by Botrytis. The results from the detached leaf assays gave comparable results to responses tested on whole plants.

Peroxymonosulfate-based catalytic degradation of reactive dyes in real wastewater by Fe/N-codoped carbocatalysts loaded on carbon cloth

This study simulated actual dyeing wastewater in dyeing factories with three types of dyeing wastewaters from laboratory cotton fabric dyeing to investigate the effects of catalyst and oxidant peroxymonosulfate (PMS) concentrations, pH level, and temperature on dye degradation in wastewater and determine the optimal conditions for dyeing wastewater treatment accordingly. The results demonstrated that the optimal conditions varied with the reactive dyes. Specifically, the optimal oxidant PMS concentration for degrading Reactive Yellow and Reactive Blue was 0.6 g/L, and that for degrading Reactive Red was 0.4 g/L. The optimal pH level for degrading Reactive Red and Reactive Blue was around 7.0, and that for degrading Reactive Yellow was about 5.0. The activation energy of the degradation and the mineralization degree of the three dyes were also discussed. Reactive Blue showed greater activation energy (47.0 kJ/mol) and a higher mineralization degree (81% chemical oxygen demand removal) than the other two dyes under optimal disposal conditions. The Fe/N-codoped carbocatalyst loaded on carbon cloth exhibited desirable reusability and good stability for the degradation of the three dyes. Mechanisms involved in their degradation were analyzed through X-ray photoelectron spectroscopy, focusing on N species, Fe-N binding, and C=C and C–N active components in the Fe/N-codoped carbocatalyst. Electron paramagnetic resonance experiments demonstrated that both the radical and non-radical pathways were accountable for the degradation of the three dyes, primarily the non-radical pathway. This study may contribute to the application of activated PMS for practical dyeing wastewater treatment.

Watering Regimes Impact on Pakcoy Mustard Growth, Yield, and Nutrient Dynamics

This study aimed to evaluate the influence of watering volumes on the growth, yield, and nutrient dynamics in Pakcoy Mustard plants grown in East Java. Conducted from July to August 2022, the experiment used a randomized block design comprising three levels: 10 liters, 7 liters, and 4 liters of water, each with five replications. Our findings underscored a strong correlation between water quantity and crop yield. Specifically, the treatment with 4 liters of water resulted in the lowest yield due to suboptimal conditions involving significant water reduction and high nutrient concentration (ppm) coupled with low pH values, yielding a wet weight of 63,432 grams and dry weight of 1,698 grams. Conversely, the best crop yield was achieved with the 7-liter treatment, which facilitated optimum nutrient absorption (ppm) and pH levels, accounting for 85.3% of the variation, while 14.7% was attributable to external factors. The study unveiled a substantial effect of reduced watering on nutrient concentration, with lower water amounts leading to increased nutrient density and more acidic conditions due to decreased pH values. These findings underscore the criticality of balancing water volume and nutrient dynamics for optimizing pakcoy mustard yields and may have significant implications for home-based agriculture and water management practices.

A new Modified Heterocyclic-Magnetite Chitosan Nanocomposite for Efficient Alizarin Red Dye Removal: Adsorption Analysis and Antibacterial Activity

Alizarin Red (AR) is one of the most colored hazardous industrial dyes. For effective removal of AR, a new sorbent of modified heterocyclic-magnetite chitosan nanocomposite labeled as AOC@MC was synthesized and characterized by FTIR, TGA, XRD, BET, TEM,SAED pattern and SEM-EDX. Effect of contact time, pH, adsorbent dosage, initial Alizarine Red concentration and temperature was investigated. The maximum AR removal was 98.9% and attained at optimum conditions which were pH = 3.0, contact time = 50 min., and adsorbent dosage = 0.03 g/L. The findings revealed that at pH 3 and 30 °C, the maximum adsorption capacity was approximately 162 mg/g. Within 50 min, equilibrium adsorption was attained. A pseudo-second-order equation might be used to fit the kinetic data that was acquired at the optimal pH level of 3. Langmuir adsorption isotherms could accurately represent the adsorption process. The antimicrobial properties of the functionalized sorbent AOC@MC and its heterocyclic base AOC were characterized by determining the zone of inhibition (ZOI) against Staphylococcus aureus and Klebsiella pneumonia as a model for Gram-positive and Gram-negative bacteria respectively. AOC@MC exhibits promising activity with clear zones of 20.1 ± 0.2 and 17.6 ± 0.4 mm for S. aureus and K. pneumonia respectively. Overall, the modified sorbent AOC@MC was efficient on AR dye removal and antibacterial activity compared to the corresponding heterocyclic compound AOC.

Development and application of photocatalytic coating for roadside NOx mitigation in Hong Kong

A facile chemical method for the development of photocatalytic coating products was proposed based on practical application perspective for the Hong Kong roadside nitrogen oxides (NOx) mitigation. TiO2-based photocatalytic coating PC-C film with crystallized size of around 5–6 nm was synthesized with the peptization of H2O2. The PC-C coating possesses a super-hydrophilicity surface and is proven to have a NOx degradation rate of 46.8% with an optimum pH level of 7. In addition, the PC-C coating presents a promising photocatalytic NOx degradation compared with other commercially available coating products and P25 when applied on two building materials of poly-methyl methacrylate (PMMA) and concrete surface. A weather resistance simulation and a 180-day on-site field trial were carried out the attenuation effects of photocatalytic coating applied in outdoor exposure. Based on epidemiological estimation and field investigation, hospital admissions for respiratory diseases (HARD) and mortality cases (MC) could be reduced with the application of PC-C coating along the street canyon. This work demonstrates the feasibility of air pollution control measures for the local roadside NOx using photocatalytic technology, offering promising health benefits with environmental remediation.

Adsorption and Kinetic Studies on Sequestering Effect of Porous Biodegradable Biochar Obtained from Pig-Bone on Hexavalent chromium from Aqueous Solution

In the current research work, the authors proposed a list of tactics to eliminate Cr (VI) with the help of pig bone biochar. The Cr (VI) was adsorbed in batches onto pig bone biochar to scrutinize the adsorption data. The studies determine the impact of adsorption dose, pH, and concentration. From the results, it was inferred that the optimum pH level was 7 for the removal of metal. The study calculated the adsorption isotherms in terms of affinity and adsorption capacity by leveraging Temkin, Langmuir, and Freundlich equations. According to the reports, the Langmuir model is suitable for the adsorption data, followed by Temkin and Freundlich equations. In this model, rapid adsorption kinetic rates were observed, whereas the equilibrium state was achieved after two hours. There seems to be a perfect collation between the kinetic adsorption data and the pseudo-second-order equation. The researchers determined both Lagergren and Ho’sconstants. When biochar was characterized with SEM (Scanning Electron Microscope), EDX (Energy Dispersive X-ray spectrometer), and FTIR (Fourier Transform Infrared spectrometer), it was revealed that the Cr (VI) ions interacted with the isolated aggregates formed on the biosorbent surface. From the results, it can be understood that the pig bone biochar can be effectively used to eliminate chromium ions from an aqueous solution.

Efficient oxidation of ibuprofen by nano-plate Bi2Fe4O9 activated peroxymonosulfate

Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) have received extensive attention in the elimination of persistent organic pollutants in recent years. The activation of PMS depends on the selection and preparation of the catalyst. This study prepared nano-plate Bi2Fe4O9 using a one-step hydrothermal method to active PMS for the elimination of ibuprofen (IBP). The influence of hydrothermal reaction parameters on the activity of Bi2Fe4O9 (BFO) toward PMS was investigated to optimize the synthesis conditions. The obtained optimal BFO exhibited higher catalytic activity toward PMS in terms of IBP degradation than its homogeneous counterpart (Fe2+/PMS). IBP (0.025 mM) was completely degraded within 5 min at pH ranging from 5 to 9; the optimal pH level was neutral. Based on EPR measurements and radical quenching tests, both SO4•− and •OH contributed to IBP degradation in BFO/PMS system. Oxygen vacancies (OVs) and Fe(III) are believed as the active sites on BFO surface to activate PMS based on EPR measurements, Raman spectra and DFT calculation. The degradation pathways of IBP include decarboxylation, the oxidation of methylene, hydroxylation and demethylation in BFO/PMS system. Based on the yield of intermediates, decarboxylation was considered as a major degradation pathway.

Fungal Hydrolysis of Food Waste: Review of used Substrates, Conditions, and Microorganisms

Food production generates significant amounts of organic waste that can have negative effects on the environment, such as water, soil and air pollution, due to lack of efficient utilisation solutions and insufficient disposal practices. Fungi have great enzymeproducing abilities that can be used for hydrolysing various types of food waste. Carried out in optimal conditions, fungal hydrolysis of generated food waste can be fast and efficient. Currently, fungal hydrolysis capacity for waste treatment has only been briefly demonstrated in previous studies. This review focuses on and summarizes different practises showing the potential of fungal hydrolysis for the use inefficient resource management. The main accent was put on what organisms and waste have been used in previously conducted studies. In addition, temperature, pH level and glucose recovery yields were reviewed. It was concluded that food waste can be efficiently hydrolysed and used as substrates for downstream production of value-added products. The optimal temperature for fungal hydrolysis is above 45 °C, and optimal pH level can differ depending on the process. The possibility of fungal strain optimization and creation of the enzymeproducing mutant, as well as the use of other GRAS fungi should be investigated. To explore a wider range of waste residues, researchers must collaborate with manufacturers to conduct tests and valorise new residues for fungal hydrolysis.

In vitro growth of nine edible ectomycorrhizal fungi under a range of pH conditions

Ectomycorrhizal fungi are considered to play an essential role in the development of forest ecosystems and can protect plant against pathogenic infections. Among other factors, soil pH may affect the successful inoculation of forest seedlings in nurseries. The effect of pH on the growth rate of strains of nine species of edible ectomycorrhizal (ECM) fungi was evaluated in vitro. In the experiments, Boletus edulis, B. aereus, B. pinophilus, B. fragrans, Amanita rubescens, Xerocomus ferrugineus, Lactarius deliciosus, Lactarius sanguifluus and Suillus luteus were grown in Petri dishes containing modified Melin Norkrans medium and adjusted at seven different pH levels. Colony area was measured at 7-day intervals for 8 weeks. Final fungal biomass and residual pH of the medium at 8th week were also measured. The optimum pH levels and pH tolerance ranges for the tested ECM fungal species are presented and discussed in the text. The results showed that the greatest growth in vitro was produced by A. rubescens and S. luteus at high pH levels (between 6.5-8.5), and by X. ferrugineus at low pH (3.5-6.5). Almost all the strains acidified the medium where they were grown after eight incubation weeks.

Effect of acid media on seed germination performance of Swiss-chard (Beta vulgarise L.)

Objectives: An experiment was designed with the objectives of studying the effect of acidity (pH) on the seed germination performance of Swiss-chard, and to determine the optimal pH level for the highest seed germination. Methods: The study was carried out in the laboratory of the Department of Horticulture of the University of Wolkite. The treatments were different pH levels (2, 4, 6 and 7) obtained from solutions of citric acid and distilled water in different concentration mixtures. The CRD design was used with three replicates. Findings: Analysis of variance (ANOVA) showed that all recorded germination parameters (germination rate, mean germination time, germination speed and germination index) were all most significantly different (p<0.001) for different pH levels. The highest seed germination rates (85.33% and 81.33%) were recorded at pH 7 and pH 6 respectively. Similarly the highest mean germination time (13 days and 11 days) and the highest germination speed (3.88/day and 3.7/day) were recorded at pH 6 and pH 7, respectively. However, the lowest seed germination rate (4%), the lowest mean germination time (0.5 days) and the lowest seed germination speed (0.18/day) at pH 2. The highest germination index (100 and 95.42) was recorded at pH 7 and pH 6 respectively while the lowest seed germination index (4.61) was recorded at pH 2. In general pH 7 and pH 6 can give the best results to the highest germination yield of Swiss chard.

Fungal Hydrolysis of Food Waste: Review of Used Substrates, Conditions, and Microorganisms

Abstract During food production significant amounts of organic waste is generated annually that can have a negative effect on the environment due to lack of efficient utilisation solutions and insufficient disposal practices. Fungi and their remarkable abilities to produce enzymes can be applied for hydrolysing different types of food waste in simpler sugars. Under optimal conditions, fungal hydrolysis of food waste can be rapid and efficient. Currently, the capacity of this process has only been briefly demonstrated in previous studies. This review describes different practices demonstrating the potential of fungal hydrolysis use for efficient resource management. The focus was on what organisms, waste substrates and parameters as temperature, pH level, have been applied in previous studies as well as glucose recovery yields. It was concluded that food waste can be efficiently hydrolysed and used as a substrate for the downstream production of value-added products using sequential fermentation. The optimal temperature was concluded to be above 45 °C, but the optimal pH level may vary depending on used organism and substate. In future research the possibility of optimizing fungal strains, creating mutants with enhanced enzyme-producing abilities, and application of more GRAS fungal species should be investigated. To conduct valorisation tests on new residues for fungal hydrolysis researchers must collaborate with manufacturers, thus exploring the suitability of a wider range of waste residues for fungal hydrolysis.

High yield production of lipid and carotenoids in a newly isolated Rhodotorula mucilaginosa by adapting process optimization approach

Rhodotorula sp. is a robust microbe, which can synthesize a wide range of products such as lipids and carotenoids. In the present study, we have attempted to enhance the production of lipids and carotenoids from a newly isolated Rhodotorula mucilaginosa using a process optimization approach. Among the carbon source screened, glucose showed enhanced lipid and carotenoid production of 46.19% (w/w) and 36.2 mg/g, respectively. The low C/N has influenced lipid production by 43.5% and the high C/N ratio favored carotenoid production (41.06 µg/g). The sodium acetate with 1.5% (w/v) concentration showed a lipid content of 48.28% and carotenoid of 41.16 mg/g. Further with the optimum levels of RPM (180), pH (6), and temperature (30 °C), the maximum lipid and carotenoid were found to be 51.89%, and 43.34 µg/g, respectively. In a batch bioreactor, MSM medium with sodium acetate showed a maximum lipid content of 54%. The lipid and carotenoid were successfully characterized by laser Raman spectroscopy, a label-free method and the FAME analysis clearly showed the high content of palmitic acid (C16:0) 21.05 (% w/w), oleic acid (C18:1) 56.18 (%w/w) and linoleic acid (C18:2) 12.25 (% w/w), which is suitable for biodiesel preparation.

Determination of optimal latex pH level and evaluation of natural rubber coagulum quality when using lactic acid for coagulation of rubber latex

The objectives of this study were to determine the optimal latex pH level for coagulation of rubber latex using lactic acid and to evaluate the effects of lactic acid on natural rubber coagulum quality. In this study, 3% lactic acid was added to the latex until the latex pH values reached 4.6, 4.9, 5.2, 5.5 and 5.8; meanwhile, the control treatment was added with 3% acetic acid until the latex pH value was at 5.4. The rubber coagula of the optimum and the control treatment were evaluated for mechanical, physical and chemical criteria based on the international standards of quality for natural rubber grades. The results showed that latex pH of 5.5 resulted from the addition of 3% lactic acid was the optimum for latex coagulation, which also helped to reduce the necessary amount of acid used in latex coagulation and therefore reducing the risk of water pollution. The quality of natural rubber coagulum that was coagulated by lactic acid met all requirements of technical standard for SVR 5 grade based on the Standard Vietnamese Rubber 3769:2004. The rubber coagulum coagulated by 3% lactic acid had a higher initial plasticity (Po) and a lower plasticity retention index (PRI) than that coagulated by 3% acetic acid.

Explanation of difenoconazole removal by chitosan with Langmuir adsorption isotherm and kinetic modeling.

In this study, the adsorption of toxic difenoconazole pesticide was investigated by using chitosan. In the first phase of the study, chitosan was extracted from deep-water pink shrimp (Parapenaeus longirostris) shells, by deacetylation of the chitin, which is separated and disposed of after meat extraction in processing facilities in Turkey. The deacetylation degree, molecular weight, viscosity, moisture, and crude-ash values of the extracted chitosan were determined. Chitosan, having a high deacetylation degree (90.21%), was used as the adsorbent. In the second phase of the study, the effects of pH, temperature, and pesticide concentration on the adsorption were investigated. The optimum pH level for pesticide adsorption was determined as 5. It was observed that the adsorption increases as the temperature increases. A rapid increase was observed within the first 5min of the 60-minute adsorption process in difenoconazole concentrations of 5, 15, and 25µg/L, and after 10min, the adsorption rate was stable. The Langmuir isotherm parameters regarding the adsorption were determined as aL = 0.635, kL = 15.10, and the Qmax value was calculated as 23.77mg/g. In the evaluation of overall study results, it was determined that the chitosan biopolymer is a suitable adsorbent for difenoconazole pesticide adsorption.