Permanganate Method Research Articles

Development of products with extended shelf life

The goal of the research is to evaluate the flavor and rheological compositions formed in the process of structuring gel-like solutions of various concentrations into individual processes of the technological scheme for the production of semi-finished products and complex interaction in the structure of the finished product, taking into account the use of gelling agents and dietary supplements. The article presents some features of the flow of physicochemical reactions that make it possible to describe the dynamics of the interaction of nutrients in the formed binary compositions of carbohydrate-fat structures of plant systems in the technological process.Methods. To carry out the tests, the potentiometric method was used and the pH of each sample was determined using the Expert-001-3pH device. Determinations of sugars were carried out according to GOST 8756.13-87 using the permanganate method; dry substances according to GOST 31640-2012; organoleptic assessment according to GOST ISO 6658–2015. Samples of semi-finished products containing 25–30% fruit and citrus juices, 0.1–0.5% freeze-dried aromatic plants, 0.3–0.5% berry or vegetable powders, 0.3–0.6% spices were the objects of the research.The results. It has been established that the use of cellulose and glycerin in the formulation of carbohydrate-fat binary compositions based on fruit, citrus juices, berry or vegetable powders and spicy-aromatic raw materials contributes to the formation of an elastic, delicate film structure and a complex of flavoring and aromatic substances, depending on the type of raw materials and VAD used. With an increase in the concentration of cellulose, the films become denser, and in combination with the main raw materials (juice, powders, spices), the amount of dry substances and extract content increase, the films become opaque and less elastic. It has been found that in all samples, with an increase in spicy-aromatic raw materials, the number of inclusions increases and the films acquire a mosaic appearance. For clarity of experiments, graphs of the dependence of the type of main raw material and VAD on the concentration of the recipe composition and the formation of the flavor and aromatic range have been presented.Conclusion. The experimental data and dependencies obtained will be useful when considering more complex processes of mass transfer, sucrose inversion, and destruction of protein-carotenoid complexes. The perception of flavor and density of edible films is complex: the balance between sweetness, extractivity and threshold values of sensory characteristics are the main criteria for the organoleptic quality of the films being developed. It increases with the concentration of VAD and the type of juices or powders used. A richer and more pronounced taste appears.

Formation of flavor compositions of vegetable casseroles using carbohydrate-fat fillers

The purpose of the research is to evaluate flavor compositions formed during the action of high temperatures on individual processes of the technological scheme for the production of vegetable semi-finished products and complex interaction in the structure of the finished product, taking into account the use of carbohydrate-protein fillers. The research presents some features of the flow of physicochemical reactions that make it possible to describe the dynamics of the interaction of nutrients in the formed binary compositions of carbohydrate-fat structures of plant systems in the process of temperature exposure. The methods used. To carry out the tests, the potentiometric method was used and the pH of each sample was determined using the Expert-001-3pH device. Determinations of sugars were carried out according to GOST 8756.13-87 using the permanganate method; dry substances according to GOST 31640-2012; organoleptic assessment according to GOST ISO 6658–2015. The objects: samples of semi-finished products containing 12, 24, 36% carrots and 4, 8, 12% onions. The results. It has been established that sauteing treatment promotes the formation of a complex of flavoring and aromatic substances, depending on the type of vegetables. With increasing intensity of processing, the concentration of carbohydrates in the sautes increases, as well as the amount of dry matter. It has been found that in all samples the amount of organic acids increases with increasing temperature, pH decreases in carrots from 6.0-6.3; 5.5-7.0 to 4.2-5.9, and onions from 5.5-6.1; 6.4-7.9 to 3.0-5.0. For clarity of experiments, graphs of the dependence of the processing intensity on the amount of dry substances, carbohydrates, tissue softening and the formation of the flavor and aromatic range have been presented. Conclusion. The experimental data and dependencies obtained will be useful when considering more complex processes of mass transfer, sucrose inversion, and destruction of protein-carotenoid complexes. The perception of raw carrots is complex: the balance between sweetness and bitterness, which are the main criteria for the sensory quality of carrots. It intensifies when sauteed. A richer sweet taste appears. This perception of sweetness is determined by the ratio: sugar and bitterness. It does not have a direct correlation with the total sugar content in samples with carrots and sautéed onions.

MICROBIAL BIOREMOVAL OF DIVALENT TOXIC METALS

The problems of polymetallic wastewater treatment from mining enterprises as well as the accumulation of organic waste are acute worldwide. The application of any existing methods of wastewater purification is ineffective and impossible due to the huge volumes and high concentrations of metals. Similarly, modern methods are ineffective for the treatment of huge amounts of organic waste. Therefore, there is a necessity to develop novel environmental biotechnologies providing the simultaneous degradation of organic waste and detoxification of toxic metals. The purpose of the work was to theoretically substantiate and experimentally confirm the possibility of toxic divalent cations removal using dissimilatory sulfate reduction via anaerobic fermentation of ecologically hazardous model organic waste. Colorimetric and potentiometric methods were used for pH and redox potential measurement; volumetric and chromatographic methods – to control volume and composition of synthesized gas; permanganate method – to determine the concentration of dissolved organic carbon (DOC); photocolorimetric method via the qualitative reaction with Nessler’s reagent was used to determine the concentration of ammonium ions. The Co2+ and Ni2+ content in medium was determined by a colorimetric method with 4-(2-pyridylazo)resorcinol (PAR). Fermentation parameters were calculated with the use of mathematical and statistical ones. Modified Postgate B medium with different sources of carbon and energy (potatoes, alanine, and meat) was used for cultivation of dissimilatory sulfate reducing bacteria. The anaerobic microbiome obtained from the sludge of methane tanks showed high efficiency to remove Co2+ and Ni2+ from the liquid medium. The highest efficiency (100% in 9 days) was observed when alanine was used as a source of carbon and energy. The slowest metal precipitation process occurred using meat (20 days). Also, the use of a protein substrate did not provide the expected alkalinization of the medium, which could significantly accelerate the process of metal precipitation. The precipitation of cobalt and nickel cations during the hydrogen fermentation of potato starch was complicated by acidification of the medium, but it was equally effective when the pH was adjusted. The proposed approach, the slow dissimilatory sulfate reduction, due to the sparingly soluble calcium sulfate as electron acceptor, can be used as a basis for the development of new biotechnologies for the treatment of wastewater contaminated with divalent heavy metals with the simultaneous treatment of ecologically hazardous compounds.

Investigation and optimisation of turbidity and organic matter removal from surface water by electrocoagulation using response surface methodology

In this research, the response surface methodology (RSM) based on the central composite design (CCD) was applied to assess and optimise the electrocoagulation (EC) process used to remove turbidity and organic matter from surface water. The effects of operating factors on turbidity and organic matter removal were investigated: reaction time, electric current, effective electrode surface area and inter-electrode distance. The potassium permanganate method was used to estimate the organic matter by chemical oxygen demand (CODMn). Analysis of variance showed that the quadratic models developed to assess the responses were found to have high coefficients of determination values of 0.9747 and 0.9851 for turbidity and CODMn removal efficiencies, respectively. The experimental results revealed that 99.08% of turbidity and 85.96% of CODMn were removed at optimal conditions. The results show that the selected operating factors are significant, and RSM effectively optimises turbidity and organic matter removal from surface water by EC process.

Design and Practice of the Experiment on the Determination of Chemical Oxygen Demand in Water Samples by Potassium Permanganate Method under the Interdisciplinary Perspective

Design and Practice of the Experiment on the Determination of Chemical Oxygen Demand in Water Samples by Potassium Permanganate Method under the Interdisciplinary Perspective

Synthesis, modification, and adsorption properties of Yb‐MOF: Kinetic and thermodynamic studies

In this paper, a novel Yb metal–organic frameworks {[Yb(L)(DMA)(H2O)]·(3H2O)}n(Yb‐MOF, H3Lis 4‐(N,N′‐bis(4‐carboxylbenzyl)amino)benzenesulfonic acid) was synthesized by solvothermal reaction. ModifiedYb‐MOFwas prepared by the potassium permanganate method for removing the Cu(II) and As(V) from simulated wastewater. The optimal pH value of modifiedYb‐MOFfor Cu(II) and As(V) adsorption was 5, and the optimal dosage of adsorbent was 0.04 mg/10 ml by static adsorption test. Four isothermal adsorption models (Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich models) were fitted and analyzed. The adsorption processes of Cu(II) and As(V) were consistent with Freundlich, Langmuir, and Temkin models. The highest Cu(II) and As(V) adsorption capacity are 59.418 and 81.169 mg/g, respectively. The adsorption kinetic model and thermodynamic analysis of the modifiedYb‐MOFfor Cu(II) and As(V) were studied. The results showed revealed that the pseudo‐second‐order kinetic had a higher correlation association with the Cu(II) and As(V) adsorption process, indicating that chemisorption was dominant in both processes. At 298 and 308 K, the Cu(II) and As(V) adsorption by modifiedYb‐MOFis spontaneous.

ANTIOXIDANT ACTIVITY OF DAIRY PRODUCTS FOR BABY FOOD

Increasing the biological and nutritional value of breast milk substitutes by enriching different macro- and micronutrients is an important issue. To a certain extent, the nutritional value of milk is determined by its antioxidant activity.
 The research aims to compare the antioxidant activity of dairy products for baby food and breast milk.
 The current research studied cow pasteurized milk, drinking ultra-pasteurized “Tyoma,” sterilized milk for baby food “Agusha,” “NAN,” “Nutrilon,” and “Malyutka” milk mixtures, as well as breast milk of 17 women. The antioxidant activity was determined by the titrimetric permanganate method in aqueous and alcoholic milk extracts. The content of antioxidants in alcoholic extracts of milk and all dairy products significantly exceeds their levels in aqueous solutions. The content of water-soluble antioxidants in breast milk is significantly lower than in cow’s milk “Luzhaykino” and “Agusha,” but in infant formula, it corresponds to the indicators of breast milk. The level of alcohol-soluble antioxidants is lower in NAN and Nutrilon milk mixtures when compared with cow and breast milk. The milk mixture “Malyutka” does not differ from breast milk in terms of the antioxidant activity of alcohol- and water-soluble components.
 Discussion. The use of separate determination of hydrophilic and hydrophobic antioxidants revealed significant differences between breast and cow’s milk. The enrichment of milk with easily destructible, water-soluble ascorbic acid did not affect the antioxidant activity of dairy products for baby food (“Agusha” and “Tyoma”).
 The results obtained on the significant differences in the antioxidant properties of dairy products based on cow’s milk from breast milk indicate the need to optimize the composition of milk antioxidants for baby food and the creation of breast milk substitutes.

Parámetros energéticos en la producción sostenible de taninos de Caesalpinia spinosa kuntze (Tara)

For the production of tannins from Caesalpinia spinosa, the optimal values were determined: Raw material / extractant ratio: 1: 3; extraction time of 45 min and a leaching temperature of 70oC; the tannin concentration being evaluated by the modified permanganate method. The optimization of the parameters was carried out using the Placket & Burman Design. The process consists of extraction, vacuum concentration, clarification for the mucilage precipitate using 95oGL ethanol; recovering the alcohol by distillation; Spray drying was carried out in batches at a temperature of 145oC, obtaining a tannin concentration of 0,840 mg / mL, with an average yield of dry product of 10,42% based on the raw material in the pod. The resulting biomass was dried, pelleted and densified to be used as fuel in a stationary grate boiler, determining a saturated steam generation index of 5,260 tonnes of steam ⁄ ton of dry biomass with 10% humidity

Statistical approaches to explore the linkages between physicochemical parameters and BQEs, and set river nutrient threshold concentrations in Hungary

Abstract The objective of the Water Framework Directive (WFD) is to achieve good ecological status in surface waters by 2027. To make a proper evaluation of the ecological status of watercourses, it is necessary to harmonize class boundaries for chemical and biological quality elements (BQEs). This paper aims to explore the linkages between physicochemical parameters and BQEs and set river nutrient threshold concentrations that support good ecological status. Regression and mismatch methods were applied to find the relationship between phytoplankton (PP) and phytobenthos (PB) ecological quality ratio and mean total phosphorus (TP) and total nitrogen (TN) concentrations. Nutrient thresholds have been suggested for several water types, which are varied in the case of highland rivers 1.8–6.2 mg TN/l, 180–400 μg TP/l; in the case of lowland rivers 1.4–5.0 mg TN/l, and 100–350 μg TP/l. These values are similar to what other studies found, but the relationship between biology and nutrients was weaker. Besides nutrients, additional data of measured dissolved organic carbon, 5-day biochemical oxygen demand, chemical oxygen demand with potassium permanganate method, and information about hydromorphological features were involved in the analysis. The research demonstrates that random forest can be used as a nonlinear, multiparametric model for predicting biological class from five variables with 35–81% error for PP and with 18–47% error for PB.

LabView based virtual calorimetric etching solution analyzer (CESA) for the online quantification of hydrogen peroxide for the semiconductor industry

A virtual instrument, calorimetric etching solution analyzer based on LabVIEW 2010 platform was developed, characterized and validated for the on-line automated H2O2 concentration monitoring in SC-1 etching solution applied in the semiconductor industry. The virtual instrument completely controls all analyzer functions including sampling, analytical response measurement, digital data processing and H2O2 concentration calculation as well as the instrument calibration and real time concentration correction by fresh solution addition to the etching machine. The hardware, the software, the user interface and the instrument functioning are presented and discussed with the analytical characterization and validation by industrial sample analysis in comparison with a standard permanganate method.

The effect of long-term soil surface mulching on SOC fractions and the carbon management index in a semiarid agroecosystem

Soil organic carbon (SOC) and its fractions are widely considered to be valuable indicators for monitoring soil carbon (C) pools and dynamics induced by mulching practices. Thus, a 10-year experiment with three treatments, including no mulching (CK), gravel mulching (GM) and film mulching (FM), was established on the Loess Plateau. The results showed that SOC under GM treatment (7.88 g kg−1) in surface soil (0–20 cm) decreased significantly compared with that of CK (8.59 g kg−1), and that of FM (8.09 g kg−1) did not change significantly. Compared with CK in surface soil, water soluble C (WSC) under FM treatment decreased by 9.36% on average, and hot-water extractable C (HWC) under GM and FM treatments increased by 12.36% and 24.56% on average, respectively. Labile organic C (LOC) determined by the potassium permanganate (P-P) method did not decrease significantly under FM treatment in surface soil, but recalcitrant organic C (ROC), determined by the P–P method, significantly decreased by 9.88% on average. Compared with CK, less labile C (CLL), determined by the modified Walkley-Black (M–W–B) method under GM and FM treatments, significantly decreased by 11.21% and 17.54% on average, respectively, which suggested that CLL was converted to very labile C (CVL) and labile C (CL). This result indicated that the M-W-B method was superior in explaining C turnover. Combined with the C management index (CMI) results of previous studies, CMI was consistently lower under GM treatment, and it was unstable under FM treatment. The sensitivity index (SI) results indicated that HWC was the most sensitive SOC fraction, and LOC and ROC determined by the M–W–B method were more sensitive than those determined by the P–P method. Moreover, CMI calculated by the M–W–B method (10–35%) was more sensitive than that calculated by the P–P method (9–12%). In conclusion, the decrease in SOC under long-term mulching is mainly from ROC, and the M–W–B method is superior to the P–P method.

Statistical variation in Soil Nutrient Characteristics near Industrial Area of Mayiladuthurai Taluk of Mayiladuthurai District in Tamilnadu, India

Surface soil samples were collected from the 0-50 centimeter depth and assessed the soil statistical variation in physico-chemical parameters. The soil grain class of the surface layer is (0-58 centimeter) of the shape. Soil samples of the experimental field were clay loam while it was clay for the subsurface (25-100 Centimeter) layers of the profile. The soil samples were air-dried, crushed and passed through a 2 mm sieve before analyzing it for Nitrogen, Phosphorus, Potassium, Organic Carbon, Organic Matter, pH and exchangeable bases. Soil pH was measured electrometrically with a glass electrode pH meter, EC was determined are by using Conductivity meter. Alkaline permanganate method, colorimetric method and Flame Photometer method is used to determine Macronutrients like N P and K. Walkley and Black method is used to determine Organic Carbon (OC) and Organic Matter (OM). While the SAR, ESP% and Cation Exchange Capacity (CEC) were calculated. Micronutrients like Zinc(Zn), Copper(Cu), Iron(Fe) and Manganese(Mn) were determined by using Atomic Absorption Spectrophotometer (AAS). Available Soil pH ranged between 7.3 to 7.9. The available Electrical Conductivity (EC) values ranged from 0.18 to 0.5dsm-1 within the range for optimal growth of plants. The ranges of available Organic Carbon are ranged between 0.23% and 0.36%, Organic matter content ranged between 0.46 and 1.11 %. Nitrogen 39.2 kg/ha-1 and 72.8 kg/ha-1 are lower than that of the control soil. Available Phosphorus is ranged between 30.00 kg/ha-1 and 67.5 kg/ha-1 and is slightly higher than that of the control soil and potassium 169 kg/ha-1 and 370 kg/ha-1 content were high respectively. Cu is available between 0.72 – 0.92 ppm and Cu was found in 100% sufficient in study area. Zn is noticed between 0.62-0.82 ppm and Zn was found in 100% deficient in study area. Mn is available between 1.18-3.92 ppm and Mn was found in 70.0% deficient and 30.0% sufficient in study area. The available concentration of Fe ranged between 3.09-4.88 ppm and Fe was found in 100% sufficient in the study area. Where all below the recommended limits. Our aim is to support the farmers to characterize the soil based on their nutrition status for best suited crops which can be used effectively for crop production and enhanced productivity [1]. The statistical variation in soil nutrition is focused in Mayiladuthurai taluk in the present study at industrial based agriculture land area of Mayiladuthurai taluk in Mayiladuthurai district. The recommendations of fertilizer can be made for the crops to enhance the productivity. Soil test assessed and recommends the application of balanced fertilizers would go a long way in enhancing soil fertility and productivity.

Assessing Methods for Estimating Potentially Mineralisable Nitrogen Under Organic Production System in New Alluvial Soils of Lower Gangetic Plain

A dedicated soil testing method for estimating available nitrogen (N) in organic production system is currently lacking. In this backdrop, an innovative approach was initiated to develop a suitable method for assessing potentially mineralisable nitrogen (PMN) as N availability index in organically fertilised soils. To address the objective, a field experiment was conducted in an organically fertilised french bean crop after a 3-year crop cycle of aromatic rice-french bean-okra. Farmyard manure, vermicompost, mustard oil-cake, poultry manure and their different combinations equivalent to 120 kg N ha−1 were applied as sources of N. Chemically fertilised plots were also maintained as a check. PMN was derived using first-order kinetics, from the disappearance of organic-N at different growth stages of french bean using the methods involving 1/15 M phosphate buffer (PB), 0.01 M calcium chloride (CaCl2), 0.01 M sodium bi-carbonate (NaHCO3), and 0.1 M sodium hydroxide + 0.05 M ethylenediaminetetraacetic acid (Basic EDTA) extractants. The conventional alkaline permanganate method for N estimation was also used for comparison. PB derived significantly 22, 39 and 47% higher PMN than Basic EDTA, NaHCO3 and CaCl2 respectively. PMNs estimated by different methods were well correlated (r = 0.53** to 0.84**) among themselves while exhibited poor correlation with alkaline permanganate N (r = 0.30 to 0.41*). PB-derived PMN depicted the strongest linear relationship with pod yield (r = 0.89**, R2 = 0.80**) and N uptake (r = 0.81**, R2 = 0.66**). The reliability of PB as the most suitable method was further established by principal component analysis as PB explained the highest proportion (73%) of total PMN variation. Beyond its consequential quantitative evaluation, the ability of PB to extract organic-N compounds of similar chemical nature (uniform C:N ratio, 12–14) from diverse organic sources confirmed its superiority. Adopting PB to estimate PMN as an index of N availability will thus assist soil testing agencies to improve nutrient management advisory for organic farmers.

Knowledge and Awareness on Fumigation of Operation Theaters among Dental Undergraduates

Disinfectants play a vital role in global infection control as a crucial weapon against the transmission of nosocomial pathogens/infections combating global disease outbreak. Because of the multifactor causation of infections the environment of operation theatre plays a great role in the onset and spread of infections. As in this advancing medical era, the microbial contamination of the hospital environment, especially the operating theatre, intensive care units had continued an increased prevalence of nosocomial infection. The people who are at risk do not only involve the patients but the health professions including the nurses as well. The aim of this study was to provide and assess knowledge on fumigation of operation theatres among the dental undergraduates. A cross-sectional study was conducted online with a pre-structured questionnaire containing 10 questions among the 100 undergraduates. Persistent data were extracted and analyzed using SPSS software by IBM. A total of 100 undergraduates attended the online survey among which 78.8% were interns followed by 12.12% and 9.1% of third years and final year dental undergraduates respectively. The most commonly used fumigants opted by the participants were predominantly of formaldehyde with 89% followed by phosphine 9%. Regarding the methods of fumigation, awareness on the electric boiler fumigation method and potassium permanganate method was predominantly high among the interns with 58.9% and 84.62% respectively. Within the limits of this study, formaldehyde was the predominantly opted type of fumigant. The potassium permanganate method of fumigation was predominantly known among the participants when compared to the electric boiler fumigation method. However, the majority of participants were unaware of the emerging compounds named Virkon and Bacillocid Rasant. These were assessed along with other factors like awareness of ammonia neutralization and also the risk involved in the fumigation process.

Analysis of Tannin Levels in Neem (Azadirachta Indica A. Juss) Leaves Extracts with Water and Ethanol Solvents

Neem Plant is a widely used in agriculture as green fertilizer, pesticides and insecticides. People usually use the leaves as for lowering blood sugar, skin diseases, preventing infection, and reducing itching. This study aims to identify and determine tannins levels containing in neem leaves extracts. This study applied extraction by maceration method using 2 different solvents, water and ethanol. Tannin is a metabolite secondary compound belong to phenolic compound groups which oxidized easily by strong oxidization agent (potassium permanganate) so then its determination utilized permanganate method (Lowenthal-Procter). The results showed that neem leaves in 250 mL water solvent contains 0.55% of tannin, while in 250 mL ethanol solvent and concentration of 96% contains 0.27% of tannin.

Synthesis and Antibacterial, Antioxidant, and Molecular Docking Analysis of Some Novel Quinoline Derivatives

2-Chloroquinoline-3-carbaldehyde and 2-chloro-8-methylquinoline-3-carbaldehyde derivatives were synthesized through Vilsmeier formulation of acetanilide and N-(o-tolyl)acetamide. Aromatic nucleophilic substitution reaction was used to introduce various nucleophiles in place of chlorine under different reaction conditions. The carbaldehyde group was oxidized by permanganate method and reduced with metallic sodium in methanol and ethanol. The synthesized compounds were characterized by UV-Vis, IR, and NMR. The antibacterial activity of the synthesized compounds was screened against two Gram-positive bacteria (Bacillus subtilisATCC6633 andStaphylococcus aureusATCC25923) and two Gram-negative bacteria (Escherichia coliATCC 25922 andPseudomonas aeruginosaATCC 27853). Most of the compounds displayed potent activity against two or more bacterial strains. Among them, compounds6and15showed maximum activity againstPseudomonas aeruginosawith mean inhibition zones of 9.67 ± 1.11 and 10.00 ± 0.44 mm, respectively, while ciprofloxacin showed mean inhibition zone of 8.33 ± 0.44 mm at similar concentration. On the other hand, compound8exhibited maximum activity againstEscherichia coliwith inhibition zones of about 9.00 ± 0.55 mm at 300 μg/mL and 11.33 ± 1.11 mm at 500 μg/mL. The radical scavenging activity of these compounds was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH), and all of them displayed moderate antioxidant activity, with compound7exhibiting the strongest activity. The molecular docking study of the synthesized compounds was conducted to investigate their binding pattern with DNA gyrase, all of them were found to have minimum binding energy ranging from –6.0 to –7.33 kcal/mol, and the best result was achieved with compound11. The findings of the in vitro antibacterial and molecular docking analysis demonstrated that the synthesized compounds have potential of antibacterial activity and can be further optimized to serve as lead compounds.

Highly active copper in dye discoloration via a heterogeneous Fenton-like process

This study presents the discoloration of methylene blue by heterogenous Fenton-like process using copper. Copper was prepared with sodium ascorbate, an eco-friendly reagent under atmospheric conditions and characterized using X-ray diffraction and scanning electron microscope analysis. Sub-micron-sized particles were formed and mainly composed of metallic copper Cu with the minor presence of Cu2O. The obtained product (labeled as CuR) was compared to a commercial zero-valent copper (labeled as CuF) in the discoloration process of methylene blue. Different parameters such as copper loading, temperature and initial dye concentration were studied. Under the same conditions, CuR and CuF registered 95.04% and 20.46%, respectively, after 10 min of reaction. The discoloration process was due to the in situ production of H2O2 which was evidenced by permanganate method. It was found the formation of 0.18 mM and 75 µM of H2O2 after 2 min of reaction with CuR and CuF, respectively. The reaction rate with CuR was 5 times faster than that with CuF and both followed a pseudo-first-order reaction kinetic. The high activity observed with CuR was found to be due to the presence of Cu2O.

Comparative study on ozone oxidation chemiluminescence method and classical alkaline potassium permanganate method for determination of chemical oxygen demand in seawater

Seawater in the coastal waters of Qingdao, China was collected, and COD was measured by ozone oxidation chemiluminescence method and alkaline potassium permanganate method which was adopted in China as the standard method for measuring COD in seawater, respectively. The results show that when COD was less than 1 mg/L, the absolute error of ozone oxidation chemiluminescence method was less than 0.1 mg/L, and when COD was more than 1 mg/L, the relative error was less than 10%. The relative standard deviation of ozone oxidation chemiluminescence method was lower than 5%, and the detection limit was 0.0022 mg/L. The results of ozone oxidation chemiluminescence method were close to those of alkaline potassium permanganate method. With higher precision, lower detection limit, faster measurement, and online measurement, ozone oxidation chemiluminescence method is an ideal monitoring method for COD in seawater in the field.

Rapid determination of dye concentration in wastewater by TiO2-KMnO4 synergistic photocatalytic oxidation system

A new method for the determination of dye concentration based on photocatalytic oxidation digestion and spectrophotometry was established by using KMnO4 synergistic TiO2 photocatalytic oxidation and methyl orange solution as simulated dye wastewater. The mechanism of photocatalytic oxidation for the determination of dye concentration was discussed, and the optimal reaction conditions for dye digestion were investigated. The optimal digestion conditions were as follows: solution pH 1.5, TiO2 amount 1.0 g/L, KMnO4 initial concentration 10.0 mmol/L, solution temperature 80°C, ultraviolet light irradiation time 10 min. Compared with potassium dichromate reflux method or potassium permanganate method, the photocatalytic digestion method of TiO2-KMnO4 synergistic system is more rapid, efficient, economical and environmentally friendly, which provides a new idea for the determination of dye concentration in wastewater.

Induksi Mutasi Tanaman Leunca (Solanum nigrum L.) untuk Meningkatkan Keragaman Kandungan Tanin

Leunca (Solanum nigrum L. ) is one of the indigenous vegetables in Indonesia. The fruit of this vegetable is green and has bitter taste because of its tannin content. The objectives of this study were to get lethal dose 50 (LD50), diversity and to obtain candidates of mutant plants with high and low tannin content in young fruit and ripe fruit in leunca. The research was conducted at Pasir Kuda experimental station, Bogor; National Nuclear Energy Agency (BATAN), Jakarta; and postharvest laboratory of the Center for Tropical Horticulture Studies (PKHT IPB), Bogor, from December 2016 to July 2017. Leunca accession of SN 20 and SN 29 were irradiated using doses of 0, 100, 150, 200, and 250 Gy of gamma ray. The LD50 values for SN 20 and SN 29 were 171.944 Gy and 190.949 Gy, respectively. The analysis of tannin content was performed based on permanganate method by titration using potassium permanganate. The results showed that the highest tannin content of green stage fruit was found in SN20D3.5 with 200 Gy dose and the lowest was found in SN29D1.5 with 100 Gy dose. The highest tannin content of ripe fruit was found in SN20D4.6 with dose of 250 Gy and the lowest was found in SN20D3.1 with dose of 200 Gy. Recommended tannin content for leunca is the low tannin content.Keywords: diversity, gamma ray, indigenous vegetable, irradiation, LD50