Color Reduction Research Articles

Synthesis of Graphene β-Cyclodextrin Nano-Composite for Removal of Dyes from Waste Water

Graphene oxide & its nano composite was synthesized using the Hummer’s method. Synthesized novel graphene oxide-beta-cyclodextrin (GO-CD) composites is applied as adsorbent for adsorption and elimination of hazardous endocrine disrupting compounds, such as Methylene Blue from the solvent phase of an aqueous solution. Methylene Blue from aqueous solutions by batch adsorption technique under varying conditions such as contact time, pH and temperature. Lower solution pH (3 to 5) favoured the adsorption of reactive dye onto graphene oxide-beta-cyclodextrin composites. Endocrine disrupting compounds are highly toxic substances that cannot be removed from treated waste water through conventional methods. The optimized values of effective parameters were 20 minute (contact time), 20mg (adsorbent dosage), and 7.5(pH) and 0.00001 (initial concentration) these values were optimized using batch adsorption study. Hence, the developed adsorbent could be efficiently used for rapid adsorption and removal of noxious impurities. The results indicated that graphene oxide-beta-cyclodextrin composites have shown reduction in colour of waste water by 60-80% and also have shown reduction in other polluting parameters.

Scale Minimization in Sugar Industry Evaporators using Nanoporous Industrial Bio-solid Waste Bagasse Fly Ash

Scale deposition on the surface of heat exchangers of the evaporators of a sugar mill is the bane of sugar industry. It causes corrosion of surfaces, restricts fluid flow and impairs heat transfer (because it has very low thermal conductivity) across the metal–fluid interface. Accumulation of scale is the combined effect of several processes involving inorganic/organic molecules or ions present in the cane juice. Bagasse fly ash (BFA), obtained from the flue-gas line of bagasse-fired boilers, exhibits unique characteristics such as very high carbon content (49%), large surface area (~ 500 m2/g), high pore volume, mesoporous pore size and spontaneous adsorption, rendering it suitable as adsorbent for clarification of cane juice, a process purporting to remove several of the impurities. The aim of the present paper is to study the feasibility of using BFA (primary mesh size of 200 μm) as adsorbent for clarification of industrial cane juice which in turn would minimize formation of scale. BFA consists of globular structures aggregated in a fractal-like configuration, with pore sizes ranging between 100 nm and 1.0 µm. After it has adsorbed impurities from cane juice (becoming A-BFA), its X-ray diffraction and FTIR spectroscopy show the presence of silica, alumina (Al2O3), CaO, CaSiO3, Ca8Si5O18, mullite, quartz, haematite, kaolinite and amorphous silica. Rate of adsorption as a function of BFA dosage and reaction time was studied using spectrophotometer and colorimeter. Up to 19% colour reduction takes place in cane juice treated with BFA. The results suggest that BFA can be effectively used for initial clarification (in particular, removal of silica, quartz, mullite and calcite) of sugar cane juice.

Reduction of Total Suspended Solids, Turbidity and Colour of Palm Oil Mill Effluent using Hybrid Coagulation-Fltrafiltration Process

High consumption and production of palm oil have led to the massive generation of palm oil mill effluent (POME). This study was intended to reduce the total suspended solids (TSS), turbidity and colour using hybrid coagulation-ultrafiltration process. POME was pre-treated with coagulation process using polyaluminium chloride (PAC) and optimization of operating condition for coagulation process was performed. The coagulation results revealed that optimum pH, dosage of coagulant and rapid mixing speed were pH 4, 600 mg/L and 200 rpm, respectively. It achieved the highest percent reduction of TSS, turbidity and colour with 99.74%, 94.44% and 94.60%, respectively. Ultrafiltration (UF) membrane was fabricated using polyethersulfone (PES), polyvinylpyrrolidone (PVP) and titanium dioxide (TiO2­) nanoparticle. Different concentrations ranging from zero and 1.0 wt% of TiO2 nanoparticles were added into the dope solution. The characterization studies of UF membranes confirmed that higher concentration of TiO2 provided higher pure water permeability and more porous structure in the UF membranes. The amount of TiO2 in membrane only affected the permeate flux but had no obvious effects on the reduction of TSS, turbidity and colour. The optimum transmembrane pressure was found to be 3 bar, resulting in the greatest reduction of TSS, turbidity and colour.

Thermal treatment for soybean flour processing with high‐quality color and reduced Kunitz trypsin inhibitor

AbstractIn this work thermal treatment was applied in whole soybean flour and bleached whole soybean flour production aimed at Kunitz trypsin inhibitor (KTI) reduction and color. A 22 Central Composite Rotational Design was developed to evaluate the effects of temperature (91.80–148.20 °C) and time (15.9–44.10 min). In general, the bleached whole soybean flour presented higher KTI reduction and better color than whole soybean flour in the evaluated temperature and time ranges. It was observed that at 148.2 °C for 30 min the whole soybean flour presented a lower KTI value (1.56 mg/g) than bleached whole soybean flour (1.48 mg/g) and good luminosity. As the bleached presents an extra step in the treatment process, new experiments were made with whole soybean flour without bleached to evaluate KTI and color reduction as a time function (10–30 min) at 148.2 °C. The time was evaluated the verify the behavior of KTI and color of whole soybean flour. The treatment at 148.2 °C for 20 and 30 min presented the lowest KTI values, however, the L* color value at 20 min was higher and soybean flour was whiter, hence 20 min was considered the best condition for whole soybean flour production.Practical applicationsIn order to increase the nutritional quality of soybeans and use them as food, the inactivation of protease inhibitors is required. As soybean nutritional value is adversely affected by protease inhibitors presence that are considered anti‐nutritional factors, these need to be eliminated. Thermal treatment has been used as a physical method to inactivate these factors. However, it must be controlled to avoid essential amino acids destruction. Thermal treatment prior to soybean processing for flour production is common. However, recommendation for the best time and temperature for the grains is nonexistent in order to inactivate and/or reduce their phytochemicals with anti‐nutritional action, to the detriment of those with functional effect, preserving their nutrients. Usually, commercial soybean products are thermally treated with less than 20% of in natura soybean trypsin inhibitory activity.

Adsorption Efficiency and Isotherms of COD and Color Using Limestone and Zeolite Adsorbents

Leachate is a liquid generated due to rainwater percolation through the wastes in a landfill or dumping site that may contain high levels of organic matter including both biodegradable and non-biodegradable which major source of water pollution. In this research work, landfill leachate has been characterized and found to contain very high COD and color. Adsorption process was performed to find out the performance of different combinations ratio between limestone (LS) and zeolite (ZEO). The removal efficiencies of different ratios were examined for reduction of COD and color. The optimum mixture ratio of adsorbents (LS:ZEO) at 10:30 and 15:25 were found to be more effective in reducing COD and color respectively as compared with the use of individual media. The highest removal percentage were found at approximately 55% of COD and 76% of color with 120 minutes of contact time, 200 rpm in shaking speed at pH7. The Langmuir adsorption isotherm model exhibited a better fit with high correlation R2=0.9991 for COD and R2=0.9827 for (color) respectively, which implies that the adsorption of leachate in this study onto LS-ZEO is homogeneous with monolayer. It was observed that limestone and zeolite mixture provides an alternative medium for removing COD and color at a considerably lower cost.

Effect of Storage Temperature and Packaging Material on Shelf Life of Thornless Blackberry

Blackberry is a highly perishable fruit and its quality decreases very quickly during postharvest period. In this research, two types of container including: oriented poly styrene (OPS), a petroleum-based material, and oriented poly corn starch (OPCS), a bio-based material, was analyzed over 14 days to determine their effects on shelf life of thornless blackberry. Packages were placed in freezer (0˚C), refrigerator (4˚C) and room (25˚C) temperatures in a factorial format based on completely randomized design. Results showed a strong positive correlation between fruit weight and marketability (R2 = 0.726). It was confirm that fruit weight loss and shriveling can be an important reason for marketability reduction in blackberry. Blackberries were survived for 14 days at 0˚C, 8 days at 4˚C and only 3 days at room temperature. A downward trend was observed for pH, TA and TSS during the storage as well as for fruit taste and visual color. Fruits TSS was decreased regardless of the packaging materials and storage. Blackberries that were kept in OPS had significantly higher marketability and lower weight loss in comparison with OPCS that caused a reduction in fruit visual color and marketability. Results indicated that OPCS permeability caused higher fruit weight loss in comparison with other treatments. Blackberries in OPCS container had the highest amount of phenolic components following 14 days at 0˚C, which was significantly more than amount of phenolic components of fruits in OPS container. Compared to OPS, OPCS container did not make any improving in its characteristics to reduce fruit water loss that can be possible by using Nano clay particles.

Oblique Projection and Cepstral Subtraction in Signal Subspace Speech Enhancement for Colored Noise Reduction

In this paper, a subspace speech enhancement method handling the case of colored noise using oblique projection in the cepstral domain is proposed. Perceptual features and variance normalization are used to reduce the residual noise and improve the intelligibility of the output speech. Initially, the additive noise present in the noisy speech is removed by removing the orthogonal noise subspace from the noisy speech subspace to obtain the speech subspace. Then, the oblique projection of the noise subspace on the speech subspace along the additive noise subspace is used to determine the colored noise that remains. Colored noise removal is performed by power spectral subtraction in the cepstral domain. The spectral domain constrained estimator that incorporates the combined masking property of the human auditory system is employed to estimate the clean speech signal using the variance of the colored noise. To avoid the occurrence of any abrupt spikes in the output, variance normalization is performed by adaptively changing the control parameter of the estimator's gain matrix. The spectrograms, the objective measures and the subjective intelligibility test show the superior performance of the proposed method over the other existing speech enhancement methods.

Removal of colour from alkali extracted wastewater of Pulp and paper mill using fly ash as adsorbent

The study aims to explore the beneficial use of fly ash and its effectiveness as low cost adsorbent for wastewater treatment of Pulp and paper industry. A comparative study was also carried out for the better colour reduction of industrial effluent using fly ash and commercial activated carbon. Batch mode adsorption experiments were carried out to optimize the different experimental conditions like adsorbent dose, contact time, rotation per minute (RPM) and pH. The treatment showed that the removal efficiency of colour increased to 86 % with the increase in adsorbent dose (0.5 – 10 g), time (30–240 min), RPM (50 - 150) and pH (4–12) of pulp and paper industry wastewater. The removal efficiency of activated carbon was found to be 100 % using 1 g adsorbent dose of commercial grade activated carbon. The Scan Electron Microscope (SEM) results of the fly ash showed that the particles looked like somewhat spherical large particles. It was concluded that though the activated carbon was very efficient adsorbent in comparison to fly ash, the better solution for disposal of solid waste such as fly ash can be good a substitute as the adsorbent for the colour reduction of the paper mill wastewater.

Evaluation of the efficiency of coagulation/flocculation and Fenton process in reduction of colour, turbidity and COD of a textile effluent

ABSTRACTThe present study investigated the efficiency of physicochemical processes of coagulation and flocculation and Fenton advanced oxidative process in reducing the parameters of colour, turbidity and Chemical Oxygen Demand (COD) of a real effluent from a textile industry. During the physicochemical process, the efficiencies of different coagulants (aluminium polychloride (Polifloc 18), ferric chloride (Acquafloc FC40), aluminium sulphate combined with organic coagulant (AST) and aluminium sulphate) and nonionic (FX NS2), cationic (FX CS6 and FX CS7) and anionic (FX AS6 and AN905) flocculants were tested. After the tests, 72.60% of COD, 36.25% of colour and 98.59% of turbidity were removed, using aluminium polychloride coagulant and AN 905 flocculant. It was also evaluated the effect of Fenton advanced oxidative process application in removal of colour, COD and turbidity of the effluent previously treated through the physicochemical process. Removals of these parameters were analysed in two different pH ranges (pH 6.0 and 7.0). In both pH 6.0 and pH 7.0, reductions were observed in all analysed parameters, obtaining 170.78 mg O2/L of COD, 22.19 mg/L of colour and 0.80 NTU of turbidity (at pH 6.0) and 151.80 mg O2/L of COD, 26.73 mg/L of colour, 0.94 NTU of turbidity (at pH 7.0), which demonstrates the efficiency of this process in the reduction of parameters analysed.

Copy-move forgery detection using binary discriminant features

Digital images have numerous applications in various fields such as cyber forensics, courts, newspapers, magazines, medical field and many more. Therefore, the trustfulness of the contents of an image is very essential. Image manipulation has become very much simple and common due to the development of high resolution digital cameras, powerful computers and numerous image editing software. Hence, falsification of visual content of images is not at all limited to specialists and detection of forged images have become a highly challenging task. Of the different kinds of image forgery, the proposed method deals with one particular kind known as copy-move forgery. The method is an integration of the conventional block-based and keypoint based methods. The method first identifies the forged keypoint locations and then localizes the forged region using a region extraction technique. To improve the accuracy of detection, a Binary Discriminative Feature descriptor (BDF) is used for feature detection and matching. The suspected regions are identified by replacing the matching feature points with corresponding superpixel blocks. The neighbouring blocks are then merged with the suspected regions based on color similarity, using Color Histogram Matching and a final morphological close operation extracts the detected forged regions. Experimental results show that the proposed method has better detection accuracy, in terms of precision, recall and F1 Score, when compared with the state-of-the-art methods of copy-move forgery detection, under conditions of plain copy-move forgery as well as post-processing conditions like brightness changes, contrast adjustments, color reduction and blurring.

Improvement of water quality of remnant from chemical retting of coconut fibre through electrocoagulation and activated carbon treatment

Remnant obtained from chemical retting of coconut fibre was found to have an exorbitant COD, BOD, TDS, sulphide content having blackish brown colour. Traditional (physico-chemical) treatment could not reduce its COD, TDS, colour substantially. Further, the traditional method was lengthy, consumed huge chemicals and time. Present paper reports a quicker, simpler, economic i.e., an industrially viable method to separate the chemicals and biomass by employing electrocoagulation (EC). The performance of EC was analyzed by keeping temperature, and pH of remnant constant, while varying current flow (100–2000 mA), time (15–90 min) and number of iron electrodes (2,4,6). Efficacy of EC was evaluated in terms of reduction in conductivity, pH, TDS, COD, TOC, colour and quantity of sludge generated from the wastewater. Six electrodes with 2000 mA current flow for 90 min were found to give noticeable reduction on COD (92.8%), TOC (56%), TDS (99%), and colour. To reduce pH, and TDS to an acceptable level, filtration with activated charcoal was attempted on recovered water from EC. Resultant water was also found to have acceptable LC50 value for safe disposal. Carbon content (53%) in the sludge was high, contained lignin and cellulose whiskers also, as revealed from the EDX and FTIR, SEM respectively. Cost of EC ($ 0.087 USD/L) was found to be much less as compared to traditional method ($ 0.384 USD/L).

Classification of Physical Soil Condition for Plants using Nearest Neighbor Algorithm with Dimensionality Reduction of Color and Moisture Information

Determining the quality of soil is an important task to perform especially on newly opened agricultural land since it may provide significant impact on the growth of plants. One alternative to determine physical soil quality is by visually observe the color of the soil and measure its moisture. This paper designed an embedded system classify soil condition for plants according to the dimensionality reduction of color and moisture information from the soil using k-NN algorithm. The dimension of attribute information was reduced using correlation analysis to achieve lower computational time and lower memory usage on embedded system. In this study, 39 sample of soil from various location were collected and categorized by soil expert using visual observation. In the accuracy testing on the system that used 4 attributes, 100% accuracy was given by 60:40 ratio with 7 neighbors. In contrast, the system that used only 2 attributes, 100% accuracy was given by 60:40 ratio with 5 nearest neighbors. The resource usage testing shown that by using reduced attributes dimension, the resource usage can be lowered as many as 188 bytes on program storage and 192 bytes on global variable usage. Moreover, the average of computation time performed by the system using reduced attribute dimension achieved 5.4 ms compared to the system that used all attributes which achieved 6.2 ms.

Sonophotocatalytic degradation mechanisms of Rhodamine B dye via radicals generation by micro- and nano-particles of ZnO

In this work, it is proposed an environmental friendly sonophotocatalytic approach to efficiently treat polluted waters from industrial dyes exploiting ZnO micro- and nano-materials. For the first time, we deeply investigated the generation of reactive oxygen species (ROS) under ultrasound stimulation of different ZnO structures by Electron Paramagnetic Resonance Spectroscopy (EPR). Indeed, five zinc oxide (ZnO) micro- and nano-structures, i.e. Desert Roses (DRs), Multipods (MPs), Microwires (MWs), Nanoparticles (NPs) and Nanowires (NWs), were studied for the Rhodamine B (RhB) sonodegradation under ultrasonic irradiation. The DRs microparticles demonstrated the best sonocatalytic performance (100% degradation of RhB in 180 min) and the highest OH radicals generation under ultrasonic irradiation. Strikingly, the coupling of ultrasound and sun-light irradiation in a sonophotodegradation approach led to 100% degradation efficiency, i.e. color reduction, of RhB in just 10 min, revealing a great positive synergy between the photocatalytic and sonocatalytic mechanisms. The RhB sonophotocatalytic degradation was also evaluated at different initial dye concentrations and with the presence of anions in solution. It was demonstrated a good stability over repeated cycles of dye treatment, which probe the applicability of this technique with industrial effluents. In conclusion, sonophotocatalytic degradation synergizing sunlight and ultrasound in the presence of DRs microparticles shows a great potential and a starting point to investigate further the efficient treatment of organic dyes in wastewater.

Combining Trinexapac‐Ethyl with a Soil Surfactant Reduces Bermudagrass Irrigation Requirements

Core Ideas We describe the use of a plant growth regulator and a soil surfactant for water conservation. We investigated whether the beneficial effects of a surfactant and a plant growth regulator on drought stressed bermudagrass were enhanced when applied in combination versus individually. We investigated if both products affect soil moisture under reduced irrigation. Soil surfactants and plant growth regulators (PGR) have shown potential to lower irrigation requirements and increase turfgrass quality under drought conditions. A study was conducted from 2014 to 2016 to investigate the soil surfactant Revolution, (modified methyl capped block copolymer [Aquatrols, Paulsboro, NJ]), or the plant growth regulator ‘PrimoMaxx’ (A.I. trinexapac‐ethyl [4‐(cyclopropylhydroxymethylene)‐3,5‐dioxocyclohexanecarboxylic acid]) (Syngenta, Basel, Switzerland), or a combination of both on percent green coverage, turfgrass color, quality, soil volumetric water content (VWC) and uniformity on Princess 77 bermudagrass (Cynodon dactylon L.) grown on a loamy sand (mixed, thermic Typic Torripsamments) and irrigated at either 80%, 65%, or 50% of reference evapotranspiration for short grass (ETOS). With the exception of plots irrigated at 50% ETos in 2015, bermudagrass receiving trinexapac‐ethyl (TE) either in combination with Revolution or alone exhibited darker green color when compared to untreated controls at all irrigation levels throughout the research period. At 50% ETos, plots treated with any of the three chemical treatments had greater quality (with 1 = worst, 9 = best) than control plots from July to September, with quality ratings of 6 or greater from June to August. Whereas VWC was not consistently enhanced by all treatment combinations, applications of Revolution, TE, and the combination of both resulted in increased VWC uniformity and greater irrigation use efficiency. Our results suggest that by using a surfactant, a PGR, or both, bermudagrass quality can be maintained with 15 to 30% less irrigation water than the optimal rate (80% ETos) without a reduction in color or quality.

Methods for reducing color and oxidability of natural waters

The qualitative indicators of natural waters of the open source of drinking water supply have been studied. The discrepancy with the regulatory requirements for such indicators as color and oxidability has been established. With the aim of reducing the color and oxidation of natural water, oxidative-sorption methods have been investigated. Based on the water quality indicators of the source, a non-reagent scheme of water treatment has been preliminarily proposed, including the filtration on sorption loads with preliminary chlorination of water with a dose within the limits of chlorine absorption. Such materials as quartz sand, granulated activated carbon of the brand "PUROLAT-ACTIVE", anthracite of the brand "PUROLAT-standard" and garnet have been investigated as possible loads for filtering plants. It has been established that effective reduction of water color in all considered periods of the year is achieved on a combined loading of "quartz sand - activated carbon". However, this loading has not shown the necessary reduction in oxidizability, in all series there has been an excess of regulatory requirements for this indicator. The best result for reducing water oxidation has been achieved on a two-layer load of "quartz sand - anthracite", which, according to the combined improvement of water quality indicators, has been recognized as the most effective.

The effectiveness of AVG used in a single and combined application with NAA against preharvest fruit drop in apple

The results of four experiments carried out in years 2007, 2008 and 2010 in the Research Institute of Horticulture in Skierniewice on the apple cultivars ‘Gala Must’ and ‘Ligol’ are presented. The preparations ReTain® (as formulation VBC-30033) containing AVG (aminoethoxyvinylglycine) and Pomonit Super 050SL (as salt of NAA with triethanoloamine) were used against preharvest fruit drop by spraying the trees alone and subsequently. Retain® was used 4 weeks before anticipated harvest at two doses: 180 and 360 mg L-1, and Pomonit Super one week before harvest at 20 or 40 mg L-1. The effect on the dynamics of fruit drop, on fruit quality at harvest and after storage, as well as on shoot growth and subsequent flowering was determined. In all experiments it was found that the lowest number of apples abscised before the harvest when both preparations were used at half of optimal doses, respectively, at four and one week earlier. The efficiency of subsequent use of preparations was better than the use of ReTain® alone at twice higher dose (optimal). The effect on preharvest fruit drop of low dose of ReTain® used alone was too weak. No significant effect of preharvest treatments with ReTain® and Pomonit Super on the total yield of apples, and on the average fruit weight was found. However, in 2008 in both cultivars the combined treatment with low doses of ReTain® and Pomonit Super, caused distinct increase in percentage of large apples (>70 mm diameter), while other treatments with preparations have no effect on the distribution of apple in the individual classes of fruit size and on average fruit weight. The effect of both preparations on other parameters of apple quality depended on the cultivar. Treatment with ReTain® alone at high and at low dose, but combined with NAA, caused a significant reduction of red color of apples in ‘Gala Must’, but significant increase in flesh firmness at harvest and after storage. However, on the cultivar ‘Ligol’ no effect on red color of apples and reduction of firmness was found. In 2010 it was also shown that before the harvest, abscission could be avoided by twice application of Retain® 40 days before anticipated harvest and Pomonit Super 10 days before anticipated harvest, both in doses reduced by half as compared to what was previously recommended.

Combination of Chemical Coagulation and Photo-Fenton Oxidation Process for the Treatment of Beet Sugar Industry Wastewater: Optimization of Process Conditions by Response Surface Methodology

ABSTRACTThe beet sugar industry generates large volumes of wastewater with high levels of chemical oxygen demand (COD) and color content, which are discharged into the nearby environment without adequate treatment. The aim of this study was to investigate the treatment possibility of this wastewater by using the photo-Fenton oxidation combined with a coagulation process. Central composite design and response surface methodology were used to evaluate the relationships between color and COD reduction and the photo-Fenton oxidation parameters (i.e. Fenton’s reagent dosage, pH, and reaction time).The combined treatment results showed 59% of COD and 83.9% of color removal were obtained at optimum conditions (pH: 6.2; Fe2+ dosage: 20 ppm; H2O2 dosage: 1500 ppm; and reaction time of 15 min). Finally, the results of gel permeation chromatography showed that low molecular weight fraction of the wastewater impurities is more degraded than high molecular weight fraction during oxidation/coagulation process. Therefore, the results obtained from this study showed that an appropriate combined method for the treatment of beet sugar industry wastewater can be designed and implemented.

Biodecolourization and biodetoxification of dye-containing wastewaters from leather dyeing by the native fungal strain Trametes villosa SCS-10

The native fungal strain Trametes villosa SCS-10 was investigated for its ability to treat wastewaters from real dyeing of leather produced in pilot-scale. Four types of wastewater using different compositions and dyes (Acid Red 357 and Acid Orange 142) were produced and used in the assays. Three culture conditions were studied. The efficiency of the treatment was assessed in terms of biodecolourization, mycoremediation: reduction of chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC) and biodetoxification. The treatment resulted in between 50–70% of biodecolourization and 40–60% of COD and TOC reduction of the raw wastewater without nutrient addition (N0). However, when wastewaters were supplemented with a high (N1) and a reduced (N0.5) nutrient supply, over 90% of biodecolourization and over 80% of COD and TOC reduction were achieved. The treatment N0.5 allowed the highest values of colour, TOC and COD reduction, which were related to the major peaks of laccase activity (1000–1300 UL−1). The ecotoxicity assays with Raphidocelis subcapitata and Vibrio fisheri demonstrated that the fungal treatment resulted in 50–70% of biodetoxification. The MTT assay revealed that the treated wastewaters did not present cytotoxic effects to the cell line V79. These promising results show that Trametes villosa is suitable for the treatment of wastewater from leather dyeing. Further studies are required to improve the applicability of selected fungal strains in the treatment of wastewater from the tannery industry.

RESULTS OF THE STUDY OF LAKE ONEGO ECOSYSTEM IN THE PERIOD OF SUMMER STRATIFICATION BASED ON MEASURED DATA FROM A 2017 EXPEDITION

New data characterizing the hydrophysical features (water temperature), water quality (water transparency, dissolved oxygen, and number of saprophytic bacteria), trophic status (chlorophyll a ), and impact of the catchment (water color) of Lake Onego ecosystem wereobtained in August 2017. The vertical profiles of these parameters along lake transects from northwestern polluted near-shore areas receiving river runoff (Petrozavodskaya, Kondopozhskaya bays) to the southern tip of the lake are shown. The results of the surveys show that the central and southern parts of Onego Lake are still characterized by high water quality and oligotrophic state. The epilimnion was about 10 m thick, the water temperature of this layer did not exceed 14.8–16.7 °C. The thermocline in the deepwater part of the lake was located at a depth of 10–20 m. The transparency of the water in pelagic parts of the lake reached 3.5–4.0 m, water color was 23–31 degrees on Pt-Co scale, oxygen saturation of the water was 87–92 %, chlorophyll a concentration in the photic layer did not exceed 3.2 μg/l, and saprophytic bacterioplankton numbers were within n∙102 CFU/ml. A significant reduction in water color and abundance of saprophytic bacteria, and an increase in dissolved oxygen concentrations were observed along the transect from Petrozavodskaya and Kondopozhskaya bays towards the pelagic part of the lake. This confirms that natural (humic substances) and anthropogenic (municipal and industrial wastewaters) allochthonous organic matter is effectively transformed in the bays. The abundances of saprophytic bacteria, the oxygen saturation of water, and the concentration of chlorophyll a in some areas of the lake were slightly lower than in previous decades. Water color, on the contrary, showed a tendency for an increase.

Delaying berry ripening of Bobal and Tempranillo grapevines by late leaf removal in a semi-arid and temperate-warm climate under different water regimes

Background and Aims Climate change is advancing grape ripening and decoupling sugar and phenolic maturity, impacting wine typicity. The aim of this study was to test whether late leaf removal (LLR) under different watering regimes delayed harvest of two Spanish red cultivars in a semi‐arid and temperate‐warm climate. Methods and Results In two trials carried out in eastern Spain with the Bobal and Tempranillo cultivars, vines were partially defoliated above the bunch zone shortly before veraison under rainfed and deficit irrigation conditions during two seasons. The rate of grape ripening in both cultivars was significantly affected by LLR under either watering regime, consequently delaying harvest. Vine water status and leaf photosynthetic rate were improved by LLR. The reduction in leaf area‐to‐fruit ratio resulting from the LLR treatments was found to be more limiting for the accumulation of anthocyanin than for TSS. Consequently, LLR negatively affected wine colour intensity. In addition, yield was constrained by LLR in Tempranillo due to a reduction in bunch and berry mass. Conclusions The reduction in the rate of accumulation of grape TSS provoked by LLR did not necessarily result in a more balanced berry maturity. The effectiveness of the LLR technique appears to depend on its final impact on leaf area‐to‐fruit ratio and vine water status, the cultivar photosynthetic compensation capacity and the environmental conditions. Significance of the Study Late leaf removal might not be effective for coupling anthocyanin and TSS in berries under moderate water stress conditions, given the observed reductions in red wine colour.