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The purpose of this paper was to find out the appropriate enzymatic hydrolysis conditions of alkali pretreated olive pomace (OP) which enable maximum yield of reducing sugar.

The commercial enzymatic preparation (Viscozyme^® L) was used for the hydrolysis of OP. The effects of pretreatment, time, temperature, pH, enzyme quantity and substrate loading on the hydrolysis yield were investigated.

This study showed that enzymatic hydrolysis of OP using Viscozyme^® L can be successfully performed at 50°C. Alkaline pretreatment step of OP prior the enzymatic hydrolysis was indispensable. The hydrolysis yield of alkaline pretreated OP was 2.6 times higher than the hydrolysis yield of untreated OP. Highest hydrolysis yield (33.5 ± 1.5 per cent) was achieved after 24 h using 1 per cent (w/v) OP load in the presence of 100 μl Viscozyme^® L at 50°C and pH 5.5 with mixing rate of 100 rpm (p = 0.05).

Reaction time, temperature, pH value and enzyme quantity were found to have a significant effect on enzymatic hydrolysis yield of alkali pretreated of OP. Although high-solid loadings of OP lowered the hydrolysis yield, it produced higher concentration of reducing sugars, which may render the OP conversion process more economically feasible.

The increasing accumulation of synthetic plastic waste in oceans and landfills, along with the depletion of non-renewable fossil-based resources, has sparked environmental concerns and prompted the search for environmentally friendly alternatives. Biodegradable plastics derived from lignocellulosic materials are emerging as substitutes for synthetic plastics, offering significant potential to reduce landfill stress and minimise environmental impacts. This study highlights a sustainable and cost-effective solution by utilising agricultural residues and invasive plant materials as carbon substrates for the production of biopolymers, particularly polyhydroxybutyrate (PHB), through microbiological processes. Locally sourced residual materials were preferred to reduce transportation costs and ensure accessibility. The selection of suitable residue streams was based on various criteria, including strength properties, cellulose content, low ash and lignin content, affordability, non-toxicity, biocompatibility, shelf-life, mechanical and physical properties, short maturation period, antibacterial properties and compatibility with global food security. Life cycle assessments confirm that PHB dramatically lowers CO₂ emissions compared to traditional plastics, while the growing use of lignocellulosic biomass in biopolymeric applications offers renewable and readily available resources. Governments worldwide are increasingly inclined to develop comprehensive bioeconomy policies and specialised bioplastics initiatives, driven by customer acceptability and the rising demand for environmentally friendly solutions. The implications of climate change, price volatility in fossil materials, and the imperative to reduce dependence on fossil resources further contribute to the desirability of biopolymers. The study involves fermentation, turbidity measurements, extraction and purification of PHB, and the manufacturing and testing of composite biopolymers using various physical, mechanical and chemical tests.

Excess sludge is an inevitable drawback of the waste‐activated sludge process. Both the reduction of the amount of sludge produced and improving its dewaterability are of paramount importance. With more stringent environmental and legislative constraints, increasing sludge production and limited disposal options, new reduction alternatives have to be found. This paper presents different advanced sludge treatment (AST) processes, i.e. thermal hydrolysis (neutral, acid, alkaline) and chemical oxidation using H₂O₂. Semi‐pilot and pilot‐scale experiments are conducted in order to achieve optimum treatment conditions (T, pH, concentration of reagent, catalyst, etc.) with respect to sludge dewaterability. Additional targets are the removal of heavy metals and pathogens from the sludge so that the residual filter cake can be used for land application. Although all methods are promising, peroxidation gave the best results with respect to improving sludge dewaterability and product quality of the residual filter cake. The amount of dry solids per equivalent‐inhabitant per day (DS/IE.d) was reduced from 60g DS/IE.d to 33g DS/IE.d and the percentage DS of the sludge cake was 47 per cent, which is a significant improvement of traditional sludge dewatering yields. This results in a significantly reduced energy for subsequent drying (94kJ/IE.d compared to 437kJ/IE.d for the traditional treatment).

Gallic acid is a substance that is widely found in nature. Initially, it was only used as a corrosion inhibitor to retard the rate of corrosion of metals. In recent years, with intensive research by scholars, the modification of coatings containing gallic acid has become a hot topic in the field of metal protection. This study aims to summarize the various preparation methods of gallic acid and its research progress in corrosion inhibitors and coatings, as well as related studies using quantum chemical methods to assess the predicted corrosion inhibition effects and to systematically describe the prospects and current status of gallic acid applications in the field of metal corrosion inhibition and protection.

First, the various methods of preparation of gallic acid in industry are understood. Second, the corrosion inhibition principles and research progress of gallic acid as a metal corrosion inhibitor are presented. Then, the corrosion inhibition principles and research progress of gallic acid involved in the synthesis and modification of various rust conversion coatings, nano-coatings and organic resin coatings are described. After that, studies related to the evaluation and prediction of gallic acid corrosion inhibition on metals by quantum chemical methods are presented. Finally, new research ideas on gallic acid in the field of corrosion inhibition and protection of metals are summarized.

Gallic acid can be used as a corrosion inhibitor or coating in metal protection.

There is a lack of research on the synergistic improvement of gallic acid and other substances.

The specific application of gallic acid in the field of metal protection was summarized, and the future research focus was put forward.

To the best of the authors’ knowledge, this paper systematically expounds on the research progress of gallic acid in the field of metal protection for the first time and provides new ideas and directions for future research.

This study aims to enhance the dyeability of polyester fabrics with turmeric natural dyes through plasma and alkaline treatments. The aim is to achieve better color strength in dyed samples without significant changes in their other properties. This is done while the weight loss is kept in a range with no considerable effect on those properties.

The surface of a poly(ethylene terephthalate) fabric was modified using oxygen plasma at a low temperature. The alkaline hydrolysis of that polyester fabric was also done through treating it with an aqueous sodium hydroxide (NaOH) solution. The untreated and treated polyester fabrics were studied for the changes of their physical characteristics such as weight loss, wetting behavior, strength loss, bending length, flexural rigidity and K/S and wash fastness. The samples were treated with plasma and sodium hydroxide and dyed with a turmeric natural dye.

In comparison to the untreated sample, the plasma-treated, alkaline-treated and plasma treatment followed by alkaline hydrolysis polyester experienced 9.3%, 68.6% and 102.3% increase in its color depth as it was dyed with a turmeric natural dye, respectively. The plasma treatment was followed by alkaline hydrolysis. The improvement in the color depth could be attributed to the surface modification.

In this paper, investigations were conducted of the separate effects of plasma treatment and alkaline hydrolysis as well as their synergistic effect on the dyeing of the polyester fabric with a natural dye obtained from turmeric.

Carbamoylethyl starch (CrES) and cyanoethyl starch (CES) were prepared by making use of the concept of the dry process under conditions which were developed to form the bases of environmentally sound (clean) technology. The obtained CrES and CES were saponified using alcoholic NaOH solution. The CrES and CES along with their saponified products were further modified by subjecting them to graft polymerization with Aam/AN mixture. Saponification of the so‐obtained grafted substances was also carried out. Presents the findings of these investigations which are explained in terms of structural changes in the starch, the ‐CN and CONH₂ groups, the Aam/AN polymeric graft and the site of attachment of the latter on the modified starch.

The purpose is to focus on improving the water or metal ion uptake of modified cellulose.

Grafting copolymerisation of hydrophilic monomers such as acrylamide or hydrophobic monomers as acrylonitrile onto cotton linters was performed.

The grafting process has two advantages. The first is to replace the hydroxyl group of C₆ of the glucose units in the substrate by carboxyl group that attract the metal ions from the solution. The second is to decrease the number of the hydroxyl groups in the cotton linters so that the hydrogen bonding between the cotton linters strands decreases and so the crystallinity index of substrate decreases by introduction of this hydrophilic group so it becomes more chemically active.

Partial substitution of hydroxyl groups of cellulose by more hydrophilic ones via grafting reaction followed by alkaline hydrolysis was performed. The effects of different conditions such as temperature, time, initiator concentration, monomer concentration and kind of substrate were studied. The polymerisation per cent, grafting per cent, the grafting efficiency and the nitrogen per cent of the grafted samples were determined. The molecular structures of cotton linters, grafted cotton linters with acrylamide and its hydrolysis product were studied using infrared spectroscopy, which indicates the fixation of the monomers on the cotton linters. Sodium binding capacity and the metal ion uptake of some metal ions by the product were determined.

The water or metal ion uptake of the modified cellulose was improved.

Alkaline oxidation of polyester/cotton blend fabrics is a topochemical reaction, and for this reason, it has been used to improve the properties of polyester/cotton blend fibers. The alkaline hydrolysis of polyester fiber and also oxidation of cotton fibers consequently reduce the degree of polymerization of the cellulosic chains. During this process, hydrogen peroxide and sodium hydroxide are used as oxidizing agent and alkali, respectively. Fabrics treated by this method could lose up to 25% in weight and attain a silk-like handle, and also achieve an improvement in properties such as hydrophilicity, dyeability and flexibility. In this study, we want to study the effects of oxidation and alkaline treatment on the optical and physical properties of polyester/cotton blend fabrics.

This study aims to study the simultaneous treatment of polyethylene terephthalate (PET) fabric with sodium hydroxide (NaOH) and TiO₂ nanoparticles (NPs).

PET fabrics loaded by TiO₂ NPs were investigated by the use of scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Fourier transformed infrared spectroscopy (FT-IR). Factors affecting the finishing process such as NaOH and TiO₂ NPs concentrations, finishing duration and temperature were discussed.

The finished PET fabrics imparted new properties such as antimicrobial and ultraviolet protection factor protection, what is undoubtedly will increase the spread of this type of fabric and its use in new areas.

The method used mainly depends on activating the surface of PET fabrics by a chemical method, specifically NaOH to cause partial decomposition, which may lead to an environmental impact.

The obtained results revealed that the simultaneous treatment of PET fabric with NaOH and TiO₂ NPs showed antimicrobial and UV protection properties. They exhibited a strong antimicrobial activity and UV protection efficiency even after five washing cycles, indicating excellent laundering durability.

The approach has simplicity and implementability on an industrial scale without cost investment.

This paper reviews the techniques available for assessing the material characteristics and long‐term performance of high alumina cement concrete construction. The use of some of these techniques is illustrated in a case study on typical pre‐cast concrete beams.