Municipal sewage sludge, a by-product of wastewater treatment plants, presents environmental challenges due to its complex composition. Particular concern is the lipophilic and aliphatic compounds that pose risks to the environment and human health. This study focuses on the efficient removal of those compounds from sewage sludge using several organic solvents (hexane, toluene, chloroform, dichloromethane, acetone, hexane-methanol mixture, ethanol, and methanol) and ionic liquids (ILs) like tetrakis(hydroxymethyl)phosphonium chloride and 1-ethyl-3-methylimidazolium acetate by solvent extraction techniques. To determine optimal conditions, various factors such as solvent types, contact time, and temperature were examined. The results reveal that solvent polarity significantly impacts extract composition, with non-polar solvents like hexane and toluene yielding profiles characteristic of lipid-type compounds. An in-depth analysis of contaminants present in the sewage sludge was studied by Fourier-transform infrared spectroscopy (FTIR). Additionally, nuclear magnetic resonance (NMR) was used to identify the extracted compounds, including triglycerides, aliphatic esters, aliphatic alcohols, and free carboxylic acids. NMR provides data on the composition of the sewage sludge and indicates that among all the solvents used, tetrakis(hydroxymethyl) phosphonium chloride was the most suitable solvent for removing lipophilic and aliphatic compounds. Regeneration potential and reusability of the IL were conducted and verified by NMR. The results showed that tetrakis(hydroxymethyl) phosphonium chloride ionic liquid could be used for several extraction cycles. Identifying these compounds in the extracted mixture demonstrates that it adds value and potential for various applications. Towards environmental sustainability and circular economy, this effort develops strategies for the safe management, disposal, and recyclability of sewage sludge and, the reduction in environmental and health hazards associated with organic compounds.

Business-as-usual municipal sewage sludge (MSS) management practices could impact significantly on public health and the environment. Administrative costs for municipal wastewater treatment plants account for more than 50 %. To reduce administrative costs, the EU has called for the reuse of waste to make it part of the circular economy. One of the options for MSS is reuse to recover bioresources. Because of toilet paper, the main component of the total solids in MSS is cellulose, which could be recovered by chemical or biological processes. Crystalline cellulose is of great use in various fields such as biomedical, pharmaceutical, mechanical and others. There are various solvents to dissolve cellulose present in renewable sources to recover. However, these solvents are not widely used at MSS. This review focuses on solvent options for MSS. It also develops an environmentally friendly protocol for the recovery of nanocellulose from primary MSS using alkali-based solvent systems.

This study focuses on the recovery of resources from Latvian dairy industrial wastewater. Specifically, lipids are important resources from the wastewater, so the study aim is to check the quality of the wastewater through COD, BOD-5, total nitrogen, total phosphorus; to separate and characterize fatty acids through various chemicals and characterization (like FTIR, NMR, and GC-MS) techniques. The COD was found to be 1680 ± 20 mg L−1 and the BOD-5 was found to be 1196 ± 50 mg L−1, indicating that the dairy wastewater contains a considerable amount of oxidizable carbon. Also, spectral studies were done to identify the fatty acids in the wastewater. The FT-IR spectrum clearly showed the presence of C–O stretching at 1092 cm−1 and the 1H NMR indicated the peaks in the range 4.72–5.08 ppm and 5.43–6.33 ppm, confirming the presence of fatty acids. Total lipid content was extracted with solvent extraction method by using hexane, and it was found to be 5.2 g L−1. The acid value of the extracted lipids was found to be 56 mg KOH g−1. Finally, GC-MS analysis confirmed the presence of palmitic acid, stearic acid, myristic acid, oleic acid, linolenic acid, lauric acid, and linoleic acids in the total lipid. Therefore, the extraction of lipids from dairy wastewater is paramount in the applications of biodiesel production.

This research investigated the feasibility of using hybrid system based on coagulation and adsorption for high-strength dairy wastewater treatment. Activated charcoal was used a non-toxic adsorbent and chitosan as a natural coagulant for the removal of odor, chemical oxygen demand (COD), total nitrogen (TN), and total phosphorous (TP) from raw dairy effluents. The surface morphology of the adsorbent and coagulant were characterized by scanning electron microscope (SEM). Bench-scale jar test experiments were conducted to evaluate the performance of the integrated treatment system to treat real wastewater with different experimental conditions. Results of the study showed that about 68% and 74% COD was removed by using adsorption and coagulation method respectively. However, a high COD removal efficiency of 90% was achieved, when the coagulation process was coupled with the adsorption process. An in-depth analysis of contaminants present in the dairy effluents after treatment were studied by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The obtained results demonstrated that the organic compound like lipids, carbohydrates and proteins were drastically reduced which in turn lowered the COD level by employing the hybrid treatment system. The above outcomes suggested that combining naturally occurring sorbents and coagulants can greatly enhance the dairy wastewater pre-treatment performance in small scale treatment plants.

Silica-titania core-shell nanocomposite (SiO2-TiO2) was successfully synthesized via nanoparticle encapsulation route. The morphology and the chemical properties of the prepared nanocomposite were evaluated by different instrumental techniques before and after adsorption of Cr(VI) as required to check the existence of Cr and its oxides on the surface of the adsorbent. Subsequently, the efficiency of the nanocomposite to adsorb Cr(VI) from synthetic solution was studied in different experimental conditions like solution temperature (30-80 degrees C), pH (2-10), initial Cr(VI) concentration (10-100 mg L-1), reaction time (10-120 min), and, amount of the adsorbent (0.1-1 g). The maximum adsorption reached 98% by utilizing 0.5 g L-1 of the nanocomposite at pH 5, with 30 mg L-1 initial Cr(VI) concentration, while the temperature was maintained 50 degrees C and the equilibrium time was 70 min. Besides, the process of Cr(VI) adsorption is well fitted with the Langmuir adsorption isotherm model and pseudo-second-order kinetic model. On the other hand, endothermic and spontaneous nature of the adsorption process was revealed by the negative Delta G and the positive Delta H values. The cytotoxicity of the nanocomposite was examined by using Drosophila as a model organism. The effects of oral ingestion of the nanocomposite (10, 40, 60, 80, and 100 mu g mL-1) were observed on the growth, development, and behavior of Drosophila and the result showed there are no major phenotypic defect on Drosophila. The above outcomes suggested that the SiO2-TiO2 core-shell nanocomposite could be a promising nontoxic material for Cr(VI) removal from contaminated water.

The objective of the research presented in this Research Communication was to access the environmental impact of the Latvian dairy industries. Site visits and interviews at Latvian dairy processing companies were done in order to collect site-specific data. This includes the turnover of the dairy industries, production, quality of water in various industrial processes, the flow and capacity of the sewage including their characteristic, existing practices and measures for wastewater management. The results showed that dairy industries in Latvia generated in total approximately 2263 × 103 m3 wastewater in the year 2019. The Latvian dairy effluents were characterized with high chemical oxygen demand (COD), biological oxygen demand (BOD) and total solids (TS). Few dairy plants had pre-treatment facilities for removal of contaminants, and many lacked onsite treatment technologies. Most facilities discharged dairy wastewater to municipal wastewater treatment plants. The current study gives insight into the Latvian dairy industries, their effluent management and pollution at Gulf of Riga due to wastewater discharge.

Titania coated silica nanoparticles, which were synthesized via nanoparticle encapsulation route, are employed to degrade safranin-O dye from aqueous solution under UV light irradiation and were characterized by FT-IR, XRD, FESEM, N2 adsorption-desorption method and Zeta potential measurement. The results showed that the nanoparticles have a core-shell structure composed of about 100 nm of diameter of silica with several TiO2 fine particles in shell. After the degradation, this process is optimized through the response surface methodology (RSM). In this response study, photodegradation efficiency was evaluated by three main independent parameters such as catalyst dose, initial dye concentration and reaction time. Parameter sensitivity studies of the degradation efficiency of titania coated silica nanoparticles have shown 93.29% degraded under the optimal conditions of catalyst dose of 89.80 mg/g, initial dye concentration of 17.61 mg/L and reaction time of 12 min. We cross-checked the predicted values of degradation efficiency with the experimental values and were found to be in good agreement (R2=0.9983 and adj-R2=0.9967).

In this study, hydroxyapatite decorated with zirconia nanoparticle (HAp-ZrO2 ) was prepared using sonochemical method and characterized by various techniques such as BET, TEM, XRD, FTIR, FESEM-EDX, XPS, Raman spectroscopy, finding that the nanoparticles were uniformly distributed on the surface of hydroxyapatite with a mean size of 10 +/- 5 nm. It was used as photocatalyst for degradation of phenols and its derivatives under UV light irradiation. The coupling of the ZrO2 and HAp significantly enhanced the separation efficiency of the photogenerated electron-hole pairs and then promoted the activity for the photodegradation of phenolic compounds. The estimation of reactive species involves in the degradation process was done by scavenger study. To determine the degradation efficiency, effect of various parameters such as catalyst dose, pH, and temperature has been investigated. Furthermore, the photoelectricalchemical study was carried out to provide further insight into the photocatalyst activity, which further confirmed the superiority of the HAp-ZrO2 in photocurrent generation. Results found no cytotoxic effects on the THP-1 cell-lines even after 72 h, confirming their excellent bio-compatibility and biodegradable nature. High reactive sites on the HAp-ZrO2 made it an effective photocatalyst for degradation of phenols (above 95%). The nanocomposites show good stability without loss of their degradation capacity up to 4 cycle, confirming their practical use in water purification.

The effects of oral intake of hydroxyapatite nanoparticles (HApNPs) were investigated on growth, development and behaviour of Drosophila. The Drosophila responses to various concentrations of HApNPs were compared. At lower concentrations, i.e. 5 mg L−1 more amount of oxidative stress was produced than that of highest concentration, i.e. 80 mg L−1. The increased amounts of oxidative stress reflect a higher amount of ROS production and increased cell damage within the larval gut. HApNPs was further shown to interfere with the calcium and phosphorus absorption pathway. Besides all these damage, HApNPs causes developmental delay in the late third instar larvae. The most significant anomaly was observed in pupae count, fly hatching after the feeding of HApNPs. Flies hatched from treated vials have decreased body weight with defective walking behaviour. Hatched flies have a phenotypic defect in the wing, eye and thorax of the bristles. Along with these changes, the adult fly becomes more prone towards stress. The findings hint that HApNPs persuade noxious effects and alter the development, structure, function and behaviour of the fly in a concentration-dependent manner.

A novel ionic liquid modified gamma-alumina was prepared via a modified sol-gel method, using 1-methyl-3-octylimdazolium chloride ionic liquid as multifunctional material in terms of solvent and template, and its ability for the removal of fluoride from synthetic as well as real contaminated fluoride solution was investigated through adsorption by batch and column mode. The interaction between the IL and alumina involves electrostatic affinity between imidazolium cations, and surface hydroxyl groups in alumina. The IL modified gamma-alumina acts as a good adsorbent for fluoride ions due to interesting interactions such as electrostatic interaction and ion exchange process. Characterizations of the material made by Fourier transform infrared spectroscopy, X-ray powder diffraction, Thermogravimetric analysis, N-2 adsorption desorption isotherm, Transmission electron microscopy, with Energy-dispersive X-ray spectroscopy elemental mapping, Field Emission Scanning Electron Microscopy, and X-ray photoelectron spectroscopy. Adsorption kinetic study showed that the adsorption process followed the pseudo-second-order kinetics and the maximum adsorption capacity is found to be 25.0 mg g(-1) from Langmuir adsorption isotherm. Fixed bed column study was carried out to check the role of flow rates on adsorption of fluoride ions using synthetic and contaminated aqueous solution. All of the results suggested that the alumina modified ionic liquid have a strong and specific affinity towards fluoride and can be considered as excellent adsorbent for treatment of fluoride contaminated water. (C) 2017 Elsevier Ltd. All rights reserved.

Zirconia nanoparticles (ZrO2 NPs) have been extensively used in teeth and bone implants and thus get a chance to interact with the physiological system. The current study investigated the oral administration of various concentrations of ZrO2 NPs synthesized by the hydrothermal method (0.25 to 5.0 mg L−1) on Drosophila physiology and behaviour. The size of the currently studied nanoparticle varies from 10 to 12 nm. ZrO2 NPs accumulated within the gut in a concentration-dependent manner and generate reactive oxygen species (ROS) only at 2.5 and 5.0 mg L−1 concentrations. ROS was detected by nitroblue tetrazolium (NBT) assay and 2′,7′-dichlorofluorescein (H2DCF) staining. The ROS toxicity alters the larval gut structure as revealed by DAPI staining. The NP stress of larvae affects the Drosophila development by distressing pupa count and varying the phenotypic changes in sensory organs (eye, thorax bristle, wings). Besides phenotypic changes, flawed climbing behaviour against gravity was seen in ZrO2 NP-treated flies. All together, for the first time, we have reported that a ROS-mediated ZrO2 NP toxicity alters neuronal development and functioning using Drosophila as a model organism.

Titania nanoparticles are used in food, cosmetic, medicine, paint and many more domestic items. Its extensive use has raised the threat to the physiological system and thus the functioning of the body. In the current study, the toxicity of TiO2 is checked by adding it in food and using Drosophila melanogaster as a model organism. Various concentrations of TiO2 (50, 100, 200, 250mg·L-1) toxicity was assessed via oral route exposure. Survivability, life-cycle, mechanosensory behaviour and structure of various mechanosensory organs were monitored as a read out of nanoparticle toxicity. TiO2 NPs generate reactive oxygen species which can modify multiple signalling pathways and thus can alter the development and behavioural pattern of the fly.

Various types of water-miscible aprotic ionic liquids (ILs) with different cations (1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-octyl-3-methylimidazolium) and anions (ethylsulfate and chloride) were used as co-solvents to investigate the stability of lysozyme. Different techniques such as fluorescence, thermal absorption, and circular dichroism (CD) spectroscopy have been used for the study. Fluorescence results reveal that the addition of ILs (1-ethyl-3-methylimidazolium ethyl sulfate and 1-ethyl-3-methylimidazolium) increases the hydrophobicity around the tryptophan environment in lysozyme. CD analysis and temperature-dependent studies were done to investigate the stability of the protein. From the CD analysis, it was observed that the ILs keep the native structure of protein intact. Thermal denaturation studies depicted that the melting temperature of the protein increased in the presence of ILs (1-ethyl-3-methylimidazolium ethyl sulfate and 1-ethyl-3-methylimidazolium), which indicates the stabilization of the protein.

In this research, mesoporous silica was synthesized via a modified sol-gel route using 1-octyl-3-methylimidazolium chloride and was employed to remove malachite green (MG) dye from aqueous solution. Subsequently, this material was characterized and identified by different techniques such as Fourier transform infrared spectroscopy (FT-IR), N-2 adsorption-desorption method, scanning electron microscopy (SEM), and thermosgravimetric analysis (TGA). Unique properties such as high surface area and pore diameter, in addition to highly reactive atoms and presence of various functional groups make the mesoporous silica possible for efficient removal of malachite green (MG). In batch experimental set-up, optimum conditions for quantitative removal of MG by mesoporous silica was attained by varying different variables such as adsorbent dosage, initial dye concentration, contact time, and pH. Optimum values were set as pH of 8.0, 0.5 g of adsorbent at contact time of 120 min. The adsorption of MG follows the pseudo-second-order rate equation. Equilibrium data fitted well with the Freundlich model at all amount of adsorbent, while maximum adsorption capacity was 5.981 mg g(-)1 for 0.5 g mesoporous silica synthesized in IL.

We report the synthesis of TiO2-supported monometallic Ag, Sn and bimetallic AgSn nanoparticle catalysts prepared using sol–gel method via a rational nanoparticle encapsulation route. The samples were thoroughly characterized by ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) with image mapping and Brunauer–Emmett–Teller (BET) surface area analyzer. The supported bimetallic AgSn catalyst had the anatase structure, surface area of 50 m2/g and 2.6 ± 0.6 nm particle size. The efficiency of the catalysts was evaluated on photodegradation of methylene blue (MB) dye under visible light. The photocatalytic activity of MB was significantly enhanced in the presence of bimetallic AgSn nanoparticles (NPs) as compared to individual metal nanoparticles. Reusability study of the photocatalyst showed that the catalyst can be reused upto 5 runs with minimal loss in activity. Kinetic study revealed that the degradation reaction follows a pseudo first-order pathway.

In this research, mesoporous silica was synthesized via modified sol-gel technique using a series of 1-alky-3-methylimidazolium bromide [(CnMIM) Br (n = 4, 10, 16)], one kind of amphiphilic room temperature ionic liquids (RTILs), as a template. Subsequently, the material was characterized and identified by various techniques such as N-2 adsorption-desorption isotherm, SEM, TGA and FT-IR analysis. To obtain the optimum condition, different variables such as adsorbent dose, contact time, initial concentration, temperature and pH were studied, and the optimum conditions were found to be 0.7 g/100 mL, 30 min, 10 mg L-1, 40 degrees C and pH of 6.0, respectively, for the adsorption of lead ions from aqueous solution. The results showed that the RTIL bearing longer alkyl chain 1-hexadecyl-3-methylimidazolium bromide [(C16MIM)Br] was a suitable adsorbent for Pb(II) removal among all the adsorbents. The adsorption of lead ions follows pseudo-second-order rate equation, and the equilibrium data fitted well with the Freundlich model with maximum adsorption capacity 5.18 mg g(-1). Various thermodynamic parameters were calculated, and the results showed that the adsorption of lead ions on the material was feasible and endothermic in nature. The results from the adsorption-desorption cycles showed that the material held good desorption and reusability. It is concluded from the results that the material can be used to remove the Pb(II) from contaminated water to permissible limit. (C) 2014 Elsevier Ltd. All rights reserved.