The focus of nanoparticle design over the years has evolved toward more complex nanoscopic core-shell architecture using a single delivery system to combine multiple functionalities within ...nanoparticles. Core-shell-type lipidapolymer hybrid nanoparticles (CSLPHNs), which combine the mechanical advantages of biodegradable polymeric nanoparticles and biomimetic advantages of liposomes, have emerged as a robust and promising delivery platform. In CSLPHNs, a biodegradable polymeric core is surrounded by a shell composed of layer(s) of phospholipids. The hybrid architecture can provide advantages such as controllable particle size, surface functionality, high drug loading, entrapment of multiple therapeutic agents, tunable drug release profile, and good serum stability. This review focuses on current research trends on CSLPHNs including classification, advantages, methods of preparation, physicochemical characteristics, surface modifications, and immunocompatibility. Additionally, the review deals with applications for cancer chemotherapy, vaccines, and gene therapeutics. Methods and Materials: This comprehensive review covers the current applications of core-shell-type lipidapolymer hybrid nanoparticles, which combine the mechanical advantages of biodegradable polymeric nanoparticles and biomimetic advantages of liposomes to enable an efficient drug delivery system.
Linear and star-shaped poly( epsilon -caprolactone) (PCL) block copolymers containing poly(meth)acrylate segments with glycidyl, 2-(trimethylsilyloxy)ethyl and tert-butyl pendant groups were ...synthesized using mono-, di- and trifunctional PCL macroinitiators and appropriate (meth)acrylate monomers by controlled radical polymerization. The well-defined structures with narrow molecular weight distributions indicate the coexistence of semi-crystalline PCL and amorphous poly(meth)acrylic phases. The hydrophobic nature of the block copolymers can be easily converted to amphiphilic, which with biodegradable and biocompatible PCL segments are promising as polymeric carriers in drug delivery systems. copyright 2012 Society of Chemical Industry Linear and star poly( epsilon -caprolactone) (PCL) block copolymers containing poly(meth)acrylate segments with glycidyl, 2-(trimethylsilyloxy)ethyl and tert-butyl groups were synthesized. The copolymers with biodegradable and biocompatible PCL segments are promising as polymeric carriers in drug delivery systems.
The main objective of this study was to evaluate the feasibility of remediating tetrachloroethylene (PCE)-contaminated groundwater (with initial PCE concentration of approximately 20mgL super(-) ...super(1)) via persulfate oxidation activated by basic oxygen furnace slag (S sub(2)O sub(8) super(2) super(-)/BOF slag) with the addition of biodegradable surfactant (Tween 80). Results indicate that only 15% of PCE can be removed in experiment with the addition of S sub(2)O sub(8) super(2) super(-) only (S sub(2)O sub(8) super(2) super(-)/PCE=30/1). PCE removal can be increased to 31% while both S sub(2)O sub(8) super(2) super(-) and BOF slag (10gL super(-) super(1)) were added. This indicates that BOF slag was able to activate the persulfate oxidation mechanism, and cause the decrease in PCE concentration via oxidation process. Results also reveal that PCE degradation rates increased to 92% with the presence of Tween 80 (S sub(2)O sub(8) super(2) super(-)/Tween 80/PCE=30/2/1). In the presence of 10gL super(-) super(1) BOF slag, the reaction rate constant (k sub(o) sub(b) sub(s)) values were found to be 3.1x10 super(-) super(3), 8.7x10 super(-) super(3), 1.6x10 super(-) super(2), and 5.8x10 super(-) super(2)h super(-) super(1), as the S sub(2)O sub(8) super(2) super(-)/Tween 80/PCE molar ratios were 30/0/1, 30/0.5/1, 30/1/1, and 30/2/1, respectively. The reaction rate constant increased as the Tween 80 concentration increased. The significantly increased k sub(o) sub(b) sub(s) could be caused by the enhanced solubilization of PCE by Tween 80. The increase in initial surfactant concentration would cause the increase in the solubilization of PCE, and thus, enhance the oxidation rate. This was confirmed by the total amount of chloride ions produced after the reaction. Results from this study indicate that BOF slag-activated persulfate oxidation enhanced by surfactant addition is a potential method to efficiently and effectively remediate chlorinated solvents contaminated groundwater.
In the present work the degradation of the lignin and its derivatives in the residual water of a paper industry by simple ozonation was investigated. The remediation of lignin was realized using the ...combination of the pre-treatment with chemical precipitation, using concentrated sulfuric acid (97.1%) at the pH 1 and 3, and of the simple ozonation of the filtered residual water at the pH 1, 3, 8 and 12. Since the high residues content (the initial chemical oxygen demand (COD) is 70,000mg/L) in the experiments the diluted samples (1:10) were used. The previous precipitation has showed a significant effect on the reduction of the COD (77%) and color (96.1%). The sludge precipitated contents sulfolignin, which in the reaction with sulfuric acid was formed. In ozonation of the filtered residual water during 25min at the pH 1, 3, 8 and 12 the follows by-products were formed: fumaric, maleic, malonic and formic acids. The biodegradability of the treated water in ozonation increases up 0.067-0.29. The effect of the precipitation and the ozonation conditions on the decolorization kinetics was evaluated.
This paper explored a novel process for wastewater treatment, i.e. microwave enhanced Fenton-like process. This novel process was introduced to treat high concentration pharmaceutical wastewater with ...initial COD loading of 49,912.5mgL super(-) super(1). Operating parameters were investigated and the optimal condition included as follows: microwave power was 300W, radiation time was 6min, initial pH was 4.42, H sub(2)O sub(2) dosage was 1300mgL super(-) super(1) and Fe sub(2)(SO sub(4)) sub(3) dosage was 4900mgL super(-) super(1), respectively. Within the present experimental condition used, the COD removal and UV sub(2) sub(5) sub(4) removal reached to 57.53% and 55.06%, respectively, and BOD sub(5)/COD was enhanced from 0.165 to 0.470. The variation of molecular weight distribution indicated that both macromolecular substances and micromolecular substances were eliminated quite well. The structure of flocs revealed that one ferric hydrated ion seemed to connect with another ferric hydrated ion and/or organic compound molecule to form large-scale particles by means of van der waals force and/or hydrogen bond. Subsequently, these particles aggregated to form flocs and settled down. Comparing with traditional Fenton-like reaction and conventional heating assisted Fenton-like reaction, microwave enhanced Fenton-like process displayed superior treatment efficiency. Microwave was in favor of improving the degradation efficiency, the settling quality of sludge, as well as reducing the yield of sludge and enhancing the biodegradability of effluent. Microwave enhanced Fenton-like process is believed to be a promising treatment technology for high concentration and biorefractory wastewater.
The degradation of two polluted textile wastewaters from SOITEX (silk and textile) industry using the plasma-catalytic process, has been studied by non-thermal Gliding arc technique coupled to ...Degussa P25 titanium dioxide (TiO sub(2)) as photo-catalyst. Experiments were carried out to optimise the amount of phtoto-catalyst. The results showed that maximum degradation was attained for 3gL super(-) super(1) TiO sub(2) concentration. For wastewater (1) degradation was 95% at the end of 60min of treatment time. The same wastewater was completely decolourised after only 30min of plasma-catalytic treatment time. In parallel, the biodegradability was significantly enhanced through 20min of exposure to the plasmagenous source for both wastewater samples. Turbidity of wastewater (1) and wastewater (2) decreased with rate constants of 0.015 and 0.017min super(-) super(1), respectively. The TiO sub(2)-mediated Gliding Arc discharge (GAD sub(T) sub(i) sub(O) sub(2)) showed potential application for the treatment of liquid wastes, resulting in the mineralization of the wastewater samples confirmed by chloride, sulphate and phosphate ions formation. In both cases of GAD treatments, with and without photo-catalyst, the plasmagenous process proves efficient in the field of wastewaters degradation.
The present study deals with pre-treatment of wastewater sludge by ultrasonic waves at frequency of 20kHz using fully automated lab-scale ultrasonication equipment. Different wastewater sludge solids ...concentrations, ultrasonication intensities, and exposure times of pre-treatment were investigated for the optimization of ultrasonication treatment process. The parameters of pre-treatment process were optimized by using response surface methodology. A 2 super(3) central composite design was performed for optimization. The screening experiment step comprised steepest ascent methodology to determine optimal domain. The effect of ultrasonication treatment was assessed in terms of increase in soluble solids and the biodegradability of the wastewater sludge. In addition, rheological parameter of wastewater sludge, namely, viscosity was also measured to ascertain the suitability of wastewater sludge for conventional treatment processes as well as submerged fermentation, a major step for the production of value-added products from sludge. It was observed that the ultrasonication intensity and pre-treatment exposure time significantly affected the efficiency of the ultrasonication process followed by the solids concentration. The optimal conditions of ultrasonic pre-treatment were 0.75W/cm super(2) ultrasonication intensity, 60min, and 23g/L total solids concentration. The increases in soluble chemical oxygen demand and biodegradability, by aerobic sludge digestion process, in terms of total solids consumption increased by 45.5% and 56%, respectively. The flowability of ultrasonicated sludge in terms of viscosity showed exponential behaviour at different total solids concentrations, and pseudoplastic and thixotropic behaviour similar to raw sludge. Nevertheless, the magnitude of viscosity values of ultrasonicated sludge was always lower than the raw sludge.
Based on literature review, a non-potable urban grey water reuse standard is proposed and the treatment alternatives and reuse scheme for grey water reuses are evaluated according to grey water ...characteristics and the proposed standard. The literature review shows that all types of grey water have good biodegradability. The bathroom and the laundry grey water are deficient in both nitrogen and phosphors. The kitchen grey water has a balanced COD: N: P ratio. The review also reveals that physical processes alone are not sufficient to guarantee an adequate reduction of the organics, nutrients and surfactants. The chemical processes can efficiently remove the suspended solids, organic materials and surfactants in the low strength grey water. The combination of aerobic biological process with physical filtration and disinfection is considered to be the most economical and feasible solution for grey water recycling. The MBR appears to be a very attractive solution in collective urban residential buildings.
•Electrochemical oxidation was used as the pretreatment of biotreatment.•Possible lignin degradation mechanism has been proposed.•Biodegradability enhancement depended strongly on the electrode ...material.•Selective and nonselective electrochemical oxidation models were proposed.
The titanium based antimony doped tin dioxide electrode (Ti/SbSnO2) and titanium based lead dioxide electrode (Ti/PbO2) were used in the pre-degradation of a sodium lignosulphonate solution (2000ppm). The performances of these two electrodes were compared by evaluating the change of water quality parameters (COD, biodegradability) and UV–Vis absorption. The parameters that influence effectiveness and efficiency of the pretreatment were investigated, including applied current, passed electric charge, solution temperature, and supporting electrolyte. Moreover, IR spectra, and GC–MS analysis were used for products analysis in order to explore the degradation mechanism. Results showed that the electrochemical oxidation is a promising approach for the pretreatment of lignin, and the aerobic or anaerobic biodegradability was enhanced significantly. Quinones and low-chain carboxylic acid were identified as important intermediate and main products, respectively. The oxidation effectiveness depends strongly on the electrode material. The Ti/SbSnO2 exhibited a better ability of UV–Vis absorption decrease and COD removal, while the Ti/PbO2 had a better capability to enhance biodegradability. Such differences could be interpreted by the theory of selective and nonselective oxidation.
PDF
