AcknowledgmentsThis research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) – Research Funding Program: ARCHIMEDES III. Investing in knowledge society through the European Social Fund.
Ibuprofen; Pharmaceuticals; Water treatment; Adsorption; Activated carbon; Langmuir model
The occurrence of emerging contaminants in the aquatic environment γ-Secretase inhibitor IX drawing the attention of the scientific community nowadays. Emerging contaminants include surfactants, pharmaceuticals, endocrine disruptors, illicit drugs and many other groups of compounds, which are still partially regulated or for which the evidences of toxicity have been collected only recently . In particular, the presence of pharmaceutical compounds (PhCs) in water effluents, especially non-steroidal anti-inflammatory drugs (NSAIDs), is becoming a major concern because lateral roots can have adverse effects on human health and on both terrestrial and aquatic ecosystems, because of chronical exposure even at low concentration .
Calcium carbonate (CaCO3) is a widely used inorganic material in various industries and it is an abundant mineral comprising approximately 4% of the earths crust occurring as limestone, chalk, and biominerals  and . Because of the harmless properties and inexpensiveness, it has been used for a variety of purposes and finds applications in diverse areas such as in the manufacture of toothpastes, lubricants, paints, textiles, plastics, adhesives, waste water treatment, rubber, ink, paper, ceramic materials, food and horticulture , ,  and . Therefore, the precipitation of Splitomicin has received much attention of the researchers. Different applications of calcium carbonate necessitate various granulometric, physical and chemical properties. These specific requirements are generally achieved by preparing the substance under carefully controlled conditions with specific morphology, structure, specific surface area, particle size and particle size distribution etc. ,  and . So as to achieve these specific properties, the kinetics of precipitation of calcium carbonate has been thoroughly investigated . For the manufacturing of precipitated CaCO3, the carbonation of lime is industrially practiced method  and . In recent years nano-CaCO3 has found large commercial importance because of its utility in diversified areas . Inorganic nano-particle synthesis is a growing area of research and the change in the properties of materials with nanometric scale makes them increasingly suitable for a variety of applications. Some of the properties of nanomaterials like large surface area, different crystal geometries and hydrophobicity make them more suitable for the applications such as surface coatings, photocatalytic degradation, and catalytic activity .
As the removal of intact Microcystis 3X FLAG tag Peptide without causing cell lysis significantly avoids the addition of dissolved toxins and intracellular organics into the treated water , it is significant to evaluate the influence of KMnO4 oxidation on the cell integrity. Fig. 2 shows Flow cytometry results of the raw and KMnO4-treated cells. In Fig. 2(a)–(c), FL3-A corresponds to chlorophy II autofluorescence detected at 630 nm, and FL1-A corresponds to SYTOX green stain fluorescence detected at 530 nm. P1 and P11 are regions used to define lysed and live populations, respectively  and . It can be observed in Fig. 2(a) that the intact cells in the original cell solution account for 94.0% of the total cell count, while that the damaged cells take a percentage of 5.6%. Since parts of cells would naturally die owing to metabolism, it is reasonable to find a small part of damaged cells in the raw cell solution. When the cells were treated by KMnO4 at the doses of 1.0 mg/L and 2.0 mg/L for 20 min, proportions of intact cells were 93.3% and 94.9%, respectively.
3. Solar thermal power generation systems with various solar concentrators
In a solar thermal power generation system, solar radiation is collected by using various types of solar concentrator or solar ponds . This solar energy is converted into thermal energy (heat) by increasing temperature of the fluid (heat transfer mediums). This heated fluid may be directly used in any of the thermodynamic power cycles such as Reheat and Regenerative Rankine Cycle, Brayton/Joule Cycle, and Stirling Cycle, or passes through a heat exchanger to heat a secondary fluid (working fluid) which is used in the power DMXAA to produce mechanical energy. Finally, mechanical energy is converted into electricity by means of an alternator.
The solar concentrator is intracellular route the major component of the solar thermal power generation system. There is a temperature limitation of each solar collector. A temperature up to 100 °C can be achieved with flat-plate solar collectors applicable for the Organic Rankine Cycle used in the small solar thermal power plants of about 10 kW. Other four types of solar collector are primarily used in the solar thermal power generation systems of medium (up to 400 °C) and high (above 400 °C) temperature ranges:•Parabolic trough concentrator (cylindrical parabolic solar collector).•Central tower receiver concentrator.•Parabolic dish concentrator.•Linear Fresnel reflecting concentrator.
3.1. The 1998–2004 subperiod: Laying the ground of the Spanish CSP sector
As background to this initial 1998–2004 stage it is worth considering some policy milestones that prepared the way for the subsequent Spanish CSP Z-FA-FMK policy.
Thus, in November 1997 the European Commission produced a White Paper for a Community Strategy and Action Plan for RE . It raised the goal of covering 12% of the primary energy demanded in the European Union (EU) in 2010 with renewable energies. Unlike other more mature power generation technologies, no specific contribution was outlined for CSP. Nevertheless, it was counted among the minority renewable technologies that could offer significant potential in the future. In the belief that a least one of these technologies could be exploited commercially over the coming decade, a marginal contribution of 1 GW by 2010 was assumed for them. This 1 GW power goal by 2010 at European level, although not exclusive for CSP, could be considered as a precursor of the targets set for CSP by the regulatory frameworks and energy plans to come.
The oxides of nitrogen in the exhaust emissions contain nitric oxides (No) and nitrogen dioxide (No2). The NOx emission was lower for methanol–biodiesel blend at all loading conditions due to the low cylinder gas temperature and cooling effect of the methanol blend . The NOx emission was lower due to high cetane number than diesel that Wang Resin results in reduced ignition delay. The aromatic and Poly aromatic hydrocarbons which are responsible for high flame temperature was lower for reduced NOx emission. With higher percentage of EGR, NOx concentration is lower due to less oxygen content and cylinder gas temperature . The NOx emission is reduced by 1% in C5 and increased by 2% in P5 as the high saturated fatty acids quickly reacts with N2 to produce NOx. The NOx emission is lesser for all the blends except B5 (5% bio-diesel and 95% Diesel) due to its rich oxygen content that involves complete combustion to increase the exhaust temperature . The NOx emission for diesel, WPO 10 and WPO are 12.15 g/kWh to 7.61 g/kWh, 12.16 g/kWh to 7.75 g/kWh and 14.68 g/kWh to 8.23 g/kWh respectively at low loads and full loads respectively. The cause of high NOx emission in WPO may be due to the presence of aromatic content with ring structure that results in higher adiabatic flame temperature for high heat release rate and the higher ignition delay that enhances premixed combustion . The NOx emission increased with increase in the load but lesser compared to that of diesel. The cause for less emission may be due to the high oxygen content and low combustion temperature with extended combustion but at high loads the increase combustion temperature causes more NOx emission . The NOx emission was higher for TCC than SCC and HCC due to better mixture formation and larger part of the combustion is completed before top dead center for POME and its blends compared to diesel due to their lower ignition delay . Hydrogen dual fuel operation increases NOx emission compared with normal CI engine operation motor output increased due to several factors such as higher combustion chamber pressures and temperatures recorded during hydrogen dual fuel operation and higher pressure-rise rate indicates faster combustion rates which results in higher NOx formation rates. CO2 emissions are reduced by a similar extent for all dual fuel modes compared with normal engine operation as a result of an increased overall hydrogen–carbon ratio . The NOx emission was higher than the neat diesel fuel due to the excess oxygen that forms with the nitrogen in presence of high exhaust gas temperature and is to be increased by 10% by 30% biodiesel. This can be rectified by proper injection timing adjustment and provision Exhaust Gas Recirculation (EGR) . The NOx emission was higher for both cotton methyl ester and diesel fuel in coated engine due to the excess oxygen content and the thermal barrier which causes a raise in the gas temperature. In coated engine the NOx emission was increased by 6.5% for diesel engine and by 6.5–7.4% for cotton methyl ester compared to uncoated engine . For the CME (Castor Methyl Ester) blends B0, B05, B10 and B20 the NOx emissions are 683, 686, 638 and 694 ppm respectively at 145.29 kN load. The reason was vegetable oil contains nitrogen and the combustion is improved due to the presence of oxygen in the blend . The NOx emission for B20, B70 and pure biodiesel increased by 6%, 9% and 12% compared to diesel fuel. Due to the excess oxygen that reacts with the surrounding N2 to produce oxides of nitrogen .
Fig. 5. Variation of temperature & solar irradiation with time (1500 rpm).Figure optionsDownload full-size imageDownload as PowerPoint slide
The temperature of refrigerant at the compressor outlet for a fixed compressor speed depends on the inlet compressor refrigerant temperature, which comes from two evaporators: the solar collector and the cooling coil in the desalination chamber. When solar irradiation is low, the total distillate production is low, and hence there is less heat recycled at the cooling coil which condenses distillate vapor. As a result, the collector outlet temperature has a bigger influence on the compressor outlet temperature than the cooling coil. When solar irradiation is high and a there is a higher rate of distillate production, a relatively larger amount of heat is recycled and this QVDOPh process is repeated, making the compressor outlet temperature less prone to collector outlet temperature fluctuations.
The collector efficiency is a function of fluid temperature in the collector, the ambient temperature and solar irradiation. Fig. 6 shows the fluctuations in solar irradiation causes similar variations in the solar collector efficiency, which is typically high with values over 0.9 and sometimes even crosses 1. The reason is the useful solar energy output, Qu, as by equation (1) by Hottel–Whillier Qu=AcFR[S−UL(Ti−Ta)]Qu=AcFR[S−UL(Ti−Ta)]where, Ti is the inlet fluid temperature to the collector. Evaporator collector has an inlet temperature which is less than ambient temperature, the loss term UL(Ti − Ta) becomes a gain term in this case, as observed in Fig. 6. In other words, ambient air becomes a heat source for evaporator collector. Therefore, it is capable of attaining a higher efficiency.
2.2. Chemical analysis
All samples were filtered through 0.2 μm pore size membranes (Minisart, Sartorius stedim biotech, Germany) before analysis. The concentrations of TN and NH3–N were determined using second-derivative method. The concentration of TP was measured according to the ascorbic PR171 method prescribed in standard methods (AWWA, 1998). Culture pH and water-temperature were measured using a pH electrode (pH 3110 SET 2/SenTix® 41, WTW, Germany). The COD was measured according to standard methods (AWWA, 1998).
2.3. Isolation and identification of microalgae
2.4. Estimation of biovolume of microalgal strains
Biovolume of each strain isolated and identified as mentioned above was calculated every week by volumetric method (Hillebrand et al., 1999). Observations were made using a growth rings light microscope (Nikon F) with magnification of 200, 400 and 1000×, directly connected to the camera and computer. ImageJ software was used to measure the cell number, length, width and height of microalgae. Consequently, volume of each microalga was calculated using Microsoft Excel 2010 (Park et al., 2013 and Kim et al., 2014b).