Integrated pretreatment with capacitive deionization for reverse osmosis reject recovery from water reclamation plant

Reverse osmosis (RO) reject recovery from the water reclamation process was demonstrated feasible using an integrated pretreatment scheme followed by the Capacitive Deionization (CDI) process. The RO reject had an average total dissolved solids (TDS) of 1276 ± 166 mg/L. Water recovery of 85% with water quality comparable with the RO feed was achieved. Pretreatments using biological activated carbon (BAC) and BAC–ultrafiltration (UF) attained total organic carbon (TOC) removal efficiencies of 23.5 ± 6.0% and 39.9 ± 9.0%, respectively. Organics removal of RO reject was attributed to simultaneous adsorption and biodegradation in the BAC pretreatment, while further biodegradation in the submerged UF membrane tank provided additional organics removal. Membrane and CDI fouling was reduced by pH adjustment of the pretreated RO reject to approximately 6.5, which prolonged the CDI operation time by at least two times. The CDI process was able to achieve more than 88 and 87% TDS and ion removals, respectively, while PO₄³⁻ and TOC removals were at 52–81% and 50–63%, respectively.     

Syngas production from CH4 dry reforming over Co–Ni/Al2O3 catalyst: Coupled reaction-deactivation kinetic analysis and the effect of O2 co-feeding on H2:CO ratio

The dry and oxidative dry reforming of CH₄ over alumina-supported Co–Ni catalysts were investigated over 72-h longevity experiments. The deactivation behaviour at low CO₂:CH₄ ratio (≤2) suggests that carbon deposition proceeds via a rapid dehydropolymerisation step resulting in the blockage of active sites and loss in CO₂ consumption. In particular, at high temperatures of 923 K and 973 K, a ‘breakthrough’ point was observed in which deactivation that was previously slow suddenly accelerated, indicating rapid polymerisation of deposited carbon. Only with feed CO₂:CH₄ > 2 or with O₂ co-feeding was coke-induced deactivation eliminated. In particular, O₂ co-feeding gave improved carbon removal, product H₂:CO ratios more suitable for downstream GTL processing and stable catalytic performance. Conversion-time data were adequately fitted to the generalised Levenspiel reaction-deactivation model. Activation energy estimate (66–129 kJ mol⁻¹) was dependent on the CO₂:CH₄ ratio but representative of other hydrocarbon reforming reactions on Ni-based catalysts.     

Energy consumption and CO2 emissions in Turkey: Empirical analysis and future projection based on an economic growth

In this study, Turkey's energy sector was overviewed during the period of 1970–2002. The total energy consumption (TEC) was modeled by using the economic growth (proxied by gross national product—GNP) and population increase, which are the two important factors to determine the energy consumption for developing countries. In addition, the relationship between the TEC and total CO₂ (TCO₂) emission was studied. For this purpose, regression analysis was performed and the strong relationship between TEC and TCO₂ (R²=0.998$R^2=0.998$) was modeled. Also, results showed that a regression model can be used to predict the TEC from the country population and the GNP with high confidence (R²=0.996$R^2=0.996$).     

Multifilter rotating shadowband radiometer calibration for spectral aerosol optical depth retrievals over S?o Paulo City, Brazil

Multifilter rotating shadowband radiometer (MFRSR) calibration values for aerosol optical depth (AOD) retrievals were determined by means of the general method formulated by Forgan [Appl. Opt.33, 4841 (1994)] at a polluted urban site. The obtained precision is comparable with the classical method, the Langley plot, applied on clean mountaintops distant of pollution sources. The AOD retrieved over S?o Paulo City with both calibration procedures is compared with the Aerosol Robotic Network data. The observed results are similar, and, except for the shortest wavelength (415 nm), the MFRSR's AOD is systematically overestimated by approximately 0.03.     

A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: ÇEDINFO

Environmental impact assessment (EIA) is a tool for decision makers to take into account the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data.

In this study, a knowledge-based software—ÇEDINFO—developed by authors was introduced. ÇEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power station, hydraulic station, nuclear station) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. ÇEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations.     

Performance of an ultra-compact biofilm reactor treating domestic and synthetic wastewaters

The performance of an ultra-compact biofilm reactor (UCBR) treating domestic wastewater (DWW) collected from a local water reclamation plant; and gradually shifting to a mono-type carbon source synthetic wastewater (SWW) combined with DDW (CWW) and finally SWW; was investigated in this study. The total COD concentrations of influent DWW and CWW/SWW were 413.6 ± 80.8 mg/L and 454.9 ± 51.3 mg/L, respectively. The UCBR was able to achieve average total COD removal efficiencies of 70 ± 10% and 80 ± 4% for DWW and SWW respectively. The total COD concentrations of the effluent of DWW and CWW/SWW were 122.5 ± 44.4 mg/L and 89.7 ± 10.3 mg/L, respectively. These observations suggested that heterotrophs in the UCBR system were able to better assimilate and remove carbon of mono-type SWW compared to diverse carbon sources such as DWW; although the influent soluble COD concentrations of the SWW were higher than those of the DWW. However, the effluent NH(4)(+)-N concentrations for both types of wastewater were rather similar, <3.0 mg/L; although the influent NH(4)(+)-N concentrations of the DWW were 1.5 times those of the SWW.     

Proton NMR studies of molecular-level mobility in vulcanised and epoxidised natural rubber

Proton spin-lattice relaxations in the laboratory and rotating frames, together with transverse relaxation (free induction decay), have been measured for natural and epoxidised rubber, plus a series of vulcanised samples. The data have been analysed by fitting procedures to give characteristic times which are discussed in terms of the mobility of the various parts of the samples, and of their compositions (including the effects of paraffin wax and oil additives). Interpretation has been aided by recording free induction decays following a period of spin-locking. Carbon-13 magic-angle spinning spectra have also been measured.     

Quantification of two basic proteins related to a thymic hormone (LSH) and their occurrence in serum of normal and cancerous adults

A quantitative assay for a thymic hormone (LSHr) was developed and utilized for biologic materials. The protein was isolated from tissue extracts or biologic fluids by precipitation with 20% (NH4)2SO4 and reprecipitation with 75% methanol with subsequent disc-electrophoresis on polyacrylamide gel. The proteins on the gel were stained with amido black. One of the two protein bands was readily identified with LSHr by its electrophoretic mobility and agar immunodiffusion tests. Comparison of the intensity of the protein bands obtained from biologic tissues with those of graded amounts of the pure LSHr allowed quantitative estimation. Another basic protein of the serum is found along with LSHr by the above fractionation procedure; it was tentatively named GEM 126 on the basis of its electrophoretic mobility. The total quantity of each of these serum basic proteins and their ratios to each other showed no correlation to any of 20 clinical and laboratory parameters in either healthy or cancerous adults. The lack of correlation between the quantity of serum protein presumed to be LSHr and cancer susceptibility suggests this thymic hormone is not deficient in patients with cancer. Treatment of female cancer patients with radiation and chemotherapy caused a decrease in serum GEM 126 when compared to healthy adults, and untreated or surgically treated cancer patients.     

Sweetness intensity perception and pleasantness ratings of sucrose, aspartame solutions and cola among multi-ethnic Malaysian subjects

As the sugar intake of Malaysians is one of the highest in the Asia Pacific region, we wanted to investigate how this high prevalence of ‘sweet tooth’ is influenced by biological determinants like age, gender, ethnicity and Body Mass Index (BMI). This study therefore sought to use the generalized Labeled Magnitude Scale to evaluate the sweetness intensity perception and pleasantness ratings of not only three increasing suprathreshold concentrations of sucrose and a popular naturally-sweetened carbonated beverage - Coca-Cola®, but also their non-nutritive sweetener (NNS) counterparts - aspartame and Coca-Cola Light®. Taken together, the overall intensity of NNS solutions and beverage was perceived as significantly higher, but not for their pleasantness. The intensity perception and pleasantness of most sweet solutions were not significantly associated with gender and BMI. Overall, Malays had a lower perceived intensity of sweet stimuli compared to other ethnicities, but a conclusion of the influence of ethnicity on sweetness pleasantness could not be met. Lastly, sweetness intensity perception and pleasantness ratings for both colas decreased significantly with age.