Screening of Cucumis sativus as a new arsenic-accumulating plant and its arsenic accumulation in hydroponic culture

Phytoextraction is a remediation technology with a promising application for removing arsenic (As) from soils and waters. Several plant species were evaluated for their As accumulation capacity in hydroponic culture amended with As. Cucumis sativus (cucumber) displayed the highest tolerance against As among 4 plants tested in this study (corn, wheat, sorghum and cucumber). The germination ratio of Cucumis sativus was more than 50% at the high concentration of 5,000 mg-As/l. In Cucumis sativus grown in a solution contaminated with 25 mg-As/l, the accumulated As concentrations in the shoot and root were 675.5 ± 11.5 and 312.0 ± 163.4 mg/kg, respectively, and the corresponding values of the translocation and bioaccumulation factors for As were 1.9 ± 0.9 and 21.1 ± 8.4, respectively. These results indicate Cucumis sativus is to be a candidate plant for phytoextraction of As from soils and water.     

The effects of self‐emotion,counterpart emotion,and counterpart behavior on negotiator behavior: a comparison of individual‐level and dyad‐level dynamics

This study expands the negotiation literature by examining how negotiator behavior is predicted by various emotions felt by the negotiators and their counterparts and by counterpart negotiation behavior. Using hierarchical linear modeling, we also compare individual‐ and dyad‐level processes that lead to negotiator behavior and outcomes. The results from a dyadic negotiation simulation showed that both the valence and agency of negotiator and counterpart emotions need to be considered to understand the roles of emotion in negotiator behavior. Negotiators tend to reciprocate counterparts' integrating, compromising, and dominating behaviors, but they also offer complementary (or matching) responses to the counterparts' dominating and yielding behaviors. Integrating behavior was more dependent on dyad‐level interpersonal dynamics than were the other behaviors. The comparison of negotiator‐level and dyad‐level results suggests that negotiation needs to be understood in the context of collective exchanges as well as individual‐level cognitive processes. Copyright © 2005 John Wiley & Sons, Ltd.     

Distinctive differences in the granulation of saline and non-saline enriched anaerobic ammonia oxidizing (AMX) bacteria

The growing interest in the anaerobic ammonium oxidizing (AMX) process in treating high nitrogen containing wastewaters and a comprehensive study into the granulation mechanism of these bacteria under diverse environmental conditions over the years have been unequal. To this effect, the distinctive differences in saline adapted AMX (S_AMX) and non-saline adapted AMX (NS_AMX) granules are presented in this study. It was observed that substrate utilisation profiles, granule formation mechanism, and pace towards granulation differed marginally for the two adaptation conditions. The different microbial dominant aggregation types aided in splitting the 471 days operated lab-scale SBRs into three distinct phases. In both reactors, phase III (granules dominant phase) showed the highest average nitrogen removal efficiency of 87.9% ± 4.8% and 85.6% ± 3.6% for the S_AMX and NS_AMX processes, respectively. The extracellular polymeric substances (EPS) quantity and major composition determined its role either as a binding agent in granulation or a survival mechanism in saline adaptation. It was also observed that granules of the S_AMX reactor were mostly loosely and less condensed aggregates of smaller sub-units and flocs while those of the NS_AMX reactor were compact agglomerates. The ionic gradient in saline enrichment led to an increased activity of the Na⁺/K⁺ – ATPase, hence enriched granules produced higher cellular adenosine triphosphate molecules which finally improved the granules active biomass ratio by 32.96%. Microbial community showed that about three to four major known AMX species made up the granules consortia in both reactors. Proteins and expression of functional genes differed for these different species.     

A study on torrefaction characteristics of waste sawdust in an auger type pyrolyzer

Torrefaction is thermo-chemical process which can improve solid fuel quality as well as grindability. In previous studies, torrefaction has been studied mainly for removal of moisture and for improving grindability. In this experiment, the characteristics of torrefied waste sawdust were studied especially for its energy yield. Hence, torrefaction was performed on varying reaction temperatures (200, 220, 240, 260, 280, 300 °C) and solid residence time (10, 30, 60 min). The results indicated that the yield of torrefaction decreases with increasing temperature and residence time. It was found that above 280 °C, the yield got remarkably decreased. The lowest yield was obtained at the residence time of 60 min. It was also noticed that the HHV of torrefied samples increases with increasing temperature. The highest HHV was found to be 26.09 MJ/kg which was obtained at 60 min and 300 °C. However, the highest energy yield was obtained to be 104.17 % which was noticed at 30 min and 260 °C.     

Development and performance verification of quality improvement equipment for recycled fine aggregate and soil

Journal of Material Cycles and Waste Management - This study aims to promote and revitalise quality control by efficiently separating impurities from recycled fine aggregates and soil. To meet this...     

Simultaneous selective removal of cesium and cobalt from water using calcium alginate-zinc ferrocyanide-Cyanex 272 composite beads

Environmental Science and Pollution Research - Composite beads consisting of Ca alginate mixed with zinc ferrocyanide (ZnFC) and Cyanex 272 were synthesized in order to selectively adsorb Cs+ and...     

Study of hydrodynamic characteristics in a circulating fluidized bed gasifier for plastic waste by computational fluid dynamics modeling and simulation

For designing an efficient circulating fluidized bed reactor, understanding the complex hydrodynamic characteristics in the reactor is required. Hence, in the present study, the modeling and simulation of the circulating fluidized bed gasifier using plastic waste were carried out with Eulerian-Granular approach. Several cases were investigated as changing superficial gas velocities or sizes of plastic waste particle. Firstly, cases were examined with four different velocities when the particle diameter is 1 mm. At the gas velocity of 6 or 8 m/s, gas volume fraction is more than 95 % throughout the reactor and particle velocity has positive value overall. Therefore, a circulating fluidized bed seems to be formed in both cases. Comparing those two cases, better solid mixing can be expected considering the mass fraction and solid velocity at the superficial gas velocity of 6 m/s. Thus this case was further studied for the effect of particle size. As the diameters of plastic waste particle are 1 or 3 mm, it is considered that a circulating fluidized bed is formed. And plastic waste and sand particles are well mixed throughout the reactor. However, the particle diameter increases over 3 mm then, it is very hard to maintain circulating fluidization condition.     

Evaluation of SWAT sub-daily runoff estimation at small agricultural watershed in Korea

A study was undertaken for the prediction of runoff flow from 0.8 ha field-sized agricultural watershed in South Korea using Soil and Water Assessment Tool (SWAT) sub-daily. The SWAT model with sub-daily configuration predicted flow from the watershed within the range of acceptable accuracy. The SWAT sub-daily simulations were carried out for a total of 18 rainfall events, 9 each for calibration and validation. Overall trend and extent of matching simulated flow for the rainfall events in 2007-2008 with measured data during the calibration process were coefficient of determination (R²) value of 0.88 and Nash and Sutcliffe Efficiency (E_NS) value of 0.88. For validation, R² and E_NS values were 0.9 and 0.84, respectively. Whereas R² and E_NS values for simulation results using daily rainfall data were 0.79 and -0.01, respectively, that were observed to be out of acceptable limits for the model simulation. The importance of higher time resolution (hourly) precipitation records for flow simulation were evaluated by comparing R² and E_NS with 15 min, 2 h, 6 h and 12 h precipitation data, which resulted in lower statistics with increases in time resolution of precipitation data. The SWAT sub-daily sensitivity analysis was performed with the consideration of hydraulic parameter and was found as in the rank order of CN2 (curve number), ESCO (soil evaporation compensation factor), GW_DELAY (ground water delay time), ALPHA_BF ( base flow alpha factor), GWQMN ( a threshold minimum depth of water in the shallow aquifer required for return flow to occur) , REVAPMN (minimum depth of water in shallow aquifer for re-evaporation to occur) , LAT_TIME (lateral flow travel time) respectively. These sensitive parameters were evaluated at 10% higher and lower values of the parameters, corresponding to 70.5% higher and 23.2% lower in simulated flow out from the SWAT model. From the results obtained in this study, hourly precipitation record for SWAT sub-daily with Green-Ampt infiltration method was proven to be efficient for runoff estimation at field sized watershed with higher accuracies that could be efficiently used to develop site-specific Best Management Practices (BMPs) considering rainfall intensity, rather than simply using daily rainfall data.     

Direct production of hydroxymethylfurfural from raw grape berry biomass using ionic liquids and metal chlorides

We report for the first time the direct conversion of raw grape berry biomass to hydroxymethylfurfural (HMF) using ionic liquid solvents with metal chloride catalysts. Exploiting raw plant biomass as a biorefinery feedstock is innovative for sustainable chemical industry. The use of the raw biomass to synthesize compounds can indeed lead to less energy consumption and less CO₂ emissions. Using raw plant biomass skips pretreatment steps that are required to produce biomaterials such as carbohydrates or cellulosic biomass. Here, grape berry biomass was used as a raw chemical feedstock for the production of hydroxymethylfurfural, a key platform intermediate for syntheses of future renewable biofuels. We examined 3 ionic liquid solvents, 3 reaction temperatures, 5 chloride catalysts, and 5 concentrations of HCl. We found an increasing HMF yields depending on reaction conditions. 1-octyl-3-methylimidazolium chloride was most effective for HMF synthesis. Addition of HCl or metal chlorides alone showed little improvement. The highest HMF yield of about 100 mg HMF per mL of grape biomass extract was obtained using 0.3 M HCl, [OMIM]Cl, and CrCl₂ at 100°C for 3 h. Our study provides a model system of sustainable production of valuable compounds from raw plant biomass.