Preparation of zeolitic material with simultaneous removal of NH4 + and PO4 3− from paper sludge ash via acid leaching

This study investigates the preparation of zeolitic material with removal of both NH₄ ⁺ and PO₄ ^3? from paper sludge ash (PSA) via acid leaching. PSA typically has a low Si and high Ca content, owing to the presence of calcite fillers. Acid leaching with 3 M HCl was used firstly to reduce the Ca content of the PSA, whereafter a zeolite-P (Na-P) product with high cation exchange capacity (CEC) was synthesized through reaction with 2.5 M NaOH solution at 80 °C. Ca-P zeolitic products were prepared by Ca-treatment with the leachant that had been in contact with the PSA. The product with high CEC capacity including Na-P could be synthesized from the acid-leached ash, and the high Ca content in the ash could be reduced by extraction of the Ca into the leachant via the acid leaching. The Ca-P zeolitic product could be prepared by Ca-treatment with the solution obtained from neutralization of the leachant with NaOH. This product was capable of removing NH₄ ⁺ and PO₄ ^3? from aqueous solution, simultaneously.     

Exposure assessment of lead to workers and children in the battery recycling craft village,Dong Mai,Vietnam

Human exposure to lead (Pb) due to uncontrolled Pb-acid battery recycling has been an environmental health issue in newly developed industrial regions. We conducted a human monitoring survey in Dong Mai, a battery recycling village in Vietnam, to assess exposure status to Pb. Lead level was measured in hair, blood and urine samples of residents in Dong Mai and two reference sites during 4 years spanning 2007–2011. In Dong Mai, Pb levels in three matrixes were significantly higher than those in reference sites. Blood Pb levels of all adults and children exceeded 10 μg/dL, the Centers for Disease Control and Prevention definition of an elevated blood Pb level. Clear increase of urinary δ-aminolevulinic acid (ALA) level with increasing blood Pb level indicated disruption of heme synthesis. One adult exceeded 100 μg/dL of blood Pb, where encephalopathy is of concern. The blood Pb levels achieved various toxic effect threshold values, and elevated blood Pb was not limited to recycling workers, but was also in children and women of reproductive age. Serious pollution status of Dong Mai village suggests an importance of further monitoring surveys in various developing Asian countries.     

Waste generation in traditional organized bazaars: a case study of organic waste sources in Da Nang City,Viet Nam

Journal of Material Cycles and Waste Management - Traditional organized bazaars are important retail venues in Viet Nam, but there are concerns about their waste management programs. This study...     

Female sex pheromone and male behavioral responses of the bombycid moth <Emphasis Type="Italic">Trilocha varians</Emphasis>: comparison with those of the domesticated silkmoth <Emphasis Type="Italic">Bombyx mori</Emphasis>

Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of (E,Z)-10,12-hexadecadienal (bombykal) and (E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of (E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.     

Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan

The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza.     

Ammonia removal from pretreated methane fermentation effluent through a soil trench system: a column experiment

In order to find the optimal running conditions and mechanisms of ammonia removal through a soil trench system that is designed for treating pretreated methane fermentation effluent, a soil column whose structure was similar to the soil trench system was prepared, and irrigated with wastewater below 30 °C. At the beginning, ammonia was mainly adsorbed by the soils, and the ammonia adsorption capacity of soils gradually saturated. After the 12th day, nitrification began in the soil column; the ammonia in the soil column decreased sharply, and the nitrite and nitrate peak appeared sequentially as the wastewater application rate decreased from 0.74 to 0.37 l h⁻¹. When the nitrification in the soil column reached a steady-state, 98% of all the ammonia in the influent was transformed into nitrate.

By changing the running conditions such as temperature, aeration, and wastewater application rate, it was found that the ammonia removal efficiency can be improved by aeration and impeded by low temperature. In these three variables, wastewater application rate has much greater affect on the ammonia removal efficiency; a lower wastewater application rate can increase the ammonia removal efficiency substantially because of the longer travel time.     

Hazard evaluation of hydrogen–air deflagration with flame propagation velocity measurement by image velocimetry using brightness subtraction

Deflagration phenomena in hydrogen–air mixtures initially filled in 1.4 m³ spherical latex balloons were measured using a high-speed digital video camera and pressure transducers. The image velocimetry using brightness subtraction was introduced to eliminate the background effects for obtaining accurate time evolution records of flame propagation velocity. The maximum flame propagation velocity of about 100 m/s was observed with maximum overpressure 15 kPa at 1 m from ignition point. According to the detailed flame propagation velocity records, there were long deceleration durations. The observed maximum overpressure was smaller than the overpressure estimated by the basis of the observed maximum flame propagation velocity and the pressure wave theories of spherical flames. A new blast curve plot of scaled overpressure vs. distance was tentatively proposed.     

Enzymatic treatment of estrogens and estrogen glucuronide

Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers.In this article we investigated the enzymatic treatment of three estrogens (estrone,17β-estradiol,and 17α-ethynyletstradiol) by a fungal laccase which oxidize phenolic compounds with dissolved oxygen.The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay.In addition,we developed an enzymatic treatment system comprised of β-D-glucuronidase and the laccase for 17β-estradiol 3-(β-D-glucuronide) degradation.The two enzymes eliminated 17β-estradiol 3-(β-D-glucuronide) and the intermediate,17β-estradiol,efficiently.     

Development of drone-type float for surface-velocity measurement in rivers

Environmental Fluid Mechanics - The present study develops a safety survey system for measuring natural river discharge. Monitoring of rivers is very important for river environment conservation...