Evaluation of pressurized liquid extraction for the determination of neonicotinoid pesticides in green onion

Abstract

A pressurized liquid extraction (PLE) method was presented for the determination of six neonicotinoid pesticides, acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam in green onion. The critical parameters of PLE, e.g. extraction solvent, temperature, pressure, number of cycles, and static extraction time, were optimized by test on the spiked green onion with six neonicotinoids and the incurred green onion applied with four commercial neonicotinoid insecticide formulations (acetamiprid, dinotefuran, imidacloprid, and thiamethoxam). As a result, the recoveries of six neonicotinoids obtained by one cycle PLE with acetonitrile at 140?°C and 50?bar for 10?min were 94.7–99.5%. These results were acceptable according to the validation guideline for testing method of agricultural chemicals in food by Ministry of Health, Labour, and Welfare in Japan. PLE was also validated by the test on the incurred green onion. The analytical values of four neonicotinoids obtained by PLE were good agreement with those obtained by solid–liquid extraction with homogenizer, which is employed for Japanese official method for the analysis of pesticide residues in food (the ratios of analytical values obtained by PLE to those obtained by solid–liquid extraction were 99.7–101.2%). These results indicate that PLE is applicable for the determination of neonicotinoids in green onion.     

Novel enzymatic activity of cell free extract from thermophilic Geobacillus sp. UZO 3 catalyzes reductive cleavage of diaryl ether bonds of 2,7-dichlorodibenzo-p-dioxin

We characterized the ability of the cell free extract from polychlorinated dibenzo-p-dioxins degrading bacterium Geobacillus sp. UZO 3 to reduce even highly chlorinated dibenzo-p-dioxins such as octachlorodibenzo-p-dioxins in incineration fly ash. The degradation of 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD) as a model dioxin catalyzed by the cell free extract from this strain implicates that the ether bonds of 2,7-DCDD molecule undergo reductive cleavage, since 4′,5-dichloro-2-hydroxydiphenyl ether and 4-chlorophenol were detected as intermediate products of 2,7-DCDD degradation.     

Phosphorus recovery from secondary effluent and side-stream liquid in a sewage treatment plant using zirconium-loaded saponified orange waste

Zirconium was loaded onto orange waste, a cheap and available agricultural waste in Japan, to investigate the feasibility of its utilization for phosphorus recovery from secondary effluent and side-stream liquid, which contain 5.9 and 68.2 mg/dm³ phosphorus, respectively. The phosphorus removal from side-stream liquid by using zirconium-loaded saponified orange waste (Zr-SOW) gel increased with an increasing solid/liquid ratio, and it was found that Zr-SOW gel showed better performance than zirconium ferrite. The prepared adsorbent was effective for phosphorus removal and exhibited a reasonably high adsorption capacity, twice than that of zirconium ferrite. The secondary effluent was treated in a column packed with Zr-SOW gel, and an dynamic adsorption capacity of 1.3 mol-P/kg was attained. The adsorbed phosphorus from the column was successfully eluted as a concentrated form by using a small amount of 0.2 M NaOH. Throughout the elution process, zirconium was not leaked from the adsorption gel.     

Leaching of heavy metals by citric acid from fly ash generated in municipal waste incineration plants

The leaching behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated in this study. The leaching process includes two steps, i.e., fly ash was firstly washed with water, and then subjected to citric acid leaching. The main parameters of the washing process such as liquid/solid ratio, washing time, and number of washing were tested. The optimum conditions for water washing were found as follows: washing time 5–10 min, liquid/solid ratio 10:1 (ml:g), and number of washing was twice; under these conditions, 86% Na, 70% K, 12% Ca, 1.2% Al, and 0.5% Pb were removed from the fly ash in the prewashing. From the results of screening tests of leaching lixiviants, citric acid was found to be the most effective leaching agent, taking account of its environmentally benign characteristics. Optimum metal extraction can be achieved with citric acid under the following conditions: pH 3.0, liquid/solid ratio 40 (ml:g), citric acid concentration 0.10 mol/dm³, contact time 20 min at room temperature.     

A fuzzy analytic network process for multi-criteria evaluation of contaminated site remedial countermeasures

The Analytic Network Process (ANP) has been proposed to incorporate interdependence and feedback effect in the prioritization of remedial countermeasures using a hierarchical network decision model, but this approach seems to be incapable of capturing the vagueness and fuzziness during value judgment elicitation. The aim of this paper is to present an evaluation method using a fuzzy ANP (FANP) approach to address this shortcoming. Triangular fuzzy numbers (TFN) and their degree of fuzziness are used in the semantic scale as human judgment expressed in natural language is most often vague and fuzzy. The method employs the alpha-cuts, interval arithmetic and optimism index to transform the fuzzy comparative judgment matrix into set of crisp matrices, and then calculates the desired priorities using the eigenvector method. A numerical example, which was drawn from a real-life case study of an uncontrolled landfill in Japan, is presented to demonstrate the process. Results from the sensitivity analysis describe how the fuzziness in judgment could affect the solution robustness of the prioritization method. The proposed FANP approach therefore could effectively deal with the uncertain judgment inherent in the decision making process and derive the meaningful priorities explicitly from a complex decision structure in the evaluation of contaminated site remedial countermeasures.     

Willingness to pay for waste management improvement in Dhaka city, Bangladesh

We employed the contingent valuation method to estimate the willingness to pay of the respondents to improve the waste collection system in Dhaka city, Bangladesh. Our objective was to estimate how WTP differs between respondents who received or did not receive door to door waste collection. The methodology consisted of asking people directly about their willingness to pay an additional waste collection service charge to cover the costs of a new waste management project. The mean value of WTP for areas that received waste collection service areas was higher than for residents of areas that did not but the difference was not statistically significant. The aggregate value of WTP of the respondents in Dhaka city was 7.6 million Taka (USD0.1 million).     

Compilation and application of a primary PM2.5 emissions inventory with high sectoral resolution in Japan

To elucidate the macro-structure of the PM_2.5 emissions generated by Japan's economic activities, this paper presents an emission inventory of primary particles of PM_2.5 with high sectoral resolution based on the Japanese Input–Output Tables, comprising some 400 sectors. These primary PM_2.5 emissions were estimated by multiplying the estimated energy consumption associated with each fuel type by a PM₁₀ emission factor incorporating the technological level of dust collection in each sector and the mass ratio of PM_2.5 to PM₁₀. Non-energy emissions from agricultural open burning were also determined. Total PM_2.5 emissions in 2000 were 252 kt, 49% of which were due to mobile emission sources. Changes in total PM_2.5 emissions between 1990 and 2000 were also calculated. This showed that a substantial increase in energy sector emissions due to rising coal consumption was offset by a sharp decline in emissions from road vehicles and shipping vessels, resulting in an overall decrease in total emissions. In addition, the emissions induced by economic demand in each sector were quantified by means of input–output analysis, which revealed that demand for construction, foods and communications and services constituted the principal causes of real domestic emissions. An assessment of sectoral contributions to PM_2.5 emissions that takes into account the effects of human exposure, expressed as external costs, suggests that the contribution of transportation is greater than indicated on the grounds of direct emissions alone.     

Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment

Ambio - Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an...     

Influence of moisture content,particle size and forming temperature on productivity and quality of rice straw pellets

A large amount of rice straw is generated and left as much in paddy fields, which causes greenhouse gas emissions as methane. Rice straw can be used as bioenergy. Rice straw pellets are a promising technology because pelletization of rice straw is a form of mass and energy densification, which leads to a product that is easy to handle, transport, store and utilize because of the increase in the bulk density. The operational conditions required to produce high quality rice straw pellets have not been determined. This study determined the optimal moisture content range required to produce rice straw pellets with high yield ratio and high heating value, and also determined the influence of particle size and the forming temperature on the yield ratio and durability of rice straw pellets. The optimal moisture content range was between 13% and 20% under a forming temperature of 60 or 80 °C. The optimal particle size was between 10 and 20 mm, considering the time and energy required for shredding, although the particle size did not significantly affect the yield ratio and durability of the pellets. The optimized conditions provided high quality rice straw pellets with nearly 90% yield ratio, ?12 MJ/kg for the lower heating value, and >95% durability.     

Production of Poly(3-hydroxyalkanoate)s by Pseudomonas putida Cultivated in a Glycerol/Nonanoic Acid-Containing Medium

The biosynthesis of poly(3-hydroxyalkanoate) (PHA) by Pseudomonas putida (JCM6160) cultivated in a medium containing glycerol, nonanoic acid, or a glycerol/nonanoic acid mixture as the sole carbon sources was investigated. The PHA content was ~20 % when glycerol was the carbon source. This relatively low content can be attributed to the glycerol end-cap effect and the absence of enzymes that can directly synthesize PHA from acetyl CoA, which is the major metabolite of glycerol. Fatty acids, containing even numbered carbons, are synthesized from acetyl CoA, and they can be used as substrates for PHA synthesis. However, this process also results in decreasing PHA content as fatty acids are siphoned off into other pathways. However, addition of 5 mM nonanoic acid into a 20 mM glycerol-containing medium dramatically increased the PHA content in P. putida, which was 1.3 times larger than the sum of the values found when glycerol and nonanoic acid were each used as the sole carbon source. The PHA, synthesized in the glycerol/nonanoic acid medium, contains 3-hydroxy alkanoate units that have 5, 6, 7, 8, 9, or 10 carbons. The units that contain the even numbered carbons are derived from fatty acids that were produced from glycerol; whereas, the PHA units with the odd numbered carbons are derived from nonanoic acid. Pentanoate units were also found in the polyester derived from glycerol and nonanoic acid, and must have been synthesized indirectly via β-oxidation of nonanoic acid with the assistance of glycerol because pentanoate units were not found in PHA when P. putida was cultivated in the presence of only nonanoic acid.