Agricultural Pesticide Residues in Farm Ditches of the Lower Fraser Valley,British Columbia,Canada

Transient and permanent farm ditches flowing to the Lower Fraser River tributary fish streams of British Columbia, Canada, were sampled at several locations in 2003–2004 to determine the occurrence and concentration of residues of selected pesticides, their transformation products, and soluble/extractable Cu⁺⁺ ions. Of the 43 compounds analyzed, 28 and 22 pesticides were detected in transient farm ditch water and sediments, respectively. About 34% fewer pesticides, however, were found in both matrices of permanent farm ditches. Average concentrations (μ g L^?1) of those most frequently detected in permanent farm ditch water were atrazine (0.20), α -chlordane (0.06), desethylatrazine (0.13), diazinon (0.55), dieldrin (0.28), endosulfan sulfate (0.16), glyphosate (6), metalaxyl (0.27); and soluble Cu⁺⁺ ions (25). Those most often found in ditch sediments (μ g kg^?1) were aminomethylphosphonic acid (AMPA) (2,300), 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane (DDT) (250), endosulfan sulfate (500), glyphosate (1,225); and extractable Cu⁺⁺ ions (58,000). The risk potential of these pesticide residues to non-target aquatic organisms inhabiting Fraser River tributary fish streams contiguous to permanent farm ditches is evaluated and discussed.     

Performance of a biogas upgrading process based on alkali absorption with regeneration using air pollution control residues

This work analyzes the performance of an innovative biogas upgrading method, Alkali absorption with Regeneration (AwR) that employs industrial residues and allows to permanently store the separated CO₂. This process consists in a first stage in which CO₂ is removed from the biogas by means of chemical absorption with KOH or NaOH solutions followed by a second stage in which the spent absorption solution is contacted with waste incineration Air Pollution Control (APC) residues. The latter reaction leads to the regeneration of the alkali reagent in the solution and to the precipitation of calcium carbonate and hence allows to reuse the regenerated solution in the absorption process and to permanently store the separated CO₂ in solid form. In addition, the final solid product is characterized by an improved environmental behavior compared to the untreated residues. In this paper the results obtained by AwR tests carried out in purposely designed demonstrative units installed in a landfill site are presented and discussed with the aim of verifying the feasibility of this process at pilot-scale and of identifying the conditions that allow to achieve all of the goals targeted by the proposed treatment. Specifically, the CO₂ removal efficiency achieved in the absorption stage, the yield of alkali regeneration and CO₂ uptake resulting for the regeneration stage, as well as the leaching behavior of the solid product are analyzed as a function of the type and concentration of the alkali reagent employed for the absorption reaction.     

Effect of sunlight radiation,rainfall and droplet spectra of sprays on persistence of bacillus thuringiensis deposits after application of dipel® 76af formulation onto conifers

Abstract

The effect of sunlight radiation, rainfall and droplet spectra of sprays on per ‐sistence of a Bacillus thuringiensis subspp. kurstaki (Btk) formulation, DiPel^® 76AF, was examined after application onto spruce [Picea glauca (Moench) Voss] foliage. The investigation consisted of three studies: (i) Study I: a laboratory microcosm study to examine the photostability of DiPel 76AF deposits on foliage after different periods of exposure to two radiation intensities, (ii) Study II: a laboratory microcosm study to examine the rainfastness of foliar deposits after exposure to different amounts of rainfall consisting of two separate droplet spectra, and (iii) Study III: a field microcosm study to investigate the influence of two different droplet spectra of DiPel 76AF sprays on foliar persistence of Btk under natural weathering conditions. In all studies, persistence of Btk was investigated both by bioassay [using spruce budworm (Choristoneura fumiferana Clemens)] and total protein assay.

The findings of Study I indicated that bioactivity of foliar deposits decreased with increasing duration of exposure to radiation, and with increasing radiation intensity. The half‐life (DT₅₀, the exposure period required for 50% of the initial bioactivity to disappear) was 5.1 d for the low intensity, and 3.9 d for the higher intensity. In contrast with the bioassay results, the total protein levels [determined by the bicinchoninic acid (BCA) method] showed no decrease with increasing duration of exposure, or with increasing radiation intensity.

The findings of Study II indicated that bioactivity of foliar deposits decreased with increasing cumulative rainfall. A new term, RF₅₀ [the amount of rain (in mm) required to washoff 50% of the initial deposit], was introduced to understand the relationship between rainfall intensity and reduction in bioactivity. When the same amount of rain was applied in different droplet sizes, the RF₅₀ value was high (5.2 mm) for the small rain droplets, and was low (2.9 mm) for the large rain droplets. Similar to the bioassay results, the total protein concentrations (determined by the BCA method) decreased with increasing amount of rain and with increasing rainfall intensity. The RF₅₀ value (obtained using ng protein /cm²) was 5.4 mm for the small rain droplets, and was 3.4 mm for the large rain droplets.

The field microcosm study indicated that when DiPel 76AF was applied in small droplets (D_v.5 of 65 μm), the persistence of bioactivity was ca 8.0 d, whereas when it was applied in large droplets (D_v.5 of 130 nm) it was ca 11 d. Bioactivity decreased with time after spray, and the DT₅₀ was 1.98 d for the spray of small droplets, and 2.87 d for that of large droplets. Similar to the bioactivity, the total protein concentrations also decreased with time after spray, and the DT₅₀ values for the small and large droplet spectra were 3.45 and 6.07 d respectively.     

Economic assessment of producing a fluting paper using agricultural residues – a case study: Iran,Mazandaran Province

Given limited forest resources and increased paper consumption and imports, establishing fluting paper mills using non-wood raw materials seems more essential than ever. This paper aims to investigate, technically and economically, the possibility of establishing a fluting paper mill (with a capacity of 10,000 tons a year) from agricultural residues in Iran's Mazandaran province. The average annual agricultural residues output (including wheat, barley, rice, corn, oil seeds and cotton) in the province was about 1.3 million tons from 2000 to 2010, showing the potential of the province as an appropriate source for providing raw material from agricultural residues. For economic evaluation of the project, economic indices such as rate of return, pay-back period and production break-even point were measured. The results indicated that establishing a fluting paper mill based on agricultural residues is feasible.     

硫化砷渣一步水热成矿转化固砷与硫回收

含砷工业废水的处理通常会产生大量的含砷废渣,砷渣中的砷元素在各种环境因素的影响下容易重新释放到环境中.因此,本研究以模拟硫化砷渣作为典型含砷废渣,通过在水热条件下添加Al³⁺、SO₄^2-和Na⁺,将硫化砷渣一步直接转化成稳定的砷钠明矾石,同时回收单质硫.结果表明,最优的转化条件为：Al/As物质的量比为3：1,pH为2,水热温度和时间分别为200 ℃和2 h;EDS测试和红外谱图表明,部分砷酸根代替了钠明矾石中的硫酸根离子,从而生成了砷钠明矾石;砷钠明矾石的短期毒性浸出实验表明其在pH值为2~11的浸出液中砷的浸出浓度均小于0.05 mg·L^-1,参照《HJ/T 300-2007固体废物浸出毒性浸出方法醋酸缓冲溶液法》的标准,利用pH=4.93的醋酸缓冲溶液浸渍砷钠明矾石90 d后,砷的浸出浓度依然小于0.05 mg·L^-1,由此说明转化后的砷钠明矾石具有优越的稳定性.最后利用该方法处理河南和福建两地的某砷渣,结果表明,两种实际砷渣中的砷浸出浓度均由原来的大于400 mg·L^-1降低到处理后的小于0.1 mg·L^-1,远低于国家危险废物鉴别标准中的限值（5 mg·L^-1）;另外,该方法在稳定硫化砷渣的同时还可以回收单质硫,为砷渣的处理与资源化利用提供了一种新思路.     

Pesticide residues in products of plant origin in the European Union

The results of a co-ordinated monitoring programme for pesticide residues in the European Union and Norway carried out in 1996 and 1997 are presented. The aim of this programme is to work towards a system, which makes it possible to estimate actual dietary pesticide intake for the population of the European Union. Based on a statistically dérived sampling plan and within the limited number of pesticides/commodities analysed, the most critical pesticides (benomyl group and dithiocarbamates) and commodities (mandarine and lettuce) were identified. In case of detected non-compliances, repeated sampling and, if necessary, enforcement actions are to be taken by national authorities. The programme will be continued in the next years.     

Distribution of Organo-Chlorine Pesticides (DDT and HCH) Between Plant and Soil System

This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels – control, normal dosage (15 kg ha^–1 of 6% HCH and 7.5 kg ha^–1 of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1–3 cm) were already below 6.4 g kg^–1 at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH <0.05 mg kg^–1. However DDT residues in the surface soil layer remained 172 g kg^–1, higher than the national standard: DDT <0.05 mg kg^–1. According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH <0.10 mg kg^–1, DDT <0.20 mg kg^–1).     

碱锰型电解二氧化锰生产环境影响与环保措施

主要以某公司9000t/a碱锰型电解二氧化锰技改项目环境影响评价为例,结合验收监测数据,简要介绍碱锰型电解二氧化锰生产的环境影响与环保措施.该公司采用氧化锰矿和硫铁矿混合硫酸溶液浸出--电解的生产工艺生产碱锰型电解二氧化锰,生产过程中大气污染源主要有锅炉排放的烟气,化合、电解工序产生的硫酸雾;生产废水主要有锅炉除尘废水、漂洗水及炭黑生产废水;废渣主要是压滤锰渣.     

火场残留助燃剂的提取分离及气相色谱/质谱分析

本文总结了从火灾现场提取样品中分离残留助燃剂的常用方法,比较了各种不同分离方法的优缺点及主要适用对象,并介绍了常见助燃剂的典型气相色谱/质谱图特性,为火灾调查识别的研究提供理论指导。     

Preparation of agricultural residue anion exchangers and its nitrate maximum adsorption capacity

Anion exchangers were prepared from different agricultural residues (AR) after reaction with epichlorohydrin and dimethylamine in the presence of pyridine and N,N-dimethylformamide (EDM method). Agricultural residues anion exchangers (AR-AE) produced by the EDM method were inexpensive and showed almost the same NO₃⁻ removal capacities as Amberlite IRA-900. AR-AE produced from AR with higher hemicelluloses, lignin, ash and extractive contents resulted in the lower yields. Sugarcane bagasse with the highest -cellulose contents of 51.2% had the highest yield (225%) and lowest preparation cost. The highest maximum adsorption capacity (Q_max) for nitrate was obtained from rice hull (1.21 mmol g⁻¹) and pine bark natural exchangers (1.06 mmol g⁻¹). No correlation was found between Q_max and -cellulose content in the original AR. AR-AE produced from different AR demonstrated comparable Q_max due to the removal of non-active compounds such as extractives, lignin and hemicelluloses from AR during the preparation process. Similar preparation from pure cellulose and pure alkaline lignin demonstrated that the EDM method could not produce anion exchangers from pure lignin due to its solubilization after the reaction with epichlorohydrin.