不同施药方式硫酰氟熏蒸高大平房仓效果比较研究（网络首发、推荐阅读）

通过比较分析3种不同实仓施药方式硫酰氟熏蒸高大平房仓的穿透力、均匀性和杀虫效果,探索硫酰氟在实仓熏蒸的最佳工艺。结果表明,硫酰氟气体可在2.5 h内自然扩散穿透粮堆,24 h左右达到整仓基本均匀。环流熏蒸可以加速气体均匀,但此次实验环流过程中导致了一定药剂损失。在整仓熏蒸、膜下上行环流和膜下下行环流的3种熏蒸方式中,整仓熏蒸操作最为简便,可用于快速杀灭成虫;膜下上行环流方式,药剂损耗量较大;膜下下行环流,浓度均匀速度快,用药量较整仓小,药剂浓度保持时间长,杀虫效果好。     

硫酰氟气体在不同品种粮堆扩散规律比较研究（网络首发、推荐阅读）

为了解硫酰氟在小麦、稻谷和大豆3种粮堆中的扩散和分布规律,通过6个实仓熏蒸的数据采集,对熏蒸气体在不同粮堆内的扩散速度、均匀性、以及衰减速度等参数进行比较分析。试验结果表明,硫酰氟气体在不同粮种中的扩散速度是大豆>稻谷>小麦;大豆粮堆最快在熏蒸后8 h后,可实现整仓气体均匀;平均气体浓度半衰期分别是大豆>小麦>稻谷;在5.0~12.7 g/m3的熏蒸药剂浓度下实现6个月无虫期的防护效果。     

磷化氢横向环流熏蒸技术在稻谷储藏中的应用

研究了18 m跨度平房仓磷化氢横向环流熏蒸系统设计方案和横向环流熏蒸技术在稻谷储藏中的应用工艺。粮堆内部磷化氢浓度检测结果表明,在磷化氢横向环流时粮堆内各竖直截面和水平层面磷化氢浓度分布均匀,变化趋势一致,没有熏蒸死角。与传统整仓熏蒸相比,采用横向环流熏蒸技术熏蒸粮堆时,磷化氢浓度均匀,熏蒸时间短,能够快速达到杀虫浓度;且覆膜密闭,能延长磷化氢浓度的保持时间,有效降低磷化氢用药量。     

小麦高大平房仓磷化氢横向环流熏蒸技术研究

研究了60 m×21 m平房仓磷化氢横向环流熏蒸系统设计方案和横向环流熏蒸技术在小麦储藏中的应用工艺。密闭小麦粮堆内部磷化氢浓度检测结果表明,在磷化氢横向环流时粮堆内各竖直截面和水平层面磷化氢浓度分布均匀,变化趋势一致,没有熏蒸死角。与传统整仓熏蒸相比,采用横向环流熏蒸技术熏蒸时,磷化氢浓度均匀,熏蒸时间短,能够快速达到杀虫浓度;且覆膜密闭,能延长磷化氢浓度的保持时间,有效降低磷化氢用药量。     

小麦粉堆垛硫酰氟熏蒸及杀虫效果的实仓试验

研究了五面密闭方式密封的小麦粉堆垛以20 g/m3硫酰氟熏蒸工艺,分析了硫酰氟的熏蒸杀虫效果和渗透性。结果表明,硫酰氟熏蒸52 h完全可以杀死常见储粮害虫。试验中,以五面密闭方式薄膜密封的小麦粉堆垛气密性较差,硫酰氟浓度半数衰减时间HLT仅为1.6 h,此种密封方式不适合进行硫酰氟熏蒸。硫酰氟可以渗透到1.5 m深度的小麦粉中,熏蒸52 h可以杀灭小麦粉堆内0.6 m深度的害虫。此外,赤拟谷盗、锈赤扁谷盗、米象、锯谷盗对硫酰氟存在不同的耐受力。     

高大浅圆仓磷化氢混合环流熏蒸杀虫技术研究

对储粮线27.15m、内径25.00m高大浅圆仓磷化氢混合环流熏蒸技术方案和混合环流熏蒸技术在进口大豆储藏中的应用进行了研究。结果表明:通过对环流通风时间的合理控制,可以减少不必要的通风,减少熏蒸药剂用量,增加熏蒸杀虫效力;与常规熏蒸相比,混合环流熏蒸可以在短时间内使熏蒸仓内磷化氢气体浓度分布均匀,并且可以节约熏蒸费用34.6%,具有较好的经济效益。     

浅圆仓磷化氢熏蒸方法的研究

在浅圆仓中进行了磷化氢熏蒸试验研究，对实验仓进行密封处理，经测试实验仓压力由500Pa降至250Pa的时间都在60s以上，用两种磷化氢熏蒸方法，借助环流熏蒸装置进行了熏蒸杀虫试验，磷化铝用药量为1．8－3．4g/m^3，磷化氢仓外发生器分两次施药，试验结果表明：磷化氢浓度保持100m/kg以上时间为15d以上，保持70mg/kg以上时间为17d以上，达到了环流熏蒸的技术要求，粮堆内的储粮害虫均被杀死，取得了 良好的杀虫效果。     

小麦仓多点施药环流硫酰氟浓度变化及对锈赤扁谷盗的致死效果

在高大平房仓采用硫酰氟20 g/m3的剂量对仓温27～30℃、中部上层粮温26～28℃、中部中下层粮温16～19℃、东北部上中下层粮温26～29℃的8 000 t小麦粮堆利用环流系统施药口和粮面多点施药并环流,测定粮面、粮面下1.5和4.5 m深处的硫酰氟浓度,以及对室内培养的锈赤扁谷盗成虫、蛹、幼虫、卵和粮堆中采集的锈赤扁谷盗成虫的致死效果。在环流条件下粮面和粮堆下4.5m深处在施药完毕硫酰氟浓度即达到或接近峰值,粮堆下1.5 m深处浓度较低。熏蒸3至12 h时各部位层点浓度均在20g/m3以上,分布较为均匀。12h时,粮堆中硫酰氟浓度总体较高,此时间后随时间延长浓度下降趋势明显。在24 h时停止环流后,各检测点硫酰氟浓度下降较快,粮温较高的东北角部位检测点浓度下降速率大于粮温较低的粮堆中部的浓度下降速率,粮温高的部位硫酰氟浓度下降比粮温低的部位明显较快。粮堆中硫酰氟浓度在降到2 g/m3(约13 d)以后衰减速率变小,从2 g/m3衰减至0 g/m3的时间约10 d。粮面硫酰氟浓度27～24 g/m3熏蒸3 h可完全杀死锈赤扁谷盗成虫和幼虫,浓度27～22 g/m3经6 h可完全杀死锈赤扁谷盗蛹,27～19 g/m3经24 h可完全杀死锈赤扁谷盗的卵。锈赤扁谷盗各虫态对硫酰氟的耐受力大小为:卵蛹成虫≈幼虫。在粮堆表层和周边粮温26～29℃、内部粮温16～19℃的粮堆中,锈赤扁谷盗4个虫态经硫酰氟浓度24 g/m3上下开始到23 d后的0 g/m3的过程均可全部被杀死。     

浅圆仓磷化氢双侧内环流熏蒸效果研究

采用粮面投药,双侧环流熏蒸的方式测试,研究了浅圆仓不同粮层、粮面空间、出粮口、环流管道中磷化氢浓度的分布变化,分析了磷化氢在粮堆内分布扩散规律。结果表明,浅圆仓粮堆内部磷化氢浓度在第6天才能达到0.6的均匀度,虽然两侧环流管内的磷化氢浓度只需1~2天即达到200 mL/m~3以上,但仓底出粮口的磷化氢浓度到第八天仍未达到200 mL/m~3。因此,只检测环流管和粮面空间的磷化氢浓度不能表明粮堆内各处浓度都达到相同水平,不能保证熏蒸杀虫效果,同时也不能以此来决定环流停止的时间,因为粮堆浓度达到均匀的时间远远滞后于环流管内浓度达到熏蒸要求的时间。这一结果对指导浅圆仓环流熏蒸,保证熏蒸杀虫效果具有重要意义,具有较大实用价值。     

硫酰氟熏杀锈赤扁谷盗实仓应用

使用硫酰氟对高抗性害虫锈赤扁谷盗进行实仓熏蒸杀虫处理,在12 h内可以灭杀成虫及卵,表明硫酰氟在熏蒸过程中具有粮堆穿透性强、杀虫时间短、杀虫效果好等优点。     

大型面粉加工车间硫酰氟整体熏蒸杀虫效果评估

研究了我国华南地区广州岭南穗粮谷物股份有限公司一面粉加工车间B区、C区,长为108 m,宽为25 m,高为35.2 m,总体积为95 040 m3,有效熏蒸体积为53842 m3的空间,采用硫酰氟剂量为40 g/m3、密闭时间为48 h的整体性结构熏蒸。在不补充硫酰氟熏蒸剂的条件下,熏蒸过程浓度随时间变化的规律,建立了熏蒸剂的日损失率Ld和浓度半数衰减时间HLT,分析了各楼层硫酰氟浓度变化规律和熏蒸剂泄漏程度,评估了杀虫效果。熏蒸剂的日损失率符合模型：（e,自然常数;b,衰减常数）,浓度半数衰减时间HLT符合模型：熏蒸剂日损失率的变化随着衰减常数的增大而增大,浓度半数衰减时间HLT的变化随着衰减常数的增大而减小。单次熏蒸时衰减常数为固定值,熏蒸剂日损失率、浓度半数衰减时间HLT为恒定变化。经模型评估,6、7、8楼的日损失率Ld和半数衰减时间介于56.7 %~71.3 %和0.56~0.83 d。3、4楼区域损失率Ld和半数衰减时间介于85.0 %~92.6 %和0.27~0.37 d;除8楼硫酰氟熏蒸剂浓度半数衰减时间HLT超过15 h,其余楼层均未超过15 h。熏蒸后22 d,取样检测发现面粉加工车间设备和管道中均发现赤拟谷盗幼虫活虫。采用硫酰氟进行建筑物结构40 g/m3剂量、密闭时间48 h方式熏蒸,可将车间空间区域害虫各虫态以及管道和设备中成虫杀死,存在于设备和管道内的卵可能存活且发育成新幼虫或蛹。     

硫酰氟气体浓度衰减与仓房气密性相关性研究（网络首发、推荐阅读）

为了解不同气密性仓房硫酰氟熏蒸过程中的浓度衰减规律,选取5个不同气密性储粮仓房,通过熏蒸过程中的硫酰氟浓度监测,分析和比较气体浓度衰减半衰期和仓房气密性的相关性。结果显示,当仓房气密性为143 s时,最长浓度半衰期为8.5 d;当仓房气密性为53、46 s时,最高浓度半衰期分别为2.7、4.6 d。无法检测出气密性的仓房气体浓度半衰期约在2~3 d。硫酰氟气体浓度越高,衰减速度越快,但研究并未发现气体浓度衰减与仓房气密性呈现明显规律。     

高大平房仓不同熏蒸方式浓度分布研究

本研究通过膜下环流熏蒸、氮气气调、氮气与磷化氢混合熏蒸三种熏蒸方式,来分析在高大平方仓中这三种方式施药后,熏蒸气体的空间浓度分布情况。结果表明,覆膜环流熏蒸仓房底部磷化氢浓度在第3 d达到最大,较常规熏蒸快2～4 d。氮气和磷化氢混合熏蒸在环流6 h后各层粮堆内气体分布基本达到均匀,整个熏蒸过程中磷化氢最低浓度与最高浓度的比值范围为0.37～0.67,氮气浓度始终保持在83%～87%之间。混合熏蒸与膜下环流熏蒸相比,可以减少用药量10.8%;同时,解决了氮气气调对气密性要求严苛以及运营成本高的难题,供粮食仓储企业在实际熏蒸杀虫工作中参考。     

A comparison between the impact of sulfuryl fluoride and methyl bromide fumigations on stored-product insect populations in UK flour mills

The impact of sulfuryl fluoride and methyl bromide fumigations upon populations of flour beetles (Tribolium spp.) and of Mediterranean flour moth (Ephestia kuehniella), was evaluated in UK flour mills. Two mills were selected for fumigation with sulfuryl fluoride and two mills for fumigation with methyl bromide. Traps baited with aggregation pheromone lure and an oil-based food attractant were used to monitor populations of rust red flour beetle and confused flour beetle. For the monitoring of Mediterranean flour moth, sticky traps baited with a pheromone lure were used. Traps were placed inside the mill buildings within the areas selected for fumigation. Infestation levels of the insects were monitored for 1–2 weeks prior to fumigation and for a total of 12 weeks post-fumigation. From the calculated percentage reduction in insects trapped per day during the post-fumigation monitoring period it was clear that sulfuryl fluoride fumigations had good efficacy against infestations of Tribolium confusum and E. kuehniella, and compared very favourably with the efficacy of methyl bromide. The absence of T. castaneum in traps pre-fumigation meant that the efficacy of sulfuryl fluoride against this species could not be assessed in this investigation. Indian meal moth, Plodia interpunctella, was also detected in some mills but only post-fumigation.     

Sulfuryl fluoride fumigation of red oak logs eradicates the oak wilt fungus

Preliminary field trials using red oak logs from trees dying from oak wilt disease were successful in eliminating the oak wilt fungus from sapwood after fumigation with sulfuryl fluoride for 72 h under tarp. These results support earlier laboratory data on the fungitoxicity of sulfuryl fluoride as a potential replacement for methyl bromide treatment of exported red oak veneer logs. However, not all other microorganisms were completely eradicated from oak sapwood at the treatment levels used in this trial.

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Effects of weather conditions on sulfuryl fluoride and methyl bromide leakage during structural fumigation in a flour mill

A validated Computational Fluid Dynamics (CFD) model of structural fumigation was used to perform 54 fumigation simulations (half with sulfuryl fluoride, SF, and half with methyl bromide, MB) using recorded hourly average weather data for 4 July and 1 September at Indianapolis International Airport for the years 1996-2006. These weather data were used as the simulation boundary conditions. Although the fumigations were simulated for the same time periods, the results indicated substantial variations in the fumigant leakage rates. The 11-year averages of wind speeds on 4 July and 1 September were 3.8 and 2.4 m/s, respectively, resulting in half-loss time (HLT) differences between the fumigations on the two days. On average, the HLT was 4 h lower on 4 July than on 1 September. When comparing the results between individual fumigations, substantial differences in the fumigant leakage were observed, regardless of the fumigant type and whether or not the fumigations were performed at the same time period. This implied that using past fumigation data as the primary means for evaluating the structural sealing quality of a current fumigation is not adequate. Predictions of fumigant leakage rate and fumigation performance should incorporate quantifiable sealing effectiveness and weather information for the planned fumigation period. Comparisons between SF and MB fumigations indicated that under exactly the same weather conditions and fumigation practices the leakage characteristics of SF and MB do not differ. In practical situations where the dosage requirements for SF and MB are typically not the same, however, the leakage rates of SF and MB fumigations could be different due to the buoyancy effect. Nevertheless, the magnitude of the difference may or may not be significant depending on other factors such as sealing quality, wind speed and direction, and ambient temperature. The effects of these factors should be further quantified.     

高大平房仓磷化氢熏蒸及散气作业过程安全防护距离研究

近年来由于熏蒸散气而产生的仓内安全事故引起了行业乃至社会各方的高度关注,但熏蒸散气阶段的作业安全研究较少,相关隐患尚未被深入研究以及重视。在实仓实验中,对高大平房仓磷化氢熏蒸和散气过程仓房内外环境空气中磷化氢浓度进行现场检测,探讨熏蒸、散气作业过程的有效安全防护距离以及防护措施,研究结果为防范熏蒸作业安全事故、减少或避免发生人身伤害和经济损失提供依据。研究结果表明,安全防护距离与仓内(粮堆内)磷化氢气体浓度大小有关,不能完全以固定的安全防护距离作为判定是否安全的依据,接近熏蒸散气区域前必须检测磷化氢浓度。