河涌淤泥处理技术分析研究

以佛山市顺德区河涌清淤工程为例,在桂畔海河水系和伦教大涌水系分别采集86个淤泥样品,监测其重金属含量是否超标,结果表明:绝大多数样本底泥的总氮、总磷的含量在0.2%以下,总钾的含量在2.5%以下,取样底泥有机质含量为4.4～216.3g/kg,比重在1.6～2.1之间。针对于不同的底泥含量,利用机械脱水处理与土工管袋脱水处理分别进行清淤处理。     

离心机污泥脱水系统技术改造

根据污水厂离心机污泥脱水系统的实际运行情况,结合生产中大量的试验结果,分析影响离心机污泥脱水效果的主要因素(液环层厚度、速差、絮凝剂投加位置),进行提高离心机污泥脱水效果的技术改造,总结使离心机稳定运行的管理与维护的经验。     

高效沉淀池实验室静态加药研究

本文通过静态加药试验对高效沉淀池的投药系统(混凝剂和絮凝剂的投加)进行了详细研究。小试研究表明,混凝剂PAC投加量为130～150 mg/L,絮凝剂PAM投加量为0.8～1.0 mg/L时,能够明显降低上清液的总磷含量,可以保证TP在0.5 mg/L以下,同时出水浊度较低。生产性试验研究表明,当PAC投加量在125 mg/L左右,PAM投加量在0.64 mg/L左右时,出水处理效果最好。     

新工艺提升超稠油脱水质量的实验研究及其应用

为提升超稠油脱水质量,提出并设计一套3段式热化学沉降脱水工艺,并在室内开展新工艺脱水模拟实验研究。实验介质来源为某超稠油脱水站进站原油,实验参数依据该站生产现状进行拟定。实验结果表明:原油在90℃下自然沉降40 h脱水率为39.3%,在90℃下按150 mg/L加药沉降30 h脱水率为62.81%,在95℃下按400 mg/L加药沉降70 h脱水率为89.82%。新工艺现场应用期间,处理后的原油含水率较旧工艺降低2%以上,日均药剂投加成本减少3.8万元。     

污水处理厂污泥加钙干化工艺应用研究

文章以邢台市某县污水处理厂污泥加钙干化处理项目的工程应用实践为基础,通过运行及检测数据,初步研究了脱水污泥含水率、干化污泥熟化时间对污泥干化处理效果的影响,并分析了干化污泥杀菌效果及资源化利用的方式。结果表明,脱水污泥含水率78%～86%、石灰投加比20%～30%、熟化时间3～5天,干化后污泥满足垃圾填埋场覆盖土、路基土的标准。     

内循环生物流化床载体挂膜特性的研究

考察了5种粒子的挂膜特性,研究固含率对内循环生物流化床流体性能的影响、水力停留时间和接种污泥浓度对载体挂膜的影响,确定最佳生物载体、最佳固含率及反应器快速挂膜启动的最佳操作条件.试验结果表明,A公司生产的生物陶粒为最佳生物载体,最佳固含率为5%,快速挂膜启动的最佳条件为水力停留时间1 h,污泥浓度为1 g/L.     

污水处理厂改良A2O工艺脱氮条件优化研究——以石家庄市某污水处理厂为例

为了适应日趋严格的污水排放标准对污水处理厂脱氮性能的新要求,在强化改良A2 O工艺脱氮效果的同时节省药剂投加成本,通过批次实验确定最佳污泥浓度范围和乙酸钠投加量,并进行为期35 d运行实践.实验结果表明:当乙酸钠投加量一定时,随着生物池内污泥浓度的增加,NO3--N及TN的浓度逐渐下降,脱氮性能提高,当污泥质量浓度高于...     

复合絮凝剂与活性砂滤池协同深度处理印染废水研究及应用

采用复合絮凝剂和活性砂滤池协同处理印染废水,研究了复合絮凝剂对浊度、COD(化学需氧量)和TP(总磷)的去除性能,在实际运行系统中考察了复合絮凝剂和活性砂滤池协同处理后的出水水质情况。结果表明:活性砂滤池在平均处理水量为3 500 m3/h情况下,当复合絮凝剂投加量为ρ(PAC)=50 mg/L,ρ(FeCl3)=10.0 mg/L,ρ(APAM)=1.0 mg/L时,出水水质指标浊度、COD和TP的平均去除率分别达到了56.6%,45.3%,59.4%,出水水质各项指标均达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准。     

异菌脲在梨和土壤中残留量的测定方法

建立了异菌脲在梨和土壤中气相色谱分析方法。梨、土壤样品用乙腈提取,Florisil固相萃取小柱净化,淋出液浓缩后用正己烷定容,气相色谱仪电子捕获器检测。试验结果表明,异菌脲的含量与峰面积之间呈线性关系,异菌脲的最小检出量为0.005ng。对于梨样本,异菌脲最低检测量为0.01mg/kg,添加平均回收率为94%～107%,变异系数为3.2%～6.5%;对于土壤样本,异菌脲最低检测量为0.01mg/kg,添加平均回收率为98%～110%,变异系数为4.0%～10.5%。结果表明该残留分析方法的灵敏度、准确度、精密度等均符合农药残留检测的要求。     

含油污泥化学清洗处理及工艺参数选择

含油污泥是石化行业的主要污染物,在固体废弃物中占比很大,不经处理排放会危害周边环境,因此,对含油污泥无害化处理非常重要。清洗法是油泥处理成本较低的方法,研究采用化学清洗法,优化影响油泥清洗效率的参数。确定清洗温度、固液比取值范围,考察单独变量作用对含油污泥残油率的影响。单因素变量对含油污泥残油浓度有显著影响。化学法处理含油污泥最佳工艺条件为化学药剂浓度0.84 g/L,测定值与预测值相对误差为2.78%。     

女式包袋的原型研究设想

迄今为止,女式包袋的结构制作尚无统一的"原型"作为设计依据。为简化女式包袋的结构制图过程,本文提出"包袋原型制图法"的研究设想,为以后研究制作其它类型的女式包袋提供了方法上的依据和实践上的铺垫。     

UASB处理甲苯氧化废水试验研究

采用UASB反应器处理甲苯氧化废水,接种颗粒污泥,当进水ρ(COD)为6 000 mg/L,运行负荷(以COD计)为6 kg/(m3.d)时,COD去除率达到84%左右,出水ρ(COD)为853~985mg/L,其适宜的运行条件为进水pH值为5~6,ρ(COD)为5 000~6 000 mg/L,水力停留时间为24 h,容积负荷(以COD计)为5~6 kg/(m3.d)。通过对污泥的培养驯化和合理的运行方式,甲苯对厌氧消化的抑制影响可以得到很好的控制。     

UASB反应器处理青霉素废水启动特性的研究

采用上流式厌氧污泥床(UASB)反应器,以高浓度青霉素废水为处理对象,研究了中温条件下UASB反应器的启动、厌氧颗粒污泥特性和废水处理效果。结果表明:接种消化污泥,水温33～35℃的条件下,采用逐步提高青霉素废水进水浓度的方式,运行80d后,可实现UASB反应器的启动。进水ρ(COD)达到4 000mg/L左右,COD去除率稳定在84%以上,容积负荷为3.36kg/(m3.d)(以COD计),产气量为5.9L/d;反应器内污泥实现颗粒化,粒径约为2mm。     

分子筛改性LDPE活性包装膜在草莓保鲜中的应用研究

新鲜草莓易腐烂,贮藏保鲜较为困难。为了延长草莓的贮藏期,本研究采用硅铝分子筛对低密度聚乙烯（LDPE）进行改性,制备了具有高透气性的改性LDPE包装膜。以LDPE膜包装的草莓和裸放草莓为实验对照组,在（5±1）℃的低温和加乙烯吸附药包的条件下,分别研究了LDPE和改性LDPE包装膜对草莓储存期的影响。实验中分别测定了草莓果肉中可溶性固形物含量、维生素C含量以及草莓的失重率、硬度、烂果率等指标。实验结果表明：对照组中裸放和用LDPE膜包装的草莓储藏期分别为3天和7天,而分子筛改性LDPE膜加乙烯吸附剂包装能够将草莓的贮藏期延长至11天,草莓的好果率、硬度和可溶性固形物含量等均明显高于对照组。该分子筛改性LDPE膜加乙烯吸附剂的综合包装方案能够有效延长草莓的低温贮藏保鲜时间。     

What drives smallholder farmers’ willingness to pay for a new farm technology? Evidence from an experimental auction in Kenya

We use an incentive compatible experimental auction to measure demand for a new agricultural technology, a triple layered hermetic storage bag. When used properly, the bag creates an airtight seal that reduces storage loss from insect pests and neutralizes aflatoxin contamination in stored grain. We find that demand for this new technology is highly elastic (4.3) and that the wholesaler could increase profit by lowering the price. We also find that farmers’ valuation for the bag is not significantly different based on the medium through which information about it is communicated to them, either text, audio or video messages. This suggests that practitioners should use the cheapest option for disseminating information, which is text messaging in this context. In addition, we find that farmers who have prior awareness of the bag are willing to pay 20% more on average than those previously unaware of it. In total, the highly elastic demand for the improved bags, along with the fact that prior awareness of the bag leads to higher willingness to pay, suggests that a one-time price subsidy for the new technology could spur demand and increase future adoption.     

从药厂废水中回收粗蛋白的研究

通过一系列实验,选出一种高效、无毒的絮凝剂——氯化铁,并确定了最适宜的回收工艺条件：原料液等电点的ｐＨ值为３５,它与１ ｍ ｏｌ／Ｌ氯化铁溶液的适宜体积比约为（８０～１３０）∶１。同时讨论了温度对絮凝效果的影响。通过与自然沉降法进行比较,说明本方法对粗蛋白的回收效果显著。     

以GC-MS法测定复合食品包装袋中2,4-二氨基甲苯残留量

复合食品包装袋用胶黏剂常以甲苯二异氰酸酯作为固化剂,它易水解成具有致癌性的2,4-二氨基甲苯并迁移到食品中,对食用者造成危害。本文用沸水浸取复合食品包装袋样品中的2,4-二氨基甲苯,再用二氯甲烷进行液液萃取,经七氟丁酸酐酰化后将衍生物进行GC-MS分析,并采用在空白样品中添加不同浓度的2,4-二氨基甲苯作为标准溶液,绘制标准工作曲线（线性方程）。通过此线性方程,由GC-MS方法测定的特征碎片离子峰面积得到2,4-二氨基甲苯浓度。该方法对复合食品包装袋中的2,4-二氨基甲苯的检出限为0.2μg/L,检测浓度范围为1～100μg/L,样品加标回收率为90%～110%,完全满足检测复合食品包装袋中2,4-二氨基甲苯的需要。     

One more tool for the food aid toolbox? Experimental evidence on food aid packaging

International food assistance reaches more than 90 million people per year, much of it through in-kind programs that distribute food. Several key aspects of in-kind programs—what food is shipped, when and from where it is sourced—have been changed to improve program effectiveness and efficiency, becoming helpful tools in the modernized in-kind food assistance toolbox. Packaging—in what food is shipped—remains an unstudied and underused tool despite more than 50 million bags per year passing through in-kind supply chains, affecting program effectiveness and efficiency. We conduct an experiment with 46 shipments using different packaging materials and sizes to measure the effect of packaging on shipment quality, cost, and timeliness. Analyzing the data with randomization tests, we find that, relative to the current materials, new materials maintain shipment quality and cost while improving timeliness and in some cases may reduce cost. One promising material that balances cost and effectiveness is a bag with a biopesticide applied, designed to prevent insects from reproducing. We also find that, relative to the current size, larger bags may improve costs at least in the domestic portion of the supply chain. Donors and their partners should consider packaging as one more tool in the modernized food assistance toolbox. As the toolbox continues to fill, the coming opportunity and challenge to identify situations where the various tools work in complementary ways.     

大型电站锅炉电袋复合除尘的技术和经济性分析

电袋复合除尘器集合了静电除尘和袋式除尘的优点,能够长期、高效、稳定地运行;对电袋复合除尘器、静电除尘器及袋式除尘器的应用进行了比较分析,并提出了电袋复合除尘技术具有广阔应用前景的观点。     

COVID-19 and changes in content usage behavior: The case of South Korea

This study examines changes in content usage time due to the COVID-19 pandemic in South Korea using Korean Media Panel data for the period 2011–2020 and explores the reasons for these changes. This study focuses on four principal contents: television programs, movies/videos/user-created content, traditional telecommunication services, and chatting/messenger/social network services. The empirical results indicate an increase in usage time for the four principal contents, as well as total content usage time because of the pandemic. The results also show that average Korean people stayed longer at home after the onset of the pandemic, leading to an increase in the time spent on all the principal contents, except for traditional telecommunication services, as well as an increase in total content usage time. Furthermore, this study suggests that whereas the effect of the pandemic on television program viewing time was mainly attributable to changes in time spent at home because of the pandemic, the effect on other contents was mainly caused by non-location-related factors. This study predicts changes in content usage time after the end of the pandemic and provides strategic suggestions.