Production of vermifertilizer from guar gum industrial wastes by using composting earthworm <Emphasis Type="Italic">Perionyx sansibaricus</Emphasis> (Perrier)

Efforts have been made to convert the guar gum industrial waste into a value-added product, by employing a new earthworm species for vermicomposting e.g. Perionyx sansibaricus (Perrier) (Megascolecidae), under laboratory conditions. Industrial lignocellulosic waste was amended with other organic supplements (saw dust and cow dung); and three types of vermibeds were prepared: guar gum industrial waste + cow dung + saw dust in 40: 30: 30 ratio (T₁), guar gum industrial waste + cow dung + saw dust in 60: 20: 20 ratio (T_2,), and guar gum industrial waste + cow dung + saw dust in 75: 15: 10 ratio (T₃). As compared to initial concentrations, vermicomposts exhibited a decrease in organic C content (5.0–11.3%) and C:N ratio (11.1–24.4%) and an increase in total N (18.4–22.8%), available P (39.7–92.4%), and exchangeable K (9.4–19.7%) contents, after 150 days of vermicomposting. A vermicomposting coefficient (VC) was used to compare of vermicomposting with the experimental control (composting). P. sansibaricus exhibited maximum value of mean individual live weight (742.8 ± 21.1 mg), biomass gain (442.94 ± 21.8 mg), growth rate (2.95 ± 0.15 mg day⁻¹), cocoon numbers (96.0 ± 5.1) and reproduction rate (cocoons worm⁻¹ day⁻¹) (0.034 ± 0.001) in T₂ treatment. In T₃ maximum mortality (30.0 ± 4.01 %) in earthworm population was observed. Overall, T₂ vermibed appeared as an ideal substrate to manage guar gum industrial waste effectively. Vermicomposting can be proposed as a low-input basis technology to convert industrial waste into value-added biofertilizer.     

Comparison of PM2.5 and PM10 in A Suburban Area in Korea During April, 2003

Airborne particulate matter (PM) concentrations were measured in Iksan, a suburban area in South Korea during April, 2003. PM_2.5 (particles with an aerodynamic diameter less than 2.5 μm) and PM₁₀ (particles with an aerodynamic diameter less than 10 μm) samples were collected, and the chemical characteristics of particles were examined for diurnal patterns, yellow dust/rainfall influences, and scavenging effects. Average concentrations of PM_2.5 and PM₁₀ mass measured were 37.3 ± 16.2 μg m⁻³ and 60.8 ± 29.5 μg m⁻³, respectively. The sum of ionic chemical species concentrations for PM_2.5 and PM₁₀ was 16.9 ± 7.3 and 23.1 ± 10.1 μg/m³, respectively. A significant reduction in PM mass concentrations during rainfall days was observed for coarse mode (PM_{2.5 − 10}) particles, but less reduction was found for fine (PM_2.5) mass concentration. SO₄ ²⁻, NH₄ ⁺, and K⁺ predominated in fine particulate mode, NO₃ ⁻ and Cl⁻ predominated in fine particle mode and coarse particle mode, but Na⁺, Mg²⁺, and Ca²⁺ mostly existed in coarse mode. The high concentration of ammonium due to local emissions and long-range transport neutralized sulfate and nitrate to ammonium sulfate and ammonium nitrate, which were major forms of airborne PM in Iksan. Average mass concentrations of PM₁₀ in daytime and at night were 57.6 and 70.0 μg m⁻³, and those of PM_2.5 were 35.4 and 42.5 μg m⁻³, respectively. NO₃ ⁻ and Cl⁻ in both PM_2.5 and PM₁₀ were about double at night than in the daytime, while the rest of the chemical species were equal or a little higher at night than in the daytime. The results suggest the formation of ammonium nitrate and chloride when high ammonia concentration and low air temperature are allowed. Backward air trajectory analyses showed that air masses arriving at the site during yellow dust period were transported from arid Chinese regions, which resulted in high concentrations of airborne PM mass concentrations. In the meantime, air mass trajectories during a rainfall period were mostly from the Pacific Ocean or the East China Sea, along with a relatively low PM concentration.     

最近130 ka的全球西风、冬季风、粉尘通量数据整合与集成

末次间冰期的气候研究对揭示地球气候变迁和预测未来气候至关重要,其环境条件与全新世相似,有助于作为预测未来气候变化的关键参考。西风环流和冬季风作为全球气候系统的关键组成部分,对地球系统的能量交换和粉尘、碳循环有显著影响,而粉尘循环则直接影响人体健康和全球生态系统的稳定。因此,有必要对西风、冬季风、粉尘循环过程进行统筹考虑以充分理解三者与全球气候变化之间的相互作用机理。综合集成并初步分析130 ka以来全球西风、冬季风和粉尘通量的长期变化特征及其对古气候变化的指示意义,结果表明：在北半球,亚欧大陆的西风变化在间冰期西风环流较强,气候较为湿润,而在冰期则相对较弱。北美大陆的西风变化则表现为冰期环流南迁,间冰期北撤,且西风控制下气候较为湿润。南半球的新西兰地区冰期西风较强,且西风带在冰期向北移动,导致较好的水汽条件。东亚冬季风的变化显示冰期风力强于间冰期,尤其在末次冰期（MIS2）达到最强。全球粉尘通量的变化则显示冰期粉尘量高于间冰期,其中北半球粉尘通量主要受控于冬季风强度,MIS4的粉尘量略高于MIS2,MIS1的粉尘量又高于MIS5;南半球粉尘通量总体与北半球类似,但MIS2显著高于MIS4,可能与粉尘源区的干湿变化有关。数据集存储为.xlsx格式,由4个数据文件组成,数据量为1.29 MB（压缩为1个文件）。该数据集旨在为理解当前气候变化归因、预测未来趋势和制定应对策略提供关键数据,助力气候模式模拟的科学发展。未来研究仍需深化对代用指标的物理意义解释,加强西风与冬季风的定量重建工作,增加研究空白区的相关数据。     

旋流板塔双碱法在熔化炉废气脱硫除尘中的应用

采用旋流板塔双碱法处理熔化炉废气 ,二氧化硫平均浓度从 12 5 9 5 5mg Nm3降至 43 9 90mg Nm3,烟尘从63 9 97mg Nm3降至 5 1 96mg Nm3,二氧化硫平均去降率 65 1% ,烟尘平均去除率 91 9%     

袋式除尘器在电炉烟尘治理上的应用

结合工程实例，介绍了“低阻、中温、大流量”除尘系统工艺在电炉上的应用，以及除尘系统各组成部分的性能特点和所采用的关键技术，阐述了关键技术的理论依据、设计原则和设计参数。     

某炼铁厂炉顶除尘系统的风量调整与仿真分析研究

某炼铁厂炉顶除尘设备运行中各吸尘点风量失衡,造成除尘系统不能发挥应有的作用.通过对除尘系统各吸尘点风量及阻力、除尘器性能、风机性能等参数进行测试,并利用Fluent对系统内流场分布进行仿真与评估、对系统阻力平衡点进行分析,重新调整各个调节阀的开度,优化系统各吸尘点风量分布.调整后,不仅使系统达到现有条件下最佳除尘效果,而且找出了除尘系统设计及运行缺陷,提出了可行的解决方案.     

医院空调回风口滤网积尘中抗生素抗性基因污染的比较

为了解医院环境中抗生素抗性基因(ARGs)的污染情况与分布特征,于2018年11月至2021年4月期间分批次采集了武汉市两家医院部分病房空调回风口滤网积尘样本127份,对其进行β-内酰胺类ARGs (mecA、bla_TEM、bla_CTX-M、bla_SHV)和碳青霉烯类ARGs (bla_KPC、bla_NDM-1、bla_IMP、bla_VIM、bla_OXA-51)及一类整合酶基因intI 1的定性与定量检测与评价.结果表明,医院不同科室及ICU空调滤网积尘中可检出以上9种β-内酰胺类,碳青霉烯类ARGs及intI 1,平均检出率分别为55.12%、37.64%和81.89%.ICU的β-内酰胺类与碳青霉烯ARGs的平均检出率显著高于外科与内科(P<0.05);4种β-内酰胺类ARGs中的bla_TEM、mecA检出率及其相对丰度在内科、外科最高(P<0.05);ICU的bla_SHV检出率及其相对丰度高于内科、外科(P<0.05).5种碳青霉烯类ARGs中的bla_NDM-1检出率及其相对丰度在内科、外科显著高于bla_KPC、bla_IMP(P<0.05).intI 1与9种ARGs的相对丰度均呈显著正相关(P<0.05).研究结果表明,两家医院不同科室病房空调滤网积尘中存在β-内酰胺类和碳青霉烯类ARGs以及一类整合酶基因intI 1的污染,内科、外科、ICU均以bla_TEM、mecA、bla_NDM-1为主,由此可认为医院不同科室空气及相关环境中可能存在与此等ARGs相关的耐甲氧西林金黄色葡萄球菌、产ESBLs肠杆菌科细菌、耐碳青霉烯大肠埃希菌与鲍曼不动杆菌等耐药菌的现时与既往污染,并且存在ARGs水平转移的风险;ICU空调滤网积尘中β-内酰胺类与碳青霉烯ARGs的污染较内科、外科严重,其中bla_SHV污染高于内科、外科,由此表明,ICU是ARGs及相关耐药菌污染的高风险科室.     

滤筒脉喷清灰过程中尘饼剥离对喷吹性能的影响

以滤筒除尘器的脉冲喷吹清灰为研究对象,考察脉冲清灰过程中尘饼剥离对喷吹性能的影响,运用CFD软件构建脉冲喷吹的数值模型,对清灰气流流场进行分析。结果表明：脉冲喷吹在滤筒中下部区域形成的压力显著高于顶部区域;与尘饼固定情形相比,尘饼剥离情形下脉冲喷吹强度更小、喷吹均匀性更差、穿过滤筒的气流更大;随着初始总过滤阻力ΔP_t（<1000 Pa时）的增加,喷吹强度和喷吹均匀性提高,穿过滤筒的气流量降低,ΔP_t>1000 Pa时则达到稳定。所得结论可为脉冲喷吹清灰除尘器的研究与设计提供理论参考。     

昆钢滇中铁合金厂6000KVA电炉烟尘治理

昆钢滇中铁合金厂6000KVA电炉采用干法袋式除尘工艺处理烟气，通过改变滤袋材质、控制在线过滤风速、延长清灰静止沉降时间等措施，使整套装置除尘效率达到99．5％。