Effect of thermal pretreatment on the physical and chemical properties of municipal biomass waste

The effects of thermal pretreatment on the physical and chemical properties of three typical municipal biomass wastes (MBWs), kitchen waste (KW), vegetable/fruit residue (VFR), and waste activated sludge (WAS) were investigated. The results show that thermal pretreatment at 175 °C/60 min significantly decreases viscosity, improves the MBW dewatering performance, as well as increases soluble chemical oxygen demand, soluble sugar, soluble protein, and especially organic compounds with molecular weights >10 kDa. For KW, VFR and WAS, 59.7%, 58.5% and 25.2% of the organic compounds can be separated in the liquid phase after thermal treatment. WAS achieves a 34.8% methane potential increase and a doubled methane production rate after thermal pretreatment. In contrast, KW and VFR show 7.9% and 11.7% methane decrease because of melanoidin production.     

石化生产装置挥发性有机化合物的泄漏检测

阐述了石化生产装置挥发性有机化合物泄漏检测工作的主要环节,介绍了主要的泄漏检测对象和检测部位,以及对检测人员的要求,给出了从检测仪器的检定和核查、响应因子、检测方法、背景干扰、数据记录等方面确保检测质量的方法.     

发酵法溶剂生产工艺的流程模拟与参数优化

对发酵法溶剂生产的精馏工艺流程采用化工流程模拟软件PROII进行了模拟。将复杂的流程分为醪塔子系统、丁塔子系统和乙丙子系统,采用液体活度系数模型NRTL和非理想物系的CHEMDIST算法,利用Distillation模块、Simple HX模块、Flash模块和Mixer模块分别进行模拟。流程模拟结果与实际运行结果吻合良好。在此基础上,以减少塔釜废液中溶剂含量为优化目标,利用中心组合设计(CCD)与PROII流程模拟相结合,对醪塔的部分操作参数进行了优化。优化后可使废液中溶媒含量减少至0.008%,远低于原工艺数据。     

废聚苯乙烯塑料共焦化过程的生命周期评价

随着我国废塑料资源化利用技术的不断发展,其资源化过程中的环境问题也日益显现。以生命周期评价为研究方法,对废聚苯乙烯共焦化过程的环境影响进行评价。研究结果表明:废聚苯乙烯共焦化过程对酸化、烟尘和粉尘、全球变暖3类环境问题的影响较大,分别占了总影响的34.0%、27.5%和23.3%。从共焦化过程的3个阶段来看,入炉炼焦阶段的环境影响最大,其次是混合颗粒制备阶段和PS颗粒制备阶段,对炼焦阶段环境污染的控制是废塑料共焦化技术发展的关键。     

酸性橙Ⅱ废水催化铁内电解法脱色研究

对催化铁内电解法处理酸性橙Ⅱ废水进行了研究,考察了进水pH、搅拌速率、进水酸性橙Ⅱ浓度、铁铜比、支持电解质浓度、进水温度等因素对脱色效果的影响。在最优反应条件下,酸性橙Ⅱ的去除率大于98％,COD的去除率大于76％。催化铁内电解法对酸性橙Ⅱ的去除非常有效,且有较宽的pH适应范围。     

红壤中交换性铝调控条件的研究Ⅱ.有机质和CaCO_3对交换性铝的影响

研究了有机质和ＣａＣＯ３。对发育于花岗岩和第四纪红色粘土母质上的红壤的交换性铝的影响。结果表明,在用Ｈ２Ｏ２去除土壤中的有机质后,交换性铝的含量随有机质的降低而降低,但降低的速度不均匀,由慢到快似有一个“突跃”。而在向土壤中添加有机质的研究结果则表明,交换性铝的含量随有机质的增加而增加;在增加的过程中由快到慢,达到极点后,有机质含量再增加,交换性铝反而下降。在相同的土壤环境中,由于作物品种不同,施用等量的ＣａＣＯ３（或石灰粉）对土壤交换性铝的含量及作物产量的影响不同,而且差异显著。     

水中痕量氰化物的反相流动注射-分光光度测定

采用巴比土酸－－吡啶（ＢＡ－Ｐ）反相流动注射分光光度法测定了水中痕量易释放氰化物和包括易释放氰化物和络合氰化物在内的无机总氰化物。将ＢＡ－Ｐ溶液注入到ＰＨ６．２ＮａＨ２ＰＯ４－ＮａＯＨ缓谁氰胺－Ｔ溶液和预蒸馏水样的混合流中,在λｍａｘ５８０ｎｍ处对反应形成的晓紫色聚亚早基染料进行分光光度检测生为０．０２～０．９０ｍｇ／Ｌ,ＣＮ＾－。检测限为０．００３ｍｇ／Ｌ,测定频率为３０次／ｈ,本法灵敏度高,选     

对锦州石化公司催化裂化装置火灾爆炸危险性的评价

根据美国道化学公司的火灾爆炸危险度评价原理,采用单元危险快速排序法,对锦州石化公司的催化裂化装置的火灾爆炸危险性进行综合评价。     

社会主义市场经济条件下企业环境保护形势分析及改革建议

在社会主义市场经济条件下如何做好企业的环境保护工作是目前企业环保部门需要探讨的重要问题,通过阐述市场经济对企业环境保护产生的积极影响,分析了当前企业环保的基本状况和存在的问题,并提出了目前企业环保改革的思路。     

Tracking Chinese newspaper coverage of elephant ivory through topic modeling

Mass media worldwide has contributed to increasing awareness of the illegal wildlife trade and its significant impact on wildlife conservation. We used mass media coverage as a proxy for macro-level public opinion to analyze the media framing of elephant ivory in 6394 Chinese newspaper articles published from 2000 to 2021 and thus determine the effects of wildlife policies on public opinion. We focused on 2 events: the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) approval of China as a trading partner in the purchase and import of ivory stockpiles from Africa in July 2008 and the Chinese government's announcement of a domestic ivory ban in December 2016. Using latent Dirichlet allocation topic modeling, we identified 8 topics about elephant ivory and grouped them into 3 frames: ivory arts and culture, ivory crimes, and elephant conservation. Over the last 2 decades, topics related to ivory crimes remained the most prevalent in news articles. Topics about ivory arts and culture showed a significant shift in media salience before and after the 2 events (from 0.44 to 0.19 and from 0.08 to 0.15, respectively, p < 0.05), whereas the other 2 frames did not change significantly. Contrary to popular belief, our results indicated that Chinese macro-level public opinion on ivory had become more negative following the CITES approval of ivory importation and less negative after the ivory ban announcement, at least for certain periods. The relationship between mass media, public opinion, and wildlife trade policies is complex and requires further examination of the sociopolitical dynamics that influence media narratives. Our results showed the value of topic modeling in monitoring and assessing media representations of wildlife issues in the era of big data. Conservationists should remain vigilant of mass media coverage and collaborate with media practitioners to produce comprehensive narratives on wildlife issues if resources permit.