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81.
为提高剩余污泥的破解效果并降低能耗,采用FS(fluid shear,流体剪切)、UC(ultrasonic cavitation,超声空化)、FS和UC联合工艺(FS-UC,UC-FS)破解剩余污泥,并应用单因素试验结合响应面法对联合工艺进行优化.结果表明:FS对剩余污泥破解效果一般,只在开始阶段具有较好效果,随作用时间延长,破解效果未有显著提高甚至下降.UC对剩余污泥破解效果明显,随作用时间延长,破解效果显著提升,但能耗也随之增大,EDR(energy disintegration ratio,效能比)明显下降.相同作用时间下,UC破解效果优于FS破解效果,UC破解剩余污泥的DDCOD(degree of disintegration,破解率)与EDR均明显高于FS方法.单因素试验得出的较优FS作用时间范围为2~8 min,较优UC作用时间范围为5~15 min.响应面法试验结果显示,联合工艺的剩余污泥破解效果和能量利用率均优于单一方法,联合工艺中FS-UC工艺的破解效果优于UC-FS工艺.FS-UC工艺的最佳参数:FS处理5.6 min再UC处理15.0 min,该条件下剩余污泥实际DDCOD为50.8%,EDR为26.8%.UC-FS工艺的最佳参数:先UC作用15.0 min再FS作用7.8 min,该条件下剩余污泥实际DDCOD为36.5%,EDR为17.1%.研究显示,以DDCOD和EDR为指标,4种工艺的高效性顺序为FS-UC > UC-FS > UC > FS,其中FS-UC工艺具有能耗低、破解效率高的特点,是4种工艺中剩余污泥破解效果最好的一种工艺. 相似文献
82.
Liyan Feng Jun Zhai Lei Chen Wuqiang Long Jiangping Tian Bin Tang 《Mitigation and Adaptation Strategies for Global Change》2017,22(6):839-861
This paper employs a review of the technical literature to estimate the potential decrease in greenhouse gas (GHG) emissions that could be achieved by increasing the application of gas engines in China in three sectors: urban public transport vehicle; shipping; and thermal power plants. China’s gas engine development strategies and three types of gas resource are discussed in the study, which indicates that gas engines could decrease GHG emissions by 520 megatonnes (Mt) of carbon dioxide equivalent (CO2e) by 2020. This would account for 9.7 % of the government’s target for decreasing GHG emissions and is dominated by methane recovery from the use of coal mine gas (CMG) and landfill gas (LFG) for power generation. In the public urban transport vehicle and shipping sectors the low price of natural gas and the increasing demand for the control of harmful emissions could spur the rapid uptake of gas engine vehicles. However, the development of CMG- and LFG-fuelled power plants has been limited by the unwillingness of local enterprises to invest in high-performance gas engine generators and the associated infrastructure. Therefore, further compulsory policies that promote CMG use and LFG recovery should be implemented. Moreover, strict regulations on limiting methane leakage during the production and distribution of gas fuels are urgently needed in China to prevent leakage causing GHG emissions and largely negating the climate benefits of fuel substitution. Strategies for increasing the application of gas engines, promoting gas resources and recovering methane in China are instrumental in global GHG mitigation strategies. 相似文献
83.
利用遂宁市2017年1月份4个国控环境空气自动监测数据,分析了遂宁市主城区环境空气质量现状,与整个成渝地区和周边城市的空气质量进行了横向比较,并阐述了遂宁市空气质量变化的原因.结果发现遂宁市主城区2017年1月份空气质量指数的范围为32~203,优良率为54.8%,首要污染物为PM2.5,空气质量同比下降了22.8%,环比下降了26.1%,但均显著优于成渝地区和周边城市的平均水平,并从4个方面阐述了空气质量下降的原因.最后,根据遂宁市大气污染现状,提出了4条针对性的防治措施. 相似文献
84.
镉是一种对人类和动物健康危害严重的重金属。土壤镉污染问题已经成为全球研究热点。重点分析了镉污染土壤中镉的来源,镉对动植物、人体的危害,并提出了对镉污染土壤的修复的方法。 相似文献
85.
The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated.Natural bentonite from Gaozhou in Guangdong Province,China was collected.Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite.The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction,N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy.The results showed that montmorillonite is the main component of the natural bentonite.The basal spacing of the natural bentonite is 1.47 nm,which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide.Moreover,both the surface area and pore volume increased with intercalation.Clear CH2 stretching(3000-2800 cm-1) and scissoring(1480-1450 cm-1) modes of the intercalated surfactants were observed for organobentonite.Compared with the pseudo first-order kinetic model,the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite.The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole,but decreased with increasing adsorbent dosage.The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model.The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g,indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole. 相似文献
86.
Supercritical water oxidation of polyvinyl alcohol and desizing wastewater:Influence of NaOH on the organic decomposition 总被引:1,自引:0,他引:1
Jie Zhang Shuzhong Wang Yang Guo Donghai Xu Yanmeng Gong Xingying Tang 《环境科学学报(英文版)》2013,25(8):1583-1591
Polyvinyl alcohol is a refractory compound widely used in industry. Here we report supercritical water oxidation of polyvinyl alcohol solution and desizing wastewater with and without sodium hydroxide addition. However, it is difficult to implement complete degradation of organics even though polyvinyl alcohol can readily crack under supercritical water treatment. Sodium hydroxide had a significant catalytic effect during the supercritical water oxidation of polyvinyl alcohol. It appears that the OH ion participated in the C-C bond cleavage of polyvinyl alcohol molecules, the CO2-capture reaction and the neutralization of intermediate organic acids, promoting the overall reactions moving in the forward direction. Acetaldehyde was a typical intermediate product during reaction. For supercritical water oxidation of desizing wastewater, a high destruction rate (98.25%) based on total organic carbon was achieved. In addition, cases where initial wastewater was alkaline were favorable for supercritical water oxidation treatment, but salt precipitation and blockage issues arising during the process need to be taken into account seriously. 相似文献
87.
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89.
分析了ABS树脂生产装置丁二烯缓冲罐中丁二烯自聚物的生成原因,提出了预防措施,避免丁二烯自聚物的生成,保证装置的安全平稳运行。 相似文献
90.