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在序批式反应器中探究了热水解处理污泥对污泥减量及脱氮除磷性能的影响。实验通过探究热水解处理污泥后回流量对污泥总产量,悬浮固体(MLSS)浓度,污泥表观产率,总氮和总磷的去除的影响。实验结果表明热水解污泥回流量最佳比例为60%,此时,20 d内污泥总产量为79 g,MLSS的浓度为4 985 mg/L,污泥表观产率为0.103 mg/mg。 相似文献
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磨盘山水库作为哈尔滨市城区主水源,确保其水源地环境安全是我市重要的民生保障。以《集中式饮用水水源地环境保护状况评估技术规范》(HJ 774-2015)为依据,对哈尔滨市磨盘山水源地2016年环境状况进行了评估。结果表明,磨盘山水源2016年度综合评估得分为98.13分,属于优秀水源。取水保证状况评估得分10分,评估结果属于优秀;水源达标状况得分60分,评估结果属于优秀;管理状况评估得分28.125分,评估结果属于优秀。针对评估结论提出了相应的保护对策,为哈尔滨市磨盘山水源地保护和环境管理工作提供了科学依据。 相似文献
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Drinking water biotic safety of particles and bacteria attached to fines in activated carbon process
Chen Wei Lin Tao Wang Leilei 《Frontiers of Environmental Science & Engineering in China》2007,1(3):280-285
In this paper, the drinking water biotic safety of particles and bacteria attached to fines in activated carbon process was
investigated by actual treatment process and advanced treatment pilot trial with granular activated carbon. In the experiment,
the particles were detected by IBR particle calculating instrument, the activated carbon fines were counted on the basis of
the most probable number (MPN) with a microscope, the total number of bacteria was analyzed between the conventional agar
culture medium and the one with R2A, and the bacteria attached to activated carbon fines was resolved by the homogenization
technique. The experimental results showed that the average total number of particles was 205 CNT/mL in the activated carbon
effluent during a filter cycle, of which the number of particles with sizes > 2 μm was 77 CNT/mL more than the present particle
control criterion of the American drinking water product standard (50 CNT/mL). The backwash of low density and long duration
lowered particle number in the effluent. The MPN of activated carbon fines in the effluent was between 400 and 600 CNT/L,
which accounted for less than 5‰ of the total particles from activated carbon filtration for a poor relative level (R
2 = 0.34). The microorganisms in activated carbon effluent consisted mostly of heterotrophic bacillus and the total bacteria
number was five times as high as that of the inflow, i.e. the effluent from sand filter. The actual bacteria number may be
truly indicated by the detection technique with R2A culture medium compared with the traditional agar cultivation. The inactivation
efficiency of bacteria attached to activated carbon fines was less than 40% under 1.1 mg/L of chlorine contacting for 40 min.
Results showed that the particles and bacteria attached to activated carbon fines may influence drinking water biotic safety,
and that the effective control measures need to be further investigated. 相似文献
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Farasat Ali Ghulam Jilani Leilei Bai Chunliu Wang Linqi Tian Helong Jiang 《Frontiers of Environmental Science & Engineering》2021,15(6):134
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为研究小群体行为作用对地铁站突发事件人群疏散效率的影响,基于社会力模型理论和智能体技术,构建地铁站人群疏散模型。分析小群体趋向性、协调一致性等行为特征,运用社会力模型理论,计算小群体成员移动速度;量化小群体行为对群体内部成员作用大小,修正成员期望速度,确定人群疏散速度;以某地铁站火灾事故为例,分别模拟单人疏散场景和混合疏散场景。研究结果表明:混合疏散场景仿真时间比单人疏散场景仿真时间延长12.29%,平均绕行距离比单人疏散增加38.8%,小群体行为降低了地铁站突发事件人群疏散效率。 相似文献
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Changhui Wang Leilei Bai Yuansheng Pei Laura A. Wendling 《Environmental science and pollution research international》2014,21(23):13528-13538
Recycling of drinking water treatment residuals (WTRs) as environment amendments has attracted substantial interest due to their productive reuse concomitant with waste minimization. In the present study, the extractability of metals within six Al/Fe-hydroxide-comprised WTRs collected throughout China was investigated using fractionation, in vitro digestion and the toxicity characteristic leaching procedure (TCLP). The results suggested that the major components and structure of the WTRs investigated were similar. The WTRs were enriched in Al, Fe, Ca, and Mg, also contained varying quantities of As, Ba, Be, Cd, Co, Cr, Cu, K, Mn, Mo, Na, Ni, Pb, Sr, V, and Zn, but Ag, Hg, Sb, and Se were not detected. Most of the metals within the WTRs were largely non-extractable using the European Community Bureau of Reference (BCR) procedure, but many metals exhibited high bioaccessibility based on in vitro digestion. However, the WTRs could be classified as non-hazardous according to the TCLP assessment method used by the US Environmental Protection Agency (USEPA). Further analysis showed the communication factor, which is calculated as the ratio of total extractable metal by BCR procedure to the total metal, for most metals in the six WTRs, was similar, whereas the factor for Ba, Mn, Sr, and Zn varied substantially. Moreover, metals in the WTRs investigated had different risk assessment code. In summary, recycling of WTRs is subject to regulation based on assessment of risk due to metals prior to practical application. 相似文献
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为解决储罐罐底点蚀问题,提出基于改进K-means和CNN的储罐罐底点蚀诊断模型,在传统聚类基础上引入肘部法则,保证k值选取3的准确性,将原始声发射信号特征参数和聚类后的类别信息输入模型进行训练,系统预测准确率高达99%。研究结果表明:该模型能够及时发现点蚀现象,指导管理者确定储罐开罐检查时间顺序,避免点蚀穿孔造成的人力、物力损失,降低储罐运行风险,保障储罐运行安全,研究结果可为罐底点蚀诊断提供技术支撑。 相似文献
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The release of biochar colloids considerably affects the stability of biochar in environment. Currently, information on the release behavior and suspension stability of biochar colloids in real soil solutions is scarce. In this study, 20 soils were collected from different districts in China and the release behavior of biochar colloids and their suspension stability in soil solutions were systematically examined. The results showed that both pyrolysis temperature and biomass source had important effects on the formation of biochar colloids in soil solutions. The formation amount of biochar colloids from low pyrolysis temperatures (400 °C) (average amount of 9.33–16.41 mg/g) were significantly higher than those from high pyrolysis temperatures (700 °C) (average amount of less than 2 mg/g). The formation amount of wheat straw-derived biochar colloids were higher than those of rice straw-derived biochar colloids probably due to the higher O/C ratio in wheat-straw biochar. Further, biochar colloidal formation amount was negatively correlated with comprehensive effect of dissolved organic carbon, Fe and Al in soil solutions. The sedimentation curve of biochar colloids in soil solutions is well described by an exponential model and demonstrated high suspension stability. Around 40% of the biochar colloids were maintained in the suspension at the final sedimentation equilibrium. The settling efficiency of biochar colloids was positively correlated with comprehensive effect of the ionic strength and K, Ca, Na, and Mg contents in soil solutions. Our findings help promote a deeper understanding of biochar loss and stability in the soil-water environment. 相似文献