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91.
葡萄糖和氯化钠对米根霉利用鱼粉废水生成乳酸的影响 总被引:1,自引:0,他引:1
米根霉AS3.254能较好地利用鱼粉废水生成乳酸,葡萄糖和NaCl浓度能显著影响该过程的实现.当外加葡萄糖浓度为30g/L,发酵培养72h的鱼粉废水CODCr去除率为97.8%,乳酸产量为19.4g/L,生物量为3.56g/L;最大乳酸得率和总氮去除率分别为0.66g/g和55%.鱼粉废水中较高浓度氯化钠(NaCl)能抑制菌株生长,降低其产酸能力.当NaCl浓度大于12g/L时,菌株生长被完全抑制,产酸能力完全丧失.图4表1参20 相似文献
92.
斜坡稳定性的二级模糊推断 总被引:2,自引:0,他引:2
根据对斜坡稳定性影响的大小,选取了七个主要因于,引用了山西明水河流域几个斜坡样点实测数据.应用模糊近似推论方法及信息分配原理,对斜坡稳定性进行了单因子灰色隶属度分析及综合二级模糊近似推论,该方法克服了传统单因子评价的弊端,能比较真实地反映实际,为布设护坡工程提供了理论依据。 相似文献
93.
聚丙烯酰胺类絮凝剂的制备及应用研究 总被引:2,自引:0,他引:2
为了研究絮凝效果与絮凝剂分子结构的关系,实验中制备了聚丙烯酰胺(PAM)、阳离子化聚丙烯酰胺(CPAM)和部分水解聚丙烯酰胺(PHP),将其分别与FeCl3复配后处理钻井废水。实验探讨了絮凝剂的分子量、PHP的水解度及阳离子度对絮凝作用的影响。实验结果表明:PAM、CPAM、PHP与无机混凝剂复配使用处理钻井废水时,最佳分子量是500万,处理效果依次为PHP>PAM>CPAM。 相似文献
94.
95.
两种表面活性剂对剩余污泥产酸影响的比较研究 总被引:2,自引:0,他引:2
在批式反应器中研究了常温下2种(两性和阳离子)表面活性剂对剩余污泥产酸的影响,结果表明,2种表面活性剂均能较大幅度地提高剩余污泥生产有机酸的产量.在污泥发酵的第4天,0.1g·g-1(表面活性剂与污泥干重比,下同)的两性和阳离子表面活性剂可分别使剩余污泥生产有机酸的浓度达到226.4和861.4 mg·L-1(以COD计,下同),而空白试验中生成的有机酸浓度仅为3.2 mg·L-1.同时,剩余污泥的有机酸产量随表面活性剂加入量的增加而增加.当表面活性剂的加入量低于0.2 g·g-1时,用两性表面活性剂处理的剩余污泥中有机酸浓度仅为用阳离子表面活性剂处理的剩余污泥中有机酸浓度的50%;当表面活性剂的加入量增至0.3 g·g-1时,两者的有机酸最大产量接近.此外,表面活性剂的种类和加入量对有机酸的组成分布也有一定的影响. 相似文献
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98.
通过应用箱工模型,模拟研究了实施排放标准对大气环境质量的影响,分析讨论了实施2排放标准的技术经济可行性。得出如下结论:(1)重庆市实施大气二氧化硫污染物排放标准能基本满足在气环境质量减级标准的要求。(2)实施标准所需二氧化硫治理静态投资费用总额计26.369亿元。(3)实施标准减少环境污染损失6.440亿元。 相似文献
99.
Mei Li Yao Zhang Chenglei Pei Jinwen Zhang Chunlei Cheng Xiufeng Lian Mubai Chen Bo Huang Zhong Fu Zhen Zhou 《环境科学学报(英文版)》2023,35(2):806-822
The real-time detection of the mixing states of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in ambient particles is of great significance for analyzing the source, aging process, and health effects of PAHs and nitro-PAHs; yet there is still few effective technology to achieve this type of detection. In this study, 11 types of PAH and nitro-PAH standard samples were analyzed using a high performance-single particle aerosol mass spectrometer (HP-SPAMS) in lab studies. The identification principles ‘parent ions’ and ‘mass-to-charge (m/z) = 77’ of each compound were obtained in this study. It was found that different laser energies did not affect the identification of the parent ions. The comparative experiments of ambient atmospheric particles, cooking and biomass burning emitted particles with and without the addition of PAHs were conducted and ruled out the interferences from primary and secondary organics on the identification of PAHs. Besides, the reliability of the characteristic ions extraction method was evaluated through the comparative study of similarity algorithm and deep learning algorithm. In addition, the real PAH-containing particles from vehicle exhaust emissions and ambient particles were also analyzed. This study improves the ability of single particle mass spectrometry technology to detect PAHs and nitro-PAHs, and HP-SPAMS was superior to SPAMS for detecting single particles containing PAHs and nitro-PAHs. This study provides support for subsequent ambient observations to identify the characteristic spectrum of single particles containing PAHs and nitro-PAHs. 相似文献
100.
Effect of citric, malic, tartaric and acetic acids on adsorption of La, Ce, Pr and Nd by and desorption from four typical Chinese soils was studied. Generally, adsorption capacities of rare earth elements (REEs) were significantly correlated with the cation exchange capacity (CEC) of soils. In the presence of acetic acids adsorption of REEs was similar to that in the presence of Ca(NO3)2. However, in the presence of citric, malic and tartaric acids adsorption of REEs by Heilongjiang, Zhejiang and Guangdong soils decreased to varying extents if compared with that in the presence of nitrate and acetic acid. The significance of suppression followed the order of citric acid > malic acid > tartaric acid > acetic acid, which was consistent with the order of stability of complexes of REEs with these organic acids. However, the adsorption increased with increasing equilibrium solution pH. For Jiangxi soil with low soil pH, CEC and organic matter these organic acids exerted an even more serious suppression effect on the adsorption of REEs. Another feature of the relationship between the adsorption of REEs and equilibrium solution pH was that the adsorption of REEs decreased with increase of pH from 2 to 4.5 and then slightly increased with further increase of pH. Desorption of REEs varied with soils and with organic acids as well. REEs were released easily from Heilongjiang, Zhejiang and Guangdong soils in the presence of organic acid. Generally, desorption of REEs decreased with increasing equilibrium solution pH. Effect of organic acids on desorption of REEs from Jiangxi soil was more complicated. In the presence of citric and malic acids no decrement and/or slight increase in desorption of REEs were observed over the equilibrium solution pH from 3 to 6.5. The reasons for this were ascribed to the strong complexing capacity of citric and malic acids and low soil pH, CEC and organic matter of Jiangxi soil. 相似文献