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991.
水性油墨废水的混凝工艺试验   总被引:10,自引:0,他引:10  
探讨了水性油墨废水处理中的混凝工艺,对混凝剂的种类及投药量、混凝最佳pH值、助凝剂种类及投药量等工艺条件进行了优化。当混凝剂为FeCl3,投药量为80mg/L,pH为4.0左右,助凝剂为壳聚糖,投药量为0.8mg/L时,处理后的废水COD去除率达87%以上,色度去除率达99%以上。  相似文献   
992.
兰州马滩水源地NO3-污染环境条件分析   总被引:12,自引:1,他引:12  
兰州市马滩地下水源地多年的水质临测资料表明,NO_3~-对地下水的污染呈日益严重的发展趋势,这种污染趋势与水源地环境条件的改变和恶化有着密切的关系。通过分析可以明显地看出,造成地下水NO_3~-污染的根本原因是农田化学氮肥的大量施用。  相似文献   
993.
Experiments on CH4/Cl2/O2/N2 oxidation were conducted in an atmospheric pressure flow reactor to understand the influence of chlorine on hydrocarbon oxidation in hazardous waste incineration. The reaction temperature varied from 973 to 1273 K and the chlorine to hydrogen mole ratio (Cl/H) of the inlet mixture varied from 0 to 0.44. The species produced in the reaction were measured online with Fourier transform infrared spectroscopy (FT-IR). It was found that the destruction and removal e ciency of CH4 increased with Cl/H mole ratio. Increasing Cl/H favored COCl2 and CO formation and inhibited the CO oxidation process. As Cl/H approached 0.44, the concentrations of CH2Cl2 and CH3Cl first increased, and then declined. Reaction temperature greatly a ected the reaction system. Increasing temperatures raised the destruction removal e ciency of CH4 and decreased the concentrations of CH3Cl and CH2Cl2. With a certain ratio of Cl/H, the concentrations of CO and COCl2 first increased and then declined. The CO and COCl2 concentration peak was observed around 1100 K and 1023 K, respectively. When the reaction temperature exceeded 1273 K, carbon in CH4 was mostly converted to CO2. It could be concluded that the presence of chlorine enhanced the destruction of CH4, but resulted in the more toxic incomplete combustion products emission such as COCl2 when the reaction temperature was not high enough.  相似文献   
994.
Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O3/mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al(OH)3(s). This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.  相似文献   
995.
Response of soil catalase activity to chromium contamination   总被引:3,自引:0,他引:3  
The impact of chromium(III) and (VI) forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from di erent depths were used in the experiment. The soil samples were amended with solution of Cr(III) using CrCl3, and with Cr(VI) using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control. Catalase activity was assayed by one of the commonly used spectrophotometric methods. As it was demonstrated in the experiment, both Cr(III) and Cr(VI) have an ability to reduce soil catalase activity. A chromium dosage of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr(III) and 68% to 76% for Cr(VI), with relation to the control. Catalase activity reached maximum in the soil material from surface layers (0–25 cm), typically characterized by the highest content of organic matter creating favorable conditions for microorganisms.  相似文献   
996.
邢奕  王骢  路培  李子宜  刘应书  于晗 《环境科学》2016,37(12):4538-4544
多孔材料过滤去除环境纳米颗粒物(nanoparticles,NPs)是空气净化治理的重要方法之一.本文采用介孔分子筛(MCM-41、SBA-15)和有序介孔碳(CMK-3)这3种典型介孔材料对2~20 nm的NPs进行过滤脱除研究,旨在探索介孔材料在NPs过滤方面的应用可行性与相关理论基础.基于3种介孔材料的物理化学性质表征结果,通过本实验发现介孔材料孔道的最可几孔径以及一定量的介孔孔容是吸附NPs的关键,而微孔分布对去除NPs贡献不大.进一步对SBA-15在不同流量及不同颗粒床厚度下对NPs的去除进行了分析,发现纳米颗粒物的最易穿透粒径(most penetrating particle size,MPPS)随着流量的增大而减小,同时MPPS颗粒物的去除效率随之降低,且MPPS基本不受颗粒床厚度变化的影响.本研究为介孔材料过滤脱除NPs提供了技术依据.  相似文献   
997.
青岛市循环经济发展水平综合评价   总被引:1,自引:0,他引:1  
运用层次分析法,基于减量化、资源化、无害化"3R"理论原则,构建了适合青岛市的区域循环经济评价体系和权重体系,确立了区域循环经济评价分级标准和评判模型,并对2005年青岛市循环经济发展状况进行了分析和评价。结果表明:青岛市循环经济发展综合评价指数为0.7291,处于Ⅱ级水平,即中等循环状态;其下属的三个功能指标评价结果表现为:资源化>无害化>减量化;人均废水排放量、农村秸秆综合利用率、危险废物处置率是影响青岛市循环经济发展的限制因素。  相似文献   
998.
CO3O4/介孔分子筛催化剂对苯催化完全氧化的研究   总被引:1,自引:0,他引:1  
分别以介孔分子筛MCM-41、MCM-48、SBA-15为载体,采用等体积浸渍法制备了氧化钴/介孔分子筛催化剂,利用N2吸附、X射线衍射、程序升温还原等技术对催化剂进行了表征,考察了Co3O4的负载量及载体的孔结构对催化剂完全催化氧化苯的性能的影响.结果表明,Co3O4的负载量为20%时,催化剂的催化活性最好;载体的孔径和催化剂的可还原性能是影响催化活性的主要因素,催化剂活性顺序为Co3O4/SBA-15>Co3O4/MCM-41>Co3O4/MCM-48.  相似文献   
999.
探讨了采用HPLC法检测某烟酰胺生产废水中所含的烟酸、烟酰胺和3-氰基吡啶的方法。结果显示,该方法的检测范围(S/N=3)为0.70~1.18 mg/L,方法的回收率为87%~102%,相对标准偏差为0.9%~3.9%,是一种快速、敏感和可靠的测定方法。  相似文献   
1000.
研究了用1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯(DCNPNPT)分光光度法快速直接测定锌的方法。在表面活性剂TritonX-15的存在下,pH=9.5~10.5的Na2B4O7-NaOH介质中,DCNPNPT与锌( )可生成1∶3的橙黄色络合物。最大吸收波长为445nm,同时在535nm配合物有一最大负吸收,建立以535nm为参比波长,445nm为测定波长的双峰双波长法进行测定,表观摩尔吸光系数可达1.12×105L/(mol·cm)。用拟定的方法测定矿山废水中的锌,与原子吸收法测定的结果十分吻合,结果令人满意。  相似文献   
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