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1.
以农业废弃物水稻秸秆为原料制备了秸秆基活性炭负载金属Fe氧化物的臭氧催化剂,主要特征为负载Fe3O4,负载量14.25%,比表面积1175.1 m2·g-1,研究其强化臭氧深度处理造纸废水的效能。结果表明,制备的秸秆基活性炭和催化剂均对造纸废水污染物具有较高的吸附性能,吸附等温线与Langmuir模型拟合相关性良好(R2>0.99);催化剂的使用显著强化了臭氧氧化污染物的性能,最佳的运行参数是臭氧和催化剂投加量分别为0.3g·h-1和1 g·L-1及原水pH,处理后出水COD、BOD5、氨氮和色度分别为46、17、5 mg·L-1和18倍,均低于我国造纸废水污染物排放标准(GB 3544-2008);重复20次的运行,催化剂具有良好的稳定性,金属离子溶出浓度极少,并通过自由基捕获剂和ESR测试探讨该催化臭氧氧化过程属自由基间接氧化为主导的反应机理。本研究制备的臭氧催化剂具有性能高效稳定和经济节约的特点,适用于造纸废水深度处理的工程化应用。  相似文献   

2.
Rice straw physicochemical characteristics and anaerobic digestion(AD) performance via ammonia pretreatment at varying ammonia concentrations(2%, 4%, and 6%) and moisture contents(30%, 50%, 70%, and 90%)under a mild condition were investigated. The results showed that the ammonia pretreatment effectively damaged the rice straw structure, increased the soluble organic concentration, and improved rice straw hydrolysis and AD performance. After pretreatment, the ester bond and ether bond were ruptured in lignocellulose and the volatile fatty acids(VFAs) were within the range of 1457.81–1823.67 mg·L~(-1). In addition, ammonia pretreatment had high selectivity on lignin removal, resulting in a maximum lignin removal rate of 50.80%. The highest methane yield of rice straw was 250.34 ml·(g VS)~(-1) at a 4% ammonia concentration coupled with a 70% moisture content, which was 28.55% higher than that of the control. The result showed that ammonia pretreatment of rice straw is technically suitable to enhance AD performance for further application.  相似文献   

3.
不同来源家庭户用沼气池沼液成分分析及风险评价   总被引:1,自引:0,他引:1       下载免费PDF全文
采集了中国8个省市的43个不同原料家庭户用沼气池的沼液,进行化学需氧量(COD)、氨氮(NH4+-N)、磷酸盐(PO43-)和重金属等指标分析,阐述不同原料导致沼液成分的差异,评价了不同来源沼液存在的生态风险,旨在为不同来源沼液的资源化利用提供理论依据。研究结果表明,以牛粪和秸秆为原料的沼液COD浓度较高,分别达到6800 mg·L-1和5800 mg·L-1;以猪粪和混合粪便为原料的沼液氨氮浓度较高,都超过1800 mg·L-1,而牛粪原料沼液氨氮浓度明显低于其他原料,平均值仅有450 mg·L-1,因此以牛粪为原料的沼液COD/NH4+-N显著高于其他三种原料,COD/NH4+-N达到15,而其他三种原料的沼液COD/ NH4+-N均低于5;所有原料沼液磷酸盐浓度的平均值均低于80 mg·L-1;沼液中汞的污染较严重,且在不同原料和不同地区的沼液中具有普遍性;潜在生态风险指数RI分析结果表明,云南、河南和湖北的沼液RI介于130~260之间,属于中等生态危害,存在一定的生态风险。  相似文献   

4.
To realize full energy recovery from grass and chicken manure(CM), the integration of high-solid anaerobic digestion(HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can be enhanced through codigestion with CM. When the volatile solid(VS) ratio of CM to grass was 20:80, C/N ratio calculated to be 21.70, the cumulative biogas yield was the highest, 237 ml·(g VS)~(-1). The enhancement of biogas production was attributed to the buffering effects of ammonia and rich trace elements in CM. In semi-continuous systems, when the organic loading rate was 4.0 g VS·L~(-1)·d~(-1), the HSAD process was stable, with the average biogas yield 168 ml·(g VS)~(-1). More than 80% fractions of the digestates were volatile matters, which meant that the digestates can be used as feedstock for gasification to produce syngas. The VS ratio of grass to CM had significant overall energy generation through HSAD and gasification. Compared with gasification of digestate,cogasification with woodchips increased syngas yield and low heat value(LHV). Increasing of mass ratio of digestates to woodchips led to the decrease of LHV.  相似文献   

5.
Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide(KOH)to decrease digestion time and enhance biomethane production and fertility value.KOH concentrations of1%(K1),3%(K2),6%(K3)and 9%(K4)were tested for wheat straw pretreatment at ambient temperature with a C:N ratio of 25:1.86% of total solids(TS),89% of volatile solids(VS)and 22% of lignocellulose,cellulose and hemicellulose(LCH)(22%)were decomposed effectively with the wheat straw pretreated by 6% KOH.Enhanced biogas production and cumulative biomethane yield of 258 ml·(g VS)~(-1)were obtained increased by 45% and 41%respectively,compared with untreated wheat straw.Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium(138%),calcium(22%)and magnesium(16%).These results show that TS,VS and LCH can be effectively removed from wheat straw pretreated with KOH,improving biodegradability biomethane production and fertilizer value.  相似文献   

6.
姜峰  蒲万芬  杜代军  任强  荆雪琪 《化工学报》2015,66(3):1215-1220
通过光引发自由基聚合的方式,将双尾型丙烯酰胺类疏水单体(N-苯乙基-N-十四烷基甲基丙烯酰胺,PETMAM),与丙烯酰胺(AM)、丙烯酸(AA)等水溶性单体进行共聚,制备出双尾型疏水缔合水溶性共聚物(DTHAP),来解决丙烯酰胺类聚合物耐温抗盐性以及稳定性差的难题。通过测定聚合物溶液的表观黏度作为评价其性能的主要手段,考察了丙烯酸加量、盐、表面活性剂(SDS)含量、疏水单体含量等因素对聚合物性能的影响,从而确定了比较理想的反应条件。实验中发现:丙烯酸加量和表面活性剂含量的变化会影响聚合物的临界缔合行为;盐的引入能够显著降低表面活性剂的用量,提高聚合物的增黏效果;疏水单体含量较低时[0.35%~0.45%(mol)],聚合物可以表现出明显的增黏效果。当聚合物浓度为1 g·L-1时,聚合物的黏度可以达到141.5 mPa·s,其临界缔合浓度(CAC)为0.75 g·L-1左右。聚合物在120 g·L-1的NaCl溶液和120 g·L-1 NaCl、0.4 g·L-1 CaCl2溶液中,80℃下老化90 d,黏度分别为47.6 mPa·s和45.9 mPa·s。采用红外光谱、扫描电镜两种手段,表征了聚合物的结构。  相似文献   

7.
首先测试了嗜盐单胞菌Halomonas sp.TD1.0对乙酸钠的耐受性,结果显示乙酸钠浓度由25 g·L-1提高到100 g·L-1时对TD1.0生长的抑制率只有45.8%。在摇瓶培养中,TD1.0在36 h内消耗完27.3 g·L-1乙酸钠,细胞干质量达到9.6 g·L-1,其中PHB质量分数为61%,表明该菌株具有很好的高浓度乙酸钠耐受性和利用乙酸合成PHB的特性。随后为进一步提高乙酸钠的利用速度,在TD1.0中分别用高拷贝和低拷贝表达载体表达了来自枯草芽孢杆菌的乙酰辅酶A合成酶基因acs,结果显示,含有高拷贝表达质粒的菌株TD-PN59的乙酸盐平均利用速率为0.91 g·L-1·h-1,比 TD1.0提高了19.7%。TD-PN59的细胞干质量和PHB质量分数分别达到9.98 g·L-1和65%,PHB产量达到6.49 g·L-1,比TD1.0提高了约10.8%。在以葡萄糖和乙酸钠为混合碳源(10 g·L-1 Glu和10 g·L-1 NaAC)的培养基中,利用低拷贝载体表达acs的TD-PN85菌株的乙酸钠利用速率显著高于TD1.0,并且在一定程度上缓解了碳分解代谢物阻遏现象(CCR),促进了葡萄糖和乙酸钠的共利用。  相似文献   

8.
Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine de-rived fungi may use small amount of nutrients to grow and produce laccases. Agricultural residues that are mainly composed of lignin, cellulose and hemicellulose are difficult to be degraded and few microbes can take them as sub-strates, so they are considered as oligotrophic nutrient and have the potential to be used to produce value added products. In this study, the ability of Pestalotiopsis sp. J63 to use agricultural residues to produce laccases was tested in the submerged fermentation. The combination of 3 g·L-1 maltose and 20 g·L-1 rice straw was the best car-bon sources and 8 g·L-1 ammonium sulfate was the best nitrogen source under the condition without inducers. The effects of five inducers, the feeding time and concentration of inducer on laccase production were investigated. Adding 0.09 mmol·L-1 phenol after 24 h of incubation led to high laccase activity (5089 U·L-1), while with 0.09 mmol·L-1 phenol in the medium and wheat bran as the nitrogen source, the laccase activity could reach 5791.7 U·L-1. Native-PAGE results showed that two laccase isozymes were present in the cultures. One existed in both in-duced and non-induced culture filtrates, while the other was only found in the fermentation with the addition of phenol, guaiacol and veratryl alcohol.  相似文献   

9.
Although simultaneous saccharification and fermentation (SSF) has been investigated extensively, the optimum condition for SSF of wheat straw has not yet been determined. Dilute sulfuric acid impregnated and steam explosion pretreated wheat straw was used as a substrate for the production of ethanol by SSF through orthogonal experiment design in this study. Cellulase mixture (Celluclast 1.5 l and ?-glucosidase Novozym 188) were adopted in combination with the yeast Saccharomyces cerevisiae AS2.1. The effects of reaction temperature, substrate concentration, initial fermentation liquid pH value and enzyme loading were evaluated and the SSF conditions were optimized. The ranking, from high to low, of influential extent of the SSF affecting factors to ethanol concentration and yield was substrate concentration, enzyme loading, initial fermentation liquid pH value and reaction temperature, respectively. The optimal SSF conditions were: reaction temperature, 35°C; substrate concentration, 100 g·L-1; initial fermentation liquid pH, 5.0; enzyme loading, 30 FPU·g-1. Under these conditions, the ethanol concentration increased with reaction time, and after 72 h, ethanol was obtained in 65.8% yield with a concentration of 22.7 g·L-1.  相似文献   

10.
曾明国  李永生  赵炀  杜鑫 《化工学报》2017,68(8):3056-3063
基于Mo(Ⅵ)-抗坏血酸、Co(Ⅱ)-KSCN反应体系和流动注射光度法,建立了一个全新的催化剂浸渍液中超高浓度CoO/MoO3的同时测定系统。研究发现:Co(Ⅱ)与KSCN络合物是由K2Co(SCN)4和K4Co(SCN)6构成,利用后者可定量Co(Ⅱ);Co(Ⅱ)对Mo(Ⅵ)-抗坏血酸反应有抑制作用,会干扰Mo(Ⅵ)测定;本研究利用Co(Ⅱ)的抑制作用,人为在测Mo(Ⅵ)的显色剂中加入一定量的硝酸钴,解决了该干扰问题。另外,对测定Co(Ⅱ)/Mo(Ⅵ)用的显色剂中的成分及浓度、进样体积、反应温度等相关影响因素进行了优选,得到的结果是:测定Mo(Ⅵ)的显色剂由15%(质量分数)抗坏血酸、10 g·L-1硝酸钴(以CoO计)及0.1 mol·L-1硫酸组成,测定Co(Ⅱ)的显色剂由37.5% KSCN、0.1 mol·L-1 NaAc-HAc(pH 5.8)组成;MoO3和CoO的测定范围分别为10~100 g·L-1和5~50 g·L-1,检出限分别为2.1 g·L-1和1.3 g·L-1,RSD<1.2%(n=11),回收率为98%~104%,分析速度为20样/小时。  相似文献   

11.
刘黎阳  刘晨光  白凤武 《化工学报》2013,64(11):4181-4186
引言随着石油资源的日益减少和环境污染的逐渐加剧,使用可再生的清洁能源已经是世界各国的共识。在众多形式的非矿物质能源中,基于生物质的燃料乙醇已得到了广泛的应用[1]。但是,由于生产成本较高,各国的燃料乙醇生产大都依靠着政策扶植和税收优惠[2]。因此,看似十分"成熟"的乙醇生产产业,仍然需要进一步开发降低成本的创新技术[3]。近些年来,通过基因工程手段改造菌种[4]、  相似文献   

12.
针对铝合金表面预处理过程存在污染严重、水耗高等问题,研究开发无氟无铵铝合金表面预处理新工艺。考察了碱性药剂配方组成及浓度、温度和时间对铝耗和铝合金表面形貌的影响,并通过正交实验确定了新工艺的优化方案。研究结果表明,经过“预处理-中和”两个步骤,铝合金表面平整、起砂细腻,铝耗仅为 2.0%。新工艺起砂效果优于传统碱蚀工艺,与传统酸蚀工艺细腻砂面相近。新工艺铝耗比传统碱蚀工艺降低约71%,与传统酸蚀工艺相近。新工艺操作时间比传统碱蚀工艺和酸蚀工艺分别缩短了23%和31%。最佳药剂配方为Na2CO3(80 g·L-1), NaOH(8 g·L-1),Na2SO4(25 g·L-1), Na3PO4(20 g·L-1), SDS(0.6 g·L-1), 甘油(5 g·L-1)。 最佳操作条件为55℃和10 min。新工艺不仅从工艺源头消除了氟和氨氮污染,还实现了除油-起砂-去机械纹等多功能一体化集成。具有低污染、低铝耗、低水耗、短流程、高效率等优点,兼具环境友好和资源节约等优势。  相似文献   

13.
采用泥浆法制备Fe3+-TiO2/AC复合材料,通过XRD和SEM对复合材料进行表征,以复合材料为粒子电极,石墨板为阴阳极,构建三维电极系统处理氨氮模拟废水,探究电解电压、电解质NaCl浓度、初始pH值及粒子电极投入量对氨氮去除的影响,并应用响应曲面法对处理废水的条件进行优化。结果表明:在电解电压为18 V,电解质NaCl浓度为6.7 g·L-1,溶液初始pH值为9.00,粒子电极投入量为10.0 g·L-1时,电解40 min后,氨氮去除率为96.86%。采用响应曲面法优化后,在电解电压为18 V,粒子电极投入量为9.9 g·L-1,初始pH值为9.10条件下,电解40 min后,氨氮去除率最佳为97.61%。以上研究结论可为氨氮废水的工业处理提供一定的参考。  相似文献   

14.
An experiment was conducted to evaluate the effectiveness of urea, ammonia sulphate or calcium hydroxide, in improving the nutritive value of wheat straw for ruminant feeding. Wheat straw was treated with each of three solutions (w/w) containing: 5% urea - 50% H2O (5U); 2% urea - 2% CaOH - 50% H2O (2U), or 5% ammonia sulphate - 2% CaOH - 50% H2O (5S). The treated straw was then ensiled in triplicate in sealed polyethylene bags for 30 days at ambient temperature (15-22 degrees C), except for the untreated straw, which was used as control (T). All treatments were then subjected to the following determinations: pH, moisture, crude protein, ammonia N, ashes, cellular walls, hemicellulose, cellulose, lignin, silica, gross energy, and dry matter in vitro digestibility. The pH value of the 5U treatment was higher (p less than 0.01) than that of 2U and 5S, and the moisture percentage increased in all treated straws, as compared to the control. Both crude protein and ammonia N contents were higher in the 5U treated straws (14.66; 0.6%), 2U (6.41; 75%), 5S (9.54; 94%) in comparison with T (2.63; 50%). The ash percentage increased significantly in 2U and 5S (p less than 0.01) in relation to T and 5U, and the cellular wall content decreased in the 5U, 2U and 5S treated straws, as did cellulose. Gross energy values were higher in the treated straws, and the dry matter per cent digestibility was also higher, although not in a significant degree (p less then 0.01) in the 5% urea-treated straw (45.03) than in 2U (42.43), 5S (34.82), and T (42.36).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
采用发酵产物中的二氧化碳(CO2)和氢气(H2)作为循环气提气源,对丙酮丁醇梭菌(Clostridium acetobutylicum CGMCC 5234)发酵产物进行原位气提,实现丙酮、丁醇和乙醇混合物(ABE)的连续纤维床固定化发酵生产。连续发酵实验进行了12批次共309 h,总溶剂ABE当量浓度为133.3 g·L-1(其中丁醇 83.5 g·L-1,丙酮38.4 g·L-1,乙醇11.4 g·L-1),葡萄糖消耗率为1.29 g·(L·h) -1,总溶剂ABE产率为0.431 g·(L·h) -1,转化率为0.333 g·g-1,其中丁醇产率为0.270 g·(L·h) -1,转化率为 0.209 g·g-1,发酵液中丁醇浓度控制在8~12 g·L-1,显著优于游离发酵的结果。气提提取之后冷凝的ABE溶液出现分层现象,其中丁醇相丁醇浓度高达603.7 g·L-1,极大地减缓后续分离提纯的负担。结果表明,自产气循环气提与纤维床固定化耦合连续发酵生产ABE(特别是丁醇)的工艺具有可行性和竞争力。  相似文献   

16.
通过对芦蒿秸秆进行酸、碱预处理和厌氧发酵制沼气实验,比较不同的预处理方法对芦蒿秸秆产气性能的影响。结果表明,与对照组相比,碱处理能较好地改善秸秆的产气性能,其中2%NaOH处理效果最好,发酵初期VFA含量高达4882.34 mg·L-1,比对照组提高了705.21%,单位TS固体产气量为288.42 ml·g-1,较对照组提高了17.08%,甲烷含量最高可达61.14%。  相似文献   

17.
刘晓  田颖  周晓慧  范丹丹  刘宗宇 《化工学报》2017,68(4):1646-1651
采用零价铝(ZVAl)在碱性条件下直接还原吡虫啉,考察了NaOH浓度、反应时间、温度对吡虫啉降解的影响。使用高效液相色谱仪(HPLC)检测。加入过量ZVAl和NaOH的水溶液中,吡虫啉的降解率随NaOH浓度的升高而增大,随反应时间的增长和温度的升高,吡虫啉的降解率增大。采用高效液相色谱-质谱联用仪(HPLC-MS)检测,结果表明吡虫啉的可能降解产物为1-(6-氯吡啶-3-甲基(-2-亚硝基亚氨基吡咯烷、1-(6-氯-3-吡啶甲基(-2-咪唑、2-氯-5-乙基吡啶和2-氯-5-甲基吡啶,并对产物的降解途径进行了分析。  相似文献   

18.
十二醇-癸酸-纳米粒子复合相变材料传热性能   总被引:4,自引:3,他引:1       下载免费PDF全文
黄艳  章学来 《化工学报》2016,67(6):2271-2276
针对有机相变材料热导率低的共性,以质量比为58.47:41.53的脂肪烃类低共熔有机物十二醇(DA)-癸酸(CA)为基液,添加纳米粒子MWNT、Cu、Al2O3及分散剂SDBS制备出纳米复合相变材料,从纳米粒子种类、添加浓度及超声时间方面研究其对复合有机相变材料热物性的影响。实验发现MWNT、Cu、Al2O3的添加都可以不同程度上提高DA-CA的热导率。当超声时间为50min、纳米粒子浓度均为0.1g·L-1时3种纳米复合材料的热导率大小依次是:MWNT>Al2O3>Cu。最优例:超声分散时间90min,DA-CA+MWNT(0.1g·L-1)+SDBS(0.2g·L-1)的热导率最大,为0.3602W·m-1·K-1,相较DA-CA提高了20.5%,在不影响基液热物性的基础上具有良好的热稳定性。  相似文献   

19.
微波辐射对青霉素菌渣破壁效果的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
韩洪军  牟晋铭  马文成  贾胜勇 《化工学报》2013,64(10):3812-3817
引言近年来,我国发酵类制药行业发展迅速,目前抗生素产量已居世界第一位。抗生素菌渣是抗生素发酵工业中的主要固体废弃物,其主要成分包括抗生素菌丝体、剩余培养基成分、发酵中微生物代谢产物及少量的残留抗生素等[1],由于菌渣对人体及环境产生潜在的耐药性风险,依据2008年修订的《国家危险废物名录》,抗生素菌渣被划入危险废物范畴[2]。抗生素菌渣产生量大、含水率高,且含有蛋白质(约占干重的30%~40%)、多糖(10%以上)及麦角固醇(0.5%~1.0%)等营养物质[3],  相似文献   

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赵博玮  李建政  邓凯文  孟佳 《化工学报》2015,66(6):2248-2255
为处理高氨氮、低C/N比的养猪废水厌氧消化液, 构建了具有缓释碳源特性的木质框架土壤渗滤系统(WFSI), 并通过运行测试了进水浓度和表面水力负荷(SHL)对系统处理效能的影响。在SHL为0.2 m3·m-2·d-1条件下, 当进水COD和NH4+-N平均浓度分别从152和175.5 mg·L-1提高到421和788.7 mg·L-1时, 系统对COD的去除率从52.3%提高到61.2%, NH4+-N去除率从84.2%下降到61.5%, TN去除率从28.6%提高到了33.5%, NH4+-N和TN去除负荷分别达到了75.5和41.7 g·m-3·d-1。当SHL提高为0.32 m3·m-2·d-1时, 系统仍能维持运行, 但处理效能受到显著影响。在进水COD 和NH4+-N分别为265和465 mg·L-1左右时, COD、NH4+-N及TN的去除率分别平均为56.5%、53.3%和20.9%。木质填料及其附着层形成的NH4+-N浓度梯度, 可使系统承受较高的SHL的同时获得缓释碳源, 并保护氨氧化细菌免受自由氨毒性。  相似文献   

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