旁路水解酸化强化污泥过程减量运行性能与机理研究

旁路水解酸化技术既能实现污泥减量,又能为污水脱氮除磷补充碳源。采用水解酸化作为污泥旁路减量化技术,研究其污泥减量的运行性能和机理,同时考察了对污水处理工艺污染物去除的影响。采用污泥水解酸化旁路处理,得到污泥减量率为30%,其中水解酸化的贡献为0.7%,延长污泥龄贡献为17.1%,能量解偶联等贡献为12.2%。污泥水解酸化旁路处理对污水生物处理工艺的出水水质以及微生物活性影响不显著。水解酸化过程中会降低微生物脱氮活性,但对污水处理主反应器中微生物活性影响较小。污泥旁路水解酸化污泥减量工艺中,对污泥减量机理的解析,需要综合考虑水解酸化与污泥龄等对污泥减量效果的影响。     

水解酸化-SBR工艺处理印染废水的研究

用水解酸化-SBR工艺处理印染废水的实验结果表明,出水COD平均为102mg/L,COD去除率平均为89.9%,色度去除率平均为70%.在实际工程中应用水解酸化(A)-好氧(O)-SBR工艺处理印染废水,出水COD平均为67mg/L,COD去除率平均为81.5%,色度去除率平均为66.7%.表明以水解酸化为预处理手段可有效提高印染废水的可生化性,提高整个工艺的COD去除率.     

水解酸化-好氧生物滤池处理炼油废水

以高炉水渣为填料,采用水解酸化-好氧生物滤池处理炼油废水。考察了好氧区气水比、水力停留时间对炼油废水处理效果的影响。实验结果表明：在水力停留时间为6h、温度为20～35℃、废水pH为6～9、好氧区气水比为10：1的条件下,该生物滤池对NH3-N,Ar-OH,COD的总去除率分别为100％,97％,85％,处理后出水水质达到国家《污水综合排放标准》一级标准。     

热水解预处理改善污泥的厌氧消化性能

先将污泥进行热水解预处理 ,其后测定生物化学甲烷势(BMP)来研究热水解对污泥厌氧消化性能的影响 .结果表明 ,热水解预处理能加速污泥中固体有机物的溶解 ,溶解后的有机物进一步水解生成低分子物质 ,其中挥发性有机酸占溶解性COD(SCOD)的30%～40% ,从而污泥的厌氧消化性能得到明显改善 .最合适的热水解温度和热水解时间为170℃、30min.此条件下 ,污泥厌氧消化时总COD(TCOD)去除率从预处理前的38.11%提高到56.78% ,污泥中TCOD的沼气产率从16.0mL/g提高到250mL/g .     

膜生物反应器在汽爆稻草秸秆酶解中应用研究

以汽爆稻草秸秆为原料,通过将几个酶解罐串联来提高最终还原糖浓度.考察了酶浓度,酶解单元组成以及稀释率对汽爆稻草秸秆酶解的影响.结果表明,最佳条件为:20FPU/g,酶解单元由4个酶解罐组成,稀释率为0.075/h.在此条件下,酶解时间为24h时,与传统批次酶解相比,汽爆稻草秸秆总转化率从18%～21%提高到39.5%.与只有1个酶解罐的膜反应器相比,每g底物还原糖产量从0.25g提高到0.4g,最终所得还原糖的平均浓度从4.56g/L提高到27.23g/L.     

Differences in the quality of steamed hull-less barley and wheat cakes北大核心CSCD

In this study, three different hull-less barley varieties were used to prepare steamed cakes, and their nutritional value, sensory qualities, textural properties, and in vitro starch hydrolysis were evaluated. The results showed that the contents of total dietary fiber (4.50%-5.12%), β-glucan (2.96%-3.96%), total flavonoids (12.56-38.73 mg/100 g), and γ-aminobutyric acid (5.08-9.53 mg/100 g) in the steamed hull-less barley cakes were significantly higher than that in the steamed wheat cake, which were 0.65%, 0.23%, 3.93 mg/(100 g), and 2.63 mg/(100 g), respectively. The sensory properties of steamed ordinary hull-less barley and wheat cakes were not significantly different, but the steamed 08-1127 (waxy hull-less barley) cake was softer and out of shape. The springiness, resilience, cohesiveness, gumminess, and adhesiveness of steamed ordinary hull-less barley cakes were similar to those of steamed wheat cake, while those of steamed 08-1127 cakes were significantly lower than those of steamed ordinary hull-less barley cakes. Steamed hull-less barley cake also showed a maximum starch hydrolysis rate (38.76%-42.74%) that was lower than that of steamed wheat cake (49.92%), and the contents of rapidly (11.58%-13.16%) and slowly digested starch (5.34%-7.56%) were lower than that of steamed wheat cake (17.21% and 15.97%, respectively). In addition, the glycemic (59.37-61.67) and hydrolysis indexes (35.82-40.00) were lower than those of steamed wheat cake (76.66 and 67.30, respectively), and the contents of resistant starch (2.74%-3.55%) were higher than those of wheat steamed cake (1.68%). Therefore, the steamed cakes of ordinary hull-less barley had a higher content of nutritional components than the steamed cake of wheat, and the in vitro starch hydrolysis parameters were better than those of steamed wheat cake. When it is necessary to consider both nutritional and sensory qualities, ordinary hull-less barley can be selected as the raw material for steamed cakes, but waxy hull-less barley is not suitable for making steamed cakes. © 2022 Science Press. All rights reserved.     

针铁矿对城市生活垃圾有机组分厌氧发酵的影响

利用PVC管构建厌氧发酵反应器,研究了铁氧化物对有机垃圾厌氧发酵过程中产气及垃圾渗滤液特性的影响.结果表明,添加针铁矿能够促进垃圾的水解酸化效率和产气速率,提高产气量至163.4 L,较空白提高了20%.通过对厌氧消化中间产物Fe2+、NH+4-N、NO-3-N、COD以及有机酸的分析表明,铁氧化物的存在有利于降低系统氧化还原电位,有助于提高厌氧微生物的水解酸化效率;铁氧化物的加入能够促进有机酸的转化,从而降低有机酸对厌氧微生物的抑制作用.     

进水比例对水解反应器出水水质的影响研究

针对城镇污水处理厂进水SS/BOD偏高、C/N比偏低的问题,通过对现有水解池结构进行改造,设置两层布水器,两层布水器之间形成污泥水解区,以强化污泥水解,改善出水水质.试验通过改变上下层布水器进水比例,力求最佳进水比例,使水解反应器起到初沉池作用的同时要提高废水的可生化性,以指导此类水解反应器的大规模应用.结果表明,4种进水比例均对COD和SS去除有不同的去除效果,但进水比例为1∶1较其他3种进水比例能够大幅提高出水中SCOD/COD比值和挥发性脂肪酸(VFA)浓度.以改善出水可生化性为原则,进水比例为1∶1时为最佳进水比例,即底部布水器进水50%,上层布水器处进水50%,既能为后续处理减少COD和SS的处理负担,又能提高出水的可生化性.     

烯啶虫胺的水解与光解行为研究

通过室内模拟实验研究了烯啶虫胺在不同pH值和温度下的水解动态及其在水和有机溶剂中的光解特性和影响因素。结果表明：烯啶虫胺在酸性和中性条件下不易水解,而在碱性条件下水解较快。烯啶虫胺的水解速率随温度升高而增加,平均温度效应系数为2.34。烯啶虫胺水解反应的活化能和活化焓与温度之间无明显相关性,而活化熵与温度表现出较好的相关性。在不同光源照射下,烯啶虫胺在水溶液中的光解速率有显著的差异,在高压汞灯、自然光和氙灯下的光解半衰期分别为42.3 s、6.9 min和55 min;烯啶虫胺在甲醇中的光解速率大于丙酮中的光解速率;烯啶虫胺的光解速率随初始质量浓度的升高而减慢;pH值对烯啶虫胺的光解影响较小。研究结果为烯啶虫胺的环境风险评价提供了科学依据。     

除草剂绿草定-2-丁氧基乙酯的降解特性及降解机制研究

按照《化学农药环境安全评价试验准则》的规定并参考美国EPA导则,采用室内模拟试验方法,研究了绿草定-2-丁氧基乙酯在环境中的降解特性.结果表明,25℃时绿草定-2-丁氧基乙酯在pH =4、7、9缓冲溶液中的水解半衰期分别为533 d、21.8 d、＜1 d;高温、碱性条件下绿草定-2-丁氧基乙酯极易水解,其水解反应速率随反应介质pH值的增大、反应温度的升高而增大;初步确定绿草定-2-丁氧基乙酯分子在水溶液中生成的水解产物主要是绿草定.绿草定-2-丁氧基乙酯在土壤中迅速降解,酸性土壤中其降解趋势遵循一级动力学模型,中性和碱性土壤中其降解动态不能用一级动力学模型进行简单的拟合;绿草定-2-丁氧基乙酯在土壤中的降解形式主要为化学水解作用,降解生成绿草定和丁氧基乙醇;土壤pH和有机质含量是影响其土壤降解速率的主要因素,pH和有机质含量越高,其土壤降解速率越快.在人工光源氙灯条件下,绿草定-2-丁氧基乙酯在水溶液和土壤表面的光化学降解均符合一级动力学反应,不同介质对绿草定-2-丁氧基乙酯光解的影响差异显著.