CAF气浮-水解酸化-SBR处理羊剪绒水洗废水

介绍了CAF气浮-水解酸化-SBR工艺处理羊剪绒水洗废水的工艺设计和运行效果.该工艺具有处理效果好、能耗低、易管理等特点.在进水COD为1 800mg·L~(-1),BOD5为300mg·L~(-1),SS质量浓度为1 200mg·L~(-1)的条件下,经过本系统处理,平均出水COD保持在200 mg·L~(-1)以下,BOD_5保持在60 mg·L~(-1)以下,SS质量浓度保持在150mg·L~(-1)以下,出水水质达到GB 8978-1996污水综合排放标准的Ⅱ级标准.     

化肥工业废水处理O/A/O脱氮工艺研究

根据化肥工业废水氨氮含量高、波动大等特点,设计了初曝池-兼气池-好氧池(O/A/O)组合工艺。利用模拟废水考察了水力停留时间(HRT)、溶氧(DO)浓度、硝化液回流比和污泥回流比对除氮效果的影响。在模拟废水实验参数基础上,得出实际运行参数为:污泥回流比100%,硝化液回流比400%,缺氧池DO0.5mg·L~(-1),好氧池DO 3mg·L~(-1)。采用O/A/O组合工艺对化肥工业产生的COD在100~1 100mg·L~(-1)、氨氮在20~130mg·L~(-1)范围波动的实际废水进行处理,出水COD均值为35.5mg·L~(-1),出水氨氮均值为1mg·L~(-1),达到《综合污水排放标准》(GB 8978-1996)的一级标准。该技术具有较好的推广应用价值。     

新疆某污水处理厂提标改扩工程案例

新疆某污水处理厂，一期采用氧化沟工艺，二期采用水解+五段Bardenpho工艺+二沉池+高密度沉淀池+微絮凝滤池+消毒工艺，出水执行一级A标准。稳定运行阶段平均出水COD为19.67 mg/L,NH₄⁺-N、TN、TP、SS平均出水质量浓度分别为1.39、5.00、0.22、5.25 mg/L，均优于一级A标准，无超标现象出现。可为该地区其他城镇污水处理厂提标改扩工程提供借鉴和参考。     

水解酸化-混凝土生态膜法处理生活污水试验研究

通过对水解酸化池处理生活污水的试验研究,考察了反应器对生活污水可生化性能的影响,并在此基础上研究了水解酸化-混凝土生物膜反应器工艺对生活污水的处理效果。试验表明,经水解酸化处理后的废水可生化性得到改善,同时也提高了生物膜反应器的处理速率和COD去除率。生活污水经水解酸化-膜生物反应器工艺处理后,出水COD、氨氮、TP的质量浓度可达50、5、1 mg/L,达到了《城镇污水处理厂污染物排放标准》(GB18918—2002)的一级B标准。     

水解酸化-厌氧-改良Carrousel氧化沟组合工艺处理城市污水脱氮中试研究

采用水解酸化-厌氧-改良Carrousel氧化沟组合工艺,通过前置水解酸化调控、氧化沟水力停留时间调控、二沉池污泥回流比调控等工艺,进行了为期8个月的混合型城市污水脱氮中试研究。结果表明,中试进水COD、NH3-N和TN的平均质量浓度分别为557、29.0、40.1 mg/L,总水力停留时间为17.5 h、污泥回流比为1、DO平均质量浓度控制在2～4 mg/L之间及无外加碳源和碱度的条件下,出水COD、NH3-N和TN的平均质量浓度分别为54.9、2.8、12.6 mg/L,对COD、NH3-N和TN的平均去除率分别达到了90.1%、90.3%和68.6%。采用水解酸化-厌氧-改良Carrousel氧化沟组合工艺,处理混合型城市污水的效果良好、稳定可靠。     

多级生物膜反应器分段进水方式对脱氮效能影响研究

提出多级生物膜反应器,考察了分段进水方式对反应器处理城镇污水生物脱氮效能的影响.结果表明,分段进水点的数量、流量分配及容积分配对反应器脱氮效能的影响显著,分段进水方式有效地提高了碳源利用率以及反应器脱氮效能.在水温为25℃左右,溶解氧为5mg·L~(-1),挂膜密度为30%,COD负荷为1.2 kg·m~(-3)·d~(-1),总氮负荷为0.22 kg·m~(-3)·d~(-1)的条件下,反应器分段进水方式采用第1级、第3级、第6级分段进水,容积分配比为2:3:4,流量分配比为2:2:1时,可使出水COD为38 mg·L~(-1),出水NH_4~+-N和TN的质量浓度分别为1.5 mg·L~(-1)和11.1 mg·L~(-1),去除率分别为80.8%,95.3%和69.2%,与单点进水方式相比TN去除率提高了8.4%.     

O/A/O工艺处理化工综合含氮废水运行优化研究

采用初曝池-兼气池-好氧池( O1/A/O2)工艺处理化肥、季戊四醇生产综合含氮废水,在进水COD、NH4+-N的质量浓度平均分别为624和59.3 mg·L-1时,出水COD在100 mg·L-1以下,平均为34.5 mg· L-1,去除率达93.2％;出水氨氮的质量浓度在15 mg·L-1以下,平均为0.8 mg·L-1,去除率高达98.7％;达到了GB 8978- 1996的一级标准.分析了系统反硝化能力较差、TN去除效率较低的原因,提出应减小硝化液回流比、适当调低O1池DO含量、充分利用厂区季戊四醇废液作为外加碳源等措施.     

水解酸化-SBR-混凝工艺处理榨菜废水试验研究

通过水解酸化-SBR-混凝工艺处理榨菜废水试验得出,在水解酸化池HRT为6h,SBR条件为0.5 h进水+10 h好氧+4 h厌氧+1 h沉淀+0.5 h闲置(曝气量6 L·min-1,污泥浓度4 000 mg·L-1),混凝试验PAC和PAM投加量分别为300mg·L-1和6mg·L-1条件下,COD、SS、氨氮和总磷平均去除率分别为96%、85.03%、84.9%和95.32%,出水水质达到污水综合排放标准二级标准.     

物化-水解酸化-A~2/O组合工艺处理高盐工业废水

为解决某工业区高盐工业废水达标排放问题,采用物化(活性污泥吸附、混凝沉淀)-水解酸化-A2/O组合工艺对该废水进行试验研究。结果表明,剩余活性污泥经简单驯化后对高盐废水中铅的吸附去除率可达99%以上;水解酸化段将B/C由进水的0.13提高到0.27;整个处理系统对该废水的处理效果显著,出水COD、TN、NH3-N、TP分别为45、7.3、2.0、0.3 mg/L,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。     

SBR和A~2/O工艺在污水处理厂的脱氮应用比较

以浙江某污水处理厂2组平行运行的序批式间歇活性污泥工艺(SBR)和厌氧-缺氧-好氧活性污泥工艺(A~2/O)为研究对象,分析2种生物处理工艺的污染物去除性能结果表明,通过控制体系DO的质量浓度在4~6mg/L,SBR和A~2/O其去除率分别达46.5%和52.7%。采用外加碳源(乙酸钠)的方式,将SBR和A~2/O工艺进水COD/ρ(TN)分别控制在8.6和7.2以上,可实现出水TN含量达到GB 18918-2002一级A排放标准。A~2/O工艺通过调整外回流体积比为35%~70%,二沉池混合硝化液回流比为20%~40%的方式,只利用内部碳源,可以保持出水TN含量达到GB 18918-2002一级A排放标准。     

Dilute acid hydrolysis of lignocellulosics: An application to medium consistency suspensions of hardwoods using a plug flow reactor

A one-stage process for the high temperature rapid dilute acid hydrolysis of hardwoods, to produce simultaneously furfural and fermentable sugars, is described. A continuous plug flow reactor unit designed to hydrolyse medium consistency wood suspensions (up to 13% w/w in solids) has been operated at capacities up to 90 kg/h, with temperatures ranging from 190°C to 240°C and 20-120 s as residence times. The final products, mainly furfural and sugars, have been analyzed using high performance liquid chromatography. Yields of 15 kg of hexoses (30% of the theoretical potential) and 10 kg of furfural (65% of the theoretical potential) for 100 kg of sawdust (dry basis) have been obtained. Two pseudokinetic modeis were used to simulate the pentosan and hexosan acid hydrolysis reactions. A Flowtran Simulation has been conducted resulting in mass and energy balances for an eventual industrial unit.     

Intensifying chitin hydrolysis by adjunct treatments – an overview

Chitin is, after cellulose, the most abundant organic natural polysaccharide on Earth, being synthesized as a dominant component in the exoskeletons of crustaceans, among other sources. In the processing of seafood for human consumption, between 40 and 50% of the total raw material mass is wasted, causing a significant problem for the environment owing to its slow degradation. Efforts to find uses for chitin derivatives, particularly their oligomers, have intensified since these chemicals are highly functional and offer a wide range of applications, especially as antimicrobial agent. As a consequence, some adjunct treatments, either chemical or physical in nature, have been employed to assist acid and enzymatic hydrolysis. This work provides a detailed review of the methods employed to intensify the formation of chitin oligomers, particularly focusing on the adjunct treatments used (microwave, ultrasonication, steam explosion and gamma irradiation), and an evaluation of the yield and characteristics of the oligomers formed. Adjunct treatments are more suitable for enzymatic hydrolysis since these treatments modify the chitin structure, and enhance the hydrolysis rate and yield of the oligomers, under milder reaction conditions. For future research, it would be worth trying pre‐treatments like the application of high‐pressure to chitin in order to lower its crystallinity. © 2017 Society of Chemical Industry     

Imidazoline hydrolysis in alkaline and acidic media—A review

The literature was reviewed for information on imidazoline hydrolysis. Conflicts involving structures and mechanisms of hydrolysis have been found. Researchers also disagree as to the role of water and whether a protonated form of the imidazoline exists. However, there is agreement that the rate of hydrolysis is dependent on pH and temperature.     

尿素水解方法的简述及展望

综述了现今国内外尿素水解技术的研究现状,对各种水解技术的优点和存在的不足进行了梳理与总结。并展望其发展前景,提出了需进一步研究及解决的问题。     

聚氨酯弹性体水解稳定性

以聚氨酯水解机理为基础，讨论了影响聚氨酯弹性体（ＰＵＲ）水解稳定性的因素，并综述了改善ＰＵＲ水解稳定性的方法。     

ETHANOL FROM SOUTHERN HARDWOODS: THE ROLE OF PRESULFONATION IN THE ACID HYDROLYSIS PROCESS

A two-stage acid hydrolysis process is currently used in the production of ethanol from hardwoods. In this process, dilute sulfuric acid in water at high pressure and short residence times hydrolyzes the wood and first stage substrate. The chemical action is particularly impeded in the second stage by the presence of acid condensed lignin.

Presulfonation followed by delignification is proposed using a sulfur dioxide/water sulfuric acid/ethanol treatment step in place of the first stage acid hydrolysis step to alleviate this problem.

Results presented include the effects caused by varying treatment time, sulfur dioxide concentration, temperature and ethanol concentration on the degree of delignification, and, on the recovery of C₅ and C₆ sugars in the hydrolysates. A preliminary economic feasibility analysis is made to determine the impact of improved ethanol yields and lignin by-product values in the production of ethanol from hardwoods.     

厌氧水解的新解读：快速水解和慢速水解

挥发性脂肪酸（VFA）具有可生化性好、附加价值高等优点而得到广泛应用,厌氧消化产VFA是目前学术界的研究热点,但对有机物经过水解后的生物降解性能则少有论及,厌氧发酵过程中的水解产物存在“数量”和“质量”之间的权衡问题。为了进一步提高厌氧发酵过程中微生物对有机物的利用效率,突破水解对厌氧消化的限制性作用,从基质碳源释放快慢及厌氧发酵过程中碳源降解性能不同,本文将厌氧水解分为快速水解和慢速水解,分别阐述了两种水解方式的含义、分类以及优缺点,指出细胞内外碳源的释放速率和释放方式的不同是影响厌氧产酸和生物降解性能的决定性因素。最后指出快速水解与慢速水解相结合的分阶段联合处理方式,是今后厌氧消化产VFA的主要研究方向。     

塑料水解稳定剂的研究进展

简述了塑料水解的机理。重点介绍了国内外塑料水解稳定剂的制备及使用情况。比较了不同的塑料水解稳定剂的优势与应用前景。     

尿素深度水解装置运行总结

简介了国内、外成熟的尿素工艺冷凝液处理工艺的主要特点,介绍了采用国内立式水解塔处理尿素工艺冷凝液的工艺流程及装置运行情况.实践证明,装置设计是成功的,吨尿素氨耗降低了8 kg,取得了明显的经济效益和环保效益.     

二甲基二氯硅烷浓酸与恒沸酸水解方法比较

聚二甲基硅氧烷主要由二甲基二氯硅烷水解制得,介绍了二甲基二氯硅烷水解的两种方法,即浓酸水解法与恒沸酸水解法,以60 kt/a二甲基二氯硅烷水解为例,对两种水解工艺过程的用能、设备投资、占地投资等进行了计算分析。结果表明,浓酸水解方法具有成本低、能耗低、流程短等优点,将逐渐取代恒沸酸水解方法成为聚硅氧烷生产的新的发展趋势。