玉米芯生产单细胞蛋白研究：生产SCP的Candida Boidinii No.22 …

本研究对用玉米芯酸水解液生产ＳＣＰ的Ｃａｎｄｉｄａ ｂｏｉｄｉｎｉｉ Ｎｏ．２２０１诱变株进行了初步筛选,选出了诱变菌株Ｙ－１０８,其产量比原菌种增加２５％左右,达到了２８ｇ／Ｌ－３０ｇ／Ｌ,产品粗蛋白含量为３５％。初步研究表明,利用诱变株Ｙ－１０８生产ＳＣＰ有可能成为未来较好的饲料蛋白添加剂。     

采用新型载体的好氧流化床的动力学研究

本文以稀释的味精废水为基质,对采用新型载体ＬＳＡＲ的好氧生物流化床进行动力学研究,求得动力学参数分别为γｍａｘ＝８．８１（ｇＣＯＤ／ｇｖｓ．ｄ）,Ｋｓ＝０２８９（ｇＣＯＤ／Ｌ）,Ｋｄ＝０．０４６ｄ＾－１,Ｙ＝０．１６（ｇｖｓ／ｇＣＯＤ）。其值基本处于文献的报导之内,说明以ＬＳＡＲ为载体的好氧微生物膜具有较好的活性,ＬＳＡＲ作为好氧流化床载体是可行的。     

硫化物恶臭脱除技术的发展

介绍了硫化物脱臭技术的现状,论述了生物脱臭技术及活性炭吸附技术的研究和进展。针对炼厂恶臭污染日益突出的特点,应用泥炭生物填料塔及活性炭吸附技术,对５０μＬ／Ｌ以下的Ｈ２Ｓ脱除工艺进行了研究。生物脱臭法采用经过驯化后的泥炭生物填料塔,Ｈ２Ｓ脱除率可接近１００％,负荷达到８５ｇＨ２Ｓ－Ｓ／（ｍ３干填料·ｈ）以上;活性炭吸附法采用日本的两种活性炭（ＩＶＰ和Ｃｅｎｔａｕｒ）,吸附容量分别达到１７０ｇ／Ｌ和８０ｇ／Ｌ以上。上述工艺均可应用于炼厂中低浓度硫化物恶臭污染的治理     

分光光度法测定COD_(Cr)的试验条件选择

用分光光度法测定水中化学需氧量ＣＯＤＣｒ,通过正交试验选择氧化的最佳选择。试验结果表明对ＣＯＤＣｒ值为５０～１０００ｍｇ／Ｌ的水样：氧化剂Ｋ２Ｃｒ２Ｏ７用量为０．２０～０．４０ｍｏｌ／Ｌ,催化剂Ａｇ２ＳＯ４用量为１０ｇ／ＬＨ２ＳＯ４,消解时间１０ｍｉｎ,加热温度１８０℃。用ＣＯＤＣｒ为１３８ｍｇ／Ｌ的质控标样进行验证试验,其绝对误差为０．５～３．０ｍｇ／Ｌ。与标准方法相比用分光光度法测定ＣＯＤＣｒ具有分析误差小,省时、省力,节约药剂的特点。     

Cl~-含量对含油污泥絮凝效果的影响

针对化学混凝处理含油污泥中混凝剂投加量大而混凝效率较低的问题,通过实验研究了Ｃｌ－对混凝剂处理含油污泥絮凝效率的影响。实验中采用抽滤的方法来测定絮凝效率。实验结果表明Ｃｌ－是影响絮凝效率的重要因素,Ｃｌ－＜１００００ｍｇ／Ｌ时,Ａｌ２（ＳＯ４）３、ＰＡＣ混凝效果较好,Ｃｌ－＞２００００ｍｇ／Ｌ时,ＰＡＭ的混凝效果较好。     

中药川附子痕量砷的测定

本文报道了以ＨＮＯ３ － ＨＣｌＯ４ 混酸消化、Ｈ２ＳＯ４ － ＫＩ－ Ｔｅ（ Ⅳ） 体系极谱法测定中药川附子中的砷。该方法使样品消化过程的砷损失大为减少并简化了分析过程。样品中砷含量在０－２ ～０－６μｇ·ｇ－ １ ,回收率８４ ％ ～１０８ ％ 。     

奶牛场废水处理技术研究

本文对奶牛场废水处理工艺进行了研究。结果表明,奶牛场废水经混凝处理后,ＣＯＤｃｒ 从２０１０ ｍｇ／Ｌ 下降到５６３ｍｇ／Ｌ～６９１ ｍｇ／Ｌ,ＮＨ３ － Ｎ 可从７１ ｍｇ／Ｌ 下降到２５ ｍｇ／Ｌ～３３ ｍｇ／Ｌ,ＣＭ 从１８０ 度下降到４０ 度～７０ 度。如采用混凝表面曝气处理工艺,可使奶牛场废水达到国家排放标准,且处理工艺简单、投资少、运行费低、易操作管理     

半挥发性有机物GC/MS分析方法研究

用气相色谱／质谱（ＧＣ／ＭＳ）研究分析了环境中的半挥发性有机标准物。以十氟三苯基磷作调机物,对ＧＣ／ＭＳ仪器系统进行了调整,离子丰度值符合美国环保局（Ｕ．Ｓ．ＥＰＡ）１９８６年推荐的离子丰度标准。测定了３２种目标化合物的保留时间及相对保留因子ＲＦ值,结果表明除五氯苯酚不达标外,其余化合物的ＲＦ值均符合要求,３１种目标化合物的加标回收率为２１％～９７％,相对标准偏差为３．１％～２４．１％,符合美国环保局８２７０方法质量控制检验标准。最后对建立定量校正库与ＧＣ／ＭＳ分析进行了讨论     

铬酐退铜液影响退铜因素的研究及分析

铬酐退铜由于成份简单、退铜速度快、易于操作而为厂家普遍采用。本文着重研究了铬酐退铜液影响退铜效果的主要因素,通过对「ＣｒＯ３」－ｔ以及「Ｃｕ」＾２＋－ｔ曲线的测量找出退铜液的反应规律。实验表明：提高「ＣｒＯ３」、酸浓度均可提高溶液的退铜能力;溶液中「ＳＯ４」＾２－的增加,则加剧铜的溶解;当溶液中的「ＣｒＯ３」＝１２３－１２６ｇ／Ｌ「Ｃｕ」＾２＋＝２２－２７ｇ／ｌ时,退铜液即失效。失效的退铜液靠单纯     

离子色谱法测定钻井废水中的S~(2-)

川东气田生产过程中产生的废水含有硫化物,且色度深、浊度大。为测定废水中的Ｓ２－含量,实验探索了将Ｓ２－氧化成ＳＯ２－４后用离子色谱测定的方法。进行了Ｓ２－的转化率实验,结果表明：Ｓ２－含量在０～２．７ｍｇ／Ｌ范围内可以被完全氧化成ＳＯ２－４,转化率为９８．８％～１０８．０％。同时进行了该方法的精密度和准确度实验,并与碘量法进行了对比,对同一标样和实际样品的测定两种方法的结果吻合较好,该方法测定钻井废水中的Ｓ２－含量,可以避免色度、浊度的干扰,且简便、灵敏、准确     

A comparison of pretreatments on release of sugars from sweet sorghum bagasse for bioethanol production

Dilute acid pretreatment and steam pretreatment were evaluated for maximum sugars release and ethanol production from sweet sorghum bagasse (SSB). The fermentation potential of the condensate and hydrolysate obtained from steam pretreatment (10 kg/cm², 10 minutes) and dilute acid hydrolysis (1% (w/w) sulphuric acid, 25% substrate loading) respectively, was checked with Pichia stipitis NCIM 3497 and Debaryomyces hansenii sp. Ethanol production and yield using acid hydrolysate was higher with Debaryomyces hansenii sp. (28.4 g/L and 0.37 g/g respectively) as compared with Pichia stipitis NCIM 3497 (21.9 g/L and 0.29 g/g respectively).     

利用酸法和酶法水解玉米芯发酵生产木糖醇

利用稀硫酸和纤维素酶预处理玉米芯,得到不同木糖含量的水解液,并利用热带假丝酵母进行发酵.结果表明,酸法获得水解液中的木糖浓度较高,酸法水解组中木糖醇产量和转化率均略高于酶法水解组,两者间差异不显著.     

Study of the influence of dilute acid pre-treatment conditions on glucose recovery from Moringa oleifera Lam for fuel-ethanol production

The influence of temperature (175 to 195°C), residence time (5 to 15 min), and sulfuric acid concentration in high (2 to 4% w/w) and low (0.5 to 1.5% w/w) levels in dilute acid pretreatment of Moringa oleifera Lam is studied. Glucose recoveries in the liquid fraction and in the hydrolyzed insoluble fraction as well as the presence of inhibitors in the liquid fraction are determined. Best experimental results are achieved at 185°C, 2% w/w acid concentration, and 5 min reaction time obtaining a glucose recovery of 83.68%. An increment in 48.81% in glucose yield compared with the one of not pretreated Moringa is obtained. 0.13 g ethanol/g Moringa from fermentation of pre-hydrolysate and hydrolysate obtained at the optimal pre-treatment conditions are obtained.     

Resource utilization of wasted black pulping liquor for biodiesel production by Scenedesmus obliquus

The possibility of application of black liquor for oil-riched algae cultivation is inspected. The results show that after ligin removal and enzymatic hydrolysis, the hydrolysate of black liquor contained 9.18 g L^?1 of reducing sugar. When the hydrolysate was used for Scenedesmus obliquus (S. obliquus) cultivation, a 1.23 g L^?1, 24.52%, and 23.20 mg L^?1d^?1 was obtained for growth yield, oil content, and the lipid productivity, seperately. The hemicellulose was extracted from black liquor and hydrolyzed. With addition of 3 g L^?1 yeast extract, the growth yield of S. obliquus in hemicellulose hydrolysate increased to 2.7 g L^?1, an increase of 26.8% than that of in glucose medium, oil content was 25.7% and the final lipid productivity reached 53.37 mg L^?1d^?1. The results indicate that black liquor can not be directly used by microalgae, but with approprate treatment, the carbohydrate of it could be recovered and uitilized for the oil production from microalgae.     

Direct utilization of kitchen waste for bioethanol production by separate hydrolysis and fermentation (SHF) using locally isolated yeast

Kitchen wastes containing high amounts of carbohydrates have potential as low-cost substrates for fermentable sugar production. In this study, enzymatic saccharification of kitchen waste was carried out. Response surface methodology (RSM) was applied to optimize the enzymatic saccharification conditions of kitchen waste. This paper presents analysis of RSM in a predictive model of the combined effects of independent variables (pH, temperature, glucoamylase activity, kitchen waste loading, and hydrolysis time) as the most significant parameters for fermentable sugar production and degree of saccharification. A 100 mL of kitchen waste was hydrolyzed in 250 mL of shake flasks. Quadratic RSM predicted maximum fermentable sugar production of 62.79 g/L and degree of saccharification (59.90%) at the following optimal conditions: pH 5, temperature 60°C, glucoamylase activity of 85 U/mL, and utilized 60 g/L of kitchen waste as a substrate at 10 h hydrolysis time. The verification experiments successfully produced 62.71 ± 0.7 g/L of fermentable sugar with 54.93 ± 0.4% degree of saccharification within 10 h of incubation, indicating that the developed model was successfully used to predict fermentable sugar production at more than 90% accuracy. The sugars produced after hydrolysis of kitchen waste were mainly attributed to monosaccharide: glucose (80%) and fructose (20%). The fermentable sugars obtained were subsequently used as carbon source for bioethanol production by locally isolated yeasts: Saccharomyces cerevisiae, Candida parasilosis, and Lanchancea fermentati. The yeasts were successfully consumed as sugars hydrolysate, and produced the highest ethanol yield ranging from 0.45 to 0.5 g/g and productivity between 0.44 g L^–1 h^–1 and 0.47 g L^–1 h^–1 after 24-h incubation, which was equivalent to 82.06–98.19% of conversion based on theoretical yield.     

Highly efficient conversion of sugarcane bagasse pretreated with liquid hot water into ethanol at high solid loading

Liquid hot water (LHW), an environmental-friendly physico-chemical treatment, was applied to pretreat the sugarcane bagasse (SCB). Tween80, a non-ionic surfactant, was used to enhance the enzymatic hydrolysis of the pretreated SCB. It found that 0.125 mL Tween80 /g dry matter could make the maximum increase (33.2%) of the glycan conversion of the LHW-pretreated SCB. A self-designed laboratory facility with a plate-and-frame impeller was applied to conduct batch hydrolysis, fed-batch hydrolysis, and the process of high-temperature (50°C) fed-batch hydrolysis following low-temperature (30°C) simultaneous saccharification and fermentation (SSF) which was adopted to overcome the incompatible optimum temperature of saccharification and fermentation in the SSF process. After hydrolyzing LHW-pretreated SCB for 120 h with commercial cellulase, the total sugar concentration and glycan conversion obtained from fed-batch hydrolysis were 91.6 g/L and 68.3%, respectively, which were 9.7 g/L and 7.3% higher than those obtained from batch hydrolysis. With Saccharomyces cerevisiae Y2034 fermenting under the non-sterile condition, the ethanol production and theoretical yield obtained from the process of SSF after fed-batch hydrolysis were 55.4 g/L and 88.3% for 72h, respectively, which were 15.5 g/L and 24.7% higher than those from separate fed-batch hydrolysis and fermentation. The result of this work was superior to the reported results obtained from the LHW-pretreated SCB.     

Characteristics of Anaerobic Fermentation with Different Parts of Corn Stalks at Low Concentrations

In order to obtain the characteristics of anaerobic fermentation with different parts of corn stalks at low concentrations, air-dried corn stalks stem bark (SB), stem pith (SP), leaves (L), and corn stalks (CS) were, respectively, mixed with cow dung to perform fermentation at the temperature of 35 ^oC and carbon-to-nitrogen ratio (C/N) of 25. Mixed with cow dung compost, the fermentation broths were adjusted to a neutral pH value. Along with the enhancing of the total solid (TS) content of SB, SP, L, and CS fermentation broths, both of the daily biogas yields and methane contents increased under the same fermentation condition, except for Sample TS 6% of L. The optimal TS content of SB, SP, L, and CS broth is 8%, 5%, 10%, and 8%, separately. In 35 days, the highest methane yield of SB, SP, L, and CS broth was 125.0 mL/(volatile solid) VS g, 115.3 mL/VS g, 109.7 mL/VS g, and 80.0 mL/VS g, respectively, and the potential of methane transformation production of broth ranks as: SB> L> SP> CS. Daily methane producing rate of SB, SP, and L broth are faster than that of CS. It is necessary to separate the corn stalks into different parts to ferment because the optimal fermentation concentrations for the different parts are different. Additionally, the Gompertz equation was also adopted to simulate the anaerobic digestion process of different materials. The Gompertz equation fitting parameters show that the biodegradation (from easy to difficult) was: L < SP < SB < CS.     

Bio-Hydrogen Synthesis from Wastewater by Anaerobic Fermentation Using Microflora

Biological hydrogen production was investigated using biomass in palm oil mill effluent (POME) and artificial wastewater containing 10g glucose under anaerobic fermentation in a batch process. Activated POME sludge and different types of composts were collected as sources of inocula for the study. The anaerobic microflora was found to yield significant amounts of hydrogen. The experimental results show that the gas composition contained hydrogen (66–68%) and carbon dioxide (32–34%). Through out the study, methane gas was not observed in the evolved gas. The hydrogen production was accompanied with the formation of acetate and butyrate. Furthermore, the cumulative hydrogen data were fitted to a simple model developed from Gompertz Equation, where the lag phase time, hydrogen production potential and hydrogen production rate at various conditions were quantitatively estimated.     

An effective approach to improve ethanol productivity by simultaneous saccharification and fermentation of rice straw

Fuel ethanol was produced using rice straw with the simultaneous saccharification and fermentation (SSF) method. The influence of cellulose liquefaction pretreatment and Fe²⁺ quantity on ethanol productivity was investigated in detail. At the same time, the optimized conditions including fermentation temperature, Fe²⁺ amount, yeast inoculation quantity, and the inoculated cellulose enzyme dosage in the SSF process were systematically investigated by analyzing fuel ethanol yield. The result indicated that fuel ethanol yield was 0.319 g per gram rice straw by SSF approach when appropriate amount of Fe²⁺ was added into the reaction system. The optimal technology parameters were: fermenting temperature of 36°C, Fe²⁺ amount of 4 mg · g^?1, inoculating proportion of 20%, cellulose enzyme of 20 IU · g^?1, and Pachysolen tannophilu/saecharomyces cerevisiae of 1:2 ratio. The ethanol yield under the best conditions was larger than that of the control group. We hope that this research can facilitate to achieve large-scale comprehensive utilization for rice straw.     

Performance analysis of bioethanol (Water Hyacinth) on diesel engine

The increasing consumption and excessive extraction of conventional fuels is the matter of serious concern. Nowadays, world is looking for alternative sources of fuel which can partially replace conventional fuel dependence. The current investigation intends to provide evaluation of bio-ethanol preparation from Water Hyacinth (WH) and its influence on diesel engine performance under various operating conditions. This study explores the extraction of glucose from WH (Eichhornia crassipes) pretreated with sulfuric acid (H₂SO₄) for production of bio-ethanol. For the production of bio-ethanol different concentrations of H₂SO₄ acid hydrolysate (1%, 2%, 4%, 6%, 8%, and 10%) were prepared which was then followed by fermentation with cellulose fermenting yeasts. From results, it was observed that 4% H₂SO₄ acid hydrolysis produces higher concentrations of ethanol than other concentrations. Bio-ethanol extracted from WH was blended with diesel in different proportions (5%, 10%, 15%, 20%, and 25%) v/v and performance and emissions were experimentally investigated on single cylinder diesel engine under various load conditions. Experimental results show that 5 BED [5% bio-ethanol (WH + 95%diesel v/v) and 10BED (10% bio-ethanol (WH + 90%diesel v/v)] produces higher brake power, brake thermal efficiency and brake mean effective pressure with improved exhaust emission profiles than any other blend.