制革污泥机械强制通风堆肥工艺的研究

利用自然通风和机械强制通风堆肥工艺对制革污泥进行了堆肥试验研究,结果表明采用强制通风堆肥技术可使污泥堆在30天内基本达到腐熟,温度、通气完全满足要求,堆肥结束后其中有机质、N、P等养分含量均能达到堆肥的成品要求。     

造纸污泥好氧堆肥处理技术研究

造纸污泥是一种生物固体废弃物，通过调节水分与C／N比，在强制通风与定期翻堆情况下，由于微生物作用，有机质发生降解，C／N比在不断下降，经过2个月左右高温堆肥，可以转化为高效的有机肥料。从堆肥过程的物理、化学及生物学指标变化可以看出，添加富含纤维素降解菌的发酵料，可以加速造纸污泥的腐熟，堆肥的阳离子交换量(CEC)与盆栽玉米增产率之间具有较好的相关性，CEC值可以作为造纸污泥堆肥腐熟程度的控制指标，CEC值≥80mmol／100g时，认为造纸污泥堆肥已经腐熟。     

造纸污泥交替式好氧厌氧堆肥实验

调节造纸污泥的水分和C/N比,经过为期50d的交替好氧厌氧堆肥处理,污泥有机质发生降解,TN、TP和TK含量都呈上升趋势,挥发性固体和有机碳分别达到60%和30%的稳定状态,堆肥的种子发芽率达到95%以上,大肠杆菌数低于国家卫生标准,实现造纸污泥无害化、稳定化和减量化的要求.腐熟的污泥堆肥成为高价值的农用产品.     

塔式高温好氧堆肥发酵处理工程实践

对某地区污水厂脱水污泥处理工程规模为处理脱水污泥20吨/日,污泥含水率为80%。采用塔式高温好氧堆肥发酵工艺,再经过二次腐熟,可使污泥达到减量化、稳定化和无害化。运行过程中对温度、有机质、含水率、无机营养成分和发芽指数等参数进行监测,结果表明,该工艺堆肥物料温度快速升至55℃以上,并且可以持续5天以上,有机质含量可达到40%,最终物料含水率小于40%,最终堆肥成为有机营养土。     

造纸污泥堆肥作为土壤改良剂的肥效研究

利用造纸污泥堆肥研制出颗粒状土壤改良剂，并进行了菜心、玉米盆栽试验及大田玉米试验，结果表明，土壤改良剂不仅能促进菜心、玉米生长，提高N、P养分吸收，而且能降低土壤容重、增加土壤有效磷含量，有一定的保氮作用，造纸污泥土壤改良剂农业应用不会造成土壤与农产品污染。     

重金属在土壤-作物体系中的累积行为研究(Ⅰ)——造纸污泥堆肥农用的重金属污染研究

选取造纸污泥堆肥作为菜园土肥源进行盆栽实验,通过种植油菜和芦荟,着重研究了施加造纸污泥堆肥后作物和土壤中的重金属含量分布。盆栽实验显示施加堆肥可以增加作物的生物量,提高土壤肥力:重金属测定结果表明,添加造纸污泥堆肥的土壤,其重金属含量符合标准规定,且作物中的重金属含量远远低于我国蔬菜质量标准规定值。在一定时期内农田施用造纸污泥堆肥不会造成重金属污染。     

污泥堆肥腐熟度的研究

污泥堆肥的腐熟度是评价堆肥稳定性及安全性的重要指标。利用自制的污泥堆肥装置进行实验,对堆肥的腐熟度指标进行研究。污泥与秸秆按照体积比为3:2进行混合,在常温下好氧堆肥30天。观测了堆肥过程中温度、pH值、有机质等参数的变化情况,以及对产生这种变化的原因进行了分析。实验研究发现,光学指标、挥发性物、种子发芽指数三项指标具有良好的评价效果。     

城市污水污泥堆肥技术研究进展

堆肥化技术是使污水厂污泥达到稳定化和无害化的一种经济而有效的手段。本文介绍了城市污水污泥堆肥技术,以及其在国内外的发展、应用,并对该技术存在的问题和应用前景进行探讨。     

造纸物化污泥好氧堆肥发酵供氧方式研究

实验证明造纸物化污泥堆肥物料采用传统的通风供氧不能完全进入好氧堆肥的过程,分析其原因是造纸物化污泥浓度低,自由空域少,通风氧不能进入其内部造成的。本文提出了一种新型的渗透供氧方式。实验证明:采用APMP制浆黑液作为渗透供氧的供给者,与通风供氧相结合,既能解决造纸物化污泥堆肥物料氧气供给问题,又能收到处置APMP制浆黑液的效果。     

城市污水厂剩余污泥快速好氧堆肥的研究

以某小区生活污水处理站的脱水压滤后的污泥为对象,将脱水压滤污泥进行堆肥实验,研究了污泥堆肥过程中污泥的温度、含水率、有机质、pH、总氮总磷含量、重金属含量及其形态等的变化情况。结果发现:在堆肥以后,污泥的含水率、有机质有明显的下降,pH保持中性,总氮有所下降,总磷有所上升。堆肥能使可被植物吸收利用的大部分重金属含量降低,即不稳定态重金属含量减少。     

Survival of coliform bacteria in static compost piles of dairy waste solids intended for freestall bedding

Dairy waste solids separated from a slurry by a centrifugal separator were composted in 12 static piles. Seven of the compost piles were naturally aerated, and five were aerated by a fan that forced air through the piles of solids. The natural aeration process aged the manure solids in an unconfined pile. The fan in the forced aeration process forced air into a perforated plenum beneath the compost piles. Dairy waste solids in each compost pile were heated into the thermophilic temperature range and generally composted well. At most sampling points, coliform bacteria declined to low or undetectable numbers early in the composting period. However, as the composting process proceeded, bacterial numbers increased to approximately those present in raw dairy waste solids. Findings of this study suggest that composting offers little benefit toward net reduction in coliform bacterial numbers in dairy waste solids.     

The influence of wort aeration and yeast preoxygenation on beer staling processes

The influence of oxygen on the beer staling process is considered to be of major importance. Therefore, the impact of wort aeration, which is thought to cause wort oxidation processes, on beer ageing, has been examined. Pilsner and ale beers were produced with the classical wort aeration technique or by the use of the yeast preoxygenation process, in which yeast cells are exposed to oxygen before fermentation. The staling of these beers was studied using P&T GC–MS and sensory analysis. GC–MS analyses of the natural and forced aged beers showed no significant differences between the two treatments. Sensory evaluation of natural and forced beers confirmed these results. Thus, normal wort aeration (8 mg/l) does not appear to determine flavour stability in a direct manner. This is probably due to the short contact of the wort with oxygen at low temperatures before the onset of fermentation.     

Mercury in municipal solid waste in China and its control: a review

Although a potentially significant and preventable source of environmental pollution, mercury in municipal solid waste (MSW) has not received adequate attention in China. Discarded mercury-containing products, if not recycled, ultimately release mercury to air, soil, and groundwater, even after being properly collected and disposed of in MSW management facilities. This review presents an overview on mercury in MSW and describes the emissions associated with landfilling, incineration, and composting in China. Besides end-of-pipe technologies for controlling mercury emissions from MSW management, strategies for controlling mercury in MSW are also discussed, focusing on mercury source reduction and recycling. Batteries and fluorescent lamps contribute to approximately three-quarters of mercury in MSW, and are expected to remain as significant sources of mercury in the near future. Reducing or eliminating the mercury contents in household products, particularly batteries and fluorescent lamps, should be the top priority in controlling mercury in MSW, while it is also important to set mercury contents in consumer products at acceptable and achievable levels based on a life-cycle approach. Meanwhile, cost-effective recycling programs should be developed targeting products containing elemental mercury, such as medical thermometers and sphygmomanometers, and waste products with high mercury contents (e.g., button cells) as well.     

通气培养对小球藻生长及生物组成的影响

采用小球藻进行了静置培养和通气培养试验,研究了通气条件对小球藻生长速度、生物量、生物组成及脂肪酸组成的影响。结果表明:相对于静置培养(不通气),通气培养条件下,小球藻在稳定期的生长速度、生物量及其单位产量上高出10倍以上,差异极显著;小球藻的蛋白质含量、总糖含量明显较高,而总脂含量、淀粉含量则较低;小球藻饱和脂肪酸含量显著降低,不饱和脂肪酸特别是多不饱和脂肪酸含量升高。不同通气量对小球藻的生长也存在差异,其较适宜的通气条件为1L/min。在小球藻的培养过程中,可通过适宜的通气措施来改善培养效果和获得较高的目标产物。     

An aeration trial of bulk stored peanuts for the control of insect infestation and quality loss

An aeration trial was conducted at Kingaroy, Queensland, Australia, to compare upward flow forced aeration with natural ventilation. Cylindrical concrete bins, each having a capacity of 170 tonnes, filled with bulk unshelled peanuts, were used. The aeration rate was approximately 2.5 l/s per tonne of peanuts with an average of 12 hr of fan operation per week.This resulted in a slight drop of the average peanut temperature (2–6°C) in a period of 9 months. The slight drop is believed to be due to unavailability of suitable inlet air temperatures during aeration.The increase in average moisture content of the aerated bulks was negligible. However, the moisture content of peanuts at the bottom of all bins increased from about 6.5 to 10%, regardless of aeration.Analysis of bulk samples after ten months of storage showed the average infestation level of the aerated bins to be considerably less than the level of the naturally ventilated bins. Free fatty acid content was also higher in ventilated bins than in aerated bins. There were no significant differences in viability and appearance of the kernels.     

改良型氧化沟工艺处理箱纸板制浆废水

介绍了采用FASJet射流曝气系统的改良型氧化沟系统处理以废纸造牛皮箱纸板废水的设计及启动调试。运行结果表明,此工艺及参数选择合理、运转稳定,出水水质可达到造纸工业水污染物排放的国家标准。     

CONTENTS OF CYTOCHROMES IN YEAST

The contents of cytochromes in yeast were determined quantitatively from the absorption spectra, using a solid cell paste of intact yeast. During the industrial production of baker's yeast, the contents of the cytochromes, particularly of cytochrome aa₃ at successive stages, increased gradually with increasing aeration. In semi-aerobically grown baker's yeast, the contents of cytochromes aa₃, b and c were 0·9, 2·9 and 2·9 × 10^?5 moles/litre of fresh yeast (total amount 6·7 × 10^?5 moles/litre), while in vigorously aerated commercial baker's yeast the respective values were 2·3, 4·8 and 5·2 × 10^?5 moles/litre (total amount 12·3 × 10^?5 moles/litre). In brewer's yeasts separated after the brewing process, the contents of cytochromes were markedly lower than in baker's yeast grown with limited aeration, whereas in top-fermenting yeast the total cytochrome content, aa₃ + b + c, was in some samples markedly higher, 7·1 × 10^?5 moles/litre, than in bottom-fermenting brewer's yeast, 2·4 × 10^?5 moles/litre. When brewer's bottom yeast was grown on a laboratory scale under increasing aeration, a maximum appeared in the cytochrome contents when aeration was moderate, and increased aeration inhibited the formation of cytochromes. The cytochrome contents in brewer's bottom yeast may exceed the amounts found in commercial baker's yeast. In addition to aeration, the type of metabolism influences the amounts of cytochromes in yeast.     

啤酒酿造过程中影响乙醛变化因素的研究

有针对性地提出了酿造过程中影响乙醛形成的生理内因和环境外因 ,并从主要的几个方面进行了研究。结果表明 ,酿造过程染菌、麦汁充氧控制不合理、二次发酵酒添加是造成成品啤酒中乙醛含量偏高的主要环境外因。在实际生产中 ,应加强CIP清洗 ,特别是种酵母罐的清洗及无菌空气过滤的控制工作 ,并合理控制麦汁的溶解氧含量 ,尽可能减少二次发酵酒的添加。     

Dynamics of the co‐composting of barley waste with liquid poultry manure

Co‐composting of barley waste with liquid poultry manure was assessed by monitoring several chemical and biological parameters related to compost stability/maturity throughout a 103 day period. A compost of solid poultry manure was used as the control, because a compost could not be obtained from the liquid manure. The materials composted reached thermophilic stage temperatures within 4 days, lasting for more than 10 days; thereafter the temperature decreased rapidly to around ambient levels. The initial pH value was around 9 for both mixtures and, despite an initial decrease, high values were maintained over the entire co‐composting process. Electrical conductivity increased with composting time, while the opposite behaviour was observed for total carbon content. Organic matter loss in the co‐composting of barley waste with liquid poultry manure was 35%. In general, the final products showed physicochemical characteristics considered normal for such materials, but pH and ammonia content values were high. The results of a bioassay test performed with seeds of three plant species (ryegrass, wheat and barley) indicated that the co‐compost could be considered mature from a biological point of view, since phytotoxicity was absent for ryegrass and barley. Comparison of these data with those obtained for solid poultry manure indicated that barley waste notably improved the composting efficiency as well as the quality of the final product. © 2003 Society of Chemical Industry