【作者】 史晓燕；

【导师】 肖波；

【作者基本信息】 华中科技大学 ， 环境工程， 2007， 博士

【摘要】 传统污水的资源化主要是研究水本身的回用,回用水主要用于绿化、洗涤、工业冷却水等。污水回用技术,从一定程度上缓解了水资源的紧张,但是忽略了污水中含有的丰富的碳氢资源,将这些更有用的资源当作“垃圾”处理掉,降低了污水的可利用价值。污水中的COD是一种含能有机碳氢物质,从污染方面来看是污染物,然而从资源方面如果利用得当的话是丰富的有机碳氢资源。如何通过技术本身降低污水处理成本,同时将有机碳氢资源从污水中分离、富集并转化成能源产生利润反馈于污水处理,达到污水处理、水资源回用、碳氢资源回收的多重目的,是污水循环经济研究的重点。污水中资源的价值分两部分,一部分是水资源回用价值;一部分是污水中有机碳氢资源价值。如果能在污水处理的同时获得能源,则可以一举两得,真正实现可持续发展。论文针对目前污水处理现状,围绕循环经济主题,提出以回收生活污水中机碳氢资源价值为主要目的的污水循环经济新思路和具体模式。本文重点研究了污水碳氢资源回收和水回用技术,使污水循环经济更具有可行性。通过对生物质锯末物理化学性质及其环境效应的讨论,将生物质锯末这种农林废弃资源作为一种新型环境材料,用于有机废水的处理,并将吸附了有机质的锯末进行碳氢资源循环研究;利用生物质催化气化技术和厌氧发酵技术,实现碳氢资源的循环;结合人工湿地作为后续工艺,使经锯末吸附-人工湿地法处理的生活污水达到国家中水回用水的标准,实现生活污水的资源化。通过大量的研究,获得的主要成果如下:(1)针对目前水处理现状存在的问题,分析了循环经济和污水处理的关系,提出了污水处理新思路,即污水及其碳氢资源回用技术思想和模式。(2)通过锯末对生活污水TOC的静态吸附实验和动态吸附试验研究,对锯末的吸附特性及对生活污水TOC的去除效果和吸附量进行系统的分析,并对其吸附机理进行了分析探讨。试验结果表明锯末对生活污水具有较好的吸附性能,为污水及其碳氢资源回用技术奠定理论基础。(3)将生物质吸附塔放大,结合人工湿地等处理单元,形成中水回用和碳氢资源回收系统。研究了系统对对色度,浊度,CODcr、BOD5、NH3-N的处理效果,经系统处理的出水的指标均达到了《生活杂用水水质标准》(CJ/48-1999),实现污水回用和碳氢资源回收双重目标。(4)利用生物质裂解气化和催化重整技术,确定工艺条件,将碳氢资源进行能源回收利用。吸附前锯末气体产量为1.19m3/kg,富集有机物的锯末催化气化气体产量1.50m3/kg,比原始锯末气体产量提高26.1%,氢产量也增加38.8%,热值增加1349kJ/Nm3,显然吸附后的锯末其他产量远大于吸附前的锯末;此外,吸附后的锯末的产氢量也高于吸附前锯末。由此可见,在相同试验条件下,富集有机物的锯末产气量和产氢量均高于原始未吸附过的锯末,这部分是由富集和截留的有机物所贡献的。(5)采用厌氧发酵系统,利用被吸附的有机物和锯末作为碳、氮源进行了吸附前后锯末的厌氧发酵试验,生产有用的发酵产品。通过三组实验对照,空白样产甲烷量只有0.87L,未吸附锯末产气量是3.94L,吸附后锯末总产气量为18.70L,是未吸附的4倍多,吸附工艺回收的锯末日产气量明显高于原始锯末,产气总量远远大于原始锯末。试验结果证明用低成本的生物质净化处理城市生活污水,浓缩富集污水中的碳氢资源,并用吸附后的生物质作为厌氧发酵原料产生沼气能源,具有理论和实践的价值。通过SEM图片和傅立叶变换红外光谱图分析了碳氢能源循环的机理。更多还原

【Abstract】 Traditional wastewater utilization is focused on the study of water reuse itself and easing the tension of water resources to a certain extent. However, the abundant hydrocarbon resource in wastewater is overlooked and treated as“rubbish”, which lower the value available in wastewater. Actually, the effluent COD is a kind of energy resource, which is regarded as pollutant commonly from the point of pollution. How to lower treatment costs through technology itself, condense the hydrocarbon resource in wastewater and reuse the resource is the focus of this study, with the purpose of wastewater treatment, water reuse and hydrocarbon resource recycling. Wastewater resource includes two parts, value of water reuse and organic hydrocarbon resource reuse. If the sewage treatment and clean energy can be obtained at the same time, they can kill two birds with one stone and sustainable development would be realized in wastewater treatment.In response to the situation of wastewater treatment, the idea and mode of the effluent hydrocarbon energy recycling technology were brought out in this paper, with the main purpose of hydrocarbon recycling. The research was focused on water reuse and hydrocarbon recycling technology, which make wastewater recyling more feasible. The physical and chemical nature and environmental effects of sawdust were discussed and analyzed,and it was studied as a new environmental material for the treatment of organic wastewater. At the same time, the utilization of the adsorbed organic matter and the sawdust itself was researched through steam catalytic gasification of biomass and anaerobic fermentation technology, which made the hydrocarbon energy circular. On the other side, the discharge could reach the state standards for reuse water after the treatment of sawdust adsorption, combined with artificial wetlands as a follow-up process, realizing wastewater reutilization.Through a lot of experiments and researches, the main achievements were obtained as follows:(1) In view of the current status of wastewater problems, the relationship between circular economy and wastewater treatment was analyzed, and a new wastewater treatment idea was proposed for the first time, namely the idea of sewage hydrocarbon resource recycling technology and its demonstration pattern.(2) Static and dynamic adsorption experiments on TOC removal were studied; further adsorption characteristic and mechanism were analyzed, which showed that sawdust had good adsorption properties for municipal wastewater. These established a theoretical basis for the wastewater carbon hydrogen energy recycling technology..(3) The effluent water quality of BOD5,chroma and CODCr and ammonia-nitrogen reached or even excelled to the " daily miscellaneous water quality standards" (CJ/48-1999) after the treatment of sawdust adsorption and secondary treatment of constructed wetland, which realize the objects of water reuse and hydrocarbon concentratation.(4) Sawdust and organic material adsorbed could be used for energy recovery through steam catalytic gasification technology. Fuel gas yield was 1.5m3/kg with used sawdust rich in organics, which was 26.1% higher than that of original sawdust, 1.19m3/kg. The hydrogen yield of former was also 38.8% higer. In the same way, the lower heat value of fuel gas of used sawdust was 1349 kJ/m3 more than that of original sawdust. Thus, the same experimental conditions, the used sawdust rich in organics had higher gas production rate and hydrogen production rate than that of the original sawdust, which was contributed to the accumulation of organic matter adsorbed.(5) The sawdust and adsorbed carbon hydrogen was used to produce methane through anaerobic fermentation system. The original sawdust and used sawdust rich in organics were experimented. The methane production of used sawdust was 18.70L, more than 4 times of original sawdust. Gas production volume of used sawdust was much higher than that of original sawdust. SEM photographs and infrared mapping of different column revealed hydrocarbon energy recycling mechanism.更多还原