| 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.
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