The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methan...The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.展开更多
The cracking behavior of lightweight aggregate concrete(LWAC) was investigated by mechanical analysis, SEM and cracking-resistant test where a shrinkage-restrained ring with a clapboard was used. The relationship betw...The cracking behavior of lightweight aggregate concrete(LWAC) was investigated by mechanical analysis, SEM and cracking-resistant test where a shrinkage-restrained ring with a clapboard was used. The relationship between the ceramsite type and the cracking resistance of LWAC was built up and compared with that of normal-weight coarse aggregate concrete(NWAC). A new method was proposed to evaluate the cracking resistance of concrete, where the concepts of cracking coefficient ζt(t) and the evaluation index Acr(t) were proposed, and the development of micro-cracks and damage accumulation were recognized. For the concrete with an ascending cracking coefficient curve, the larger Acr(t) is, the lower cracking resistance of concrete is. For the concrete with a descending cracking coefficient curve, the larger Acr(t) is, the stronger the cracking resistance of concrete is. The evaluation results show that in the case of that all the three types of coarse aggregates in concrete are pre-soaked for 24 h, NWAC has the lowest cracking resistance, followed by the LWAC with lower water absorption capacity ceramsite and the LWAC with higher water absorption capacity ceramsite has the strongest cracking resistance. The proposed method has obvious advantages over the cracking age method, because it can evaluate the cracking behavior of concrete even if the concrete has not an observable crack.展开更多
基金Project(2014BAC31B01)supported by the National Science&Technology Support during the 12th Five-Year Plan Period,ChinaProjects(2015GSF117016,2015GSF115037)supported by the Key Research&Development Project of Shandong Province,China
文摘The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.
基金Project(51078090)supported by the National Natural Science Foundation of China
文摘The cracking behavior of lightweight aggregate concrete(LWAC) was investigated by mechanical analysis, SEM and cracking-resistant test where a shrinkage-restrained ring with a clapboard was used. The relationship between the ceramsite type and the cracking resistance of LWAC was built up and compared with that of normal-weight coarse aggregate concrete(NWAC). A new method was proposed to evaluate the cracking resistance of concrete, where the concepts of cracking coefficient ζt(t) and the evaluation index Acr(t) were proposed, and the development of micro-cracks and damage accumulation were recognized. For the concrete with an ascending cracking coefficient curve, the larger Acr(t) is, the lower cracking resistance of concrete is. For the concrete with a descending cracking coefficient curve, the larger Acr(t) is, the stronger the cracking resistance of concrete is. The evaluation results show that in the case of that all the three types of coarse aggregates in concrete are pre-soaked for 24 h, NWAC has the lowest cracking resistance, followed by the LWAC with lower water absorption capacity ceramsite and the LWAC with higher water absorption capacity ceramsite has the strongest cracking resistance. The proposed method has obvious advantages over the cracking age method, because it can evaluate the cracking behavior of concrete even if the concrete has not an observable crack.
