超高温堆肥是近年出现的一种新技术，能够加速有机物分解，缩短堆肥腐熟时间。综述了超高温堆肥工艺方法的优缺点，总结了超高温堆肥在资源化和无害化方面的研究进展，表现在提高了难降解有机物的降解率和总氮的保留率，改善了传统堆肥中抗生素抗性基因难降解的问题，对重金属有一定的钝化效果；论述了超高温堆肥现有研究中的不足，并提出相关建议，旨在优化超高温堆肥工艺，为实际应用提供理论指导。

The aim of this work was to study the chemical and structural changes of dissolved organic matter (DOM) at the molecular level during hyperthermophilic composting (HTC) of sewage sludge using excitation-emission matrix-parallel factor (EEM-PARAFAC) combined with two-dimensional correlation spectroscopy (2DCOS) analyses. Results showed that HTC accelerated the humification process by decreasing protein-like and increasing humus substances more quickly compared to conventional thermophilic composting. The rapid humification process of HTC was related to the structural changes of DOM, in which the C-O stretching within polysaccharides could be the main factor responsible for the formation of humus substances. Redundancy analysis enabled the relationship between spectral indices and composting parameters to be explained, demonstrating that these indices can be used for assessing the degree of humification. This work has contributed to resolving the humification mechanism of HTC and expanding the application of EEM-PARAFAC and 2DCOS.Copyright © 2018 Elsevier Ltd. All rights reserved.

Composting is an efficient way to convert organic waste into fertilizers. However, waste materials often contain large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) that can reduce the efficacy of antibiotic treatments when transmitted to humans. Because conventional composting often fails to remove these compounds, we evaluated if hyperthermophilic composting with elevated temperature is more efficient at removing ARGs and MGEs and explored the underlying mechanisms of ARG removal of the two composting methods. We found that hyperthermophilic composting removed ARGs and MGEs more efficiently than conventional composting (89% and 49%, respectively). Furthermore, the half-lives of ARGs and MGEs were lower in hyperthermophilic compositing compared to conventional composting (67% and 58%, respectively). More-efficient removal of ARGs and MGEs was associated with a higher reduction in bacterial abundance and diversity of potential ARG hosts. Partial least-squares path modeling suggested that reduction of MGEs played a key role in ARG removal in hyperthermophilic composting, while ARG reduction was mainly driven by changes in bacterial community composition under conventional composting. Together these results suggest that hyperthermophilic composting can significantly enhance the removal of ARGs and MGEs and that the mechanisms of ARG and MGE removal can depend on composting temperature.

This study models and evaluates the kinetics of C-CO(2) evolution during biodegradation of plastic materials including Polyethylene (PE), PE/starch blend (PE/starch), microcrystalline cellulose (MCE), and Polylactic acid (PLA). The aerobic biodegradation under controlled composting conditions was monitorated according to ISO 14855-1, 2004. The kinetics model was based on first order reaction in series with a flat lag phase. A non-linear regression technique was used to analyze the experimental data. SEM studies of the morphology of the samples before and after biodegradation testing were used to confirm the biodegradability of plastics and the accuracy of the model. The work showed that MCE and PLA produced the high amounts of C-CO(2) evolution, which gave readily hydrolysable carbon values of 55.49% and 40.17%, respectively with readily hydrolysis rates of 0.338 day(-1) and 0.025 day(-1), respectively. Whereas, a lower amount of C-CO(2) evolution was found in PE/starch, which had a high concentration of moderately hydrolysable carbon of 97.74% and a moderate hydrolysis rate of 0.00098 day(-1). The mineralization rate of PLA was 0.500 day(-1) as a lag phase was observed at the beginning of the biodegradability test. No lag phase was observed in the biodegradability testing of the PE/starch and MCE. The mineralization rates of the PE/starch and MCE were found to be 1.000 day(-1), and 1.234 day(-1), respectively. No C-CO(2) evolution was observed during biodegradability testing of PE, which was used for reference as a non-biodegradable plastics sample.Copyright © 2011. Published by Elsevier Ltd.

The application of conventional thermophilic composting (TC) is limited by poor efficiency. Newly-developed hyperthermophilic composting (HTC) is expected to overcome this shortcoming. However, the characterization of microbial communities associated with HTC remains unclear. Here, we compared the performance of HTC and TC in a full-scale sludge composting plant, and found that HTC running at the hyperthermophilic and thermophilic phases for 21 days, led to higher composting efficiency and techno-economic advantages over TC. Results of high-throughput sequencing showed drastic changes in the microbial community during HTC. Thermaceae (35.5-41.7%) was the predominant family in the hyperthermophilic phase, while the thermophilic phase was dominated by both Thermaceae (28.0-53.3%) and Thermoactinomycetaceae (29.9-36.1%). The change of microbial community could be the cause of continuous high temperature in HTC, and thus improve composting efficiency by accelerating the maturation process. This work has provided theoretical and practical guidance for managing sewage sludge by HTC.Copyright © 2018 Elsevier Ltd. All rights reserved.

Hyperthermophilic pretreatment composting (HPC) is superior to traditional composting (TC) with shortened maturity period and increased nitrogen (N) retention. However, the mechanism associated with N retention in HPC remains unclear. In this study, we compared the impact of HPC and TC on N retention, and found the proportion of N retained in the final compost was 83.3% and 67.2% for HPC and TC, respectively. Decreased ammonification rate, urease and protease activities together with an elevated temperature were found in HPC. Illumina amplicon sequencing showed that HPC caused a major decline in microbial community richness and diversity in the thermophilic phase. Notably, bacterial (Pseudomonas and Bacillus) and fungal ammonifiers (Acremonium, Alternaria and Penicillium) decreased remarkably in HPC during this phase. Changes in the microbial community could be related to unfavorable modifications of environment from HPC, and which resulted in decreased ammonification and enzyme activities and improved N retention.Copyright © 2018 Elsevier Ltd. All rights reserved.

In considering the impact of inoculation time and the characteristics of composting material and inoculants on the usefulness of inoculation, a new composting strategy has been proposed and studied, in which three inocula were inoculated at three stages of composting process respectively: inoculum A (Thermoactinomyces sp. GF1 and GF2) was inoculated before fermentation to increase or maintain high temperature of pile, inoculum B (Coprinus cinerea and Coprinus comatus) was inoculated after thermophilic phase to promote degradation of lignin, and inoculum C (Trichoderma harzianum and Rhizopus oryzae) was inoculated after 30-day fermentation to promote degradation of cellulose. The results showed that the inoculations could significantly enhance the temperature of pile and the degradation of lignocelluloses. When inocula A, B, and C were inoculated into pile, temperature increased from 25°C to 65°C, from 33°C to 39°C and from 33°C to 38°C respectively and 35% lignin and 43% cellulose had been degraded in inoculated pile compared to the degradation of 15% lignin and 25% cellulose in control pile. As a result, the C/N ratio dropped more rapidly degraded in the inoculated pile (reached 20 after 33-day fermentation) than that in the control pile (reached 21.7 after 45-day fermentation). In addition, the volume loss in inoculated pile (76.5%) was higher than that in control pile (53.2%). The study, therefore, indicated that inoculating proper microorganisms at appropriate time improved the composting process and our new composting strategy would be propitious to the co-composting dairy manure with rice straw. Copyright © 2015 Elsevier Ltd. All rights reserved.

为了解决畜禽粪便特性不清、基质化利用研究存在片面性等问题,提高畜禽粪便基质化利用的创新支撑和产业化发展,分析了全国范围内畜禽粪便的养分特征及理化特性,归纳了通过好氧堆肥、轻简化发酵、厌氧发酵及过腹转化等方式制备无土栽培和育苗基质的典型模式和应用效果,提出基质化是畜禽粪便高值化利用的重要方式,建议尽快制定农业废弃物基质化利用标准体系,推进生物基质的高标准研发,为提高畜禽粪便的利用率和附加值、降低无土栽培的成本提供借鉴和参考。