Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review

• Diversity and detection methods of pathogenic microorganisms in sludge. • Control performance of sludge treatment processes on pathogenic microorganisms. • Risk of pathogen exposure in sludge treatment and land application. The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.     

Water resource conservation promotes synergy between economy and environment in China’s northern drylands

•Considering evenness provides a more accurate assessment of sustainable development. •Water resource conservation drives industrial transformation. •Synergy between economic development and environmental protection is achieved. •Regional collaboration over water could promote sustainable development in drylands. Water resource availability is the major limiting factor for sustainable development in drylands. Climate change intensifies the conflicting water demands between people and the environment and highlights the importance of effective water resource management for achieving a balance between economic development and environmental protection. In 2008, Inner Mongolia, typical dryland in northern China, proposed strict regulations on water exploitation and utilization aimed at achieving sustainable development. Our study is the first to investigate the effectiveness and performance of these long-standing water conservation regulations. Our analyses found that the regulations drove industrial transformation, evidenced by the decreasing proportion of environmentally harmful industries such as coal and steel, and the increasing proportion of tertiary industries (especially tourism). Following industrial transformation, economic development decoupled from industrial water consumption and subsequently led to reduced negative environmental impacts. Based on these results, adaptive strategies were developed for 12 cities by revealing and integrating their development pathways and relative status in achieving sustainable development. Integration and cooperation between cities were proposed, e.g., a water trade agreement between eastern Inner Mongolia (an economically underdeveloped region with relatively abundant water resources) and central Inner Mongolia (an economically developed region with high water stress). Such an agreement may enable the holistic achievement of sustainable development across regions. By integrating the findings of our research, our study presents a reproducible framework for water-management-based sustainable development strategies in drylands.     

Estimation of bed shear stress and analysis of sediment resuspension in Lake Chaohu,China

Resuspended sediment is an important carrier of underwater material circulation, and bed shear stress is usually considered to be closely related to sediment resuspension. To analyze the resuspension dynamics in severely eutrophic Lake Chaohu, China, three fixed stations were set up to collect wave, current, and suspended sediment concentrate (SSC) data under windy weather, and two significant sediment resuspension events were recorded. Based on the Gaussian-shaped spectrum characteristics of waves in Lake Chaohu, the wave orbital velocity was estimated by using the wave parameter method. The selection of the general wave spectrum is important for the accurate estimation of wave orbital velocity. The results of the simple linear wave method were very similar to those of the wave parameter method with a Gaussian-shaped spectrum in Lake Chaohu. The total bed shear stress combining waves and currents during the observation period was calculated, and most of it was contributed by wind-driven waves. The bed material of Lake Chaohu has silt-enriched and weak cohesive features, and an examination of critical shear stress showed that the modified Shields curve method was still applicable to Lake Chaohu. When a sediment resuspension event occurred, the vertical gradient of SSC increased significantly, and the peak SSC value depended on the peak value of bed shear stress. As a predictor, bed shear stress only showed a good linear relationship during sediment resuspension events. At other times, the prediction of SSC using bed shear stress may be biased, especially at the time after a significant sediment resuspension event.

     

Associations of long-term ambient air pollution and traffic-related pollution with blood pressure and hypertension defined by the different guidelines worldwide: the CHCN-BTH study

Environmental Science and Pollution Research - The assessment of the generalization of the strict hypertension definition in the 2017 ACC/AHA Hypertension Guideline from environmental condition...     

火力发电厂煤粉锅炉炉膛爆炸原因解析

文章论述火力发电厂锅炉炉膛爆炸产生的原因,并采用事故树分析方法对锅炉炉膛爆炸原因做定性分析,采用布尔代数运算法则确定各基本事件引起炉膛爆炸事故的排列顺序.     

Defining agents' behaviors to simulate complex residential development using multicriteria evaluation

Cellular automata (CA) have been increasingly used to simulate complex geographical phenomena. These models may have limitations on reflecting individuals' behaviors which should be considered in urban simulation. Agent-based modeling can solve some of the problems in addressing individuals' influences in urban systems. However, there is a general lack of methodology on how to define agents' properties. This paper uses multicriteria evaluation techniques to determine some of the parameters for the agent-based model. Empirical data from GIS are used to define agent's properties. Sensitivity analysis is also carried out to assess the influences of parameters on simulation outcomes. This model has been applied to the simulation of the residential development in a fast growing city, Guangzhou, in south China.     

莱州湾海域水质石油类的分布特征

根据2011年5月~2013年11月莱州湾海域表层海水中石油类污染状况进行的现场调查，研究分析了莱州湾表层海水中石油类的平面分布和季节变化特征。结果表明，2011~2013年，莱州湾表层海水中石油类的浓度变化范围分别为0.009~0.101mg/L、0.00875~0.0879mg/L和0.0118~0.0687mg/L，石油类含量总体年际变化不大，但2011年与2012年、2013年呈现不同的季节变化，2011年夏季（8月）高于春季（5月），而2012年~2013年表现为春季>夏季>秋季（5月 >8月 >10月 >11月）。从石油类的平面分布来看，基本呈现近岸高、湾中部及湾口低的特点，高值区主要集中在小清河口和黄河口等河口附近海域。     

激光质谱法对机动车尾气中污染物的测量

本文详细介绍了一种全新的污染物测试方法———激光质谱法的原理和特点。我们应用这一方法对机动车尾气进行了初步探测 ,得到了 2 6 6nm激光作用下汽车尾气的激光电离质谱图 ,并对摩托车发动机运行状态与苯系列污染物排放量之间的关系进行了初步的在线测量