Evaluation of a portable in-house greywater treatment system for potential water-reuse in urban areas

This study aims at improving greywater reuse potential. An advanced physical filtration system named as GAC-MI-ME was developed to attain multi-grade effluents for versatile reuse of greywater. It consists of a matrix of treatment trains including coarse filtration, microfiltration, activated carbon, ultrafiltration, ultraviolet, and reverse osmosis. A preliminary set of experiments were conducted to characterize the greywater originating from shower, washbasin, and laundry. The samples were subsequently treated through GAC-MI-ME system. It was observed that the activated carbon along with microfiltration and coarse filtration played vital roles as pre-filtration for ultrafiltration and reverse osmosis. The contaminant load distributions of GAC-MI-ME system were observed with an average of 90.4% turbidity and 53.2% of biochemical oxidation demand (BOD₅₎ as the pre-filtration, whereas the effluents at ultrafiltration and reverse osmosis showed unrestricted water reuse possibilities. The GAC-MI-ME system can be envisioned as advancement to the conventionally applied greywater treatments.     

Shadowsocks及ShadowsocksR安全性分析

对网络代理软件Shadowsocks和ShadowsocksR产生的流量的安全性进行分析。首先,还原Shadowsocks和ShadowsocksR的报文格式;其次,澄清其使用的密码算法,包括密钥生成算法和加解密算法;最后,分析Shadowsocks(R)的理论和实际安全性,提出了流量解密的方法。综上所述,建议Shadowsocks的开发者使用SHA-3、SM3替代MD5、SHA-1用于密钥生成,并采用加盐方式生成主密钥;建议用户使用长的随机值作密码。     

Energy,water and food security through a waste-driven polygeneration system for sustainable dairy production

Ensuring secure and sustainable food production amidst growing demand requires developing high-yield sustainable food production systems, noting that conventional food production systems are large consumers of energy and water resources. Moreover, they induce substantial environmental impacts. In this context, this study considers dairy food production systems, and proposes a dairy waste driven polygeneration system that can increase the milk yield of the dairy food production system whilst reducing its environmental impact. The system utilises dairy manure, very low concentration methane, wastewater, and harsh environmental conditions in an integrated manner to fulfil the dairy farms' vital needs, including air-conditioning, electricity, and freshwater. In addition, the system also provides a solution concerning social perception related to wastewater reuse for potable purposes in the form of an integrated electrolyser and fuel-cell cycle. Unique to this study is the harnessing of the energy of the methane, which is in very low concentrations in the barns, and benefitting from the harsh environmental conditions in an integrated manner. Comprehensive thermodynamic investigations revealed that the system generates 2.17 MW of Electricity, 1152 m³ of freshwater daily, 6970 tons of cooling capacity, and 1.6 kg/day of H₂. Besides, on a daily basis, the system consumes 864 tons of manure, recycles 732.5 m³ of wastewater, and utilises 87.62 tons of methane (resulting in savings of ～711,750 tons of CO₂ eq. annually). The calculated energy and exergy efficiencies of the polygeneration system are 50% and 4%, respectively. Moreover, in the design of polygeneration systems, the importance of the proper definition of the thermodynamic system's boundaries and the effects of technology choice for the same purpose is illustrated. Furthermore, the parametric investigations revealed that the system performs stable with variations in the inputs and ambient conditions. Also, unlike other systems, the system's performance improves in harsher environmental conditions. This study also illustrates that the food production systems can be developed for decentralised operations with near zero-waste outputs and near-zero emissions.     

Fate of carbamazepine and anthracene in soils watered with UV-LED treated wastewaters

Water disinfection technologies based on ultraviolet (UV) radiations emitted by Light-Emitting Diodes (LED), as a wastewater tertiary treatment, have been shown to be promising for water reuse. Here, we assessed the fate of two ubiquitous pollutants, carbamazepine and anthracene, in soil watered with either UV-LED treated wastewaters or irrigation water. After 3 months, anthracene and carbamazepine were transformed two and three times faster respectively, in soils watered with UV-LED wastewater than in soils watered with tap water (probably because of the addition of organic matter by the effluent). Laccase activity was induced in the presence of the pollutants and anthraquinone was found as anthracene product of oxidation by laccases. Moreover, the addition of these pollutants into soil did not affect the functional diversity of autochthonous microbial communities assessed by Ecolog plates. Cellulase, protease and urease activities increased in soils watered with UV-LED treated wastewaters (UV-LED WW), showing transformation of organic matter from the effluent and lipase activity increased by anthracene addition, confirming the potential role of these enzymes as indicators of hydrocarbon contamination.     

滤池反冲洗水回用试验研究

通过对新开河水厂排水工艺的深入分析，进行了滤池反冲洗水回用的试验研究。研究结果表明，滤池反冲洗水回用原水配水井是可行的，是节约大量的水资源，并带来一定的经济效益。     

青海省城市生活污水回用的探讨

实现污水资源化,避免水资源危机,是关系全球经济发展和人类生存环境的重大课题。目前,水资源短缺构成的水危机已威胁到世界上的很多国家,使各国的经济、社会和科技的发展都面临着严峻的考验,污水回用已作为第二水资源所重视。因此,文章通过对青海省中、小城市污水现状的调查和查大量文献的基础上,对西宁市污水的开发和利用进行了深入的探讨。     

CBR for the management and reuse of image-processing expertise: a conversational system

The development of an image-processing (IP) application is a complex activity, which can be greatly alleviated by user-friendly graphical programming environments. The major objective of the work described in this paper is to help IP experts reuse parts of their applications. A first step towards knowledge reuse has been to propose a suitable representation of the strategies of IP experts by means of IP plans (trees of tasks, methods and tools). This paper describes the CBR module of an interactive system for the development of IP plans. After a brief presentation of the overall architecture of the system and its other modules, the authors explain the distinction between an IP case and an IP plan, and give the selection criteria and functions that are used for similarity calculation. The core of the CBR module is a search/adaptation algorithm, whose main steps are detailed: retrieval of suitable cases, recursive adaptation of the selected one and memorization of new cases. The system’s implementation is presently completed; its functioning is described in a session showing the kind of assistance provided by the CBR module during the development of a new IP application.     

Utilization of waste vehicle tires in concrete and its effect on the corrosion behavior of reinforcing steels

The mechanical and physical properties of concrete specimens obtained from replacing natural coarse aggregate with waste vehi-cle rubber tires at levels of 2vol%, 5vol%, 7vol%, and 10vol% were studied, and the corrosion behavior of reinforcing steels was investigated in these specimens. Corrosion rates were determined by measuring the galvanic current between steel-reinforced concrete specimens both with and without chloride addition. The change in electrode potential of reinforcing steels in these concrete specimens was measured daily for a period of 60 d in accordance with the testing method in ASTM C876. The results show that the use of waste vehicle tires in concrete in-stead of coarse aggregate decreases the mechanical strength of the specimens, and increases the corrosion rates of the reinforcing steels em-bedded in the concretes.