Determination of triazine herbicide residues in water samples by on-line sweeping concentration in micellar electrokinetic chromatography

A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography （MEKC） was developed. Various parameters affecting sample enrichment and separation efficiency were systematically studied. Compared with the conventional MEKC method, up to 60-200-fold improvement in concentration sensitivity was achieved in terms of peak height by using this sweeping injection technique. The compound strychnine was used as the internal standard for the improvement of the experimental reproducibility. The limits of detection （S/ N = 3：1） for atrazine, simazine and prometryn were 9, 10 and 0.5 ng mL-1, respectively. This method has been successfully applied to the analysis of atrazine, simazine and prometryn in lake, steam and ground water.

Decomposition of oil cleaning agents from nuclear power plants by supercritical water oxidation

Oil cleaning agents generated from nuclear power plants(NPPs)are radioactive organic liquid wastes.To date,because there are no satisfactory industrial treatment measures,these wastes can only be stored for a long time.In this work,the optimization for the supercritical water oxidation(SCWO)of the spent organic solvent was investigated.The main process parameters of DURSET(oil cleaning agent)SCWO,such as temperature,reaction time,and excess oxygen coefficient,were optimized using response surface methodology,and a quadratic polynomial model was obtained.The determination coefficient(R^(2))of the model is 0.9812,indicating that the model is reliable.The optimized process conditions were at 515 C,66 s,and an excess oxygen coefficient of 211%.Under these conditions,the chemical oxygen demand removal of organic matter could reach 99.5%.The temperature was found to be the main factor affecting the SCWO process.Ketones and benzene-based compounds may be the main intermediates in DURSET SCWO.This work provides basic data for the industrialization of the degradation of spent organic solvents from NPP using SCWO technology.

Application of Ice Pigging in a Drinking Water Distribution System:Impacts on Pipes and Bulk Water Quality

Ice pigging is an emerging technique for pipe cleaning in drinking water distribution systems.However,substantial confusion and controversy exist on the potential impacts of ice pigging on bulk water quality.This study monitored the microstructural features and composition of sediments and microbial community structures in bulk water in eight multimaterial Chinese networks.Chloride concentration analysis demonstrated that separate cleaning of pipes with different materials in complex networks could mitigate the risk of losing ice pigs and degrading water quality.The microstructural and trace element characterization results showed that ice pigs would scarcely disturb the inner surfaces of long-used pipes.The bacterial richness and diversity of bulk water decreased significantly after ice pigging.Furthermore,correlations were established between pipe service age,temperature,and chloride and total iron concentrations,and the 15 most abundant taxa in bulk water,which could be used to guide practical ice pigging operations.

Seawater desalination of arid regions:comparing the policy of the Kingdom of Saudi Arabia and Indonesia

Problems with clean water in coastal areas alongside an increase in population and community economic activities have diversified community activities.Coastal settlements bordering the high seas are characterized as arid areas with a lack of clean water.Here,the use of the range groundwater supply against seawater intrusion means that the water consumed by the community tastes salty and brackish.The availability of abundant seawater,processed through desalination technology,can be used to meet the daily clean water needs of coastal communities.Sustainable development goal(SDG)6 Water and Sanitation is concerned with ensuring that everyone has access to clean water and sanitation.In this regard,desalination technology is considered viable to achieve the SDGs in the environmental sector.Some countries have focused on using desalination technology to achieve target 6.4 by 2030.This goal aims to improve the efficiency of water use to reduce the number of people experiencing clean water scarcity by ensuring a sustainable supply of fresh water.The objective of this study is to examine the application of seawater desalination technology for clean water in the Kingdom of Saudi Arabia(KSA)and Indonesia,and identify the implications of desalination policies in these countries.Comparative studies were conducted using secondary data and literature studies on transforming seawater into clean water with technology.KSA applies seawater desalination technology to meet water needs.However,in Indonesia,policymaking has not holistically examined the potential of using seawater desalination technology for clean water.Until now,unlike in the KSA,Indonesia has not addressed the importance of the use of desalination technology in state policy.

Superhydrophobic Micro/Nanostructured Copper Mesh with Self-Cleaning Property for E ective Oil/Water Separation

In this work, a simple method was carried out to successfully fabricate superoleophilic and superhydrophobic N-dodecyltrimethoxysilane@tungsten trioxide coated copper mesh. The as-fabricated copper mesh displayed prominent superoleophilicity and superhydrophobicity with a huge water contact angle about 154.39° and oil contact angle near 0° Moreover, the coated copper mesh showed high separation efficiency approximately 99.3%, and huge water flux about 9962.3 L·h^-1·m-2, which could be used to separate various organic solvents/ water mixtures. Furthermore, the coated copper mesh showed favorable stability that the separation efficiency remained above 90% after 10 separation cycles. Benefiting from the excellent photocatalytic degradation ability of tungsten trioxide, the coated copper mesh possessed the self-cleaning capacity. Therefore, the mesh contaminated with lubricating oil could regain superhydrophobic property, and this property of self-cleaning permitted that the fabricated copper mesh could be repeatedly used for oil and water separation.

The Mechanical Analysis and Experimental Study of Shock Wave Effect of Electrical Discharge under Water In Filth Cleaning

Filth adhering to metal pipes can be cleaned by shock wave generated by electrical discharge under water. The mechanism of shock wave effect of electrical discharge under water on filth cleaning is analyzed by building a mechanical model. A metal pipe coated with cement to simulate real filth is cleaned by using electrical discharge under water. The experimental results confirm the mechanical analysis and also show the technology of electrical discharge under water is an very effective method for filth cleaning.

DETERMINATION OF ANTIMONY IN WATER SAMPLES BY FLOW-INJECTION HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY WITH ON-LINE ION-EXCHANGE COLUMN PRECONCENTRATION

On-line ion-exchange separation and preconcentration were combined with flow-injection hydride generation atomic absorption spectrometry (HGAAS) to determine ultra-trace amounts of antimony in water samples. Antimony(Ⅲ) was preconcentrated on a micro-column packed with CPG-8Q chelating ion-exchanger using time-based sample loading and eluted by 4 mol l^(-1) HCl directly into the hydride generation AAS system. A detection limit (3σ) of 0.0015μg l^(-1) Sb(Ⅲ) was obtained on the basis of a 20 fold enrichment and with a sampling frequency of 60h^(-1). The precision was 1.0% r.s.d.(n=11) at the 0.5μg l^(-1) Sb(Ⅲ) level. Recoveries for the analysis of antimony in tap water, snow water and sea water samples were in the range 97-102%.

Slim Water Injection Nozzle for Silicon Wafer Wet Cleaning Bath

In order to effectively and quickly clean the surface of semiconductor silicon wafers, the fluid flow is one of the significant issues. For a batch-type silicon wafer wet cleaning bath, a slim water injection nozzle consisting of a dual tube was studied, based on theoretical calculations and experiments. A thin inner tube was placed at the optimum position in the water injection nozzle. Such a simple design could make the water injection direction normal and the water velocity profile symmetrical along the nozzle. The water flow in the wet cleaning bath was observed using a blue-colored ink tracer. When the nozzle developed in this study was placed at the bottom of the bath, a fast and symmetrical upward water stream was formed between and around the wafers.

Application of response surface methodology to the chemical cleaning process of ultrafiltration membrane

A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Response Sur- face Method （RSM） and Central Composite Design （CCD）. The factors considered in the experimental design were sodium hydroxide （NaOH） concentration, sodium bypochlorite concentration （NaCIO）, citric acid concentration and cleaning duration, The interactions between the factors were investigated with the numerical model. Humic acid （20 mg· L-1） was used as the model foulant, and chemical enhanced backflush （CEB） was employed to sim- ulate the chemical cleaning process. The concentrations of sodium hydroxide, sodium hypochlorite, citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3% 100-300 mg· L-1 1%-3% and 0.5-1.5 h, respectively. Among the variables, the sodium hypochlorite concentration and the cleaning dura- tion showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However, the data was sharply decreased when at a low level of sodium hydroxide concentration. In total, 54 sets of cleaning schemes with 80% to 100K cleaning efficiency were observed with the R＆M model after calibration.

Investigations of Physical and Chemical Characteristics of Masonry Stones and Bricks during Building Cleaning： Part 1. Physical Testing

This series of study focused on analysing and assessing the changes of the physical and chemical characteristics of the surfaces of the masonrystones and bricks during the sandblasting cleaning process by conducting various physical and chemical tests. Seven masonry stones and bricks were adopted, including yellow sandstone, red sandstone, limestone, marble, granite, white clay brick and yellow clay brick. The physical testing included evaluating the cleaning degree, determining the Vickers hardness, and detecting the water absorption. Using a digital imaging analysis method, the greyscale and cleanness were introduced to quantitatively assess the effectiveness of masonry building cleaning and confirmed to be useful and appropriate. The cleanness analysis, together with the hardness and water absorption tests showed that a masonry stone or a brick with a higher cleaning degree corresponded to a brighter and harder stone surface. In general, the physical properties were found to vary largely during the building cleaning.

Rationalizing the Use of Water in Industry—Part 1: Summary of the Instruments Developed by the Clean Technology Network in the State of Bahia and Main Results Obtained

Based on cleaner production concepts, a method for water use minimization has been developed by the Clean Technology Network of Bahia (TECLIM) at one of the largest industrial complexes in Latin America located in the State of Bahia, Brazil. This method is concerned with an area of secondary interest to the productive sector: the use of water. Based on the best cleaner production principles (CP), nine instruments have been developed during cooperative projects with chemical, petrochemical and copper metallurgical industries. These instruments are described in Part 2 of this paper [1]. The main benefits derived from partnership schemes include: a reduction in water consumption and effluent generation;the development of a techno-operational culture to increase eco-efficiency;and the introduction of conceptual projects to ensure the continuity of the activities in the company after the projects have been completed. The specific consumption of water was reduced by 20% as a consequence of the application of this method in Company A;a specific reduction in the generation of effluents of more than 40% was observed in Company B;a 42% fall in fresh water consumption in Company C;and a 20% decrease in the cost of effluent treatment in Company D. Among the difficulties encountered were the limited time availability of the operators and engineers for the project, the lack of measurement and calibration of available flow meters and the lack of detailed technical data.

Rationalizing the Use of Water in Industry—Part 2: Instruments Developed by the Clean Technology Network in the State of Bahia

The instruments developed by the Clean Technology Network of Bahia (TECLIM) at the Federal University of Bahia (UFBA) (cited in Part 1 of this paper) are presented. Factors regarding water management in industry were examined, on the basis of experience acquired over the period of a decade in cooperative research projects with large industrial process plants located mostly in the Camacari Petrochemical Complex, Bahia State, Brazil. The main results consist of training about 1700 industry professionals in CP, the identification of about 500 ideas for the rationalization of water use, the presentation and publication of 90 articles in journals, conferences and other academic events, identification of ideas with potential water savings estimated at around 1400 t·h–1 and the reduction of at least 500 t·h–1 in effluents. Other sectors that make use of water, for example public buildings, commercial buildings, homes, shopping centers and airports can adapt and use the TECLIM method as will be exemplified.

Low-Cost Sustainable Technologies for the Production of Clean Drinking Water—A Review

Water has always been an important and life-sustaining drink to humans and is essential to the survival of all known organisms. Over large parts of the world, humans have inadequate access to drinking water and use water contaminated with disease vectors, pathogens or unacceptable levels of toxins or suspended solids. Drinking such water or using it in food preparation leads to widespread, acute and chronic illnesses and is a major cause of death and misery in many countries. The UN estimates that over 2.0 billion people have limited access to safe water and nearly 800 million people lack even the most basic supply of clean water. The main issue is the affordability of water purifying systems. Many people rely on boiling water or bottled water, which can be expensive. Therefore, technologies that are cost effective, sustainable, ease of operation/maintenance and the treatment processes with locally available materials are required. In this article, some unique low-cost sustainable technologies available/or in-use, i.e. natural filtration, riverbank filtration, biosand filtration, membrane filtration, solar water disinfection technique, biologically degradable materials such as moringa powder, scallop powder treatment, and biosand pitcher treatments have been discussed.

Clean and Safe Supply of Fish and Shellfish to Clear the HACCP Regulation by Use of Clean and Cold Deep Ocean Water in Rausu,Hokkaido,Japan

For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is essential. According to HACCP （Hazard Analysis and Critical Control Points）, it is important to meet such requirement by keeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water （DOW） characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly for salmon, cod, and sea urchin in Town ＇Rausu＇ in Hokkaido, Japan. DOW below 2.9℃ of an amount of nearly 5 000 m^3 is planned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land. DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in clean and cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOW are also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of 2005.

Assessment of Environmental Cleaning Practices and the Impacts on Infection Prevention and Control in Selected Hospitals in Tanzania

To achieve Sustainable Development Goal (SDG) in healthcare facilities (HCFs,) the provision of water, sanitation, healthcare waste management, hand hygiene and environmental cleanliness services is crucial. Good WASH services in HCFs settings have the potential to reduce healthcare acquired infections (HAIs), increase trust and uptake of healthcare services, increase efficiency and improve staff morale. To address this, a National Assessment was carried out to ascertain environmental cleanliness condition of the healthcare facilities at all levels. The assessment of healthcare waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland including districts and lower healthcare facilities. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste management using open source software for data collection (ODK). Data were analyzed using SPSS computer software. It was observed that most of permanent staff (88%) in the Healthcare facilities had knowledge on hand hygiene, but the gap was observed to the waste handlers (12%) who were not equipped with the hand hygiene knowledge. About 89% of the hand washing stations were available at mortuary units, followed by 75% at main entrance and the lowest was 3% at waste zone areas of the healthcare facilities. Hand washing materials like soap were mainly found at theaters (64%) followed by mortuary (60%) and last at waste zones. The assessment concludes that handling of healthcare wastes is not practiced to the expectations, and there is a need to strengthen the situation. The findings provide evidence for those engaged in improving HCF conditions to develop evidence-based policies and efficient programs, enhance service delivery systems, and make better use of available resources.

CV issues the first Sustainable Development Report to promise its responsibilities for “Green Mountains and Clean Waters”

On March 13th, the second day of this year's Yan Expo (Spring and Summer),“Promising Responsibilities for Nature: From Forests to Fashion-Release Conference of CV Sustainable Development Report" was held in the National Exhibition Center (Shanghai). On the conference, the Collaboration for Sustainable Development of Viscose (CV) officially issued the first sustainable development report.

Photothermal-photocatalytic thin-layer flow system for synergistic treatment of wastewater

The integration of the photocatalytic effect into solar steam is highly desirable for addressing freshwater shortages and water pollution.Here,a ternary film structure for the adsorption and photothermal and photocatalytic treatment of wastewater was designed by combining the technique of self-assembled carbon nano paper with a nitrogen composite titanium dioxide(N-TiO_(2))deposited on the surface of carbon nanotubes(CNT)using polyvinylidene fluoride(PVDF)as a substrate.The photogeneration of reactive oxygen species can be promoted by rapid oxygen diffusion at the three-phase interface,whereas the interfacial photothermal effect promotes subsequent free radical reactions for the degradation of rhodamine B(93%).The freshwater evaporation rate is 1.35 kg·m^(-2)·h^(-1)and the solar-to-water evaporation efficiency is 94%.Importantly,the N-TiO_(2)/CNT/PVDF(N-TCP)film not only effectively resists mechanical damage from the environment and maintains structural integrity,but can also be made into a large film for outdoor experiments in a large solar energy conversion device to collect fresh water from polluted water and degrade organic dyes in source water simultaneously,opening the way for applications in energy conversion and storage.

Clean River Water for Thirsty Beijing in Six Years

PLAGUED by frequent floods in its history,Beijing is now suffering a grave water short-age.

基于改进YOLOv8n-seg的蟹塘水草区域分割与定位方法

目前蟹塘内水草清理以人工作业为主,劳动强度大,作业效率低,自动水草清理船能大幅降低劳动强度,提高作业效率,而确定蟹塘水草分布是规划水草清理船高效作业路径的关键基础。针对无人机采集的蟹塘水草图像中水草与岸边植被相似性高、难以准确区分等问题,该研究提出一种基于改进YOLOv8n-seg的蟹塘水草区域分割与定位方法。改进模型从降低模型大小和提高召回率的角度出发,首先基于RT-DETR(real-timedetectiontransformer)的HGNetv2(hierarchical graph network)轻量化网络结构重设主干特征提取网络,缩减模型体积;其次以Efficient Rep轻量化结构为基准重构颈部网络,在降低参数量的同时增强模型的多尺度特征融合能力;接着在特征提取层引入SegNext注意力机制,加强模型对蟹塘水草区域的敏感度。为了消除模型在识别过程中产生的冗余区域,进一步提高分割精度,采用二值化处理对分割结果进行优化,并结合图像处理算法对水草区域进行面积筛选;经过坐标转换后得到精确水草轮廓经纬度坐标。试验结果表明:改进模型对蟹塘水草具有良好的区分度和分割效果,其参数量和计算量分别为1.49 M和8.4 GFLOPs,召回率和平均精度均值分别为91.5%和95.6%,与原YOLOv8n-seg模型相比,模型体积减小了49.7%,分割速度提升了32.3%。在坐标转换试验中,水草定位精度平均误差为0.22 m,验证了改进模型能够满足蟹塘水草区域分割与定位要求。研究结果为后续水草清理船自动作业路径规划研究提供参考。

全球天然氢勘查开发最新发展态势分析

随着氢气地表异常显示的广泛发现以及对地下氢气成因机制和成藏机理认识的逐步深化,天然氢作为一种清洁能源,因其可能的巨大资源潜力和可再生性,有望成为全球实现能源转型和碳中和的关键能源。通过对全球天然氢勘查开发最新进展的跟踪研究认为:天然氢已成为全球地质与能源领域关注热点,多成因机制下资源调查发现呈点多面广特征,欧美强国持续投入带动全球发展,氢氦地质资源具有“兼探共采”潜力,等等。鉴于我国在天然氢资源发现方面取得的初步进展,以及对成藏条件及有利区带的初步评估,建议我国应尽快开展全国性天然氢资源调查评价工作。