Application of high-pressure water jet technology and the theory of rock burst control in roadway

This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rotational way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress superposition zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static combined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

Determinants of agricultural water saving technology adoption:an empirical study of 10 provinces of China

In recent years, China has been faced by an increasingly severe water shortage due to the continual growth of demand on water resources. Although the Chinese government has been actively promoting the agricultural water-saving technology adoption, it is ill-informed of the adoption degree of the current agricultural watersaving technologies as well as the function of the governmental policies, Therefore, this paper＂ analyzes the aforesaid problems based on investigative data of 10 provinces in China. The results demonstrate that although there is a rapid increase of adopted agricultural water-saving technologies, the actual adoption area is rather limited. Moreover, the governmental policies and scarcity of water resources are the deierminants of agricultural water-saving technology adoption. Ultimately, the paper proposes some policy suggestions.

The technology and practice of water saving at Baosteel

With the development of the production scale and the increasing of the process technologies and facilities,product quality and the requirement of water supply continuously put forward new requirements to water treatment technology.The practice of the water saving technology should ensure the safe of water using and the innovation of technique data.Especially the stabilization of water quality should also meet the production at full capacity,reduce equipment failure rate and maintain the sustainable development under the condition of the minimal resource consumption.This article describes the practice of Baosteel saving technology,water-saving ideas from the system to start,according to Baosteel raw water intake requirements and process water and drainage characteristics,water and salt water tidal according to changes in the Yangtze River and the Yangtze River upstream and downstream trends in water discharge on water quality factors,established the electrical conductivity,chloride ion indicators for the control of the Yangtze River water,the implementation of 'avoid salt build light' water at the same time,combined with the actual situation of water pollution in the Yangtze River,the use of force coefficient correlation theory,the implementation of 'avoid taking clear pollution' to ensure the quality of raw water intake. System and cascade utilization of water,process water,based on whole plant water balance testing, analysis,technical parameters of the system and processes the user running the pressure balance pipe network,and implemented a stabilization system to adjust water pressure,reducing the water supply network systemwater loss;application of electrochemical principles,the implementation of the protection of underground pipes Baosteel,implemented a water use,steps to use,the operating mode of water supply in series to increase water reuse,reduce wastewater discharge system. Water quality stability and water-saving in the process;carry out water quality stability technology in the different complicated processes of the steel industry;apply the environmental protection and water quality, sterilization,non-phosphorus and low phosphorus technologies which are suitable for high concentration of circulating water.By these technologies,we achieved the water-saving in the process in different seasons and solved the technical problems affecting production such as equipment corrosion,scaling and the formation of the water quality proprietary technology under the conditions of high heat load production as well. The use of water ecological conservation and biological treatment technology:the implementation of the reservoir to the ecological technology is characterized by food chain and wetland environmental technology characterized by plants chain.Reservoir ecological management techniques in the use of natural conditions, wind direction,temperature,light and fish biomass in the reservoir water level regulation of balance and combination of organic,control and resolve the reservoirs in spring and summer algae problems and water quality changes rot of the 'fresh' operating problems.The artificial wetland technology develops a new way for metallurgical plants' wastewater treatment.All the measures by the implementation of water to create the conditions for the system to achieve the water target of constant innovation,reaching the advanced level of iron and steel enterprises.

Application Effect of Integrated Water and Fertilizer Technology for Tomato

Integrated water and fertilizer technology has the advantages of saving water,fertilizer and labour,which is widely applied in tomato plantation. Integrated water and fertilizer technology in topdressing and whole process of big and small tomatoes were studied,and their application effects were contrasted and analyzed,and application advantages and scopes of the two models were concluded.

Energy and Water Conservation Technology Analysis of Water Supply and Drainage of the Building

At present,China’s social and economic development is faster and faster.At the same time,people pay more and more attention to the construction concept of energy and water conservation.We can see the popularization and development of the concept of energy saving and water saving in every major field of our country,the same is true in the construction field.In order to effectively protect the ecological environment and maximize the use of limited resources,the energysaving and water-saving technology of the building,as well as water supply and drainage technology should be actively used.Based on this,this paper first analyzes the application significance of water supplydrainage and energy-water conservation technology in the construction field,analyzes the current situation of water supply and drainage in China,and proposes the application of water supply-drainage and energy-water conservation technology of the building for reference.

Application of Whole Membrane Water Treatment Technology in Environmental Protection

In the current social development of our country,environmental protection has become a key content,and water treatment process is a key step to achieve environmental protection.This paper analyzes the application of whole membrane water treatment technology in environmental protection.It is hoped that this analysis can be helpful for the rational application of the whole membrane water treatment technology and the improvement of environmental protection quality.

Analysis on Technology Requirements of Garden Irrigation for the Recycling and Use of Reclaimed Water

The lack of water resource is the resource and environmental problem of various countries in the current international environment face, and a better way to solve the shortage of water resource is to adopt the reclaimed water for civil irrigation. But the development of science and technology in China started late, it leads to that our country doesn＇t have deep experience in the use of the reclaimed water application technology, thus, the development and requirements of this technology in the domestic world are very urgent and demanding. In this paper, the author makes a detailed technology requirement explanation for the technology requirement level of supervision, technology, technics and management aspect on wastewater reuse technology.

Discussion about the standard system on urban domestic water saving technology in China

Standard is the technical foundation of national economic and social development, and it is the basic rule of establishing social regulation. Researching and constituting the standard system of urban domestic water saving technology is to offer important science basis for revising standard plan and standardize research plan. This paper introduces the present situation of our urban domestic water saving technical standard system, problem and the development direction in the future, as well as project planning of constructing urban domestic water saving technical standard system.

A comparative study of dust control practices in Chinese and Australian longwall coal mines

Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in China and Australia.This paper presents a comparative study of dust control practices in Chinese and Australian longwall mines,with particular references to statutory limits,dust monitoring methods and dust management practices,followed by a brief discussion on the research status of longwall mine dust control in both countries.The study shows that water infusion,face ventilation controls,water sprays,and deep and wet cutting in longwall shearer operations are commonly practiced in almost all underground longwall mines and that both Chinese and Australian longwall mine dust control practices have their own advantages and disadvantages.It is concluded that there is a need for further development and innovative design of more effective dust mitigation products or systems despite the development of various dust control technologies.Based on the examinations and discussions,the authors have made some recommendations for further research and development in dust control in longwall mines.It is hoped that this comparative study will provide beneficial guidance for scholars and engineers who are engaging in longwall mine dust control research and practice.

Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China

Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing.

Israeli Water Achievements Today and Enlightenment to China

Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing population. The achievements of water supply in Israel can be summarized as water technologies (like water transportation and purification, desalination, wastewater treatment, effluent reuse, storm water catchment, control systems, rain enhancement and drip irrigation, etc.), water management and legislation as well as water industry. In view of the national concern regarding the quality and quantity of the water, the skills, technologies and know-how that Israel has accumulated in water supply and irrigation can give us enlightenment that is also presented in this paper.

Algorithmic Procedure to Design Water Utilization Systems Featuring Multiple Contaminants in Process Plants

This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.

Experiment and analysis of the formation,expansion and dissipation of gasbag in fine sediments based on pore water pressure survey

Deep-seated gas in seabed sediments migrates upwards from effect of external factors,which easily accumulates to form gasbags at interface of shallow coarse-fine sediments.Real-time monitoring of this process is important to predict disaster.However,there is still a lack of effective monitoring methods,so we attempt to apply multi-points pore water pressure monitoring technology when simulating forming and dissipation of gasbags in sediments through laboratory experiment.This study focuses on discussion of sensitivity of pore water pressure monitoring data,as well as typical changing characteristics and mechanisms of excess pore water pressure corresponding to crack generation,gasbag formation and gas release.It was found that the value of excess pore water pressure in sediments is negatively correlated with vertical distance between sensors and gas source,and the evolution of gasbag forming and dissipation has a good corresponding relationship with the change of excess pore water pressure.Gasbag formation process is divided into three stages:transverse crack development,longitudinal cavity expansion,and oblique crack development.Formation of gasbag begins with the transverse crack at the interface of coarse-fine sediments while excess pore water pressure attenuates rapidly and then drops,pressure remains almost unchanged when cavity expanses longitudinally,oblique crack appeared in final stage of gasbag evolution while excess pore water pressure accumulated and dissipated again.The variation curve of excess pore water pressure in gas release stage has saw-tooth fluctuation characteristics,and the value and time of pressure accumulation are also fluctuating,indicating the uncertainty and non-uniqueness of gas migration channels in sediments.

Soil and Water Conservation Technology in the Zhifanggou Watershed

Soil and water conservation technology plays an important role in soil and water loss control and the construction of the ecological civilization in vulnerable areas. Here, soil and water conservation technology use over 70 years for the Zhifanggou watershed is summarized and ecological, economic and social backgrounds are determined through consultation with experts and reference to published literature. We found that soil and water conservation technology use includes soil and water conservation engineering technology, soil and water conservation cultivation technology and soil and water conservation biotechnology. Soil and water conservation technology utilization varied with people＇s demands and core problems at different developmental stages of the agricultural eco-economic system. The coupling process of the agricultural eco-economic system at Zhifanggou went through three stages. In stages I and II, soil and water conservation cultivation technology was applied to meet farmers＇ basic life demands. In stage III, all three technologies were applied comprehensively to solve eco-environmental problems and adjust industrial structure. To facilitate regional ecological civilization construction and sustainable development of the ecological economy and society, more emphasis should be given to research and development, implementation of soil and water conservation technology, stand structure improvement, forest grass quality enhancement, biodiversity, ecosystem functional improvement, development of soil and water conservation ecological resources, the coupling of soil and water conservation, and agricultural industry-resource optimization.

Performance of pond–wetland complexes as a preliminary processor of drinking water sources

Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the ＂hidden＂ diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.