Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

The Potential Contribution of Subsurface Drip Irrigation to Water-Saving Agriculture in the Western USA

Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation （SDI） provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics （i.e., paying for the SDI system）, including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.

Application Research of Water-saving and Drought-resistant Landscape Plants:A Case Study of Inner Mongolia Drought-resistant Mongolian Grasses

Construction of "water-saving landscape architecture" is a crucial content of building "conservation-minded society'',an important approach of ensuring the sustainable development of landscaping industry.It targets at exploring a reasonable means of using the nature,so as to improve ecological conditions and environment,save resources and energies,and promote the harmonious coexistence of man and nature.Landscape plant is a significant component of landscape architecture,it is a key section to choose proper drought-resistant plant species for the landscape construction.

A Review on Development Water-Saving Agriculture in Asia

The development of water-saving agriculture is of great significance not only for increasing farmers’ production and income, but also for protecting water resources. The purpose of this paper is to learn from the experience of Israel, Japan, Korea and Singapore, improve the low efficiency of agricultural water use in China, and solve the problem of water shortage, promote the development of agriculture. This article concludes that the experience of water-saving agriculture in Israel is advanced irrigation technology, sound laws and regulations, and emphasis on science and technology. Japan’s water-saving agriculture is characterized by an efficient irrigation program and a strict agricultural water management policy. Korea’s experience in water-saving agriculture is that it has a strict water management system, with the government subsidizing the cost of irrigation projects and integrating water into agricultural development planning. Singapore’s experience in water-saving agriculture is to raise awareness of water conservation and to use step water prices. In order to promote the sustainable development of water-saving agriculture in China, the research on water-saving agriculture in the future can be carried out from the aspects of agricultural production or related agricultural technology.

Problems and Development Countermeasures of Agricultural Water-Saving Irrigation

Agriculture is the biggest water user in China,and the development of agricultural water-saving has great significance to the national economy and social development. In this paper,the present situation of water used in agriculture irrigation and water-saving potential were analyzed,and the ＂ bottleneck＂ and main problems existing in water-saving irrigation in China were discussed. From the aspects of engineering investment channels,agricultural water-saving policies and management system,reform of agricultural water price and water right transfer,improvement of farmers＇ water-saving consciousness,and promotion of rural land transfer,suggestions were proposed for the development of China＇s agricultural water-saving in future,which will provide a technical support for the sustainable use of agricultural water resources in China.

A Review on Water-Saving Agriculture in Europe

This paper aims to analyze the research on the current situation of water-saving agriculture development in Europe. Water-saving agriculture in Europe started early, governments and farmers in various countries have a strong awareness of water-saving in agriculture and have achieved certain results. Due to the global spread of the COVID-19 pandemic, the lack of up-to-date field research, the complexity of various agricultural disciplines and categories, and the lack of information sharing, the current cognition of recent progress in the development of water-saving agriculture in Europe is not comprehensive enough. This paper selects four representative European countries: Spain, Germany, Italy, and Denmark as the research objects. Based on the existing research of Chinese and Western scholars, this paper analyzes and studies the current situation of water-saving agriculture in Europe. It has far-reaching significance for other countries in the world to have further development in water-saving agriculture and to protect water resources.

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.

Assessment of rehabilitation strategies for lakes affected by anthropogenic and climatic changes: A case study of the Urmia Lake, Iran

Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.

Analysis on the Water-saving Irrigation Technique Based on the Perspective of Food Safety

The paper analyzed the important role of water saving in protecting the food safety,introduced the present development of agricultural water-saving technique,pointed out the potential risks of water resources,and proposed the future development of water-saving irrigation.

Sea water intrusion in coastal areas of Yellow Seaand Bohai Sea

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Effects of Continuous Plastic Film Mulching on Soil Bacterial Diversity, Organic Matter and Rice Water Use Efficiency

Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental variabilities in Zhejiang Province, China, under non-flooding condition. The experiment started in 2001 at two sites with one rice crop annually. Three treatments included plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and traditional flooding management (TF). Soil samples were collected and analyzed for bacterial diversity by DGGE and organic matter content, and water use efficiency (WUE) was calculated. The results showed that PM treatment favored the development of a more total bacterial community compared with TF management, the total number of bands was 33.3, 31.7 at tiller stage and heading stage (p < 0.05*). Hence, organic matter content was decreased by 36.7% and 51.4% under PM at two sites. PM also produced similar rice grain yield as TF at Duntou site and Dingqiao site, the average was 7924 kg?ha?1 and 7015 kg?ha?1 for PM and 8150 kg?ha?1 and 6990 kg?ha?1 for TF, respectively. Compared to TF, WUE and irrigation water use efficiency were increased significantly by 70.2% - 80.4% and 273.7% - 1300.0% for PM. It is essential to develop the water-saving agriculture.

Construction of Water-saving Ecological Aquaculture Model in Ponds in North China

[Objectives]To explore the ecological aquaculture model in ponds in North China,several single techniques were assembled into the same culture system.[Methods]Three ponds were selected,the species and stocking rate were exactly the same,the water was not changed during the culture period,and the water loss due to evaporation and leakage was recovered.Since the middle of May,the hydrochemical indicators such as ammonia nitrogen,nitrite nitrogen,water temperature,dissolved oxygen and pH were monitored every 10 d.According to the monitoring results of ammonia nitrogen,carbon sources were added to the culture ponds to adjust the ratio of C to N,and carbon sources were added 9 times during the culture period.The stocking rate and yield per unit area were accurately measured at the beginning and end of the experiment,and no less than 30 fishes were randomly sampled to calculate the relevant growth indicators and feed coefficients.[Results]Except that the nonionic ammonia in pond 3#exceeded the standard by 10.3%on July 25,all other hydrochemical indicators met the Fisheries Water Quality Standard,and there was no significant difference in all hydrochemical indicators at the same time(P>0.05).The survival rate in 3 ponds was more than 95.0%,the average body weight of individuals out of the pond had no difference(P>0.05),and the feed coefficient was 1.41-1.43.There was no disease during the culture period,and the water was saved by 46.6%compared with the traditional culture model.[Conclusions]This study can provide a basis for the construction of a new model suitable for ecological aquaculture in ponds in North China.

Implications of Israeli Agricultural Water Price Sharing System to China

This paper introduces Israeli agricultural water price sharing system. According to Israeli agricultural water cost composition,water price sharing by farmers as well as government subsidy and its forms,the financial subsidy-based agricultural water price system has been established on the basis of the farmers' income in our country and reasonable water price sharing,thus to promote the development of water-saving agriculture in China.

Survey and Assessment of Land Ecological Quality in Cixi City

Soil,atmosphere,water and quality of agricultural product constitute the content of land ecological quality.Cixi City,through survey pilot project of basic farmland quality,carried out high precision soil geochemical survey and survey of agricultural products,irrigation water and air quality,and established ecological quality evaluation model of land.Based on the evaluation of soil geochemical quality,we conducted comprehensive quality assessment of atmosphere,water,agricultural products,and assessed the ecological quality of agricultural land in Cixi City.The evaluation results show that the ecological quality of most agricultural land in Cixi City is excellent,and there is ecological risk only in some local areas such as urban periphery.The experimental results provide demonstration and basis for the fine management of basic farmland and ecological protection.

中国农业节水十年:成就、挑战及对策

水是农业的命脉。在水资源紧缺形势下,保障国家食物安全和农产品有效供给,必须实施农业节水,发展高水效农业。在系统总结过去10年我国农业节水在保障国家食物安全和农产品有效供给、促进区域农业可持续发展和生态环境改善、促进现代农业转型升级和提质增效以及带动农业节水产业发展等方面取得的巨大成就基础上,分析了当前我国农业节水与国际先进水平的差距,以及在农业节水相关基础数据观测和长期积累、节水评价指标体系和考核标准、灌溉面积盲目扩张与农业适水发展、灌区续建配套节水改造和高标准农田建设衔接、高效节水灌溉与农艺技术配套、农业水价综合改革与节水灌溉工程设施可持续运行机制和政策、农业节水科技创新与节水产业发展等方面面临的问题和挑战,提出了促进农业节水高质量发展的建议。

基于物联网农业灌溉系统精准控制模型的研究

为进一步提升我国农业灌溉系统的综合作业效率,体现灌溉的先进性与科学性,提出以精准控制模型为切入点,以物联网技术为主体支撑平台,针对其作业系统展开设计与优化。通过引入物联网强大的系统性架构,规范与强化各网络节点的部署与协作关系,科学搭建用于实现精准灌溉控制的数学模型,同时导入合理的系统软件设计程序与硬件功能组件配置,形成完整集成式的农业智能灌溉系统。结果表明:基于物联网平台技术的精准控制模型应用后,整体的作业效率得到显著提升,系统精准度、系统响应率分别相对提高了6.25%和7.68%,动作延迟率相对降低了2.72%,灌溉节水效率提升至91.50%。物联网平台下的精准控制模型应用效果良好,设计理念正确,可为灌溉领域实施节能降耗提供参考。

基于物联网农业灌溉系统的参数检测方法研究

为提升农业灌溉系统检测环节准确性及整体作业效率为目标,基于物联网灌溉及参数检测方法应用展开设计。以当前灌溉作业机理及通信结构布局为出发点,通过建立合理正确的参数检测架构,选定高效适应的参数检测方法,实现整体灌溉系统功能优化。进行灌溉系统作业监测试验,结果表明:参数数据通信监测准确率及系统执行效率分别提升至93.70%与95.89%,系统丢包率相对降低至0.79%,平均节水效率相对提升了6.39%。基于物联网平台进行参数检测的有效性与适应性改进,较好地满足了智能灌溉的发展趋势,其方法研究理念对于灌溉系统及类似农机培育系统开发应用具有参考价值。

川渝地区农业绿色高效用水科技攻关方向与对策建议

川渝地区农业种植面积大、从业人员多、产业份额大、战略意义强,但该地区长期面临严重的季节性干旱和工程性缺水,且农业绿色高效用水发展水平与经济发展、区域地位并不匹配,需提高农业节水抗旱减灾保产能力和水资源利用效率,推动川渝现代节水农业高质量发展。总结了川渝地区农业用水现状和高水效农业发展面临的问题,分析了该地区农业绿色高效用水的实际需求,在此基础上提出开展川渝农业绿色高效用水关键科技项目攻关、构建农业绿色高效用水专家智库、构建西南季节性干旱区农业绿色高效用水技术体系、建设特色水果产业节水科技创新中心、建立川渝农业绿色高效用水产业联盟等一系列对策建议。

基于自然地下水矿化度分布的北方沿海区水稻适宜规模研究

基于自然地下水矿化度分布规律,探究北方沿海区水稻合理种植规模具有重要的节水压盐意义。本研究以唐山市为例,基于地下水矿化度监测及Landsat遥感影像等数据,分析了水稻种植规模时空分布,结合水稻生长的矿化度阈值,利用叠加分析法提出适宜种植规模和调整措施。结果表明:受水资源短缺影响,1991年以来唐山沿海区的水稻种植面积逐年减少,现状水稻种植面积基本稳定在6.28万hm^(2)。地下水矿化度大于3、1~3 g/L和小于1 g/L的区域分别为水稻保留区、探索退减区和优先调减区,面积分别为4.80、1.69和1.05万hm^(2)。结合国家粮食安全要求,唐山市沿海区适宜水稻种植面积为5.00~5.33万hm^(2)。研究成果为北方沿海区水田的开发利用和粮食节水增产策略提供了新思路。

黄河流域农业水资源生态韧性与用水效率耦合协调及驱动因素研究

韧性与效率是可持续发展的两个核心要素,统筹农业水资源生态韧性和用水效率协调发展,对于推动黄河流域生态治理和农业高质量发展具有重要现实意义。利用熵权-Topsis法、超效率SBM模型对黄河流域农业水资源生态韧性与用水效率进行测度,构建耦合协调度模型分析两者间的协调发展水平,借助核密度估计、ArcGIS图示法、Dagum基尼系数和空间自相关考察耦合协调度的时空演变格局及空间集聚效应,并运用地理探测器模型识别其驱动因素。结果表明:①时空演化上:2007-2021年全流域耦合协调度均值呈现先降后升的“U”形演化趋势,良好协调区呈现由点到片、由北至西南、由外围向内部蔓延的空间格局。②区域差异上:中游区域内差异扩大,上游和下游区域内差异缩小但两者区域间差异最大。③空间集聚上:偏向于随机分布且空间集聚较弱,未形成连片效应。④驱动因素上:自然灾害、研发投入与产业发展是协调发展度的主要影响因子。针对协调演化发展现状,提出“中心带动边缘”、“技术协同管理”、“政府结合市场”的一体化、系列化、多元化发展策略。