Coagulation of micro-polluted Pearl River water with IPF-PACls

Water samples collected from early March 2001 to the end of April 2002 at the branch of Pearl River around the Guangzhou City were analyzed for its micro-polluted characteristics. The coagulation behavior of polyaluminum chlorides(PACls) was then examined focusing on the effect of primary water quality and speciation distribution. The results showed that PACls exhibit better coagulation efficiency than alum in accordance with the different speciation. The turbidity removal property of PACls is evidently better than alum at low dosage. While in neutral zone(about 6.5—7.5), the turbidity removal of PACls decreases owing to the restabilization of particles at higher dosage. The organic matters in raw water exhibit marked influence on coagulation. In acidic zone, organic matters complex with polymer species and promote the formation of flocs. With an increase in pH, the complexation of organics with polymer species gradually decreases, and the removal of organics mainly depends on adsorption. The effect is evidently improved with the raise of B value.

Preparation of New Poly Silicate Iron Coagulants and Their Coagulation Property on Micro-polluted Water

The sodium silicate, ferric chloride, ferrous sulfate, sodium chlorate and other common inorganic materials were used to synthesize two new poly silicate iron coagulants： Polysilicate Ferric Chloride （PFSiC） and Polymeric Ferric Silicate Sulfate （PFSiS）. Their coagulation effect on micro-polluted water was compared with the poly ferric choride （PFC） saled in the market. The results showed that turbidity, organic matter, total phosphorus, total nitrogen removal rate ofPFSiC, PFSiS coagulant were better than PFC on micro-polluted water treatment at the same dosage. The coagulation effect of PFSiC was the best. The surface morphology of three coagulants was observed by scanning electron microscopy （SEM）, and the coagulation mechanism was discussed preliminarily.

Performance of BAC process for treatment of micro-polluted water

Biological activated carbon (BAC) has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies for nitrobenzene, permanganate index, turbidity and ammonia were investigated. Effects of shock loading and SEM (Scanning Electron Microscope) observation on BAC were studied. Backwashing and its intensity of BAC were also discussed. The results showed that BAC took short time to start up and recover to the normal condition after shock loading. The shock loading studies showed that the removal efficiency of BAC was not completely inhibited even at high concentration of nitrobenzene. Backwashing performed once every 10-20 d, or an average of 15 d. Backwashing intensity was 12-14 L/(s·m2) with air and 3-4 L/(s·m2) with water.

The Occurrence and Prevention of Filamentous Algae in Ecological Purification System of Micro-polluted Water

[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.

Surface flow constructed wetland with composite plant bed for pretreatment of micro-polluted Yellow River raw water in China

In order to investigate the feasibility of pretreating the micro-polluted Yellow River raw water by constructed wetland, an experiment was conducted using a surface flow constructed wetland with composite plant bed. The contamination removal efficiency and their trends in the wetland treatment system were studied under different hydraulic loading rates(HLR). The contamination removal efficiencies were compared according to the seasonal change under optimum HLR. The result shows that in the same season, under different hydraulic loadings ranging from 2 to 6 m3/(m2·d) at the same period, the best HLR is 4 m3/(m2·d) in the experimental system. The average removal rates of COD, TN, ammoniacal nitrogen(NH4+-N), and TP in the constructed wetland are 38.37%, 45.97%, 39.86% and 41.69%, respectively. According to China Standard for Surface Water Resources (GB3838-2002), mean effluent of COD, TN, NH4+-N and TP can nearly reach Grade Ⅲ, GradeⅤ, GradeⅠand GradeⅠ, respectively. Furthermore, treatment efficiency of the system in summer is obvious higher than that in other seasons. The expenditure of constructing the constructed wetland with the average treating capacity of 176 m3/d and lifetime of 20 years is 17075.00 RMB. The average disposal cost is summed up to 0.17 RMB/m3, which shows that the pretreatment of the micro-polluted Yellow River raw water by constructed wetland is feasible.

Oil Pollutants Degradation of Nano-MgO in Micro-Polluted Water

The removal of oil pollutants from water and purifying process of oil-polluted water are studied through catalytic degradation method with nano-MgO. The results indicated that catalytic degradation effect of nano-MgO on the oil pollutants was associated with dosage of nano-MgO, pH and water temperature. When oil content was 1.8 mg/L, 0.17 g nano-MgO was used and the removal rate of oil was 93.92%. Furthermore, nano-Mgo was a non-photosensitive catalyst. GC/MS analysis showed that the amount of petroleum-based pollutants in water was reduced 73.77% from the previous 61 kinds to 16 kinds, and the total peak area was reduced 96.05% after catalytic degradation of nano-MgO. Therefore, nano-MgO has an excellent effect on the catalytic degradation of oil pollutants and can be applied in the treatment of oil wastewaters.

Application of Green Technology Using Biological Means for the Adsorption of Micro-Pollutants in Water

It is true that the world we have today is not the world we use to know. The Covid-19 pandemic has paralyzed all sector, hence the need for safety and enabling environment for mankind is of high importance. Adsorption technology is far the best and cheapest treatment technology for water and has extensively proven its worth for the uptake of micro-pollutant from surface, ground and water which are the major channels of home water. Over the years activated carbon is considered as the most common and universally used adsorbent for the eradication of different types of micro-pollutants from water. The contamination of surface water by micro-pollutant is a potential threat for the production of high quality and safe drinking water. Adsorption operation onto granulated activated carbon (GAC) in fixed-bed filters is often applied as a remedying step in the synthesis of safe and drinkable water. Activated carbon actively tends to act as a carrier material for a thin usually resistant layer of microorganisms (mostly bacteria) that forms on the coat of various surfaces (biofilm), hence biological simplification can be an alternative removal approach that can be adopted in granulated activated carbon filters. To evaluate the capacity of biofilm to biologically simplify micro-pollutants, it is very imperative to distinguish adsorption from biological simplification (biodegradation) as a removal mechanism. Experiment was carried out under the operating condition of a temperature range of 6?C to 20?C with biologically activated and autoclaved GAC to assess the biological simplification by the biofilm adsorbed on the GAC surface. Five micro-pollutants were selected as model compounds, of which some of them were biologically simplified by the GAC biofilm. Additionally, we observed that temperature can increase or decrease adsorption. Conclusively, comparison was made on the adsorption capacity of granulated activated carbon used for more than 50,000 beds.

黄河流域水资源超载地区和短缺地区的判定与动态管理

黄河流域水资源短缺,而能源富集,工业用水需求强劲,水资源开发利用率高达80%,如何协调生态保护和高质量发展的关系,实现对水资源超载地区、短缺地区的动态管理,至关重要。在分析水资源承载能力的概念定义和内涵发展的基础上,总结了水资源超载地区和短缺地区的定义和判定标准,对黄河流域九省(自治区)进行了综合研判,并从水资源刚性约束、水资源监测和管控策略等方面提出了水资源动态管理的关键措施,以期为黄河流域生态保护和高质量发展国家战略的水安全保障提供决策参考。

17α-Ethinylestradiol removal from water by magnetic ion exchange resin

Magnetic ion exchange(MIEX) resins have received considerable attention in drinking water treatment due to their fast and efficient removal of dissolved organic carbon(DOC). Two types of mechanisms, i.e., ion exchange,reversible and irreversible adsorption, may occur during pollutants removal by MIEX. This work examined the removal mechanism of 17α-Ethinylestradiol(EE2) by MIEX. As one of typical estrogen micro-pollutants,EE2 existed as neutral molecule in natural water, and its charge density was close to zero [(0.00000219 ±0.00000015) meq·(μg EE2)^(-1)] based on the potentiometric titration method. However, the removal of EE2 by MIEX was much higher than that of other micro-pollutants previously reported. Multi-cycle adsorptionregeneration experiments and ion exchange stoichiometry analysis were conducted to elucidate the removal mechanism of EE2 by MIEX resin. The results suggested that the main removal mechanism of EE2 by MIEX was ion exchange instead of reversible micro-pore adsorption. The experimental analysis based on Donnan theory indicated that the internal micro-environment of resin beads was alkaline, in the alkaline environment EE2 would be ionized into negatively charged groups. As a result, ion exchange reaction occurred inside the pore of MIEX resin, and the removal process of EE2 by MIEX was dominated by the ion exchange reaction.

观测资料短缺地区水文模拟与地表水资源时空分布评价——以马莲河流域为例

传统的资料短缺地区水文设计多采用水文移用方法,但受黄土高原空间异质性影响,估算结果常存在较大误差,且黄土高原区产流机制较为复杂,地下水补给强烈,简单的水文模型多难以准确模拟区域水文过程。鉴于此,以马莲河流域为研究区域,透过SWAT-MODFLOW耦合模型实施马莲河流域尺度的水文模拟,并评价其地表水资源在不同地表覆盖下的时空分布格局及其演化特征,以期为以马莲河流域为代表的资料短缺地区的地表水资源量评价提供参考。模型校验结果表明,构建的SWAT-MODFLOW耦合模型在以马莲河流域为代表的黄土高原具有较好的适用性,出口站点的NSE系数高达0.92。相比水文设计中常用的面积比推算法,基于耦合模型获取的地表水资源量空间分布成果更具有参考价值。近天然条件下马莲河流域内不同子流域或区域的出口断面径流及产水能力具有显著的空间异质性,出口断面径流整体呈现自西北向东南逐渐递增的趋势,流域上游东川、西川干流区域产水能力最强,环江上游区域产水能力较弱,其他区域产水能力介于二者之间。以耕地向草地和林地转移的流域植被覆盖改变,对马莲河流域地表水资源量的影响有限,而以取用水为代表的流域直接人类活动对径流减少的影响强烈。

气动钻机在无水陡峻山区输电线路工程勘察中的应用实践

本文通过分析关键困难点,在广泛调研的基础上,确立了采用气动钻机结合孔内成像的思路。进而开展针对性选型设计,优选出一套模块化气动钻机,实现拆卸后最大单体可双人搬运,满足了陡峻山区搬运要求;结合智能孔内电视仪观察孔内情况并生成电子岩芯,用于界定地层分布。通过某无水灰岩山区塔位实施情况,表明气动钻机在无水山区钻探效率、总效率上较百型钻机有较大优势,配合智能孔内电视仪可准确界定地层,该套设备及勘察模式,在无水陡峻山区具有一定推广价值。

不确定性多目标模糊规划在水资源优化配置中的应用

在充分考虑水资源系统中供需水不确定性的基础上,基于多目标规划、模糊规划和区间规划原理,以经济效益、社会效益和环境效益最大为目标,以需水量、可供水量和不同子区用水部门间的用水公平性为主要约束,构建一种适用于多水源、多子区、多用户的考虑供需水不确定性的多目标模糊规划模型,以期通过平衡水资源配置系统中用户配置水量、缺水风险与系统收益三者的关系,实现系统综合效益最大。模型以衡水市历年供水、用水及社会经济等数据确定规划年的水资源参数及经济参数,采用区间参数反映系统中的不确定性,通过引入模糊隶属度函数,利用两步交互式算法,将多目标规划转化为单目标规划进行求解,以2025年为衡水市规划水平年,得到规划水平年下的11个子区、4种水源、4个用水行业的最优配水方案。结果表明:本研究制定的水资源优化配置方案可实现“外调水优先利用、地下水控制利用”,同时考虑用水的公平性约束后,在缺水条件下可有效控制水资源向每立方米水效益高的区域和部门流动,有利于多区域、多部门共担缺水风险;该水资源优化配置方案可有效缓解衡水市水资源供需矛盾,实现多水源和多目标之间的协同互补。研究成果可为河北省其他县域的水资源优化配置提供技术参考。

缺资料地区产流径流时空特性分析及其关系研究——以洮河流域为例

为了解决缺资料地区的产流、径流时空特性分析问题,采用SWAT模型、多元统计分析法、相关系数法、弹性分析法等方法,研究分析缺资料地区——洮河干流分区段产流、径流的时空变化规律,揭示降雨量P、产流量Y、径流量R三者之间关系以及径流变化影响因素。结果表明:洮河流域红旗站1956-2019年径流量整体呈显著减小趋势,1987年发生突变;SWAT模型率定、验证期决定系数分别为0.78、0.79,Nash-Suttcliffe系数分别为0.78、0.77,相对误差均小于10%,模拟效果令人满意;河道径流中游占比最大(50.71%),其次为上游(37.21%),下游占比最小(12.08%),中游是径流量的主要来源;产流量由上游到下游呈减少变化,依次为214.18、179.43、81.16 mm;代桑曲子流域产流量最大,岔河、东峪沟最小;相关性排序为P与Y、Y与R、P与R,且相关性由上游到下游逐渐减弱;气候变化和人类活动对径流变化的贡献率分别为20%和80%,人类活动是主要因素。研究成果有利于揭示洮河流域各区段产水径流变化及影响机理,同时为缺资料地区产流径流时空分析提供理论支撑。

Removal of bentazone from micro-polluted water using MIEX resin:Kinetics,equilibrium,and mechanism

The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the effect of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal efficiency of bentazone. Results showed the sorption process was fast and bentazone could be efficiently removed in 30 minutes. The kinetic process of bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle diffusion was the rate controlling step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting, Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the sorption characteristics on MIEX resin. The different removal efficiencies of ionic and non-ionic pesticides, combined with the charge balance equations of bentazone, SO4^2-, NO3- and Cl-, indicated that removal of bentazone using MIEX resin occurred primarily via ion exchange.

Sulfur-based autotrophic denitrification from the micro-polluted water

Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic denitrification with the sulfur compound as electron donor was investigated in the biofilter reactors. Through the lab-scale experiment,it was found that different sulfur compounds and different carriers caused very different treatment performances. Thiosulfate was selected to be the best electron donor and ceramsite was chosen as the suitable carrier due to the good denitrification efficiency, low cost and the good resistibility against the high hydraulic loads. Later the optimum running parameters of the process were determined. Then the pilot-scale experiment was carried out with the real micro-polluted water from the West Lake, China. The results indicated that the autotrophic denitrification with thiosulfate as electron donor was feasible and applicable for the micro-polluted lake water.

水资源紧缺对北京市GDP增长造成的不利影响分析

采用水资源模糊定价模型探讨了北京市水资源紧缺对国内生产总值（ＧＤＰ）增长带来的不利影响，结果表明：水资源紧缺使北京市ＧＤＰ增长产生较大的损失，１９８１－１９９５年ＧＤＰ损失量达１２８．１４亿元，平均年损失率为１．７２％，并且这种损失还在逐年递增．

缺资料流域的非点源污染模拟研究

针对非点源污染模型在缺资料流域应用较为困难的问题,以赣江袁河流域为例进行研究。通过插补延长、参数移用等技术手段处理分析,构建了基于分布式SWAT模型的袁河流域非点源污染模拟方案。对流域内水量、泥沙及主要污染物氨氮(NH3-N)和总氮(TN)模拟计算结果显示,纳西效率系数和相关系数基本达到0.7以上,模拟精度较为满意,说明了SWAT模型在资料缺乏流域应用的可行性。所用的技术方法对其它流域的类似研究具有一定的参考价值。

滨海缺水城市海水淡化全成本分析——以华能威海电厂为例

随着滨海城市的快速发展,常规的地表水、地下水已远远不能满足社会经济的发展。以华能威海电厂为例,基于全成本理论,构建海水淡化全成本分析模型,分别从资源成本、工程成本、外部性成本展开核算,从有用性价值和稀缺性价值考虑资源成本,工程费用和前期投入费用计入工程成本,运用污染物当量法测算海水淡化对生态影响,计算得出威海市华能电厂海水淡化水全成本为7.166元/m3,其中资源成本为0.123元/m3,工程成本为6.597元/m3,外部性成本为0.446元/m3。对比目前自来水水价和外调水水价,淡化水不存在明显的价格优势。但因为其水量稳定、水质安全等特性,未来在城市供水系统中仍存在一定的应用潜力。最后为提升淡化水在纳入滨海缺水城市供水系统方面的竞争力,提出了相关政策建议。

节水型社会建设“十三五”规划城市领域中期评估研究

通过分析全国“十三五”中期城市节水规划目标实现程度、主要任务完成情况和节水潜力,结合城市节水管理机制完善和组织实施情况评估,总结节水型社会建设“十三五”规划全国城市领域的实施进展与存在问题。结果表明,从“十一五”至“十三五”中期,我国以城市公共供水总量39%的增长支撑了新增60%的城市公共供水用水人口的正常用水需求,用水效率显著提升。“十三五”期间城市节水量和投资额呈井喷式增长,再生水利用量和利用率大幅升高,但仍面临公共供水管网漏损量逐年升高、再生水利用水平区域差异大等问题。运用SPSS的双变量分析方法,通过等级相关系数可知城市节水影响因子呈现极显著和显著相关的关系,由此剖析城市节水工作的内驱力和外.动力,说明因子协同发挥作用的重要性。建议调整和优化规划目标、主要任务,切实推进少部分工作基础薄弱地区的城市节水工作,同时使北京、江苏等地区继续发挥城市节水工作优势,从而推动规划顺利实施。

缺水型大城市多水源调配管理技术体系与方法研究

针对缺水型大城市多水源供水系统日益庞杂带来的规范化和精细化调配管理问题,通过强化最严格水资源管理制度对城市多水源统一调配和管理的指导作用,从前期调配评估、调配系统构建、调度规程制定、调配方案编制四方面,探讨了缺水型大城市多水源调配管理技术体系,提出了城市水源-工程-单位-用户四层供水系统网络拓扑结构、城市供用耗排水量流转关系、水资源调配工程与管理体系、水资源日常调度规程、多水源联合调度模型等关键技术问题的解决思路与方法。将该技术体系应用于北京市水资源统一调配管理,结果表明:北京市供水系统可划分为4类水源-11类供水工程-4大水管系统-5大用户的网络拓扑结构。在此基础上,可构建由36家机关单位组成的水资源三级调度管理体系,按照调度会商-决策-实施-调整为核心的调度流程,依据统筹用水管控、水源配置、水量调度原则编制的水量调配方案开展日常水量调度工作。研究成果可为水行政主管部门推进水资源精细化调配管理工作提供技术支撑。