Incoming Water Research Articles

Coarse-Grained Model of Underground Thermal Energy Storage Applied to Efficiency Optimization

Seasonal storage of thermal energy, by pumping heated water through a borehole array in the summer, and reversing the water flow to extract heat in the winter, can ameliorate some of the intermittency of renewable energy sources. Simulation can be a valuable tool in enhancing the efficiency of such storage systems. This paper develops a simple, efficient mathematical model of spatial temperature dynamics that focuses on the radial water flow in a cylindrical borehole array. The model calculates the time course of the temperature difference between outgoing and incoming water accurately, and allows new optimization strategies to be explored easily. A strategy based on discharging water heated by the array before it reaches the array center can increase the storage capacity by 25% for a system with a 20% smaller radius than the well-studied Drake Landing system. If the density of boreholes is also doubled, the improvement is 29%.

Restoration of Hatirjheel Lake by designing submerged aeration system and settling zone

Hatirjheel Lake is known as the centre of the Dhaka city, the capital of the Bangladesh, a South Asian riverine country. But, unfortunately, soon this lake will be darken due to huge pollution. Therefore, to augment dissolve oxygen level, aeration system has been acknowledged as an effective way for the lake restoration, and an aeration zone and for further improvement settling zone have been designed. First of all, our study is assessed bifurcating the total area into two segments: aeration zone and sedimentation zone. Total oxygen requirement and other fundamental tests have been derived from sample. Later, to meet 83mg/l of oxygen demand number of diffusers of 8in diameter have been enumerated, and additionally three root lobe blowers of a centrifugal pump are selected, and desludging time interval has been computed. Conclusively, the percentage removal of particles has been substantialized through laboratory-based batch column. In our study, we have considered maximum discharge of 6 ft3/s whilst even during the rainy season more than 50% incoming water will be transferred via twin diversion sewers. Therefore, we can say our design is in the satisfactory zone.

A Study on the Change of Displacement according to the Drainage Pump Outlet Shape and Size of Combat Equipment.

Combat equipment is designed to cross the river on its own. The important thing here is that first, the inflow of water should be minimal, and the second is draining out the inside of the inflow. In this study, we have studied how to effectively discharge the incoming water. The purpose of this study is to compare the flow rate, so the pump pressure was not considered. The flow analysis was carried out only by considering the head pressure and atmospheric pressure. The outlet shape was found to have 13% more emissions than the spiral, which caused vortices due to the helical grooves and protrusions inside the hole, resulting in the loss of flow energy due to the increase in frictional resistance. As a result of checking the drainage according to the size, when the hole size is small, the drainage of water is gradually progressed. When the hole size is large, the drainage is increased rapidly and it is confirmed that it is discharged in a short time. If the hole size is infinite, the effect of drowning is maximized, but it may affect the structural strength of combat equipment, so it should be considered when designing the size of the outlet. Drainage pumps can save the combat equipment from the risk of flooding for water inflows below a certain level. Therefore, when the drainage pump is maintained, the pump is maintained, the pump efficiency should be guaranteed by thorough inspection and performance test.

Performance of multi-soil-layering (MSL) urban domestic wastewater treatment system

This research has the objective of examining the efficiency optimization of a multisoil-layering (MSL) system in three stages through the selection of the most efficient material for permeable layers. The utilized charcoal variations were coconut shell charcoal, rice husk charcoal, and corncob charcoal. The utilized incoming discharge for Q1 and Q2 were 0.0063 L/second and 0.0126 L/second. In the first stage of processing, the pumice and zeolite in Q1 had not been able to reduce the TSS below the quality standard, while silica sand in both discharges were still in accordance with the quality standard. In the second stage of processing, Q1 MSL A-s had the best elimination capability, with the efficiencies of TDS, TSS, pH, and DO respectively being 18.13%, 79.68%, 2.60%, and 126.67%, while for Q2, they were 29.99%, 77.76%, 1.62%, and 95.80%. In the third stage, it was shown that MSL B-m was the most optimal reactor compared to all reactors that had their water qualities measured. For Q1 for MSL B-m, the parameters of TDS, TSS, pH, and DO were respectively 33.16%, 84.32%, 1.29%, and 126.67%, and for Q2 they were 30.80%, 80.54%, 1.50%, and 112.30%. In the third stage of processing, MSL A-m, MSL B-m, and MSL C-m that included the addition of soil mixtures and modifications of soil mixture blocks could increase the efficiency of each parameter and had a more stable quality of water outflow compared to standard MSL; this is because the incoming water flow was slower, which caused water contact with the processing media to be more optimal.

Sodium Hypochlorite Treatment: The Impact on Bacteria and Endotoxin Concentrations in Drinking Water Pipes of A Pig Nursery

Poor drinking water quality can affect pigs’ health and performance. The disinfection of water may enhance microbial water quality. In this study, bacteria and endotoxins in sodium hypochlorite-treated and -untreated water from one pig nursery were analyzed. Water samples were taken from incoming water and from compartments with treated and untreated water at the beginning and end of pipes and from nipples. The farm was visited 14 times to measure total bacteria counts and concentrations of Pseudomonas spp. and endotoxins. Additionally, the occurrence of coliform bacteria was analyzed. A mixed model analysis revealed significant reductions in total bacteria counts and Pseudomonas spp. in treated water at the beginning of pipes and at nipple drinkers. The differences between bacteria concentrations at the end of pipes had no clear trend. Endotoxin concentrations were approximately equal at the beginning of pipes and at nipple drinkers but were found to have differences at the end of pipes. The occurrence of coliform bacteria was significantly reduced in treated water. The application of sodium hypochlorite can significantly reduce bacteria in water pipes. Endotoxin concentrations were mostly unaffected by water treatment. Disinfection of the dead-end pipe sections failed, and thus these parts should be regarded as potential contamination sources.

Water quality parameters contributing to the invasion of water hyacinth (<em>Eichhornia crassipes</em>) in the Anawilundawa reservoir in Sri Lanka

Eichhornia crassipes has been found to invade the Anawilundawa reservoir located within Ramsar wetland in the northwestern region of Sri Lanka. Present study was carried out to determine the water quality parameters that could contribute to its invasion and identify an effective control measure. During the study period of March-November 2017, mean values for Secchi depth, water depth and nitrate content in areas where E. crassipes was present (7.9 cm, 12.4 cm and 475 µg L-1 respectively) were found to be significantly lower (p<0.05) than in areas where it was absent (9.0 cm, 14.0 cm and 726 µg L-1 respectively). In areas where E. crassipes was present, low nitrate content may be due to its absorption and low Secchi depth may be due to trapping of detritus. Principal Component Analysis showed that during the monsoon period, high pH combined with low levels of conductivity, salinity, total dissolved solids and total phosphorus contributed for its invasion. From March to July, coverage of E. crassipes gradually decreased and in August the reservoir was completely dry and E. crassipes was present only as sparsely distributed individual plants rooted to the exposed reservoir bed. In September, with incoming water of inter-monsoonal rains and surface runoff, these plants got uprooted and started floating and by October they were flowering. In June, E. crassipes was confined to an area of about 0.5 ha with a mean depth of 13.3 cm. During this month it can be easily removed manually with a little amount of human labour which can be obtained from the riparian community who use this reservoir for irrigation and domestic purposes. However, if it is to be removed, a suitable indigenous plant species that interact with aquatic avifauna has to be introduced to ensure the continuity of some environmental services provided by this reservoir.

Over-winter persistence of supraglacial lakes on the Greenland Ice Sheet: results and insights from a new model

AbstractWe present a newly developed 1-D numerical energy-balance and phase transition supraglacial lake model: GlacierLake. GlacierLake incorporates snowfall, in situ snow and ice melt, incoming water from the surrounding catchment, ice lid formation, basal freeze-up and thermal stratification. Snow cover and temperature are varied to test lake development through winter and the maximum lid thickness is recorded. Average wintertime temperatures of −2 to$-30^{\circ }{\rm C}$and total snowfall of 0 to 3.45 m lead to a range of the maximum lid thickness from 1.2 to 2.8 m after${\sim }250$days, with snow cover exerting the dominant control. An initial ice temperature of$-15^{\circ }{\rm C}$with simulated advection of cold ice from upstream results in 0.6 m of basal freeze-up. This suggests that lakes with water depths above 1.3 to 3.4 m (dependent on winter snowfall and temperature) upon lid formation will persist through winter. These buried lakes can provide a sizeable water store at the start of the melt season, expedite future lake formation and warm underlying ice even in winter.

Pollution and contamination assessment of heavy metals in the sediments of Jazmurian playa in southeast Iran

Jazmurian playa was an ephemeral lake with a large catchment in southeast Iran, which dried up over the last 10 years as a result of prolonged drought. As the lake was recipient of incoming industrial water with trace metals deposited to the sediment, the dust is the cause of environmental concern of the region and requires evaluation and better management. The aim of this study was to evaluate the environmental and ecological pollution of Jazmurian playa. Hence, 24 collected surface sedimentary samples were analyzed with ICP-OES. The environmental pollution indices including degree of contamination (Cd), geoaccumulation index (Igeo), enrichment factor (EF), pollution load index (PLI) and potential ecological risk (PER) were determined. The study revealed moderately to strongly pollution levels of Pb, Ni and Al, while Dy, Pb, Y, Yb, Sm, Te, U, Cu, Mn, Sc represented moderate pollution. The EF values indicated four sites were highly enriched with Dy, Pb and Ni. The PER results showed high risk for four sites and considerable risk for others. Cluster analysis illustrated interconnection between the contaminants and the sites with major pollution at six sites. Obviously, climate change has considerable complex environmental impacts through transformation of local water and sediment pollution problem.

Climate Change Implications for Water Availability: A Case Study of Barcelona City

Barcelona city has a strong dependence on the Ter and Llobregat reservoir system to provide drinking water. One main concern for the next century is a potential water scarcity triggered by a severe and persistent rainfall shortage. This is one of the climate-driven impacts studied within the EU funded project RESCCUE. To evaluate potential drought scenarios, the Hydrologiska Byråns Vattenbalansavdelning (HBV) hydrological model reproduces the water contributions by month that have reached the reservoirs, regarding the accumulated rainfall over each sub-basin, representing the available historical-observed water levels. For future scenarios, we adjusted the input data set using climate projections of rainfall time series data of the project RESCCUE. Local outputs from 9 different climate models were applied to simulate river basins’ responses to reservoirs’ incoming water volume. Analyzing these results, we obtained average trends of the models for each scenario, hypothetical extreme values, and quantification for changes in water availability. Future water availability scenarios for Barcelona central water sources showed a mean decrease close to 11% in comparison with the period 1971–2015, considering the representative concentration pathway 8.5 (RCP8.5) climate change scenario in the year 2100. This research forecasts a slight downward trend in water availability from rainfall contributions from the mid-21st century. This planned future behavior does not mean that the annual water contributions are getting lower than the current ones, but rather, identifies an escalation in the frequency of drought cycles.

Artificial flow regime promotes abiotic and biotic gradients: Testing the concept of longitudinal zonation in an off-river reservoir

Fragmentation and interconnection of water bodies cause severe changes in the natural flow regime of continental water systems. However, assessments of these impacts on the freshwater fish distribution are still scarce. We investigated whether an artificial flow regime generated by discharges from an aqueduct would promote a longitudinal environmental gradient in an off-river reservoir. We tested the hypothesis that the incoming water from aqueduct discharges promotes environmental gradient between lotic and lentic conditions. We expect that environmental changes and the artificial flow regime promote the structuring of fish assemblage and that the lotic-lentic transition areas present the highest fish species richness. A longitudinal gradient in environmental characteristics with differing fish assemblage structure was found. Temporal changes in the fish assemblages occurred only in areas near the discharge of the aqueduct. The highest fish richness and diversity were recorded in the transition zone during the wet season, associated with the greater environmental heterogeneity of this ecotone, whereas the lowest was found in the lotic zone, probably associated with the altered flow regime. The greatest abundance was recorded in the upper lentic zone in the wet season, whereas the lowest was found in the lower lentic zone in both seasons. Our results corroborate the hypothesis that the artificial flow regime, modulated by the seasonality of discharges and the influence of environmental variables, promotes longitudinal gradients in reservoirs when rivers are not present. The findings are relevant in a scenario where ever more interconnections of aquatic bodies have been diffused around the world.

Hydrate—A Mysterious Phase or Just Misunderstood?

Hydrates that form during transport of hydrocarbons containing free water, or water dissolved in hydrocarbons, are generally not in thermodynamic equilibrium and depend on the concentration of all components in all phases. Temperature and pressure are normally the only variables used in hydrate analysis, even though hydrates will dissolve by contact with pure water and water which is under saturated with hydrate formers. Mineral surfaces (for example rust) play dual roles as hydrate inhibitors and hydrate nucleation sites. What appears to be mysterious, and often random, is actually the effects of hydrate non-equilibrium and competing hydrate formation and dissociation phase transitions. There is a need to move forward towards a more complete non-equilibrium way to approach hydrates in industrial settings. Similar challenges are related to natural gas hydrates in sediments. Hydrates dissociates worldwide due to seawater that leaks into hydrate filled sediments. Many of the global resources of methane hydrate reside in a stationary situation of hydrate dissociation from incoming water and formation of new hydrate from incoming hydrate formers from below. Understanding the dynamic situation of a real hydrate reservoir is critical for understanding the distribution characteristics of hydrates in the sediments. This knowledge is also critical for designing efficient hydrate production strategies. In order to facilitate the needed analysis we propose the use of residual thermodynamics for all phases, including all hydrate phases, so as to be able to analyze real stability limits and needed heat supply for hydrate production.

Small Scales Dynamics Inferred from Tidal Measurements to Mitigate Daily Floodings in the City of Douala: A Case Study of the Besseke's Flood Drain

The recently constructed Besseke’s flood drain is always filled with water due to individual or combined effect of the tide, urbanization drainage, underground plumes and precipitations runoffs. This study focused on the analysis of small scales dynamics inferred from short term tidal measurements to mitigate the daily flooding in the Besseke’s flood drain. The methodology used is based on field measurements observation. The sampling of water level was conducted during two (02) different tidal regimes in May 2019. The volume of brackish water moving in and out of the Besseke’s flood drain was calculated using the formula of O’Brien. The results showed that Spring conditions had greater amplitudes than Neap tide conditions. During Spring tides, the tidal prism that passed in the midsection of the Besseke’s flood drain (S4) was 3.5 × 101 m3. This means that only a negligible amount of the incoming brackish water reaches the Besseke’s flood drain, amplifies and causes the daily flooding. The unexpected stronger amplitudes and dynamics observed in S4 could be due to its sub estuary nature. Furthermore, the percentage composition of water in this section, showed that the fraction of brackish water changes from 85.7% during Spring tide to 77.8% in the Neap tide conditions. The overall spatial evolution revealed that, the trend in tidal prism (during Spring conditions) was (S0) > (S2) > (S1) > (S3) > (S4) with corresponding values of 2.1 × 104, 1.3 ×104, 1.0 × 104, 2.5 × 102 and 3.5 × 101 m3 respectively. Finally, Tidal prism and Cross-sectional area showed a perfect correlation (r2 = 0.96). The best fitted Cross-sectional area-Tidal prism relationship was obtained in S3 (Market) during Spring tide condition.

Production of lumpfish (Cyclopterus lumpus L.) in RAS with distinct water treatments: Effects on fish survival, growth, gill health and microbial communities in rearing water and biofilm

Lumpfish (Cyclopterus lumpus L.) in Norway is currently produced in traditional flow-through systems (FTS). Hatcheries frequently show signs of bacterial infections, unstable microbial communities in the rearing water and varying mortality. Recirculating aquaculture systems (RAS) is proposed to create stable and healthy microbial environments, with less probabilities for blooming of opportunistic microbes. Studies have also shown that RAS increases the survival of marine fish. The aim with this study was to investigate the effect of various RAS water treatment designs on water and biofilm microbiota, survival, growth and gill health of lumpfish. An experiment with lumpfish was conducted, from 2 months post hatch to the transfer into sea cages. Five different water treatment regimens were compared: 1. RAS with no additional water treatment, 2. RAS with a filtration unit for removal of small particles, 3. RAS with filtration and disinfection with UV-irradiation, 4. RAS with filtration and disinfection with UV-irradiation and ozone and 5. FTS as a reference. The microbiota of the rearing water and tank wall biofilm were sampled and characterized by Illumina sequencing of 16S rDNA amplicons. Lumpfish juveniles reared in the RAS treatments were exposed to a more stable and diverse rearing water microbiota, with a lower share of opportunistic bacteria, a probable reason for the higher survival and better gill health of the fish compared to siblings reared in the FTS. Lumpfish reared in RAS without disinfection were exposed to a more diverse and stable water microbiota, with a lower share of opportunistic and potential harmful bacteria, compared to the lumpfish reared in RAS with disinfection and FTS. This resulted in better gill health. Fish in RAS with filtration, but no disinfection, had a better gill health than the fish in the RAS without filtration, possibly due to the reduction of small particles. The lumpfish were exposed to different microbial communities of both water and biofilm, due to the different treatments of the incoming tank water. In conclusion, our results indicate that implementation of RAS in the production of lumpfish has a potential to increase both survival, growth and gill health of the fish and that RAS with filtration of small particles, but without disinfection, result in the best fish health and performance among the investigated treatments.

Numerical analysis of rectangular fins in a PCM for low-grade heat harnessing

Harnessing waste thermal energy from greywater (GW) in non-industrial buildings is becoming necessary to reduce energy demands, make heating/cooling technologies more efficient and to increase the share of renewables in the consumption. Harnessing this low grade energy to heat incoming cold water (CW) linked with phase change materials (PCMs) would decouple demand and supply along with integrating heat recovery with storage in a single unit, unlike technologies of the past.Radially installed rectangular copper fins around the GW and CW pipes of such heat exchanger (HE) enhance the thermal conductivity of the PCM which is the biggest obstacle in this high-impulse application, with the flow rate being high only for a short duration of time. Initially an experimental test rig is used to validate a numerical model as the basis of a sensitivity analysis to find the optimum geometric parameters of the finned HE for this application. A 40 × 90 mm fin with a 10 mm pitch provides complete phase change for both melting and freezing in the constrained time duration of 900s. Compared to a non-finned geometry this optimized fin configuration enhances the effective thermal conductivity of the PCM by a factor of 1.38 for melting and 4.75 for freezing. Although the development of buoyancy induced natural convection vortices are inhibited by fins the eventual heat transfer is enhanced due to a lower overall thermal resistance compared to a non-finned configuration. The GW to CW energy transfer efficiency is 72.4% with higher fluid flow temperature increments, compared to only 47.3% for a non-finned version.

EVOLUTION ANALYSIS OF WATERCOURSE AND SHOALS OF THE XUNJIANG RIVER IN WUZHOU BASED ON TIME-SERIES REMOTE SENSING DATA

Abstract. Wuzhou reach of Xunjiang River is the most valuable waterway in Guangxi. The research on the evolution of Xunjiang River in Wuzhou is of great practical significance in the aspects of river regulation and water conservancy construction. Based on Landsat images of normal water level in 1997, 2001, 2005, 2009, 2014 and 2018, this paper firstly conducts a quantitative analysis of evolution of the watercourse and shoals in Wuzhou section of Xunjiang River through using RS and GIS. Then the relationships between the changes of river course and sandbars of the research area and the annual rainfall and vegetation coverage of the upstream region are analyzed to determine the causes of the changes of watercourse and shoals of Xunjiang River in Wuzhou. The results show that the riverway contracted with a contraction amount of about 9.93 km2 from 1997 to 2005, and the expansion volume of sandbars was about 12.21 km2. From 2005 to 2014, the watercourse approximately expanded 12.33 km2, and the shoals shrank about 12.49 km2. From 2014 to 2018, the river course was a contraction trend, reducing about 1.57 km2 in area; the sandbars showed an expanding trend, with an expanding amount of about 0.82 km2. The changes of river channel and shoals are mainly influenced by the incoming water and silt from the upper reaches and are related to the annual rainfall and vegetation coverage of the upstream area. The correlation coefficient between watercourse area and upstream annual rainfall is 0.26, and that between riverway area and upstream vegetation coverage is 0.78. However, the correlations between the area of shoals and the annual rainfall and vegetation coverage of the upstream region are contrary to that of the river channel. The correlation coefficients between the area of shoals and the annual rainfall and vegetation coverage of the upstream district are −0.28 and −0.83 respectively.

Drain water heat recovery horizontal for energy conservation and reduction of CO2 emissions

One of methods to reduce energy consumption for hot water heating is install of Drain Water Heat Recovery (DWHR) units. The purpose of using this device is to take the thermal energy of the warm drainage water and transfer it to incoming cold water. Many DWHR systems work optimally in a vertical position. Due to the waste water flow in drain pipes. But these requirements are prohibitive to be applied on a large scale of this technology, as many buildings do not have enough space to accommodate the vertical DWHR in their sewage drainage system. This paper presents testing and analysis of the horizontal DWHR system. The result of the test showed the level of effectiveness of the horizontal DWHR unit created by 25.54 percent. Implementation of this technology in regional area, is one of the potential opportunities for energy saving, and reduce CO2 gas emissions.

Delftia acidovorans pseudo outbreak in portable reverse osmosis machines: Interventions to ensure safe and cost-effective hemodialysis

Reverse osmosis (RO), a major advance in hemodialysis (HD) safety, effectively clears most water organisms. Delftia acidovorans is an environmental water-borne pathogen that is rarely reported to cause human infections. We report a pseudo outbreak caused by colonization of RO machines with D acidovorans with no reported human infections and interventions to improve HD safety. Repeated positive RO product water cultures triggered our hospital to initiate an investigation, RO machines were examined for mechanical integrity by biomedical engineers. Cultures of product water as well as RO parts were done. Testing for bacterial relatedness after identification was performed. An investigation was conducted in a systematic fashion to determine the cause and the extent of the problem. Upon formal review of policies and procedures, there were minor deficiencies. Rectifying these deviations from policies did not stop the repeated positive water cultures. A 7-step investigation and correction was successfully conducted. City water testing with filtration and concentration methods was positive for D acidovorans. Major renovation of the HD unit with replacement of all RO machines and a 2-step water filtration resulted in elimination of the pseudo outbreak. City water was the source of biofilm formation of D acidovorans in RO machines that was not possible to eradicate. Application of incoming water filters was an effective preventive strategy. Replacement of RO machines after 4 failed disinfection attempts is the most cost-effective strategy as well for persistent positive water cultures. The HD remains RO water culture negative 2 years after changes.

Effect of water diversion from the Yangtze River to Lake Taihu on total phosphorus rebound after 2016

针对“引江济太”工程将总磷浓度偏高的长江水引入太湖后对2016年后太湖总磷反弹的影响，本文实测并收集整理了2016年前后“引江济太”调水入湖水量、磷通量及全太湖入湖水量、磷通量与太湖磷存量等数据，对2016年前后“引江济太”调水入湖水量、磷通量、磷形态与其他入湖河道水量、磷通量、磷形态以及全太湖的水质、受水区贡湖的水质进行了分析.结果表明：2016年前后，“引江济太”年均入湖磷通量为97.56 t，年均入湖水量为8.16亿m³，从调水量、入湖磷通量、调水后短期磷响应及各湖区磷增量来看，“引江济太”与2016年后太湖总磷反弹相关性不强.“引江济太”调水累计入湖磷通量为877.97 t，占太湖总入湖磷通量的4.58%，累计入湖水量占太湖累计入湖水量的7.36%，单位水量携带的磷通量仅为其他来水的一半左右，占比相对有限.与太湖主要入湖河流相比，“引江济太”调水属于优质来水，湖泊的入湖河流总磷浓度一般都高于湖泊本身的总磷浓度，“引江济太”调水总磷浓度偏高属于正常范围.目前“引江济太”工程在保证供水安全、缓解水华危机的同时对处于严重富营养化状态的太湖具有一定的改善效果，但未来引水量增加的情况下，必须继续关注引水带来的磷通量与太湖磷循环系统的关系，确保“引江济太”对太湖继续产生良性的影响.;In order to figure out the influence of the water diversion from the Yangtze River Project (WDP) on the rebound of total phosphorus (TP) concentration in Lake Taihu after 2016,this study analyzed the water quantity, phosphorus flux and phosphorus form of Yangtze River and other inflowing rivers including Lake Taihu and Gonghu Bay around 2016 based on the data of water quantity, phosphorus flux transfer from Yangtze River and the phosphorus stock in the lake. The result shows that the average annual phosphorus flux into the lake was 97.56 t and the average annual water inflow volume was 816 million m³ around 2016. From the perspective of water volume, phosphorus flux into the lake, short-term phosphorus response after water diversion and phosphorus increment in each lake area, the correlation between the WDP and the TP rebound in the lake after 2016 is not strong. The cumulative phosphorus flux from the WDP was 877.97 t, accounting for 4.58% of the total TP flux into the lake, and the accumulative amount of lake water accounted for 7.36% of the accumulative amount of lake water in Lake Taihu, the phosphorus flux per unit of water is only about half of that of other water, which accounts for a relatively limited proportion. Compared with the main inflow rivers of Lake Taihu, the water quality from Yangtze River is good. The TP concentration in the inflow rivers is generally higher than the TP concentration of the lake itself. At present, in addition to ensuring the safety of water supply and alleviating the water bloom crisis, the incoming water from the WDP has certain improvement effect when the lake is serious eutrophic. In the next step, we must pay attention to the relationship between the phosphorus flux brought by water diversion and the phosphorus circulation system in Lake Taihu, so as to ensure the ongoing WDP continue to have a positive impact.

A Degassing Inlet Structure for Aquaculture Ponds

Structures separating fish hatchery ponds from open spring water sources must restrict fish movement from the pond to the spring, allow for constant water flow, and potentially reduce incoming spring water gas supersaturation. This article describes a novel inlet structure that fulfills those requirements. In addition, it requires minimal maintenance, and allows for the quick and easy removal of debris in the event of partial plugging. This simple aluminum structure consists of a mount for attachment to the inflow pipe and a terminal splash plate with aeration holes. The splash plate is perpendicular to the water flow during normal operations to both prevent fish from jumping into the pipe and aerate the incoming water. However, it can be easily swiveled upward for the efficient removal of debris. Use of the inlet structure consistently decreased gas supersaturation in the spring water as it entered the fish production pond. By decreasing gas levels and maintaining water flows, potentially hazardous fish health issues can be avoided by using this structure. In addition, this relatively inexpensive and simple device will greatly reduce the labor required for removing debris compared to traditional screens.

Оценка объемов поступления инфильтрационных вод в централизованные системы водоотведения

The article is devoted to determination of the infiltration water volume entering centralized water disposal systems. The analysis of the currently used calculation methods and the main factors influencing the formation of infiltration water volumes is given. New approaches and calculated dependences are proposed that allow taking into account the degree of wear and material of pipelines when determining the volume of incoming infiltration water from areas, where sections of gravity pipelines are temporarily or permanently located below the ground water horizon.