Implications of de Facto Reuse on Future Regulatory Developments for Beaufort-Jasper Water & Sewer Authority in Okatie, South Carolina, USA

A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resource Recovery Facility (WRRF) effluent to waters that supply drinking water treatment plants has been documented by some communities. In the United States (US), among the top 25 most impacted drinking water treatment plants by upstream WRRF, 16% of the influent flow to the drinking water treatment plant under average streamflow and up to 100% under low-flow conditions is WRRF effluent. Currently, the full extent of de facto reuse in the US may be much higher because of population growth. The scenario is no different for Beaufort-Jasper Water and Sewer Authority (BJWSA) in South Carolina, US, with contributions to the Savannah River originating from numerous WRRF and other upstream dischargers. South Carolina coastal utilities such as BJSWA are considering direct and indirect potable reuse options, driven by disposal limitations and challenges. Currently, South Carolina does not have a framework, guidelines, or regulations for reuse, but discussions have started among the regulated community. In addition to understanding the extent of de facto reuse, the state will need to develop standards and best practices to enable future adoption of planned potable reuse solutions to water resources challenges. Such guidance should address human health risk management and technical considerations regarding treatment in addition to other factors, including source control, storage, fail-safe operation, monitoring, non-cost factors, and public acceptance. This study conducted a mapping assessment specific to BJWSA, sampled at four locations on Savannah River, and observed that de facto reuse is approximately 4.6% to 5.9% during low-flow months and is within the range generally observed nationwide. When coupled with evidence that planned potable reuse can improve human health and environmental risks, this practice is a meaningful option in the water supply portfolio for many utilities.

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.

Experimental Study of Wastewater Treatment of Reactive Dye by Phys-Chemistry Method

Wastewater, which involves easy-soluble reactive dyes, especially non-degradable dyes, is very difficult to decolor efficiently by normal processes such as coagulation process and biological treatment. The high chromaticity se- riously hinders the reuse of reactive dye waste water. In this paper, a new method by bentonite adsorption and coagulation (PAC) is employed for removing color from synthetic dye waste water which contains reactive red K-2G, K-RN blue, K-GR blue, X-3B red, K-GN orange, KB-3G yellow, K-2BP red, K-RN yellow and K-6G yellow. Bentonite pre- treated by 4% CTMAB and milled to 160 order screen is proven to the best decoloring agent. For a 100 mL reactive red K-2G sample (CODcr 400 mg/L, 25 000 chromaticity color), 0.5 g bentonite pretreated and 2.5 mL PAC is enough to decolor wastewater up to 99.92% and the sediment time is short. Non-degradable dyes such as active red X-3B and K-GN orange are declored completely as well. Raw sewage (low chromaticity color) is decolored completely at a ben-tonite dosage of 0.001g. More researches prove the high practical value of this process.

An Integrated Planning for Rense and Wetland Strategyof Waste Water from Rural Enterprises: A Case Stndy

A waste water reuse engineering was designed and then operated in Hongshan, a small town in ZhejiangProvince, China, in order to solve pollution and shortage of water resources due to the development of ruralenterprises. The results showed that series-structure design and cycling model were two effective modes ofsaving water and decreasing pollutants into environment, and wetland strategy should be a component partof the integrated planning for waste water reuse of rural enterprises. This case study could provide a basisfor the optimum utilization and pollution avoidance of water resources.

Three industries and water consumption of Beijing

Beijing has been experiencing a severe shortage of water. At present serious wastes of water resources result from the unreasonable structure of water uses in various industries sectors. The current conditions of the municipal water use structure and its changes in the industrial sectors were analysed and discussed in terms of the indicators, such as direct water use coefficient, complete water use coefficient, water use multiplier and water reuse rate, by taking a year of 1990s as the base year. Some response strategies for water conservation have been studied and the corresponding recommendations were put forward. All of these have provided a basis for coordinating the relationship between aquatic environment and economic growth in this city, establishing a system for rational utilization of water resources, and promoting the implementation of a strategy for sustainable development.

Potential contributions to Beijing's water supply from reuse of storm-and greywater

In order to find new approaches to alleviating the water crisis in Beijing which is caused by among others dwindling precipitation and rapid growth of population and manifests in a rapidly declining groundwater table this study explores decentralized stormwater harvesting and greywater reuse at household level as a means to reduce groundwater abstraction and water transfer from other regions.Based on a desktop case study two concepts for combined harvesting and reusing of storm-and greywater are presented.With rough pre-assumptions calculations show that a saving of 67.8%of tap water consumption can be achieved with the upgrading concept compared with 5.9% with the simple downgrading concept.The saving with the upgrading concept equals 0.545 ×109 m3 annual water volume if 20 million Beijing people apply this approach.Despite numerous prerequisites such as water treatment technology space demand energy and cost and public acceptance this paper advocates combining stormwater harvesting and greywater reuse in households with other measures for Beijing’s sustainable water management.

Gray Water Measurement and Feasibility of Retrieval Using Innovative Technology and Application in Water Resources Management in Isfahan-Iran

Reuse of wastewater for agriculture and green spaces purposes is significant.A mean yearly precipitation in Esfahan is 150 mm.The drinking water and agriculture usually used underground resources in the city.Gray water recycling is known as a suitable option today.Delivering all the water requirements of a home from refined water rises the cost of water.Whereas the essential water quality for garden,toilet and irrigation is less than drinking water.Therefore,the aim of this study is to analyze the evaluation of gray water and estimate the amount of recycle gray water which can use for drinking water with innovation method in Esfahan region in Iran.Previous studies did not measure the value of recycling gray water with new method of waste water treatment that can use for drinking purpose.In this study,gray water in Esfahan city is measured and technical aspects of its recycling is examined.Because of the lack of referable guidelines and official technical reports,studies from other similar countries applied in this study and on the basis of which the amount of recoverable gray water was calculated.Evaluations indicates that the overall recovery of gray water in Esfahan saves nine million cubic meters of water.The price of the rial of this value established on water is 190 billion Rials.Given the lack of water sources in Esfahan,the recycle of gray water seems to be a good option,however more research is required to select a recovery strategy.

Reuse rate of treated wastewater in water reuse system

A water quality model for water reuse was made by mathematics induction. The relationship among the reuse rate of treated wastewater（R）, pollutant concentration of reused water（ Cs ）, pollutant concentration of influent（ C0）, removal efficiency of pollutant in wastewater（ E）, and the standard of reuse water were discussed in this study. According to the experiment result of a toilet wastewater treatment and reuse with membrane bioreactors, R would be set at less than 40%, on which all the concerned parameters could meet with the reuse water standards. To raise R of reuse water in the toilet, an important way was to improve color removal of the wastewater.

Renovated water reuse for rapid infiltration system

The renovated water in the rapid infiltration system (RI) as area for fish and duck farming is feasible. The flesh of fish and duck is edible. The farming of fish for 5 months and duck for 120 - 130 days can be accepted. It is beneficial to environment and economy, especially in developing countries. The production of fish and duck can make up for the cost of wastewater treatment.

Water conservation in the Arab region: a must for survival

The Arab region covers an area over 13 million square kilometers in size, with almost 90% of its area classified as arid or ex- tremely arid with very little precipitation, extremely high evaporation and almost no vegetation cover. The region is classified in many international reports as the poorest region in the world in the context of renewable water resources and critical water scarcity which hinders the socio-economfic development of many countries in this region. The rapidly increasing population has reduced the per capita share of renewable water to less than the poverty line of 1,000 m3/（capita＇a） and, in some Arab countries, to less than the extreme poverty line of 500 m3/（capita＇a）. This has led to over-exploitation of non-renewable groundwater and desalination of salty water in many countries with considerable costs and contamination of many renewable sources. Atmospheric processes re- sponsible for aridity in the Arab region are projected to intensify due to climate change, resulting in an alarming decrease in pre- cipitation and increase in evaporation rates. Many concerned entities in the region consider water security as a key element for food security and ultimately political stability. Hence, various efforts have been exerted to identify key problems and suggested solutions. The Arab Water Ministers Council of the Arab League, as well as Reports of the Arab Forum for the Environment and Development （AFED） and the recommendations of the 13th Regional Meeting of the Arab National Committees of the Interna- tional Hydrological Programme of UNESCO （niP）, have all made similar recommendations on the need to address the issues of water scarcity in the Arab region which will be further discussed in this paper. However, none of these reports focused on ＂Water Conservation＂ as an equally important action for coping with water scarcity in the region. There are many definitions for ＂Water Conservation＂ in the scientific literature, including huge water savings from irrigation, industrial use, and domestic use as well as methods and approaches for augmenting water supply through non-conventional practices such as water harvesting and waste water reuse. In this paper, a review is provided for definitions, methods and impacts of water conservation and its role in alleviat- ing water scarcity in the Arab region.

Latent dimensions between water use and socio-economic development: A global exploratory statistical analysis

Water use and socio-economic development are interconnected in complex ways.Causalities are not easy to identify but it is evident that a nexus between water use and socio-economic development does exist.Considering the diversity of national situations relating to these interrelated phenomena,its study should be considered from a global perspective.This article critically reviews the literature and information from official sources on the relevance of water use and circular economy in order to create a global picture,linking water with socio-economic development.Data from 195 countries were analyzed statistically.A factor analysis defined five essential latent dimensions on the nexus between water use and socio-economic development:development and basic services,population and resources,economic volume,health and well-being,and population density.Based on the identified factors,countries were classified into six groups:Global South in difficulty,global semi-periphery,advanced economy,Middle East and other Global South developing economy,global weight,and small highly developed economy.The clustering results clarify connections between water use conditions and socioeconomic development.Understanding the variety of national profiles is helpful to reveal the magnitude and urgency of dealing with the nexus between water use and socio-economic development for many countries.

Reverse Osmosis Performance in MBR-RO Process with Recirculation of RO Concentrate to MBR for Water Reclamation

An integrated membrane system, membrane bioreactor-reverse osmosis (MBR-RO), has become highly efficient in producing high-quality water for municipal wastewater reclamation. However, disposal of a highly concentrated waste stream (RO concentrate or RO retentate) generated in this combination is an important issue. This work investigated RO behaviour in an integrated pilot scale MBR-RO system for municipal wastewater reuse with the continuous recycling of RO retentate to the MBR influent. RO membrane retention and the fouling propensity were studied. RO concentrate, produced by the RO process at a fixed concentration factor (CF) of 3, was recycled continuously to the MBR, leading to water recovery of the entire process around 92%. Osmotic pressure model, saturation index method, high performance liquid chromatography equipped with size exclusion column (HPLC-SEC) and specific filtration test were used to analyse the fouling potential of the RO membrane. The results obtained showed that even though RO concentrate recycling changed remarkably, the compositions of both MBR permeate and RO concentrate, the quality of RO permeate remained almost constant in terms of organic matters, conductivity, and ionic salts. However, these high concentrations of organic or inorganic substances in RO concentrate were major factors leading to the RO membrane fouling. Before RO concentrate recycling, a decline of approximately 30% of the initial RO permeate flux was observed in the period when the CF was increasing to 3, mainly due to the osmotic pressure effect of retained ions and the deposits of organic matters at the RO membrane surface. After RO concentrate addition to the MBR, due to the continuous accumulation of ionic salts on the RO membrane surface, a gradual reduction in RO permeate flux (additional 19%) was also mainly attributed to the osmotic pressure effect of the retained ions. These observations showed that the continuous addition of RO concentrate to the MBR was successful in a combined MBR and RO process in terms of the excellent quality of RO permeate.

Five Years of Rice Cultivation in Paddy Fields for Treated Water from Humus Bioreactor-Type Rural Wastewater Treatment Plants

The treated sewage has a color as well as odor and is difficult to reuse.Physical methods to reduce color with odor are costly and more difficult to reuse.Since the color and odor were reduced by pellet-type bioreactor sewage treatment using humus,rice was cultivated for 3 years.Industrially,3 years is sufficient to investigate the stability of treatment facilities,but when biological treatment is applied,5 to 10 years of investigation is required.In addition,in rice cultivation,a similar 5 to 10 years survey is required to investigate the accumulation of low-concentration pollutants.This report is a five-year report and is the result of paddy rice cultivation in a stable wastewater treatment facility.The cultivated rice fully satisfied the edible standards and was able to obtain safe rice,and the effect of reducing fertilizer applied was obtained by using nitrogen and phosphorus from the treated water.In addition,the yield was able to be within the range of the standard yield of 500 kg to 550 kg/1,000 m^(2).

Research on optimal design of wastewater reclamation and reuse for a university

An optimal design of wastewater reuse for a University is concerned in this paper. The raw water and the capacity of wastewater reuse were determined according to the wastewater characteristic of a university; the treatment process was chosen by building a cost-benefit model; and the modeling test was performed about the operation effect of the proposed project and the recommended water quality of reclaimed water. It is estimated that 3.4×10^5 m^3/a tap water and 6.1×10^5 Yuan/a will be saved if the project was put into operation and the proposed project will reduce the total quantity of pollutant efficiently and bring lots of social and economic benefits.

Using Condensed Water of Air Conditioners for Toilet Flushing： A Case Study in Brazil

Within the concept of sustainable construction, with sensible and conscious use of finite natural resources, every effort to save and reuse raw-materials is considered an important step to be adopted in buildings, from project, implantation and construction to operation and maintenance throughout their lifecycle. This study aims at showing the application of a system that reuses condensed water drained from air-conditioner evaporators （which are usually disposed of）, and a plan to use this water for toilet flushing, reducing consumption of treated water bought from water companies. The authors verified that each air-conditioner specified in the project of a commercial building--used as reference here--produces 4.8 L of water per hour of operation. This result in a daily accumulated volume of 4,290 L, which represents a significant part of the amount needed to supply all the toilets in the building. A water capture system located at a strategic intermediate floor would be able to store this water and pump it into a special reservoir on the roof of the building, to be distributed into toilet flush pipes. By applying this technology, the authors seek to considerably reduce the expected treated water consumption and consequently decrease water bill costs.

AQUAREL： Project Aimed at Improving Water Management in French Dairy Plants

The AQUAREL project was launched in 2015 by the CNIEL （French Dairy Interbranch Orgainzation） to propose solutions to dairy processors for the development of water reuse scenarios on their plants. The project focused particularly on the valorization of water from milk which is water obtained during concentration and evaporation processes of milk and its by-products. Firstly, a literature review was done to identify the current uses of water from milk on French plants but also on foreign sites, the technologies used to treat it and the regulations related to water reuse in food industry. Secondly, a field survey was led to establish an overview of the water consumptions and practices existing on the plants. Then, samples were collected on five dairy plants in order to determine the physico-chemical and microbiological composition of water from milk. Thus, the important collection of results obtained was used as a basis for exchanges with water treatment equipment suppliers in order to identify the suitable technologies to treat and reuse water from milk. Two treatment channels were identified, each of them including a filtration and a disinfection step. All this work led to the writing of reports which are now available for the dairy sector professionals.

One-Step Reverse Osmosis Based on Riverbank Filtration for Future Drinking Water Purification

The presence of newly emerging pollutants in the aquatic environment poses great challenges for drink-ing water treatment plants.Due to their low concentrations and unknown characteristics,emerging pol-lutants cannot be efficiently removed by conventional water treatment processes,making technically,economically,and environmentally friendly water purification technologies increasingly important.This article introduces a one-step reverse osmosis(OSRO)concept consisting of riverbank filtration(RBF)and reverse osmosis(RO)for drinking water treatment.The OSRO concept combines the relatively low-cost natural pretreatment of river water with an advanced engineered purification system.RBF pro-vides a continuous natural source of water with stable water quality and a robust barrier for contami-nants.With the pre-removal of particles,organic matter,organic micro-pollutants(OMPs),and microbes,RBF becomes an ideal source for a purification system based on RO membranes,in comparison with the direct intake of surface water.OSRO treatment removes almost 99.9%of the particles,pathogens,viruses,and OMPs,as well as the vast majority of nutrients,and thus meets the requirements for the chlorine-free delivery of drinking water with high biostability.The OSRO treatment is cost effective com-pared with the standard conventional series of purification steps involving sprinkling filters,softening,and activated carbon.Artificial bank filtration(ABF),which functions as an artificial recharge in combi-nation with a sand filtration system,is proposed as an alternative for RBF in the OSRO concept to supply drinking water from locally available resources.It is also suggested that the OSRO concept be imple-mented with wind power as an alternative energy source in order to be more sustainable and renewable.An OSRO-based decentralized water system is proposed for water reclaiming and reuse.It is suggested that future water treatment focus on the combination of natural and engineered systems to provide drinking water through technically efficient,financially feasible,resource reusable,and environmentally relevant means.

Sustainable wastewater treatment and reuse in space

Exploring the vast extraterrestrial space is an inevitable trend with continuous human development.Water treatment and reuse are crucial in the limited and closed space that is available in spaceships or long-term use space bases that will be established in the foreseeable future.Dedicated water treatment technologies have experienced iterative development for more than 60 years since the first manned spaceflight was successfully launched.Herein,we briefly review the related wastewater characteristics and the history of water treatment in space stations,and we focus on future challenges and perspectives,aiming at providing insights for optimizing wastewater treatment technologies and closing the water cycle in future.

Treatment of Reused Comprehensive Wastewater in Iron and Steel Industry With Electrosorption Technology

Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant o{ WISCO [Wuhan Iron and Steel （Group） Corporation]. The results of the on-site in- dustrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1 000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580--780 μS/cm to 100--350 μS/cm. The average removal efficiency of CI and Ca2＋ was about 75% and 68%, respectively, and CODcr of the treated wa- ter was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 0.6 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel eleetrosorption technology can be used in enhanced desalination and purification treatment of reused com- prehensive wastewater in iron and steel industry.

Salinity exchange between seawater/brackish water and domestic wastewater through electrodialysis for potable water

Two-thirds of the world’s population has limited access to potable water.As we continue to use up our freshwater resources,new and improved techniques for potable water production are warranted.Here,we present a general concept called“salinity exchange”that transfers salts from seawater or brackish water to treated wastewater until their salinity values approximately switch,thus producing wastewater with an increased salinity for discharge and desalinated seawater as the potable water source.We have demonstrated this process using electrodialysis.Salinity exchange has been successfully achieved between influents of different salinities under various operating conditions.Laboratory-scale salinity exchange electrodialysis(SEE)systems can produce high-quality desalinated water at~1 mL/min with an energy consumption less than 1 kWh/m3.SEE has also been operated using real water,and the challenges of its implementation at a larger scale are evaluated.