A Novel, Safe, and Environmentally Friendly Technology for Water Production Through Recovery of Rejected Thermal Energy From Nuclear Power Plants

Concentrations of perfluoroalkyl and polyfluoroalkyl substances before and after full-scale landfill leachate treatment

Do PFAS changes in landfill leachate treatment systems correlate with changes in physical chemical parameters?

Most of the published studies on pharmaceutical products (PhPs) focus on their occurrence in the influent/effluent at wastewater treatment plants (WWTPs) in urban areas with high population density. In peri-urban/rural areas not collected to any WWTP, despite the lack of sewage collection, and often (poor) on-site treatment, data on PhPs occurrence in surface water bodies is scarce. In this study, we investigated the impact of onsite wastewater treatment systems on the occurrence of six PhPs, along with hydrological and hydrochemical data, in the drainage network of a peri-urban/rural area in Italy.Our results, along with data from other studies, show onsite treatment systems are a major source of PhPs. In the drainage water 76% of the analyses positively quantified the presence of PhPs, with carbamazepine and clarithromycin always quantifiable, even in scarcely inhabited areas, at generally higher concentrations of PhPs than those reported in previous studies. As a result, onsite treatment systems may cause ubiquitous, even if at low concentrations, PhPs occurrence in the aquatic systems.In order to allow data comparison, studies reporting PhPs environmental concentration values should clearly detail the urban /environmental setting (population density, presence of WWTPs) and the hydrological/hydrochemical conditions. Furthermore, the joint use of hydrochemical parameters and PhPs data may provide useful proxies for the occurrence of PhPs or to identify nitrate sources of urban origin. Discharge, T, EC and ORP values may help understanding relevance of mixing and, then, the importance of dilution processes in reducing PhPs concentration.The occurrence of PhPs in surface water has to be duly considered in order to protect the aquatic ecosystems and groundwater, and the use of such water for safe irrigation purposes. Further treatment trains based on the concept of nature-based solutions (i.e, vegetated channels, artificial wetlands) could constitute a valuable solution exploiting the soil–water-plant continuum around main residential areas in order to enhance degradation processes.

A life-cycle assessment (LCA) study was completed to assess the environmental impacts of an on-site wastewater treatment system in the fresh-cut fruit processing industry consisting of a membrane bioreactor (MBR), followed by reverse osmosis (RO) and ultraviolet (UV) disinfection. The system boundaries comprised raw materials extraction and processing, transportation, construction, operation, and waste disposal. SimaPro 8.0.4.26 was used as the software tool, supported by two impact assessment methods (ReCiPe v1.11 and TRACI v2.1). Analysis showed that the treatment capacity of the MBR and tertiary technologies contributed the least damage to the ecosystem when compared with the other three scenarios and can provide water for reuse. Treating wastewater in municipal wastewater treatment plants (WWTPs) mitigated eutrophication like the MBR system but resulted in more environmental impacts from climate change and human health when compared with the on-site treatment system. Findings will be informative to stakeholders in the fresh-cut agri-food sector seeking input into selecting the appropriate treatment approach, with water reuse a goal. PRACTITIONER POINTS: Life-cycle analysis was completed on a fruit processing facility using MBR + RO + UV. On site treatment with MBR + RO UV provides least amount of environmental impact. Use of MBR + RO + UV treatment on fruit wastewater allows for water reuse. ReCiPe v1.11 and TRACI v2.1 give similar LCA results, with TRACI recommended for North American analysis.

Effluents from on-site wastewater treatment systems can influence surface water quality, particularly when infrastructure is aging, malfunctioning, and improperly installed. Municipal wastewater often contains chemical compounds that can lead to adverse biological effects, such as reproductive impairment, in organisms that are chronically exposed. A significant number of these compounds are endocrine-disrupting chemicals. Water quality influences of on-site systems are poorly studied in semi-arid regions where instream flows are seasonally dependent on snowmelt, and when instream dilution of wastewater effluents is minimal during other times of the year. Here we examined surface water estrogenicity in low order tributaries of two unique semi-arid streams with on-site wastewater treatment systems, for which seasonal instream flow fluctuations occur in Park City, UT, USA. Water samples were collected from a total of five locations along two lotic systems downstream from active on-site treatment systems. Samples were extracted for targeted chemical analyses and to perform in vivo and in vitro bioassays with juvenile rainbow trout. Estrogenic activity was measured by quantifying the concentration and expression of vitellogenin (VTG) in plasma and liver, respectively. Plasma VTG presented elevated levels in fish exposed to water samples collected at the two sites in close proximity to on-site systems and during seasons with low stream discharge, though the levels observed did not suggest severe endocrine disruption. However, long-term exposure to these surface water could compromise the fish populations. While the sensitivity of in vitro bioassays was low and targeted chemical analyses did not identify causative compounds, the use of complementary lines of evidence (e.g., in vivo biological models) was advantageous in identifying estrogenic activity in waters influenced by effluents from on-site wastewater systems.

The rapid growth in population has rendered the centralized sewerage systems a non-realistic option in sparsely populated areas. Consequently, an on-site wastewater treatment system (OWTS) is a viable alternative and cost-effective solution of sewerage system. Septic tanks with soil absorption systems are a simple mean of onsite treatment of the domestic wastewater. However septic tanks have low treatment efficiency along with several technical and constructional drawbacks. In order to improve the performance efficiency of conventional septic tank, a two-stage anaerobic reactor was developed. The main purpose of the study was to develop a two-stage onsite treatment system, which could become attractive from technical, economical, social and environmental viewpoints, to the technologies that are currently employed. The treatment unit consists of a cylindrical tank, where half of the volume is used as a modified septic tank and the other half as an upflow anaerobic filter. The system was operated at a hydraulic retention time of 24 h. The system was operated at ambient temperatures in laboratory-scale. During one year of continuous operation and performance evaluation, it was observed that a steady state condition was achieved after 120 days of operation without inoculation. The system was found to deliver highly satisfactory removal rates of 88.7±3% chemical oxygen demand (COD), 86.3±4% biochemical oxygen demand (BOD), and 91.4±10% total suspended solids (TSS), observed at steady state condition. It also showed a very good endurance against imposed hydraulic shock load. On account of the highly satisfactory experimental results, low cost, and no requirement of electricity, this system can be a potential alternative to the conventional septic tank in the developing countries like India. Keywords: Anaerobic system, domestic wastewater, on-site treatment, two-stage Cite this Article Meena Kumari Sharma, Kazmi AA. Performance Appraisal of Two-stage On-Site Domestic Wastewater Treatment System under Ambient Environment. Recent Trends in Civil Engineering & Technology. 2018; 8(1): 20–28p.

ity. On-site treatment systems are now an integral part of our wastewater infrastructure and are collectively referred to as decentralized wastewater systems. Decentralized wastewater technology and management refers to wastewater treatment and dispersal systems from the individual on-site treatment system (septic systems) to small community collection and treatment systems (cluster systems) and includes the process involved in siting, installing, operating and maintaining the systems. These systems rely upon land application by surface or subsurface dispersal and proper treatment of the wastewater. They allow the treated wastewater to re-enter the hydrologic cycle close to where the potable water was removed. Often, as in the case of an individual system, this is less than a few hundred feet. They are considered to be non-point source discharges by federal and state standards. Often septic systems are portrayed in a negative light but they are now an integral part of our wastewater infrastructure. Photo by David Lindbo and courtesy of Soil Science @ NC State's Flickr photostream.

Pakistan has a population of 140 million with more than 30% of the population living in cities and towns. Karachi, the major port city of the country, is the most densely populated with a population crossing the 11 million mark. The city receives 435 MGD of drinking water from the River Indus and other sources. However, the net demand for the year 2000 was 594 MGD thus there is a gap of 159 MGD in demand and supply. Statistics show that the water demand in Karachi is increasing at the rate of 100 MGD every five years. The coastal belt of the country extends to 1046 sq. km. Of this, 930 km is from the Karachi to Gwader region in the province of Baluchistan. Most of the coastal areas lie outside the monsoon system of weather and therefore the climate is extremely dry. The annual rainfall in this belt is about 15 cms. Therefore, fresh water availability is a major factor for development of the coastal belt of Pakistan. In the wake of the looming water crisis it is becoming increasingly clear that all available and appropriate technologies, including nuclear and related technologies, have to be used for the sustainable development and management of freshwater resources in Pakistan. One particular approach is the desalination of seawater, and countries are increasing their capacity to harness the seas for tapping fresh water. The prospects of using nuclear energy for seawater desalination on a large scale are attractive since desalination is an energy intensive process. Pakistan Atomic Energy Commission (PAEC) is planning to actively participate in the activities of IAEA in the field of nuclear desalination by offering one of its nuclear power plants for coupling a demonstration nuclear desalination plant. Karachi Nuclear Power Plant (KANUPP), which is the country's first nuclear plant has been successfully operating for the last 30 years. This plant is proposed to be used as a potential site for installation of a demonstration nuclear desalination plant. KANUPP is already operating a Sea Water Reverse Osmosis (SWRO) plant to meet its operating requirements, contributing to its ultimate heat sink. The experience gained in the installation and commissioning of the RO plant will be very useful for the proposed nuclear desalination plant. The objective of this paper is to present the work done by PAEC in preparing the engineering feasibility for coupling a 1MGD demonstration nuclear desalination plant with KANUPP. The paper discusses in detail the criteria for selection of the most appropriate thermal desalting process, capacity of the plant and the coupling arrangement with the existing power plant without disturbing the normal operation of KANUPP.

The Ultimate Heat Sink (UHS) of a nuclear power plant is a complex cooling water system which serves the plant during normal and accident conditions. For some next generation nuclear plants, the UHS sizing is a major design and licensing analysis task. The analysis involves detailed modeling of the transient heat loads and the selection of worst-case meteorological data for the plant site. The UHS sizing requirements for a representative next generation nuclear power plant are evaluated on a month-to-month basis. This paper assesses the UHS water requirement for each month of year. The UHS analysis for a representative next generation nuclear plant with mechanical draft cooling towers and a water basin is used to determine the maximum evaporation of the basin for the worst-case meteorological data on a month-to-month basis. To size the cooling tower basin, automated methods have been developed which determine the highest evaporative losses from the basin and highest basin temperature over a 30-day design basis accident period. This paper also evaluates the month-to-month basin temperature changes. This assessment is done for a representative next generation nuclear power plant and considers the monthly historical meteorological data over 45 years. The result of this assessment of monthly UHS water requirement is of interest in assessing the margin in the UHS design. This monthly assessment is also useful in demonstrating that the automated methods used to establish the limiting 30-day meteorological condition are indeed accurate. In addition, these results may be useful in helping to plan plant maintenance activities.

Make-up water is treated at thermal power stations (TPS) with high-pressure or superhigh pressure boilers using membrane processes implemented in ultrafiltration, microfiltration, or reverse-osmosis (RO) units. Among the criteria of the efficiency of reverse osmosis units is the amount of highly mineralized effluents (or concentrate). At present, the RO concentrate is disposed of at TPSs by discharging it into an industrial sewage system in accordance with the applicable standards on the salt content limit of waste water, routing it into a district heating network, or returning it into recirculation water supply systems, decreasing as far as possible the volume of the discharged concentrate which is to be reused, for example, in regeneration of Na-cation exchangers installed upstream of the reverse-osmosis unit. The adsorption process is proposed for treatment of the reverse-osmosis concentrate using sludge from the makeup water treatment. The characteristics of carbonate sludge are presented. The regularities of adsorption of sulfate- and chloride-anions from the RO concentrate by carbonate sludge are described. An adsorption isotherm was obtained. The mechanism of adsorption on a sorption material is proposed. The effect of pH on adsorption of sulfate- and chloride-ions by a sorption material was investigated. A system is proposed for the treatment of the concentrate from the RO units at the Kazan Cogeneration Power Station TETs-2 to remove sulfate- and chloride anions using a three-stage adsorption method with a counter-current injection of the sorbent, namely, the carbonate sludge. The calculated values of the consumption of the sorption material required to achieve the desired residual concentration of sulfate- and chloride-anions in the treated water are presented. The economic effectiveness from implementation at the Kazan TETs-2 of the adsorption treatment of the RO concentrate by carbonate sludge to remove sulfate- and chloride-ions is estimated.

PurposeAs the United States is making a significant move toward rejoining the Paris Agreement on climate change, there is a high demand for sustainable solutions across various industries, including construction and hospitality sectors. The aim of this project was to design and model an on-site greywater treatment system for a hotel building for the effective reuse of sewage water. The study considered Los Angeles, California, as a case study location and referred to respective climate conditions and construction standards.Design/methodology/approachThis study considered various options of greywater treatment plants such as membrane bioreactor (MBR), sequencing batch reactor and reverse osmosis with upflow anaerobic sludge blanket which were carefully reviewed and modeled using the GPS-X software. The design and modeling results were verified by hand calculations and were followed by the estimation of capital and operational expenses required for the implementation of the plants.FindingsHaving relatively low capital and operational expenditure requirements as well as superior technical performance, the MBR plant proved to be the most effective solution for the considered location and standards and was recommended for use in hotel buildings.Practical implicationsDesigning and modeling several greywater treatment plants allowed selecting the most optimal option which in the long run will help to preserve the eco-system, stay compliant with the government laws and regulations and be financially sustainable.Originality/valueThe outcomes of the present study provide a detailed procedure for designing and modeling a greywater treatment plant for a hotel building that can be used for the localities with a similar climate. The most effective option selected as a result of cost-benefit analysis provides an efficient and viable solution for the relevant industry and the type of buildings.

When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where the NSCW (nuclear service cooling water) pumps locate, by sea current and wind drift (induced) current. The NSCW pumps take the essential service water from the sea being used as the ultimate heat sink and supply to the component cooling water heat exchangers to remove the decay heat generated from reactor. The NSCW system shall provide sufficient cooling capacity during the reactor normal operation, transients, and loss-of-coolant accidents (LOCAs). In this regard, it is very important to confirm if the cooling function of the NSCW system can be threaten due to spilled oil which may overspread the surface of sea water in the intake area. Thus, in this work, when an incident of crude oil spill occurs in the sea near a nuclear power plant using sea water as the ultimate heat sink, possibility of crude oil ingression into the component cooling water heat exchangers through the NSCW pumps has been evaluated in a conservative manner. To do this, for a flow field surrounding a NSCW pump equipped in an intake pit where a limited volume of sea water is initially contained and its surface is covered with spilled crude oil, a numerical simulation is performed using a CFD (Computational Fluid Dynamics) code. The objective of the present simulation is to find out the critical sea water level at or below which oil or air floating on the surface of sea water begins to be sucked in the pump inlet nozzle. The numerical simulation results show that in general, the oil covering the free surface of sea water in the intake can hardly flow into the pump inlet until the floating oil changes into tars which are heavier than oil as long as the sea water level does not fall below the limit value specified in the Technical Specification of each nuclear plant. It is also shown that the critical sea water level increases as the pump flowrate increases. This is physically plausible considering the effect of gravitational force.

Radioactive wastewater treatment with modified aromatic polyamide reverse osmosis membranes via quaternary ammonium cation grafting

Innovations that enable cost-effective and resource-conserving treatment of human waste are required for the 4.2 billion people in the world who currently lack safe and reliable sanitation services. Onsite treatment and reuse of blackwater is one strategy towards this end, greatly reducing the need to transport wastewater over long distances either via sewers or trucks. Here, we report on the field testing of a prototype onsite blackwater treatment system conducted over a period of 8 months. The system was connected to a women's toilet in a public communal ablution block located in an informal settlement near Durban, South Africa. Liquid waste was treated by separation and diversion of large solids, settling of suspended solids, and filtration through activated carbon prior to disinfection by electrochemical oxidation. System performance was monitored daily by measurement of chemical and physical water quality parameters onsite and confirmed by periodic detailed analysis of chemical and biological parameters at an offsite lab. Daily monitoring of system performance indicated that the effluent had minimal color and turbidity (maximum 90 Pt/Co units and 6.48 NTU, respectively), and consistent evolution of chlorine as blackwater passed through the system. Weekly offsite analysis confirmed that the system consistently inactivated pathogens (E. coli and coliforms) and reduced chemical oxygen demand and total suspended solids to meet ISO 30500 category B standards. Significant reductions in total nitrogen load were also observed, though these reductions often fell short of the 70% reduction required by ISO 30500. No significant reduction in total phosphorus was observed. Maintenance requirements were identified, and the resilience of the system to restart following a prolonged shutdown was demonstrated, but significant improvements are required in the design of the solid/liquid separation mechanism for application of this system in a wiping culture.

When onsite treatment and disposal systems (OSTDS) are not properly sited or installed, they can be a potential risk to public health and a source of environmental degradation. There are estimated to be over 2.3 million onsite sewage treatment and disposal systems currently in use in Florida, serving approximately 4.5 million people. These systems discharge over 426 million gallons of treated effluent per day in to the subsurface soil environment. Nearly 40% of those systems are found along Florida's southeastern Atlantic coastline. Onsite system failure can result in problems that include direct exposure to inadequately treated sewage, ground and surface water pollution, and contamination of shellfish beds. Throughout the State of Florida, where the water table is high, septic tanks have proven to be problematic from a water resource perspective. Impacts are traced to a lack of regulation prior to the 1980s and to high densities of septic tanks on small lots. Moreover, many of these high-density developments were historically inhabited only in the winter months when the water table is low and performance optimal. When the water table is high, septic tanks cannot operate properly because the water table is above the drainage pipes, interfering with the normal hydraulic specifications and complicating pollutant migration modeling. Thus, the potential for groundwater and surface water contamination is increased, and clearly there is a need to quantify the contribution of environmental degradation attributable to OSTDS. The research team has investigated differences in sewered and non-sewered areas in Broward and Palm Beach Counties in Florida to attempt to quantify the nutrient loading contribution from septic tanks and also to determine the extent of observed nutrient contamination from other sources in a major urban setting. Recently, a unique opportunity to study a rural area in Taylor County, allowed the research team to investigate newer tracers. Taylor County (see Figure 1) is located in Northwest Florida along the Gulf of Mexico coastline directly south of Tallahassee. The total area of the County is 789,000 acres (3,191 km2), of which approximately 15% is comprised of water bodies. Taylor County has four rivers, numerous canals, creeks, and springs, and nearly 60 miles of Gulf of Mexico coastline. The major tourist attractions are fishing and scalloping, particularly from July through September. Half of its southern coast is part of the "Big Bend Sea Grasses Aquatic Preserve" and is classified as "Outstanding Florida Waters." Prior studies have been conducted by the Suwanee River Water Management District (SRWMD) and the Taylor County Health Department (TCHD) in Taylor County to determine if water quality criteria are being met. An ongoing beach monitoring program posts advisories approximately 46% of the time due to high concentration of indicator bacteria (>400 CFU/100mL for fecal coliform, >100 CFU/100mL for Enterococcus). Maintenance of the microbiological quality and safety of water systems used for drinking, for recreation, and for the harvesting of seafood is imperative. Contamination of these water systems can result in high risks to human health and significant economic losses due to closures of beaches and shellfish harvesting areas.