Reusing and recycling dialysis reverse osmosis system reject water

Ten tips from the Swiss Working Group on Sustainable Nephrology on how to go green in your dialysis unit

The health-care system and particularly renal replacement therapy has a significant carbon footprint adding to global warming and extreme weather conditions. Improving sustainability has become the focus of national and international working groups. Many reviews underline the need for improvement of sustainability in nephrology, in particular dialysis, and provide recommendations on how to reduce waste, energy, and water consumption. However, how to implement these recommendations, and where to start, is not always clear. This paper summarizes discussions within the 'working group on sustainable nephrology' of the Swiss Society of Nephrology. We do not provide a detailed review of the topic but instead present a practical 10-point action plan to help health-care workers in nephrology make a start and improve the carbon footprint of their dialysis centres. We emphasize the importance of ongoing research, cooperation, and dialogue, and welcome additional ideas from the wider renal community.

Climate crisis and nephrology: a review of climate change's impact on nephrology and how to combat it

Climate change is worsening with tangible effects on our healthcare system. This review aims to examine the repercussions of the climate change on nephrology and explore potential strategies to mitigate its impact. This review examines dialysis's environmental impact, resource recycling methods, and plant-based diets for kidney health. Recent research highlights the advantages of plant-based diets in managing and preventing chronic kidney disease (CKD) and its complications. Integrating these practices can significantly lessen the environmental impact of nephrology.

PURPOSE OF REVIEW

The aim of this study is to discuss the bidirectional relationship of climate change and kidney disease and the impact of nephrology on climate change and to discuss potential solutions.

RECENT FINDINGS

Each dialysis session consumes significant amounts of resource; reusing them will aid the environment. Plant-based diets slow renal disease and have a lower carbon footprint, making them ecologically friendly.

SUMMARY

Climate change is a growing threat to population health and healthcare. Rising temperatures raise the risk of kidney problems. Dialysis treatments also impact the environment through its high resource requirements while generating high volumes of waste and greenhouse gases. Opportunities exist to reduce the environmental impact of dialysis treatments. Plant-based diets serve to benefit both kidney disease and the environment.

Green Dialysis: Let Us Talk about Dialysis Fluid

BACKGROUND

Hemodialysis is one of the most resources consuming medical intervention. Due to its concept, the proper amount of dialysis fluid passed through dialyzer is crucial to obtain the expected outcomes. The most frequent source of dialysis fluid is production from liquid concentrate (delivered in containers or plastic bags) in dialysis machine. Alternatively, concentrates for dialysis may be produced in dialysis center by dilution in mixing devices dry or semidry premixed compounds connected with system of central dialysis fluid delivery system. Dialysate consumption depends on various factors like type of hemodialysis machine, session duration, prescribed flow, etc. Summary: Modern hemodialysis machines are equipped with the modules which automatically reduce flow rate of dialysis fluid to the patient blood flow and minimize dialysate consumption during preparation and after reinfusion. Smart using of available options offered by manufacturers allows to save additional portion of acid concentrate and water. The weight of concentrates to be delivered to the dialysis center is the major factor influencing the cost (financial and environmental) of transportation from the manufacturer to the final consumer. The crisis on the energy carriers market and extremely high fuel prices made the transportation cost one of the significant costs of the treatment, which must be bear by supplier and finally influence on the price of goods.

KEY MESSAGES

The careful choice of the concentrate delivery system can improve cost-effectiveness of dialysis. Such solutions implemented in dialysis unit helps make significant savings and decrease the impact on natural environment by carbon footprint reduction.

Current Status and Future of Artificial Kidney in Humans

The number of patients needing renal replacement therapy (RRT) is increasing rapidly with an increase in lifestyle diseases such as diabetes, hypertension, and metabolic syndrome. Kidney transplantation, whenever feasible, is the most preferred mode of RRT. However, there is a growing shortage of donor kidneys for transplantation. While dialysis is partially able to perform the filtration and excretion function of the kidneys, it is still not able to perform the other renal tubular and endocrine functions of a normal kidney and has quality-of-life issues with significant long-term morbidity. The need of the hour is to develop an ideal artificial kidney that would be wearable or implantable and would be able to perform the complete excretory, filtration, tubular, endocrine, and metabolic functions of the kidney while preserving the quality of life and minimizing complications. In this review, we discuss the characteristics of an ideal artificial kidney, the challenges of developing such a device, a brief description of the past and current work on this topic, and what the artificial kidney of the future should look like.

Redesigning Kidney Care for the Anthropocene: A New Framework for Planetary Health in Nephrology

Climate change is one of the greatest threats to human health in the 21st century. The human health impacts of climate change contribute to approximately 1 in 4 deaths worldwide. Health care itself is responsible for approximately 5% of annual global greenhouse gas (GHG) emissions. Canada is a recent signatory of the 26th United Nations Climate Change Conference (COP26) health agreement that is committed to developing low carbon and climate resilient health systems. Kidney care services have a substantial environmental impact and there is opportunity for the kidney care community to climate align clinical care. We introduce a framework of redesigned kidney care and describe examples of low carbon kidney disease management strategies to expand our duty of care to the environment which completes the triple bottom line of optimal patient outcomes and cost effectiveness in the Anthropocene.

The high-volume haemodiafiltration vs high-flux haemodialysis registry trial (H4RT): a multi-centre, unblinded, randomised, parallel-group, superiority study to compare the effectiveness and cost-effectiveness of high-volume haemodiafiltration and high-flux haemodialysis in people with kidney failure on maintenance dialysis using linkage to routine healthcare databases for outcomes

BACKGROUND

More than a third of the 65,000 people living with kidney failure in the UK attend a dialysis unit 2-5 times a week to have their blood cleaned for 3-5 h. In haemodialysis (HD), toxins are removed by diffusion, which can be enhanced using a high-flux dialyser. This can be augmented with convection, as occurs in haemodiafiltration (HDF), and improved outcomes have been reported in people who are able to achieve high volumes of convection. This study compares the clinical- and cost-effectiveness of high-volume HDF compared with high-flux HD in the treatment of kidney failure.

METHODS

This is a UK-based, multi-centre, non-blinded randomised controlled trial. Adult patients already receiving HD or HDF will be randomised 1:1 to high-volume HDF (aiming for 21+ L of substitution fluid adjusted for body surface area) or high-flux HD. Exclusion criteria include lack of capacity to consent, life expectancy less than 3 months, on HD/HDF for less than 4 weeks, planned living kidney donor transplant or home dialysis scheduled within 3 months, prior intolerance of HDF and not suitable for high-volume HDF for other clinical reasons. The primary outcome is a composite of non-cancer mortality or hospital admission with a cardiovascular event or infection during follow-up (minimum 32 months, maximum 91 months) determined from routine data. Secondary outcomes include all-cause mortality, cardiovascular- and infection-related morbidity and mortality, health-related quality of life, cost-effectiveness and environmental impact. Baseline data will be collected by research personnel on-site. Follow-up data will be collected by linkage to routine healthcare databases - Hospital Episode Statistics, Civil Registration, Public Health England and the UK Renal Registry (UKRR) in England, and equivalent databases in Scotland and Wales, as necessary - and centrally administered patient-completed questionnaires. In addition, research personnel on-site will monitor for adverse events and collect data on adherence to the protocol (monthly during recruitment and quarterly during follow-up).

DISCUSSION

This study will provide evidence of the effectiveness and cost-effectiveness of HD as compared to HDF for adults with kidney failure in-centre HD or HDF. It will inform management for this patient group in the UK and internationally.

TRIAL REGISTRATION

ISRCTN10997319 . Registered on 10 October 2017.

Sustainability and environmental impact of on-line hemodiafiltration

Environment has become a main issue of human activities. Chronic hemodialysis (HD) therapy saves lives but consumes large amounts of water and power and produces a lot of care-related waste. On-line hemodiafiltration (HDF) improves patients' outcomes but increases water consumption from ultra-pure water needs and infusion volume. New-generation water treatment systems have much reduced the proportion of reject water that can also be reused. Reducing the dialysate flow in standard HD decreases significantly the water consumption but impacts negatively dialysis efficiency. When on-line HDF is prescribed, reducing the dialysate flow may be applied to decrease water needs while maintaining dialysis efficiency. Nowadays, dialysis prescription cannot ignore its impact on natural resources and environment.

Mixed Matrix Membranes Adsorbers (MMMAs) for the Removal of Uremic Toxins from Dialysate

We developed Mixed Matrix Membrane Adsorbers (MMMAs) formed by cellulose acetate and various sorbent particles (activated carbon, zeolites ZSM-5 and clinoptilolite) for the removal of urea, creatinine and uric acid from aqueous solutions, to be used in the regeneration of spent dialysate water from Hemodialysis (HD). This process would allow reducing the disproportionate amount of water consumed and permits the development of closed-loop HD devices, such as wearable artificial kidneys. The strategy of MMMAs is to combine the high permeability of porous membranes with the toxin-capturing ability of embedded particles. The water permeability of the MMMAs ranges between 600 and 1500 L/(h m² bar). The adsorption of urea, the limiting toxin, can be improved of about nine times with respect to the pure cellulose acetate membrane. Flow experiments demonstrate the feasibility of the process in a real HD therapy session.

Towards zero liquid discharge in hemodialysis. Possible issues

Scarcity of water and energy, and legal requirements for discharge of waste and wastewater are forcing hemodialysis facilities to change their approach to a more integrated concept of connecting the residual output (in terms of waste, wastewater and energy loss) to the input (in terms of water and energy). Zero liquid discharge is an expanding water treatment philosophy in which hemodialysis wastewater is purified and recycled, leaving little to no effluent remaining when the process is complete, thereby saving money and being beneficial to the environment. This article explores the possible ways to treat hemodialysis wastewater, thus achieving ZLD conditions.

Disinfectants in a Hemodialysis Setting: Antifungal Activity Against Aspergillus and Fusarium Planktonic and Biofilm Cells and the Effect of Commercial Peracetic Acid Residual in Mice

Aspergillus and Fusarium cause a broad spectrum of infections in humans, mainly in immunocompromised patients. Among these, patients undergoing hemodialysis are highly susceptible to infections, requiring a constant and adequate environmental disinfection program. Nevertheless, monitoring the residual disinfectants can contribute to the morbidity and mortality reduction in these patients. Here, we evaluated the susceptibility of Aspergillus spp. (n=19) and Fusarium spp. (n=13) environmental isolates against disinfectants (acetic acid, citric acid, peracetic acid, sodium hypochlorite, and sodium metabisulphite) at different concentrations and time exposures. Also, we investigated the in vivo toxicity of the peracetic acid residual concentration in mice. Fusarium isolates were identified by F. equiseti, F. oxysporum and F. solani while Aspergillus presented clinically relevant species (A. fumigatus, A. niger and A. terreus) and environmental ones. Against planktonic cells, only two disinfectants (acetic acid and sodium hypochlorite) showed a fungicidal effect on Fusarium spp., while only one (sodium hypochlorite) was effective against Aspergillus spp. Both fungi formed robust in vitro biofilms with large amounts of the extracellular matrix, as evidenced by electron micrographs. Exposure of fungal biofilms to disinfectants showed sensitivity to three (acetic, citric, and peracetic acids), although the concentrations and times of exposure varied according to the fungal genus. Mice exposure to the residual dose of peracetic acid during 60 weeks showed anatomopathological, hematological, and biochemical changes. The implementation of news control measures and those that already exist can help reduce infections, the second cause of death and morbidity in these patients, besides providing safety and well-being to them, a priority of any quality health program.

Towards zero liquid discharge in hemodialysis. Possible issues

Scarcity of water and energy, and legal requirements for discharge of waste and wastewater are forcing hemodialysis facilities to change their approach to a more integrated concept of connecting the residual output (in terms of waste, wastewater and energy loss) to the input (in terms of water and energy). Zero liquid discharge is an expanding water treatment philosophy in which hemodialysis wastewater is purified and recycled, leaving little to no effluent remaining when the process is complete, thereby saving money and being beneficial to the environment. This article explores the possible ways to treat hemodialysis wastewater, thus achieving ZLD conditions.

Haemodialysis therapy and sustainable growth: a corporate experience in France

Introduction

Sustainable growth and environmental issues are currently a topic for all human activities, and dialysis represents a real challenge in this field because of high water and power consumption and the production of large amounts of care-related waste. In this article we describe data collection implemented in the NephroCare centres in France and the changes observed during a 13-year period regarding environmental parameters.

Methods

Monthly data collection (eco-reporting) was implemented in NephroCare centres in France in 2005. It covers three topics designed as key performance indicators (KPIs): electricity and water consumption and care-related waste production expressed, respectively, as kilowatt-hour (kWh), litres (L) and kilograms per session. We report on the three action plans (2005–10, 2011–14 and 2015–18) and changes observed during this 13-year period.

Results

During the period, power and water consumption declined by 29.6% (from 23.1 to 16.26 kWh/session) and 52% (from 801 to 382 L/session), respectively. At the same time, the yearly number of dialysis sessions has increased from 169 335 to 399 336. The sources of savings came both from improvements in the dialysis technology (dialysis machines and water treatment systems) and from updating and remodelling of the dialysis unit equipment and buildings. The care-related waste decreased from 1.8 to 1.1 kg because of regular staff training and the retrofiltration system, allowing the voiding of the remaining saline solution after dialysis. These savings have been estimated as equivalent to 102 440 tons of carbon dioxide.

Discussion

Implementation of KPIs and their regular monitoring by trained staff to evaluate water and power consumption and the reduction of care-related water production are essential to implement actions to reduce the impact of dialysis on the environment. These data show the importance of water treatment and dialysis technology to decrease water and power consumption and the production of care-related waste as well as upgrading or remodelling of buildings housing dialysis units. Other measures are discussed, including the reuse of rejected water by reverse osmosis, as well as behavioural changes that are needed to reach sustainable development of dialysis.

Conclusion

The first step to reach ‘green’ dialysis is to collect precise information from defined KPIs. This is the only way to design action plans to reduce the impact of dialysis therapy on the environment. Beyond this, the nephrology community must be sensitized to this challenge to be proactive and to anticipate future regulations.

Reuse of dialysis reverse osmosis reject water for aquaponics and horticulture

BACKGROUND

Water crisis is becoming a threat to the well-being of the human population worldwide and use of water for healthcare contributes substantially to this resource depletion. Hemodialysis consumes large quantities of water. A huge volume of high purity dialysis water is required to safely perform dialysis treatment. In this process, up to 60-70% of source water is discarded. Many strategies have been suggested to promote green dialysis, and these include reuse of water, however, very few dialysis facilities have taken the preliminary steps to employ it.

METHODS

We share our experience in a developing country on an innovative reject-water reuse program combining aquaculture, hydroponic and horticulture activities. This is by far the first report on a "green dialysis" project involving aquaponics that reuse dialysis reverse osmosis (RO) reject water.

RESULTS

Our expereince suggests that reject water can be reused to promote water conservation with encouraging results. It provides a good and biosecure environment for fish breeding and vegetable farming . This project promotes a reduction in carbon footprint, a reduction in water waste, a sustainable organic food source, may lead to income generation, and provides a shared purpose and sense of pride among staff and dialysis patients.

CONCLUSIONS

Encompassing "environmental protection" practices into a hemodialysis unit can be done with relatively simple and practical steps.

Performance Evaluation and Fouling Propensity of Forward Osmosis (FO) Membrane for Reuse of Spent Dialysate

The number of chronic renal disease patients has shown a significant increase in recent decades over the globe. Hemodialysis is the most commonly used treatment for renal replacement therapy (RRT) and dominates the global dialysis market. As one of the most water-consuming treatments in medical procedures, hemodialysis has room for improvement in reducing wastewater effluent. In this study, we investigated the technological feasibility of introducing the forward osmosis (FO) process for spent dialysate reuse. A 30 LMH of average water flux has been achieved using a commercial TFC membrane with high water permeability and salt removal. The water flux increased up to 23% with increasing flowrate from 100 mL/min to 500 mL/min. During 1 h spent dialysate treatment, the active layer facing feed solution (AL-FS) mode showed relatively higher flux stability with a 4–6 LMH of water flux reduction while the water flux decreased significantly at the active layer facing draw solution (AL-DS) mode with a 10–12 LMH reduction. In the pressure-assisted forward osmosis (PAFO) condition, high reverse salt flux was observed due to membrane deformation. During the membrane filtration process, scaling occurred due to the influence of polyvalent ions remaining on the membrane surface. Membrane fouling exacerbated the flux and was mainly caused by organic substances such as urea and creatinine. The results of this experiment provide an important basis for future research as a preliminary experiment for the introduction of the FO technique to hemodialysis.

Green nephrology and eco-dialysis: a position statement by the Italian Society of Nephrology

High-technology medicine saves lives and produces waste; this is the case of dialysis. The increasing amounts of waste products can be biologically dangerous in different ways: some represent a direct infectious or toxic danger for other living creatures (potentially contaminated or hazardous waste), while others are harmful for the planet (plastic and non-recycled waste). With the aim of increasing awareness, proposing joint actions and coordinating industrial and social interactions, the Italian Society of Nephrology is presenting this position statement on ways in which the environmental impact of caring for patients with kidney diseases can be reduced. Due to the particular relevance in waste management of dialysis, which produces up to 2 kg of potentially contaminated waste per session and about the same weight of potentially recyclable materials, together with technological waste (dialysis machines), and involves high water and electricity consumption, the position statement mainly focuses on dialysis management, identifying ten first affordable actions: (1) reducing the burden of dialysis (whenever possible adopting an intent to delay strategy, with wide use of incremental schedules); (2) limiting drugs and favouring "natural" medicine focussing on lifestyle and diet; (3) encouraging the reuse of "household" hospital material; (4) recycling paper and glass; (5) recycling non-contaminated plastic; (6) reducing water consumption; (7) reducing energy consumption; (8) introducing environmental-impact criteria in checklists for evaluating dialysis machines and supplies; (9) encouraging well-planned triage of contaminated and non-contaminated materials; (10) demanding planet-friendly approaches in the building of new facilities.

Green nephrology

Clear evidence indicates that the health of the natural world is declining globally at rates that are unprecedented in human history. This decline represents a major threat to the health and wellbeing of human populations worldwide. Environmental change, particularly climate change, is already having and will increasingly have an impact on the incidence and distribution of kidney diseases. Increases in extreme weather events owing to climate change are likely to have a destabilizing effect on the provision of care to patients with kidney disease. Ironically, health care is part of the problem, contributing substantially to resource depletion and greenhouse gas emissions. Among medical therapies, the environmental impact of dialysis seems to be particularly high, suggesting that the nephrology community has an important role to play in exploring environmentally responsible health-care practices. There is a need for increased monitoring of resource usage and waste generation by kidney care facilities. Opportunities to reduce the environmental impact of haemodialysis include capturing and reusing reverse osmosis reject water, utilizing renewable energy, improving waste management and potentially reducing dialysate flow rates. In peritoneal dialysis, consideration should be given to improving packaging materials and point-of-care dialysate generation.

A call-to-action for sustainability in dialysis in Brazil

Human-induced climate change has been an increasing concern in recent years. Nephrology, especially in the dialysis setting, has significant negative environmental impact worldwide, as it uses large amounts of water and energy and generates thousands of tons of waste. While our activities make us responsible agents, there are also several opportunities to change the game, both individually and as a society. This call-to-action intends to raise awareness about environmentally sustainable practices in dialysis and encourages this important discussion in Brazil.

Sister Earth, Our Common Home: Toward a Sustainable, Planet Friendly Approach to Dialysis, a Paradigm of High Technology Medicine

In our high-technology, highly polluted world, medicine plays an important role balancing saving lives with the expenses of growing amounts of waste products, not only biologically dangerous (the potentially "contaminated" or "hazardous" waste) but also potentially harmful for the planet (nonrecyclable, plastic waste). Dialysis, the prototype of high-technology medicine, is central to these problems, as the present treatment of about 2 million patients produces an enormous quantity of waste (considering hazardous waste only about 2 kg per session, with 160 sessions per year, that is 320 kg per patient, or about 640,000 tons of hazardous waste per year for 2 million patients, roughly corresponding to 6 nuclear aircraft carriers). Furthermore, obsolete dialysis machines, and water treatments are discharged, adding to the "technological waste." Water produced by the reverse osmosis is also discharged; this is the only nonhazardous, nonpolluting waste, but in particular in dry areas, wasting water is a great ecologic concern. The present review is aimed at discussing strategies already in place and to be further implemented for reducing this particular "uremic toxin" for the earth: dialysis waste, including dialysis disposables, water, and dialysis machines.

From portable dialysis to a bioengineered kidney

INTRODUCTION

Since the advent of peritoneal dialysis (PD) in the 1970s, the principles of dialysis have changed little. In the coming decades, several major breakthroughs are expected.

AREAS COVERED

Novel wearable and portable dialysis devices for both hemodialysis (HD) and PD are expected first. The HD devices could facilitate more frequent and longer dialysis outside of the hospital, while improving patient's mobility and autonomy. The PD devices could enhance blood purification and increase technique survival of PD. Further away from clinical application is the bioartificial kidney, containing renal cells. Initially, the bioartificial kidney could be applied for extracorporeal treatment, to partly replace renal tubular endocrine, metabolic, immunoregulatory and secretory functions. Subsequently, intracorporeal treatment may become possible.

EXPERT COMMENTARY

Key factors for successful implementation of miniature dialysis devices are patient attitudes and cost-effectiveness. A well-functioning and safe extracorporeal blood circuit is required for HD. For PD, a double lumen PD catheter would optimize performance. Future research should focus on further miniaturization of the urea removal strategy. For the bio-artificial kidney (BAK), cost effectiveness should be determined and a general set of functional requirements should be defined for future studies. For intracorporeal application, water reabsorption will become a major challenge.