Decentralized Peritoneal Dialysis Fluid Production
Over two million people die annually from a lack of access to kidney dialysis, with these deaths overwhelming occurring in low- and middle-income countries. Barriers to conventional hemodialysis (HD) include limited treatment capacity, high costs, and long treatment and transportation times. Peritoneal dialysis (PD) has the potential to lower the direct and indirect costs of treatment, as it can be carried out by patients in their homes. However, a key limitation to expanding PD services is a lack of PD fluid availability due to high costs and importation challenges. This project aims to develop technology for decentralized PD fluid production. This technology is expected to enable the accessibility and affordability of PD, increase supply chain reliability, and reduce the environmental impact of dialysis treatment.
Brine Management
Crystallization in modular brine management systems
The team is developing modular brine management systems with two-stage configurations designed for scaling-free operation and enhanced resource recovery. By predicting crystallization onset during concentration, crystallization can be directed to occur selectively away from heat and mass transfer surfaces. To support this, the team has developed a robust integrated model combining machine learning with Smoluchowski-based kinetics to predict gypsum induction time under varying conditions of solution saturation index, temperature, and background salt concentration. Current efforts focus on extending this predictive framework to continuously concentrating systems. Ongoing research also explores control strategies to prevent clogging and system failure caused by crystallization in highly concentrated feedwater desalination and brine management processes.
Home-scale desalination and brine reuse pilot in Navajo Nation
Project description coming soon!
Circular Energy Systems for Food Sovereignty
According to the FAO, 29% of the global population experience moderate or severe food insecurity, yet an estimated one third of food produced for human consumption is lost or wasted globally. Defined as “the right of peoples to healthy and culturally appropriate food produced through ecologically sound and sustainable methods, and their right to define their own food and agriculture systems,” food sovereignty aims to holistically address challenges within our global food system. The Wright Lab is investigating circular energy systems within greenhouses in efforts to advance food sovereignty in local and global contexts.
Hybrid Greenhouse Solar Dryers for drying mango in Kenya
If crops are not promptly cooled to optimal temperatures or properly managed after harvest, the quality, shelf-life and marketability rapidly decline. Greenhouses referred to as Hybrid Greenhouse Solar Dryers (HGSDs) are being used for value-addition by drying (dehydrating) produce to create a shelf-stable product. In Kenya, mango is the second highest produced fruit yet 25-50% of mangoes are lost post harvest. The Wright Lab is collaborating with Kenyan partners to improve and optimize the drying process in HGSDs to dehydrate mango and other local produce. This project has three key objectives: (1) instrument a HGSD in Kitui, Kenya to collect +6 months of data, (2) computationally model the drying process to predict environmental conditions and develop optimal energy management strategies, and (3) conduct a market analysis for local and foreign markets. Future research will investigate opportunities of dehydration within the Minnesotan context, such as for farm to school purchases from emerging farmers.
Rockbed thermal batteries in Deep Winter Greenhouses to bridge growing seasons in Minnesota
Small- and medium-sized farmers make up the majority of farmers in Minnesota but many are unable to continue their work throughout extreme winter months. Deep winter greenhouses (DWGs) (left figure) are being developed and constructed throughout the state to provide cost-effective options for smallholder farmers to grow cold season crops such as brassicas, chenopods, and lettuces. In addition to passive solar heat gain, DWGs can be constructed with a rockbed to act as a thermal battery. The rockbed is charged during the day as excess heat is stored by using a fan to blow warm air into the thermal mass (middle figure). Overnight, the rockbed is discharged as cool air is blown into the rockbed and warmed air is released back into the DWG (right figure). Using a 2D, single-phase porous media method, the Wright Lab computationally modelled a coupled DWG-rockbed system to predict environmental conditions and annual auxiliary energy consumption to maintain a minimum temperature within the DWG. Analyses investigated the influence of insulation around the rockbed and rockbed fan control scheme with consideration for annual variations and location-dependent parameters.
Electrodialysis (ED) Desalination
Electrodialysis (ED) is one of the leading technologies for application such as groundwater desalination. Groundwater accounts for nearly one-third of Earth’s freshwater resources; however, salinity levels are often too high for continuous human consumption. Electrodialysis uses electrical current and ion-selective membranes to separate salt components in feedwater, thus creating streams of high and low salinity. Feedwater temperature and conductivity may have a significant impact on the system’s desalination rate, limiting current density, and total energy consumption. These impacts were modeled and will be tested on bench-scale setups.
Previous Projects
Brine Management
The team is working on the development of a novel convection-enhanced evaporation (CEE) system. The proposed system represents a modular brine management option for decentralized desalination plants and small-scale industries. Brine is released over horizontally packed evaporation surfaces forming liquid films and forced convection is induced by means of a fan. As air flows over liquid films, the difference in vapor pressure between the air and liquid surfaces induces evaporation. The project includes mathematical modeling, design optimization and experimental testing.
Gas Extraction in Anaerobic Wastewater Treatment
Anaerobic wastewater treatment is used across the country to treat both household and industry wastewater and consumes ~25 million kWh of energy in the Twin Cities alone, costing approximately $1.7 million/year. This cross-departmental project aims to build an anaerobic wastewater treatment system that recovers the energy consumed in the form of hydrogen and methane gases collected from the liquid effluent of the wastewater treatment system. This project aims to investigate and determine the most efficient gas extraction system through both modelling and experimental work.
This work is a joint effort with Prof. Paige Novak (Civil, Environmental, and Geo- Engineering, UMN), Prof. Bill Arnold (Civil, Environmental, and Geo- Engineering, UMN), and Prof. Jeremy Guest (Civil and Environmental Engineering, University of Illinois at Urbana-Champaign).