Recipient Organization
UNIVERSITY OF OKLAHOMA
(N/A)
NORMAN,OK 73019
Performing Department
(N/A)
Non Technical Summary
The overall objective of this project is to develop and test low-cost materials for treatment of brackish water. Growing water demands and a changing climate are driving the need to utilize non-traditional water sources for irrigation. This project will treat two model brackish waters with compositions similar to waters from Texas and California. Treatment of these waters for anion (mainly chloride) removal will be by adsorption to calcined layered double hydroxides and by precipitation of calcium chloroaluminate (Friedel's salt). Treatment for cation (mainly sodium) removal will be using cellulose-based cation exchange polymers prepared from wheat straw and corn cobs. The cost to treat brackish waters to the treatment goal of 500 mg/L total dissolved solids will be estimated to evaluate the feasibility of adoption. Expanding water resources available for irrigation by tapping currently underused brackish water supplies has the potential to increase the resilience and sustainability of food production. Specifically, the proposed work has the potential to reduce the demand for freshwater use in agriculture by developing innovative techniques for brackish water treatment.
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Goals / Objectives
The overall goal of this work is to evaluate several lower-cost alternatives for treatment of brackish water to a level suitable for irrigation. The rationale for the work is to reduce the freshwater demand and thereby improve agricultural resilience and sustainability under a changing climate. To accomplish this goal, several materials will be synthesized and evaluated for treating two model brackish waters to the treatment goal of 500 mg/L. The model waters differ in their ratio of hardness (Ca+2 and Mg+2) to sodium, and in their concentrations of sulfate and alkalinity, all of which could affect treatment effectiveness. The specific objectives are:Objective 1: Measure adsorption of chloride by calcined AlMg(CO3) layered double hydroxide foreach model wastewater.Objective 2: Measure removal of chloride by precipitation of Friedel's salt (Ca2Al(OH)6Cl·2H2O), in both a one-stage and two-stage process, foreach model wastewater. Objective 3: Use the treated waters from Objectives 1 and 2 to measure the removal of sodium by cation exchange polymers prepared from crop residues foreach model wastewater.Objective 4: Evaluate treatment costs for allthe methods described above.
Project Methods
The methods to be usedinclude control of pH and ionic composition to yield minerals for chloride uptake;extraction, partial oxidation, and functionalization of cellulose from crop wastes to yield polymers for sodium uptake;and sorption isotherms to test treatment material uptake capacity. Data will be analyzed and fit to sorption andother equilibrium models using least squares regression. Standard laboratory quality assurance/quality control practices will be employed to ensure data accuracy. Cost analyses will be done using current commodity and labor prices.