Membrane Bioreactor Phosphorus Recovery for High-Quality Fertilizer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for recovering phosphorus from wastewater result in products with inconsistent quality, high operational costs, and environmental impact, limiting their use as fertilizers due to undesirable solubility and bioavailability, and inefficient energy consumption.
Innovation Solution
A method involving a membrane bioreactor system with pH adjustment, aeration, and coagulation to produce high-quality calcium phosphate from wastewater, utilizing calcium-containing coagulants to precipitate phosphorus, and recycling CO2 for residual hardness removal, achieving a phosphorous content comparable to mined rock phosphates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical precipitation methods are used to recover phosphorus from wastewater, then phosphorus removal efficiency is improved, but the quality and solubility of the recovered phosphorus product deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the precipitation process by controlling pH levels and using specific metal salt concentrations to produce phosphorus products with improved solubility and quality while maintaining high removal efficiency
Solution Approach 2:
The patent introduces intermediary substances such as metal salts (iron, magnesium, calcium) that mediate the precipitation process to form soluble phosphorus compounds like struvite and calcium phosphate, which maintain both removal efficiency and product quality
2Reliability
If biological phosphorus removal methods are used, then phosphorus removal efficiency is improved, but operational complexity and system instability increase
Solution Approach 1:
The patent replaces complex biological treatment systems with simpler chemical precipitation methods that use metal salts and pH adjustment, eliminating the need for skilled manpower and complex operational controls while maintaining high phosphorus removal efficiency
3Object-affected harmful factors
If conventional wastewater treatment focused on nutrient removal is used, then environmental pollution is reduced, but valuable nutrient recovery is lost
Solution Approach 1:
The patent converts the harmful discharge of nutrient-rich wastewater into a beneficial resource by recovering phosphorus and nitrogen through chemical precipitation to produce usable fertilizer products, transforming waste into valuable nutrients
4Reliability
If struvite is produced as the final phosphorus product, then phosphorus recovery is achieved, but versatility and application range are limited
Solution Approach 1:
The patent changes the chemical composition parameters of the recovered phosphorus product by adjusting metal salt ratios and pH levels to produce diverse phosphorus compounds including struvite, calcium phosphate, and other soluble phosphates with varying solubility and application characteristics
Solution Approach 2:
The patent creates a universal phosphorus recovery system that can produce multiple types of phosphorus products (struvite, calcium phosphate, amorphous calcium phosphate) with different solubility and bioavailability characteristics, enabling applications across diverse agricultural and industrial uses
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process produces high-quality phosphorus-based fertilizers with controlled phosphorous levels, solubility, and bioavailability, reducing environmental impact and energy consumption, while enabling diverse applications beyond fertilizers.
Implementation Method 1
treating a wastewater stream in a membrane bioreactor
Implementation Method 2
membrane bioreactor system
Implementation Method 3
adjusting the pH of at least a portion of the liquid permeate stream in a pH adjustment zone
Implementation Method 4
aerating at least a portion of the pH-adjusted liquid permeate stream with a stripping gas in an aeration zone
Implementation Method 5
precipitating at least one nutrient from the aerated permeate stream in a solids recovery zone
Implementation Method 6
utilizing calcium-containing coagulants to precipitate phosphorus
Data Source
AI summary
Methods and systems for recovering nutrient-enriched products from wastewater are provided. Liquid permeate streams recovered from a membrane-type bioreactor may be further treated to remove carbonate species, and then contacted with at least one calcium-containing coagulant. The resulting solids-containing product may be enriched in one or more nutrients, such as phosphorous, and can be used in subsequent applications. such as fertilizers. The resulting liquid stream may also be treated to provide a treated water stream. Methods and systems described herein provide energy-efficient, sustainable processes for treating wastewater and recovering valuable products therefrom.