Advanced oxidation process using hydrogen peroxide/microwave system for solubilization of phosphate

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Chemical Oxidation Processes

Background:

• Municipal sludge from enhanced biological phosphorus removal processes contains significant amounts of bound phosphorus.
• Conventional sludge treatment methods often do not efficiently recover phosphorus, leading to resource loss and environmental concerns.

Purpose of the Study:

• To investigate the efficacy of an advanced oxidation process (AOP) combining hydrogen peroxide and microwave heating for phosphate solubilization from secondary municipal sludge.
• To evaluate the potential of this process for phosphorus recovery from wastewater sludge.

Main Methods:

• An advanced oxidation process (AOP) was employed, utilizing hydrogen peroxide as the oxidant and microwave irradiation for both heating and radical generation.
• Secondary municipal sludge from an enhanced biological phosphorus removal process was treated under varying microwave heating conditions (time and temperature).

Main Results:

• The AOP facilitated the release of a substantial amount of sludge-bound phosphorus.
• Over 84% of the total phosphorus was solubilized within a microwave heating time of 5 minutes at 170 degrees C.
• Microwave irradiation effectively acted as both a heating source and a generator of oxidizing radicals.

Conclusions:

• The combined hydrogen peroxide and microwave heating AOP is a highly efficient method for solubilizing phosphorus from municipal sludge.
• This innovative process demonstrates significant potential for application in simple sludge treatment within domestic wastewater treatment plants.
• The technology offers a viable route for the recovery of phosphorus from wastewater, contributing to resource circularity.