Wastewater Nutrient Removal - An Overview: Part 2
This article is a continuation of another, so if you haven't already, please go back and read Wastewater Nutrient Removal - An Overview: Part 1.
Bio-treatment of Wastewater Nutrient Removal for Treatment Plants
The main focus of biological processes is organic impurities. For the treatment of industrial wastewater nutrient removal in microbial-based technologies were developed over the past century. These technologies have enabled the successful destruction of waste components that are easily biodegradable under aerobic conditions.
Aerobic degrading in the presence of oxygen can be an inexpensive, simple, and eco-friendly way of nutrient removal to reduce waste. The factors that affect the optimal degradation of the substrate are temperature, humidity, pH, nutrients, and the aeration rate. Temperature and aeration are the two most important parameters for nutrient removal that determine the microorganism's degradation rates.
The main disadvantage of the aerobic bioprocesses for nutrient removal to treat wastewater is the high amount of sludge that they produce. The aerobic bioreactor can accumulate a lot of biomass because the biomass yield (mass per unit of biodegradable material) for aerobic microorganisms tends to be higher than that for anaerobic ones.
Industrial wastewater can have a toxic effect upon microorganisms without nutrient removal in activated sludge systems. These contaminants and compounds cannot be used by microorganisms as their sole source of carbon and can vary in toxicity.
For industrial wastewater treatment and nutrient removal, activated sludge has been extensively used. The two-phase partitioning reactor is also effective in treating toxic substrates. Anaerobic reactors are different from aerobic reactors in that the former must be closed to prevent oxygen from entering the system.
An anaerobic reaction vessel should have a suitable vent or collection system for nutrient removal and the removal of gases (mainly carbon dioxide) during anaerobiosis.
There are many advantages to anaerobic microbial process:
Sludge produced at a lower rate
Operable at toxic and influent levels
There is no cost to deliver oxygen to the reactor
Methane (biogas), is a useful byproduct
Anaerobic processes are more expensive than aerobic processes due to the fact that they require more capital and operating costs for nutrient removal. Anaerobic bioprocesses to treat hazardous wastewater streams are usually limited to low flow rates streams.
The various biological conversions should be sufficiently coupled to ensure that the digestion process is balanced and does not accumulate any intermediates. For industrial wastewater treatment and nutrient removal, anaerobic reactors like the up-flow anaerobic batch reactor and anaerobic sequencing reactor have been used.
Advanced Oxidation for Wastewater Nutrient Removal Treatment in Processing Plants
By definition, oxidation is the process by which electrons transfer from one substance into another. This leads to a potential expressed as volts, also known as normalized hydrogen electrode. This is how you can determine the oxidation potentials for different compounds.
Chemical oxidation is a solution that conforms to treated wastewater legislation and is part of the qualifications for nutrient removal. It is often used in conjunction with secondary treatment to destroy non-biodegradable substances. The chemical oxygen demand (COD) is a reference parameter for chemical oxidation.
These processes can usually be used to treat wastewater and for nutrient removal with low COD content. Higher COD would require expensive reactants. There are two types of chemical oxidation processes:
Chemical treatment in the classic way
Advanced oxidation (AOPs).
AOPs refer to wastewater treatment processes and nutrient removal at near ambient temperatures and pressures that produce highly reactive radicals, especially hydroxyl radicals, in sufficient quantities for wastewater purification. These treatments are promising for remediation of non-biodegradable organic pollutants in ground, surface and wastewater.
Hydroxyl radicals, which are extremely reactive species, attack almost all organic molecules.
These units are very effective at converting recalcitrant compounds to intermediates that can be biologically oxidized via recirculation to their inlet or, even better - completely mineralizing them when they are applied to the outlet of a biologic treatment facility as a final polishing stage of nutrient removal.
In-Pipe Technology offers a variety of solutions for nutrient removal that is effective in the treatment of industrial wastewater components, including aromatic amines, dyes and other substances.
Check out our other blog posts about nutrient removal and the like by clicking here.