5 Wastewater Treatment Technologies You Should Know About

Wastewater Treatment Technologies - YASA ET Knowledge Sharing



Industrial wastewater includes the water used in the production line, sewage, and for cooling purposes. As environmental protection requirements become more stringent, it's important to know more about various wastewater treatment technologies.


This article will give you a brief overview of the 5 most common wastewater treatment systems currently used by environmental services companies all around the world.



1) Evaporation and Crystallization Technology


In the treatment process of industrial salty wastewater, the water enters the evaporation and crystallization equipment and is separated into desalinated water (desalinated water may contain traces of low-boiling organic matter) and concentrated crystalline slurry or sludge waste; inorganic salts and part of organic matter can be furtherly separated by crystallization.


The concentrated waste liquid of organic matter that cannot be crystallized can be treated by a drum evaporator to form solid waste residue and then incinerated; the desalinated water can then be returned to the production system to replace the demineralized water for reuse.


The evaporation, concentration and crystallization system cannot only be used in the concentration process and crystallization process of chemical production, but also for industrial high salinity wastewater. The current evaporative crystallization technology has a variety of technical routes such as single-effect, multi-effect, heat pump, and MVR, which can be selected and used according to different conditions.



2) Biological Treatment


Biological treatment is currently one of the most commonly used methods for wastewater treatment. It has the characteristics of wide application range, strong adaptability, economic efficiency and harmlessness. In general, the commonly used biological methods include the traditional activated sludge method and the biological contact oxidation method.


a) Traditional Activated Sludge

Activated sludge method is a kind of aerobic biological treatment method of sewage, and it is currently the most widely used method for treating urban sewage. It can remove soluble and colloidal biodegradable organic matter, suspended solids and other substances that can be adsorbed by activated sludge from sewage, and it can also remove part of phosphorus and nitrogen.

The activated sludge method has a high removal rate and is suitable for treating wastewater with high water quality requirements and relatively stable water quality.


b) Biological Contact Oxidation

Biological contact oxidation is a method that mainly uses microorganisms (i.e. biofilms) attached to the surface of certain solid objects to treat organic sewage.

Biological contact oxidation method is a kind of submerged biofilm method, which is a combination of biological filter and aeration tank. It has the characteristics of activated sludge method and biofilm method, and has good effects in the water treatment process.

The biological contact oxidation method has a higher volumetric load and strong adaptability to shock loads; less sludge generation, simple operation and management, simple operation, low energy consumption, economical and efficient.


However, biological treatment can't adapt to changes in water quality, and the oxygen supply cannot be fully utilized; the air supply is evenly distributed along the pool water, resulting in insufficient oxygen in the front section and excess oxygen in the rear section; finally the aeration structure covers a large area.



3) SBR Process


SBR is the abbreviation of Sequencing Batch Reactor. As an intermittently operating wastewater treatment process, in recent years, it has attracted widespread attention and research interest.

The working principle of SBR is composed of five procedures: inflow, reaction, precipitation, discharge and idleness. Sewage enters each reaction process in sequence and intermittently in the reactor, and the operation of each SBR reactor is also arranged in sequence and intermittently in time.


The SBR method has advantages of simple operation, small area, few equipment, and investment saving.

Although the method SBR has the above advantages, it also has certain limitations. For example, if the inlet water flow is large, the reaction system needs to be adjusted, thereby increasing the investment costs. Also in some cases the special requirements for the effluent water quality, such as nitrogen and phosphorus removal, cannot be guaranteed.



4) MBR Process


MBR is a new type of high-efficiency sewage treatment process that combines high-efficiency membrane separation technology with traditional activated sludge method. It uses a unique structure of MBR flat membrane module placed in the aeration tank, after aerobic aeration and biological treatment the water is pumped out after being filtered through the filter membrane by the pump.


The MBR process equipment is compact and occupies a small area; the effluent quality is stable and the organic matter removal efficiency is high; the remaining sludge output is small, which reduces the production cost; it can remove ammonia nitrogen and refractory organic matter; it is easy to transform from the traditional process. However, the high cost of membrane construction makes the capital investment of the membrane bioreactor higher than that of the traditional sewage treatment process; membrane pollution often occurs, which brings issues of operation and management; high energy consumption and high process requirements are inevitable as well.



5) Electrolysis


In conditions of high salinity wastewater has high conductivity. This feature is ideal for the electrochemical method in the treatment of high salinity organic wastewater. The high-salt wastewater undergoes a series of oxidation-reduction reactions in the electrolytic cell to produce water-insoluble substances, which are removed by precipitation (or air flotation) or direct oxidation-reduction to harmless gases, thereby reducing COD.


Because of the limitations of electrochemical theory, high energy consumption, and lack of electricity, the current electrolytic treatment of high-salt wastewater is still in the research stage.



 

At YASA ET we are experts in wastewater treatment and can offer the best solutions for dealing with your water pollution and contamination.


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