DAV-DDBF

   DAV-DDBF

   1.Process Introduction

   DAV-DDBF filter is a gravity flow biological filter integrating filtration and denitrification. It can effectively removes TSS and NO_x-N in one treatment unit.

   The filter employs 2-3 mm natural quartz sand as the filter medium to provide a good attachment environment for the growth of biofilm. Denitrifying bacteria utilize the external carbon source as the electron donor and nitrate-N as the electron acceptor to convert nitrate-N into nitrogen, which not only effectively denitrifies, but also effectively improves the interception efficiency of SS. The effluent TN≤3 mg/L, SS≤5 mg/L and TP≤0.3 mg/L can easily reach the Class IV effluent standard.

   2.Core Technology

   1) Automatic Nitrogen Drive System

   During the operation of denitrification deep bed filter in denitrification mode, nitrogen accumulation will occur, and the water level of the filter will rise rapidly. Davco's unique nitrogen drive technology will effectively release the nitrogen attached to the biofilm, effectively prolong the filtration cycle of the filter, reduce backwashing water volume and save energy and consumption.

   2) Automatic Carbon Source Dosing System

In the denitrification mode, carbon source needs to be added to the filter. In order to reduce the dosage of carbon source and decrease the consumption of carbon source by dissolved oxygen, Davco provides carbon source precise dosing system, arc weir water distribution system and constant water level operation system. Combined with the unique AI deep learning and big data analysis system, Davco forms an all-round intelligent control system to control the carbon dosage at a lowest level, bringing huge economic value to customers.

   3) Automatic Backwashing Control System

The filter requires backwashing after running for a period of time. Good backwashing is necessary to ensure the efficient operation of the filter. Davco knows the importance of filter backwashing and provides an intelligent backwashing control system to accurately judge whether the filter needs to start backwashing and prolong the operation cycle of the filter to the greatest extent. At the same time, Davco's unique clean water tank water distribution system will also minimize the impact of backwashing on downstream treatment units, and the backwashing water volume is usually controlled below 3%.

   3.Core Components

   1) DAV-Block

   Water and gas are distributed on all sides to provide more uniform gas and water distribution.
    The disc design is more stable and completely solves the overturning risk of traditional concrete filter brick.
    Simple installation and no wearing parts.
    4% nominal opening rate, not easy to block.
    Lifelong maintenance free, service life up to 50 years.

   The uniformity of gas and water distribution of Dav-Block double block has been verified by tens of thousands of CFD flow pattern simulation and engineering practice.

   2) DAV-Sand Media

   High quality natural sand media, select natural sand and strictly control the quality.

   Silicon content ≥ 95%.

   Effective particle size: 2-3 mm.

   Uniformity coefficient ≤ 1.40.

   Specific gravity ≥ 2.6 T/m³.

   Mohs hardness 6-7.

   4. Application

   As a post denitrification process, it can be used in the advanced treatment stage of sewage plant to solve the instability of total nitrogen, SS and total phosphorus effluent. It can meet the upgrading transformation of water treatment plant from class I B and class I A to Class IV, and easily reach Class IV effluent standard.

   5. Automatic Control

   For the operation of external auxiliary equipment of the filter, the automatic control system is launched from the perspective of users. Users can customize the system based on their own needs. The standard version of Davco intelligent system provides real-time data, alarm push, history query and statistical analysis functions. The customized version provides cloud image customization, intelligent report, auxiliary operation and maintenance, panoramic cruise function.