CN-119977179-B - Composite filler for urban source pollution control and preparation method thereof

CN119977179BCN 119977179 BCN119977179 BCN 119977179BCN-119977179-B

Abstract

The invention relates to the technical field of water treatment, in particular to a composite filler for urban source pollution control and a preparation method thereof, and the composite filler comprises, by mass, 30-40 parts of ceramsite, 20-30 parts of quartz sand, 5-10 parts of modified sodium alginate containing nitrifying bacteria, 1-3 parts of sodium persulfate, 5-15 parts of modified montmorillonite, 5-15 parts of zeolite, 5-10 parts of ferric hydroxide and 4-10 parts of binder, wherein the modified sodium alginate containing nitrifying bacteria is polyurethane and nano silicon dioxide composite crosslinking modification, then the modified sodium alginate containing nitrifying bacteria is inoculated, the modified montmorillonite is modified by ammonium polymethacrylate, and the problems of poor nitrogen and phosphorus removal effect and serious secondary pollution of the composite filler in the existing biological detention facility are solved.

Inventors

JIANG YI
CHEN JIANJUN
DU MEI
WANG XIAOLONG
YANG CHANGMING
WANG CHAO
Lin Qiweng
WANG PEISHENG

Assignees

中铁四局集团有限公司
中铁四局集团第四工程有限公司
同济大学

Dates

Publication Date: 20260512
Application Date: 20250310

Claims (9)

1. The composite filler for urban source pollution control is characterized by comprising, by mass, 30-40 parts of ceramsite, 20-30 parts of quartz sand, 5-10 parts of modified sodium alginate containing nitrifying bacteria, 1-3 parts of sodium persulfate, 5-15 parts of modified montmorillonite, 5-15 parts of zeolite, 5-10 parts of ferric hydroxide and 4-10 parts of binder, wherein the modified sodium alginate containing nitrifying bacteria is polyurethane, nano silicon dioxide is subjected to composite crosslinking modification, and then the modified sodium alginate containing nitrifying bacteria is inoculated, and the modified montmorillonite is modified by ammonium polymethacrylate; The preparation method of the modified sodium alginate containing nitrifying bacteria comprises the following steps: A1, mixing sodium alginate solution, polyurethane solution and dispersed nano silicon dioxide, heating to 40-50 ℃ in a stirring state, and continuously stirring for 1-2 hours; A2, adding pentosal to carry out a crosslinking reaction, keeping the temperature between 50 and 60 ℃ to react for 1 to 2 hours, standing for 24 hours, and drying to obtain modified sodium alginate; a3, enriching whole nitrifying bacteria through sludge, and inoculating the whole nitrifying bacteria to the modified sodium alginate to obtain the modified sodium alginate containing nitrifying bacteria.
2. The composite filler for urban pollution control according to claim 1, which is characterized by comprising, by mass, 35 parts of ceramsite, 25 parts of quartz sand, 7.5 parts of modified sodium alginate containing nitrifying bacteria, 2 parts of sodium persulfate, 10 parts of modified montmorillonite, 10 parts of zeolite, 7.5 parts of ferric hydroxide and 7 parts of a binder.
3. The composite filler for urban pollution control according to claim 1, wherein in the step A1, the mass ratio of sodium alginate to polyurethane solution to nano silica is 3:1:1.
4. The composite filler for urban pollution control according to claim 1, wherein in the step A3, the specific inoculation process is that the sludge containing the whole nitrifying bacteria is diluted to 3500-4500mg/L by clean water, and then the sludge is sprayed into the modified sodium alginate for a plurality of times.
5. A method for preparing the composite filler for urban source pollution control according to any one of claims 1 to 4, comprising the steps of: S1, cleaning ceramsite and quartz sand with deionized water, drying, and preparing a binder solution with the mass concentration of 4-6%; s2, uniformly stirring ceramsite, quartz sand, modified sodium alginate containing nitrifying bacteria, sodium persulfate, modified montmorillonite, zeolite and ferric hydroxide, and spraying a binder solution while mixing to form a primarily mixed composite filler; S3, granulating the preliminarily mixed composite filler, standing and solidifying in a ventilation environment, and drying to obtain the composite filler.
6. The method for preparing the composite filler for urban pollution control according to claim 5, wherein in the step S2, the modified montmorillonite is prepared by mixing montmorillonite with a solution of ammonium polymethacrylate, stirring thoroughly, reacting at room temperature for 2-4h, and drying.
7. The method for preparing a composite filler for urban pollution control as defined in claim 6, wherein the ammonium polymethacrylate solution is used in an amount of 5-10% by mass of montmorillonite.
8. The method for preparing composite filler for urban pollution control according to claim 5, wherein the zeolite has a particle size ranging from 3mm to 5mm in step S2.
9. The method for preparing composite filler for urban pollution control according to claim 5, wherein in step S3, the particle size of the composite filler is 4mm to 6mm.

Description

Composite filler for urban source pollution control and preparation method thereof Technical Field The invention relates to the technical field of water treatment, in particular to a composite filler for controlling pollution of urban sources and a preparation method thereof. Background Urban source pollution refers to a pollution form caused by bringing dissolved or solid pollutants into a water body from a non-specific place when rainwater flushes urban ground surfaces in the rainfall process. It is a type of water environmental pollution relative to point source pollution, also known as urban non-point source pollution. With the effective management of point source pollution, the problem of non-point source pollution caused by initial rainwater is increasingly focused. The low impact development technology is widely adopted as a new concept for treating rainwater because it can effectively reduce environmental burden. For the treatment of the initial rain water surface source pollution, three strategies, namely source control, process control and tail end control, are generally adopted. Specific measures include, but are not limited to, bioretention facilities, overflow reservoirs, constructed wetlands, and the like. Most of the runoff treatment facilities represented by the bioretention facilities have a function of removing suspended contaminants, but the effect of removing nitrogen and phosphorus is poor. The core of the biological detention facility is to use a composite filler which needs to have the characteristics of high water retention and good adsorptivity. Currently, composite fillers are mainly of the following types: 1. Based on humus soil, although good growth conditions can be provided, nutrients in the humus soil are easy to run off to a water body along with runoff, secondary pollution is caused, and the permeability is relatively poor. 2. Peat is based on peat which has excellent water retention and nutrient retention, but its exploitation is severely limited as a non-renewable resource. 3. The sandy soil is based on the sandy soil, and has excellent permeability, but the sandy soil has insufficient water retention capacity, so that the selection of plant types can be limited, and the landscaping attractiveness is further influenced. 4. The planting soil is used as a foundation, the planting soil also has the problem of nutrient loss, and the permeability to water is poor. Therefore, a composite filler for fixing phosphorus, adsorbing and decomposing ammonia nitrogen and reducing secondary pollution is required. In view of the above drawbacks, the present inventors have finally achieved the present invention through long-time studies and practices. Disclosure of Invention The invention aims to solve the problems of poor nitrogen and phosphorus removal effect and serious secondary pollution of the composite filler in the existing biological detention facilities, and provides the composite filler for controlling the pollution of the urban source and the preparation method thereof. In order to achieve the aim, the invention discloses a composite filler for urban source pollution control, which comprises, by mass, 30-40 parts of ceramsite, 20-30 parts of quartz sand, 5-10 parts of modified sodium alginate containing nitrifying bacteria, 1-3 parts of sodium persulfate, 5-15 parts of modified montmorillonite, 5-15 parts of zeolite, 5-10 parts of ferric hydroxide and 4-10 parts of a binder, wherein the modified sodium alginate containing nitrifying bacteria is polyurethane, nano silicon dioxide composite crosslinking modification, and then is inoculated with the modified sodium alginate containing nitrifying bacteria, and the modified montmorillonite is modified by ammonium polymethacrylate. The composite filler comprises the following raw materials, by mass, 35 parts of ceramsite, 25 parts of quartz sand, 7.5 parts of modified sodium alginate containing nitrifying bacteria, 2 parts of sodium persulfate, 10 parts of modified montmorillonite, 10 parts of zeolite, 7.5 parts of ferric hydroxide and 7 parts of binder. The invention also discloses a preparation method of the composite filler for controlling the pollution of the urban source, which comprises the following steps: S1, cleaning ceramsite and quartz sand with deionized water, drying, and preparing a binder solution with the mass concentration of 4-6%; s2, uniformly stirring ceramsite, quartz sand, modified sodium alginate containing nitrifying bacteria, sodium persulfate, modified montmorillonite, zeolite and ferric hydroxide, and spraying a binder solution while mixing to form a primarily mixed composite filler; S3, granulating the preliminarily mixed composite filler, standing and solidifying in a ventilation environment, and drying to obtain the composite filler. In the step S2, the preparation method of the modified sodium alginate containing nitrifying bacteria comprises the following steps: A1, mixing sodium alginate solution, pol