CN102153183A - Nano ferric oxide-cationic polyelectrolyte coupled multielement composite flocculant - Google Patents

Abstract

The invention provides a nano ferric oxide-cationic polyelectrolyte coupled multielement composite flocculant, relating to an inorganic-organic composite flocculant. The invention provides a novel high-efficiency composite flocculant compounded by nano ferric oxide and cationic polyelectrolyte, wherein the nano ferric oxide is nano alpha-FeOOH, Fe3O4, alpha-Fe2O3, gamma-Fe2O3 and the like, and the cationic polyelectrolyte is polyamine, polyacrylamide, poly (diallyldimethylammonium chloride), chitosan and the like. The composite flocculant provided by the invention is applicable to micro-pollution water source strengthening treatment, the treatment effect on toxic and harmful pollutants (heavy metals, toxic organic matters and the like), humic acid and chromaticity is higher, and the composite flocculant provided by the invention has the advantages of good separating effect, rapid sedimentation, low effluent turbidity, wide pH application range and the like.

Description

Nano-iron oxide-cation polyelectrolyte coupled multi-element composite flocculant

technical field

The invention relates to an inorganic-organic composite flocculant, in particular to a composite flocculant with good removal effect for organic matters, turbidity and chroma in drinking water.

Background technique

In the face of changes in water quality and the improvement of water quality requirements, the conventional coagulation process can no longer meet the requirements. Experimental research and actual production results at home and abroad show that conventional coagulation, sedimentation and filtration can only remove 20% to 30% of organic matter in water, and due to the presence of dissolved organic matter, it is not conducive to destroying the stability of the colloid and the turbidity removal effect is significantly reduced. , Therefore, more and more attention is paid to the research on composite flocculants, as patent CN1821114A discloses a kind of preparation method of composite flocculants such as aluminum sulfate, slaked lime; Formaldehyde polymer, polyaluminum sulfide and/or polysulfide aluminum calcium to make an organic-inorganic composite flocculant; patent CN101327977A composites aluminum salt, iron salt, polyacrylamide and starch into double-layer or Multi-layer flocculant, the multi-layer slow-release structure increases the efficiency of the agent and improves the efficacy of the agent; patent CN101717144A mixes polyaluminum iron silicate and chitosan in an appropriate proportion to obtain stable performance, good storage performance, Easy to use and other advantages. At present, the preparation of composite flocculants is made of iron salts, aluminum salts and polyaluminum salts combined with high-molecular organic matter to form flocculants to enhance the coagulation effect; or to improve the coagulation effect by increasing the dosage of coagulants. cost, and may also increase the concentration of metal ions in the effluent. Nanomaterials have unique nanoeffects: small size effect, interface effect, quantum effect, and macroscopic quantum tunneling effect. There are more and more researches on its application in the field of environment. Iron oxide has large reserves, simple extraction, simple pollution control equipment, and good treatment effect. It has a very promising prospect as an environmental protection material. Cationic polyelectrolyte is used as an organic flocculant. Compared with inorganic flocculants, it has less dosage and faster flocculation speed. It is less affected by coexisting salts, pH value and temperature. It generates less sludge and is easy to handle. Disposal and reuse play an important role. The enhanced coagulation improves the matching of chemicals and optimizes the coagulation process to increase the impact, adsorption, and removal of ultrafine particles in the water by flocs, reduce the turbidity of the effluent, and increase the removal rate of organic matter. This kind of treatment technology that can solve the problem of micro-pollution of water source water without a large amount of capital investment can play a role in protecting human drinking water safety, solving water quality-related water shortage problems, and promoting social and economic progress.

Contents of the invention

The purpose of the present invention is to form a multi-component composite flocculant through the coupling of nano-iron oxide-cationic polyelectrolyte. Nano-iron oxide has exclusive adsorption, but due to the unique effect of nano-materials, it is not easy to disperse in water, and will agglomerate into large particles, forming a stable Colloids affect flocculation. Coupling nano-iron oxide with cationic polyelectrolyte, using cationic polyelectrolyte to better disperse nanoparticles, and at the same time exerting the "polyelectric complexation effect" of cationic polyelectrolyte to form flocs that are easy to settle, and at the same time can remove organic matter, Very good removal of heavy metals and toxic pollutants. The preparation method of the present invention is specifically described as follows:

1. An efficient nano-material-cation polyelectrolyte coupled multi-element composite flocculant, which is prepared by coupling nano-iron oxide and cationic poly-electrolyte. The multi-element composite flocculant is prepared by weight percentage, nano-iron oxide: 5-60%, polymerized organic matter : 0.1-2%, the balance is water.

2. The high-efficiency nano-material-cation polyelectrolyte coupled multi-element composite flocculant is characterized in that: in nano iron oxide such as nano α-FeOOH, Fe ₃ O ₄ , α-Fe ₂ O ₃ , γ-Fe Cationic polyelectrolyte is added in the preparation process of ₂ O ₃ etc. After the reaction is completed, the multi-component composite flocculant is obtained through washing and refining processes (or the multi-component composite flocculant dry powder is obtained through drying and grinding processes).

3. The high-efficiency nano-material-cation polyelectrolyte coupling multi-element composite flocculant is characterized in that: the water treatment flocculation process is to add nano-iron oxide and cationic polyelectrolyte respectively, and coagulate after adding nano-iron oxide Stirring and coagulation conditions: fast stirring: 100-1000r/min, 0.5-30min. Slow stirring: 20-120r/min, 5-60min. After stirring quickly for 0.2-10min, add cationic polyelectrolyte, coagulation temperature: 4-60℃.

4. The high-efficiency nano-material-cation polyelectrolyte coupled multi-element composite flocculant is characterized by: nano-iron oxide: α-FeOOH, Fe ₃ O ₄ , α-Fe ₂ O ₃ , γ-Fe ₂ O ₃ , etc.; cationic polyelectrolyte: polyamine, polyacrylamide, polydimethyldiallylammonium chloride, chitosan, etc.

The characteristics of the nano-iron oxide-cation polyelectrolyte coupled multi-element composite flocculant prepared by the present invention are:

1. The raw materials used are convenient and easy to obtain, without any organic compound, and the preparation is carried out under normal temperature and pressure, which can reduce production costs and is environmentally friendly.

2. The removal of organic matter, turbidity, and chromaticity in water by this new type of high-efficiency composite flocculant is less affected by the pH of the water quality, and it has more advantages than traditional flocculants and polyferrons.

3. This new type of high-efficiency composite flocculant is suitable for intensive treatment of micro-polluted water sources. It has a high treatment effect on toxic and harmful pollutants (heavy metals, toxic organic substances, etc.), humic acid, and chroma, and has good separation effect and settlement Fast, low water turbidity, wide pH range and other advantages.

4. The process operation is simple and can be applied industrially.

Detailed ways

Provide several specific embodiments of the present invention below, to describe the present invention in more detail

Example 1

Add 1000mL of raw water samples from the Jiantian Reservoir into a series of 250mL beakers, add 50mg/L, 100mg/L, 200mg/L, 300mg/L, 400mg/L, 600mg/L nano-Fe ₃ O ₄ flocculants for mixing Coagulate and stir, add 1mg/LPDADMAC after fast stirring for 1 minute, take the supernatant after coagulation and stirring, let it settle down, pass through a 0.45μm filter membrane in a 50mL centrifuge tube, and measure the removal of humic acid with a TOC instrument The total organic carbon content is expressed, and the changes of water turbidity and color before and after treatment are measured. The results show that the removal rate of humic acid is 49%, the removal rate of turbidity is 77%, and the removal rate of color is 88%.

Example 2

In a 1000mL beaker, put the concentration of 50mg/L, 100mg/L, 200mg/L, 300mg/L, 400mg/L, 600mg/L nanometer α-FeOOH flocculant in a series of 1000mL beakers, the pre-adjusted The pH values were 5, 6, 7, 8 respectively, and 1000mL of humic acid solution with an initial concentration of 10mg/L was added to the beaker for coagulation and stirring. After stirring for 1 minute, 5mL of 400mg/LPDADMAC solution was added. The coagulation temperature is 25°C. Take the solution supernatant after standing and settling, and filter it into a 50mL sample tube through a 0.45um filter membrane. The removal of humic acid is indicated by measuring its total organic carbon content with a TOC instrument, and measuring the water turbidity and chromaticity before and after treatment. Changes, the results show that: after adding cations, the results show that under different pH conditions, the removal rate of humic acid continues to increase, at 75%-95%; turbidity removal rate: 60%-90%; chromaticity removal Rate: 80%-95%.

Example 3

The composite flocculant samples of nano-α-FeOOH and PDADMAC were weighed to be 5.0, 10.0, 15.0, 20.0, 30.0 and 50 mg/L respectively, the initial concentration of PFOS was 2 mg/L, and the pH value was 3.0. Shake at a constant temperature of 25 °C , take the supernatant, measure the concentration of PFOS, the results show that the removal rate: 70%-93%.

Example 4

Take 400mL water samples and add them to a series of 500mL beakers, and add α-FeOOH and PDADMAC composite flocculant samples with mass concentrations of 50, 100, 200, 300, 400 and 600mg/L respectively for coagulation and stirring. After coagulation and stirring, take the supernatant of the solution after standing and settling, and measure the change of Mn ²⁺ in the water. The results show that the removal rate of Mn ²⁺ is 65%-83%.

Claims (6)

1. nano material-cationic polyelectrolyte polynary composite flocculation agent that is coupled efficiently.The flocculation agent efficient stable is removed in the technology in flocculation, the nano material good separating effect, and sedimentation is fast, and delivery turbidity is less than 3NTU, and the settling time is less than 30 minutes, improves more than 50% to the clearance of organic or hazardous contaminant by the coupling synergy.

2. a kind of nano material-cationic polyelectrolyte efficiently according to claim 1 polynary composite flocculation agent that is coupled, it is characterized in that: be coupled to form polynary composite flocculation agent with nano-sized iron oxide and cationic polyelectrolyte and be prepared by weight percentage, nano-sized iron oxide: 5-60%, polymerized organics: 0.1-2%, surplus is a water.

3. a kind of nano material-cationic polyelectrolyte efficiently according to claim 1 polynary composite flocculation agent that is coupled is characterized in that: at nano-sized iron oxide such as nanometer alpha-feooh, Fe ₃O ₄, α-Fe ₂O ₃, γ-Fe ₂O ₃Etc. adding cationic polyelectrolyte in the preparation process, reaction finishes and makes polynary composite flocculation agent (or technology such as drying, grinding makes polynary composite flocculation agent dry powder again) after technology such as wash, make with extra care.

4. a kind of nano material-cationic polyelectrolyte efficiently according to claim 1 polynary composite flocculation agent that is coupled, it is characterized in that: the water treatment flocculation process is for to add nano-sized iron oxide and cationic polyelectrolyte respectively, after nano-sized iron oxide adds, carrying out coagulation stirs, coagulation condition is: stir soon: 100-1000r/min, 0.5-30min.Slowly stir: 20-120r/min, 5-60min.Add cationic polyelectrolyte after stirring 0.2-10min soon, coagulation temperature: 4-60 ℃.

5. a kind of nano material-cationic polyelectrolyte efficiently according to claim 1 polynary composite flocculation agent that is coupled is characterized in that: nano-sized iron oxide: alpha-feooh, Fe ₃O ₄, α-Fe ₂O ₃, γ-Fe ₂O ₃Deng; Cationic polyelectrolyte: polyamine, polyacrylamide, Poly Dimethyl Diallyl Ammonium Chloride, chitosan etc.

6. a kind of nano material-cationic polyelectrolyte efficiently according to claim 1 polynary composite flocculation agent that is coupled, it is characterized in that: the settling time, reaches more than 65% the clearance of humic acid less than 3NTU, pH 4.0-10.0 applied widely less than 30min, delivery turbidity; Turbidity removal rate reaches more than 90%; Chroma removal rate reaches more than 93%.