203 results about "Extracellular polymeric substance" patented technology

A wastewater treatment process having improved solids separation characteristics and reduced biochemical oxygen demand (BOD) in the purified wastewater comprising the steps of: passing wastewater through a main aerobic biological oxidation zone and therein oxidizing a portion of the BOD a portion of the ammonia nitrogen content (NH3-N); passing the effluent from said aerobic biological oxidation zone to an aerobic/mixing zone and therein mixing said effluent with effluent from the anoxic/anaerobic zone; passing the effluent from said aerobic/mixing zone to a settling zone and therein separating purified wastewater having reduced BOD and suspended solids, and sludge containing suspended solids; passing a portion of the sludge formed in the settling zone and volatile acids to an anoxic/anaerobic zone and therein increasing the extracellular polymer content of said sludge, the release of phosphorus into solution and the reduction of nitrate nitrogen to molecular nitrogen gas; and recycling an effective amount of the effluent from said anoxic/anaerobic zone to said aerobic/mixing zone. In an alternative embodiment, a volatile acid is added to a zone to which no additional oxygen has been added that is in the flow path from the main aerobic biological oxidation zone or, alternatively, it may be added to the anoxic/anaerobic zone and the thus-treated effluent is passed to the aerobic/mixing zone wherein phosphate is removed from the effluent.

The invention provides a sludge-dewatering compound conditioning agent and an application method thereof. The sludge-dewatering compound conditioning agent comprises a Fenton reagent or / and similar Fenton reagent and a skeleton construct, and the weight ratio of the Fenton reagent or / and similar Fenton reagent and the skeleton construct is 1: (0.05-300); and the skeleton construct adopts a powder body. The application method comprises the following steps: adding the Fenton reagent or / and similar Fenton reagent into sludge slurry, and mixing for oxidation; and adding the skeleton construct into the sludge slurry with the Fenton reagent or / and similar Fenton reagent, and mixing. Due to synergy of the Fenton reagent or / and similar Fenton reagent and the powder type skeleton construct, extracellular polymeric substances in sludge can be destructed effectively, the compressibility of organic substances can be reduced, and the sludge dewatering performance of the sludge-dewatering compound conditioning agent can be improved greatly. The procedures of the application method are simple, the conditions can be controlled easily, the sludge dewatering time can be shortened, and the large-scale treatment of the sludge can be realized.

Chronic wounds may be treated by debriding necrotic and other devitalized tissue from the wound, and applying to the wound an extracellular polymeric substance solvating system comprising a metal ion sequestering agent, surfactant and buffering agent. The solvating system disrupts biofilms which may be present in the wound and aids or enables the resumption of normal healing.

The invention is named as 'a joint-conditioning dehydration method for sludge', belonging to the technical field of environmental engineering and sludge treatment. The joint-conditioning dehydration method comprises the following steps of: adding H202 and FeSO4 into the sludge (with pH being equal to 5) acidified by mineral acid, degrading organic matter by virtue of strong oxidation of a Fenton reagent, and dissolving and cracking microbial cells and extracellular polymeric substances in the sludge; adding a surfactant CTMAB (Cetyl Trimethyl Ammonium Bromide) into the sludge to reduce the surface tension of the sludge and change the surface characteristics of the sludge, and transforming a part of interstitial water into free water; and flocculating sludge particulates with disperse structure, small particle diameter and large specific surface area by virtue of flocculation action of polyacrylamide (CPAM) to the sludge particulates. After the sludge is subjected to joint conditioning of the Fenton reagent, the surfactant and the CPAM, the moisture content of the sludge after being centrifugally dewatered is reduced to 78.2% from 87.7%, and the output of mud cakes is reduced to 0.115t/m<3> from 0.218t/m<3>, therefore, the dehydration property of the sludge can be improved remarkably, the investment and operation costs are reduced effectively, and an ideal sludge reduction goal is reached.

The invention discloses a preparation method of a compound microbial algaecide. The method comprises the following steps: reasonably combining separated and purified extracellular polymeric substances, kaolin and the like so as to prepare a compound microbial flocculant; then fossilizing separated alga dissolving bacteria and algal toxin degrading bacteria; finally, reasonably compounding the compound microbial flocculant with the fossilized alga dissolving bacteria and algal toxin degrading bacteria so as to prepare the compound microbial algaecide. The compound microbial algaecide is good in alga killing effect and algal toxin degrading effect; source materials adopted during the preparation of the compound microbial algaecide are low in cost, so that the compound microbial algaecide is low in preparation cost and harmless to natural ecosystems. The prepared compound microbial algaecide is organically integrated with functions of flocculation-type alga removing, microbial alga dissolving and micro-biological degradation of algal toxin, so that the safe and efficient treatment of water blooms is realized.

This application relates to a coating method of lactic acid bacteria and a lactic acid bacteria complex produced by the coating method, the coating method comprising: (a) a step of culturing lactic acid bacteria in a medium including casein and coating the lactic acid bacteria with casein; (b) a step of mixing the casein-coated lactic acid bacteria with a solution comprising a coating agent, an edible oil, an extracellular polymeric substance (EPS) of Lactobacillus plantarum and alginic acid; and (c) a step of adding the mixture of step (b) to a calcium-containing solution to form alginic acid-calcium beads, wherein the alginic acid-calcium beads contain the casein-coated lactic acid bacteria, the coating agent, the edible oil, and the EPS of Lactobacillus plantarum.

The invention provides pseudomonas aeruginosa phage and application thereof. According to the pseudomonas aeruginosa phage, the strain name is vB_PaeM_QKL1, the preservation number is CGMCC No.13381, the classification name is pseudomonas aeruginosa phage, and the pseudomonas aeruginosa phage was preserved in China General Microbiological Culture Collection Center (CGMCC) in December 8th, 2016. The invention also provides application of the pseudomonas aeruginosa phage. Degrading enzyme of an extracellular polymeric substance exists in the caudal spine of the pseudomonas aeruginosa phage and can crack cell envelope to crack biofilm generating bacteria so as to completely remove the bacterial biofilm; the pseudomonas aeruginosa phage provided by the invention has remarkable inhibition effect on a pseudomonas aeruginosa biofilm, can break the pseudomonas aeruginosa biofilm, and also can be combined with antibiotics and the common chemical detergents.

The invention discloses a method for relieving blockage of a constructed wetland. The method comprises the steps as follows: A, the blockage is desolventized: 0.09-0.15 g/L of a biosurfactant, namely, rhamnolipid is dosed into inflow water of the wetland, inflow water enters the wetland and remains for desolventizing of the blockage of the wetland, the hydrophobic group end of rhamnolipid is bound with an organic group of an extracellular polymeric substance, the hydrophilic end is bound with pore water in the constructed wetland, and large-particle blockages connected by the extracellular polymeric substance are dispersed and solubilized; B, the blockages are eluted out of a wetland system: the wetland is emptied; C, the desolventizing action generates positive effects: the solubilizing and dispersing effects of rhamnolipid destroy the structure of the extracellular polymeric substance, so that bound enzymes are released, and contact among microorganisms, the enzymes and substrates is promoted; D, according to the condition of the wetland, desolventizing is performed for a plurality of times on the constructed wetland which begins to show a trend in blockage or is blocked till the blockage condition is improved. The method is easy to use, an appropriate amount of rhamnolipid is directly dosed into the inflow water of the wetland, the inflow water enters the wetland and remains for an appropriate period, and the method is suitable for recovery of the wetland which begins to show a trend in blockage or is blocked.

The invention relates to a flocculating agent for simulating composition of microorganism extracellular polymeric substances and an application method thereof. The flocculating agent is formed by compounding microorganism exopolysaccharides (sodium alginate, xanthan gum and pulullan) and hydrophobic amino acid (tryptophan, tyrosine and phenylalanine), the weight ratio (ammonia acid/polysaccharide) is 2-8, the optimal ratio is 8, and the concentration of the flocculating agent in the system when in charging is controlled at 20-40mg/L. The flocculating agent has the characteristics that the bridging attraction effect of the exopolysaccharide and the hydrophobic attraction effect of the hydrophobic amino acid can be adequately played after all components are compounded, so that the formation of non-biological particle sludge in the heavy metal waste water treatment process can be effectively promoted by integrating the bridging attraction effect and the hydrophobic attraction effect. Compared with the flocculent sludge, the flocculating agent has the advantages that the settleability of the non-biological particle sludge can be increased by 2-5 times, and the weakness of the difficulty in solid-liquid separation in the heavy metal waste water treatment process and toxicity and harm of the traditional macromolecular flocculating agent can be overcome.

The invention relates to an operation method for extracting a blue-green algae extracellular polymeric substance in a grading manner. The method comprises the following steps of: firstly, carrying out middle/low-speed eccentric shearing to obtain a soluble and loosely combined type extracellular polymeric substance; and secondly, extracting a tightly combined type extracellular polymeric substance in a mode of subalkaline hot bath with the combination of high-speed eccentric shearing. The physical and chemical analysis result shows that the soluble and loosely combined type extracellular polymeric substance contains a small amount of organisms, and the tightly combined type extracellular polymeric substance contain a great amount of organisms; and three-dimensional fluorescence and infrared spectroscopy result shows that the soluble extracellular polymeric substance is only composed of polysaccharide, protein substances and humus substances, and the loosely combined and tightly combined extracellular polymeric substances only consist of polysaccharide and protein substances. The invention discloses an operation method for grading extraction of the blue-green algae extracellular polymeric substance. The method has the advantages that the operation is simple, the cyanobacterium is free of damage, the cyanobacterium is analyzed in different grades, and the like; and the method has high guiding significance in industrial application of the blue-green algae extracellular polymeric substance.

The invention relates to a sludge conditioning-horizontal alternating current field dewatering method and device. The method is completed in a conditioning and dewatering integrated device, the synergistic effect of alternating-current electric field disintegration and sulfate radical free radical oxidation is used, so that the sludge is subjected to homogenization disintegration, extracellular polymeric substances (EPS) are decomposed, part of bound water is converted into free water, and then the bound water and the free water are uniformly removed under the electroosmosis action of the horizontal alternating current field. The method comprises the following steps: adding a zero-valent iron (Fe<0>) and persulfate into the sludge, applying an alternating current field for sludge conditioning, then performing sedimentation and horizontal alternating current field dewatering. The integrated device comprises a conditioning dewatering tank, an alternating current power supply, a mechanical stirrer, a sludge conveying pump and a valve. The conditioning dehydration method disclosed by the invention is high in dehydration efficiency; the moisture content of the dewatered sludge can be reduced to 80%; the corresponding integrated device is compact in structure, simple to operate and capable of recycling the conditioner.

The invention provides a method for efficiently extracting an extracellular polymeric substance of activated sludge. The method comprises cleaning, extracting a slime layer by a centrifugal method, extracting a loosely bound extracellular polymeric substance (LB-EPS) by a high-speed centrifugal method and extracting a tightly bound extracellular polymeric substance (TB-EPS) by a formaldehyde-acetic acid potassium acetate heating method. The method has the beneficial effects that the method provided by the invention can be used for simply, conveniently and quickly extracting the extracellular polymeric substance of the activated sludge, moreover, can be used for avoiding the decomposition of protein and polysaccharide, which is caused when a cellular content is dissolved out into an extracting solution and is extracted, and the purity of an extract is furthest guaranteed.

The invention discloses a method for regulating and controlling synthesis of an extracellular polymeric substance of clostridium acetobutylicum. The method is characterized in that an intron sequence is interpolated into a gene Spo0A of the clostridium acetobutylicum by using a type II intron gene knockout technology. The invention provides a simple and efficient method for regulating and controlling EPS (Extracellular Polymeric Substance) synthesis; a recombinant strain obtained based on the method is relatively good in regulating and controlling effect on the EPS; in case of taking glucose as a carbon source, when cultivated in an anaerobic bottle with the volume of 100 ml by using a slide biomembrane cultivation method, a clostisdium acetobutylicum biomembrane is 5.81 mum in thickness, and the thickness of a strain biomembrane cultivated under the same condition is 24.6 mum.

The invention relates to a method for enhancing anaerobic fermentation of algal waste liquid to generate methane. The method comprises the following steps of: firstly adopting a centrifugation method to extract extracellular polymeric substances of anaerobic sludge; mixing and adding the algal waste liquid and anaerobic sludge into an anaerobic bioreactor; adjusting the nutritive ratio of C/N/P in the anaerobic bioreactor, wherein the inflowing water quality after the nutritive ratio is adjusted is as follows: COD is 20000-25000mg/L, C/N/P is (100-200):5:1, and pH value is 6.0-9.0; and after preheating, preparing the extracted extracellular polymeric substances and NiCL2.6H2O into mixed liquid A and adding the mixed liquid A into the anaerobic bioreactor. The method has the advantages that necessary trace element Ni for growing the methanogen is chelated into a dissolved-state biological promoter for utilization of the methanogen, the chemical precipitation action is overcome, the utilization ratio of the trace element is increased, the gas generation ratio for anaerobic fermentation of the algal waste liquid is increased to the maximum extent, the adding amount of the promoter is less, the cost is low and the operation is simple.

The invention discloses a bioleaching method for anaerobic digested sludge and belongs to the technical field of sludge treatment. Bioleaching work flora is compounded by introducing new microbial strains, continuous domestication is performed, an inoculum obtained through domestication is mixed with the anaerobic digested sludge for bioleaching treatment, the new microbial strains are used for degrading small-molecular organic acids and secreting surface active materials to rapidly remove EPSs (extracellular polymeric substances) wrapping surfaces of sludge cells, bioleaching reaction time isshortened to 12-24 h, the sludge obtained after bioleaching directly enters a plate-and-frame filter press for dehydration, and a mud cake with water content lower than 60% is obtained. The method adopts simple process, no chemical reagent is needed due to complete dependence on action of microbes, and the method has the advantages of high dehydration efficiency, low operation cost and low technological operation difficulty.

The invention relates to a method for rapidly solving sticky sludge bulking problem and belongs to the field of biochemical wastewater treatment. For a sticky sludge bulking problem caused by a high organic load, a means that inflow water supply is diluted and an operation mode of a reactor is changed is adopted, so that a system operates under the conditions of low inflow water organic load and high substrate concentration gradient; the sludge settleability is controlled in real time and conditions are improved in real time by detecting parameters such as a sludge volume index, an extracellular polymeric substance and a Zeta potential in an operation process. Practice shows that the sludge settleability can be obviously improved by continuously operating the method for rapidly solving the sticky sludge bulking problem for 2-8 days; in a later operation process, recurrence of the sticky sludge bulking problem can be effectively prevented by improving an inflow water and operation mode of a system. The method for rapidly solving the sticky sludge bulking problem has the advantages of short period, low recurrence rate, low economic cost and small influence on sludge activity and can be taken as an alternative scheme for rapidly and efficiently solving the sticky sludge bulking problem in an activated sludge process system.