CN1301671A - Purifying technology for micro polluted water source - Google Patents

Abstract

The micro-polluted source water purification process consists of coagulation sedimentation tank, powder activated carbon biological aeration tank, ultrafiltration equipment, nanofiltration equipment, and disinfection equipment. The slightly polluted raw water is treated by the coagulation sedimentation tank and the powdered activated carbon biological aeration tank to ensure the water quality requirements for ultrafiltration treatment and nanofiltration treatment, so that the slightly polluted source water treated by the purification process of the present invention meets the national requirements. drinking water standards. The present invention is suitable for purifying source water suffering from organic pollution, eutrophication pollution and heavy metal pollution to produce potable water. It has strong anti-pollution impact ability, low investment, low operating cost, less land occupation, simple equipment and easy operation. flexible.

Description

The purification process of micro-polluted source water

The purification process of micro-polluted source water relates to producing the treatment technology of drinking water source water, is applicable to the surface water or the phreatic purification that suffer organic contamination, eutrophication pollution and heavy metal contamination.

The surface water, underground water are a kind of source waters of good production tap water.But the difference of the surface water, underground water geographical position of living in, environment all can be subjected to pollution in various degree, mainly is turbidity and microorganism, must carry out purifying treatment for before drinking.At present, the water purification process that adopts under the goodish condition of source water water quality mainly contains: 1, be suitable for a. coagulation-precipitation-filtration-sterilization that extensive water purifies, b. coagulation-precipitation-activated carbon filter-sterilization, c. air supporting-filtration-sterilization, d. coagulation-precipitation-ozone and activated carbon filter tank-sterilization; 2, be suitable in, on a small scale a. coagulation-micro-filtration (ultrafiltration)-sterilization of purifying of water, b. charcoal absorption-ultrafiltration-sterilization, c. micro-filtration (ultrafiltration)-sterilization, d. nanofiltration-sterilization.When the water quality of China's source water can reach the surface water one-level of national regulation or secondary standard, all can produce qualified tap water by above-mentioned art breading.But, the practical situation of China are: the nearly half of the section water water quality in the city of flowing through, part urban groundwater, China's seven big water systems is subjected to pollution in various degree, as: organic content (oxygen consumption organic, a small amount of agricultural chemicals) or ammonia-nitrogen content severe overweight, most source water water quality is below grade III Standard.And the water purification process that China present city tap-water factory adopts is a. coagulation-precipitation-filtration-sterilization, b. coagulation-precipitation-activated carbon filter-sterilization, c. air supporting-filtration-sterilization.These technologies are extremely limited to the processing power of polluted source water: very high or because heavy rain when making the source water water quality mutation, the turbidity of water outlet can exceed standard when the source water turbidity; Control to free property bacteriophage relies on chlorination in the water outlet fully; High or when having transmissible disease virus, the dosage that must increase chlorine guarantees out that the water bacteriology index reaches the tap water requirement, but can cause a large amount of generations of " three cause " material thus, can cause potential to endanger to HUMAN HEALTH when entering organic matter of water content; And powerless substantially to the processing power of ubiquitous organic contamination of present source water and ammonia and nitrogen pollution, effluent quality can't satisfy drinks needs.

The source water of or little pollution contaminated at China, what apply at present is the water-purifying process of bio-contact oxidation-conventional water purification technology combination, this technology mainly is that the microorganism that relies on filling surface in the biological contact oxidation pond carries out decomposition and inversion to organism in the polluted source water and ammonia nitrogen, improves the influent quality that enters conventional water purifying plant.Bio-contact oxidation-conventional water purification technology combination process is not less than in water temperature under 15 ℃ the condition, and NH3-N removes 80-90%, and CODMn removes 20-30%, turbidity removal 50-80%, and when water temperature was lower than 15 ℃, NH3-N removed below 30%.The deficiency of this technology is: the clearance to pollutent is limited, makes effluent quality still undesirable; Temperature influence is big, and when temperature was lower than 15 ℃, microbic activity was subjected to very big inhibition, and organism and ammonia-N removal rate are descended significantly; In order to guarantee the efficient of clean water treatment, guarantee the normal operation of water treating equipment, higher to operator's technical requirements; Impact when load when the burst Pollution accident appears in source water, the serious phenomenon that descends can appear in effluent quality, can't drink at all.In addition, in recent years, domesticly begin to adopt coagulation-precipitation-ozone and activated carbon filter tank-sterilization process that the source water that is subjected to ammonia and nitrogen pollution is carried out purifying treatment, the shortcoming of this technology is: when source water organic contamination and ammonia and nitrogen pollution and when depositing, processing efficiency is had a strong impact on, and the required power consumption of water-purifying process increases; Ozone can and polluted source water in the reaction of some organism generate some objectionable impuritiess, make THMs (haloform) and the rising of Salmonella reversion test positive rate in the treated water outlet, even above former water.

At existing deficiency to the micro-polluted source water purification process technique, the contriver is through the further investigation to water-purifying process, it is strong to have proposed a kind of anti-water quality mutation ability, to pollutants removal rate height and investment and the relatively low purifying technology for micro polluted water source of working cost.

Technology of the present invention be by coagulative precipitation tank, Powdered Activated Carbon bio-aeration pool, ultrafiltration be not equipped with, nanofiltration with ing fully and sterilization equipment constitute.Micro-polluted source water at first enters coagulative precipitation tank and removes colloid and larger molecular organics, suspended solids, and according to coagulating agent kind and the dosage that phosphorus amount situation adjustment in the water will add, phosphorus carries out chemical reaction to remove excessive phosphorus in making it and intaking.The water outlet of coagulative precipitation tank enters the Powdered Activated Carbon bio-aeration pool subsequently, its principal mode is the suspension growth biological treating equipment that adds Powdered Activated Carbon, rely on microorganism to decompose by biodegradable organism, ammonia nitrogen then is converted into nitrous acid nitrogen and nitrate nitrogen by nitrifier and is finally finished by the conversion of nitrate nitrogen to nitrous acid nitrogen, nitrogen by denitrifying bacteria, and the organic pollution materials of difficult degradation is then removed by charcoal absorption in the source water.Squeeze into ultrafiltration not fully by water pump subsequently through the source water that the Powdered Activated Carbon bio-aeration pool is handled, utilize ultra-filtration membrane that the excellent cutoff performance of bacterium, virus, larger molecular organics, pyrogen body is come out water sepn, guarantee effluent quality.Do not exceed standard as heavy metal ion in the source water of handling, and CODMn is less than 12mg/L, water outlet can directly carry out disinfection for drinking after uf processing.As the source water CODMn that handles greater than 12mg/L, or heavy metal ion exceeds standard, then after the ultrafiltration water outlet, adopt the nanofiltration device processes again, utilize nanofiltration membrane that the excellent cutoff performance of high volence metal ion, natural water body organism, colourity is separated heavy metal ion and remaining organism from water, make water outlet meet national drinking water standard, the nanofiltration membrane water outlet supplies to drink through the sterilization back.

Characteristics of the present invention are: 1. utilize ultra-filtration membrane to substitute the solid-liquid separating equipment (water through carry out a biological disposal upon after directly enter ultrafiltration apparatus) of second pond as biological treatment, make the nitrifier that in bio-contact oxidation is handled, is difficult to grow in this technology, obtain good growing environment, rely on the high density nitrifier of holding back formation to guarantee to remove ammonia nitrogen efficiently and stably under all temps.2. in the Powdered Activated Carbon bio-aeration pool, directly add Powdered Activated Carbon, make the difficult for biological degradation pollution substance adsorbed by gac, not only guaranteed the stable of ultra-filtration membrane water flux, prolonged the work-ing life of cleaning interval and film, and improved the effluent quality of ultra-filtration membrane.3. admit filter equipment behind the ultrafiltration apparatus, instrument has not guaranteed the requirement of nanofiltration membrane separation to influent quality, make the steady running of nanofiltration equipment, and can further reduce remaining organic pollutant in the water, as CODMn, agricultural chemicals, simultaneously can remove heavy metal ion, obviously improve effluent quality, satisfy many-sided needs.4. compare with common process, adopt ultra-filtration membrane to separate and not only improved effluent quality, made things convenient for operational administrative, and, the impact of various pollution loads is had extremely strong tolerance, can not worsen the serious deterioration that cause effluent quality suddenly because of water quality.5. in ultrafiltration or the nanofiltration water outlet, not only organic content is low, and the residual quantity of bacterium is also few, and sterilizing agent dosage required during sterilization can reduce significantly, not only helps HUMAN HEALTH but also reduced working cost.Adopt this combination process, during to the reconstruction of existing waterworks, at first can make full use of the coagulating sedimentation device of existing waterworks, secondly, filtration unit can be transformed into the Powdered Activated Carbon bio-aeration pool, only need add the ultra-filtration membrane tripping device and the Powdered Activated Carbon dosing system just can be dealt with problems.Investment for trnasforming urban land is few, and quantities is little, and working cost is low with respect to existing water purification treatment technology.

Accompanying drawing is the process flow diagram of the embodiment of the invention, is that 1000 tons/day ground pollution source water is handled and to be further described to scale in conjunction with the accompanying drawings.

Technology of the present invention is not to be equipped with and sterilization equipment constitutes by coagulative precipitation tank, Powdered Activated Carbon bio-aeration pool, ultrafiltration apparatus, nanofiltration.CODMn concentration＜the 12mg/L of ground pollution source water, NH3-N＜7.5mg/L, enter coagulating sedimentation after, adopt FeCl ₃Coagulating sedimentation, behind removal larger molecular organics, colloid, microcosmic salt and the suspended solids, CODMn can reduce about 30%, has also alleviated the organic loading of subsequent biological treatment simultaneously; The coagulating sedimentation water outlet enters the Powdered Activated Carbon bio-aeration pool subsequently, the Powdered Activated Carbon that adds 50mg/L in the pond is carried out a biological disposal upon, water outlet through biological treatment enters ultrafiltration apparatus processing, CODMn concentration＜3mg/L in the water outlet, NH3-N＜0.5mg/L, the removal of bacteria rate is greater than 99.5%, turbidity＜0.5NTU, through sterilization back (1.0mgCl2/L) long storage time, the bacteriology index also reaches requirement, the drinking water standard that meets national regulation, and the water treatment expense is 3 yuan/ton.

Claims (3)

1. purifying technology for micro polluted water source is characterized in that: be made of coagulative precipitation tank, Powdered Activated Carbon bio-aeration pool, ultrafiltration apparatus, nanofiltration equipment, sterilization equipment.

2. source water purification process according to claim 1 is characterized in that: after the Powdered Activated Carbon bio-aeration pool is arranged on coagulative precipitation tank, adopt the mode that adds Powdered Activated Carbon to carry out a biological disposal upon in the Powdered Activated Carbon bio-aeration pool.

3. source water purification process according to claim 1 is characterized in that: water outlet directly adopts ultrafiltration apparatus to handle after carrying out a biological disposal upon, and is not equipped with the back in ultrafiltration and connects nanofiltration equipment.