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1.
高效复合微生物菌剂对聚丙烯酰胺的无害化降解   总被引:3,自引:0,他引:3  
聚丙烯酰胺(PAM)对环境的污染日趋严重,尤其是降解后的单体丙烯酰胺对人类的神经系统有很大的危害。筛选出的优势菌可对PAM溶液有良好的降解效果,降解率达到89%。但是,PAM不能成为菌种的最佳营养物,添加基础营养液可使其达到最佳降解的目的。通过对培养条件的优化,提高了菌种的降解能力。本复合菌剂在降解PAM的同时,迅速降解掉脱落的丙烯酰胺单体,不会对环境造成二次污染。  相似文献   

2.
聚丙烯酰胺(PAM)在油田中的大量使用,其环境和生态行为及降解产物对环境的潜在危害,都亟待去研究。本文分析论述了其物理、化学性质及化学降解、机械降解、热降解、生物降解性,及影响其在土壤中的被吸附的因素和生态毒理学研究,提出有待进一步研究的课题为:PAM在油藏条件下的降解机理和降解速度;PAM及其衍生物在环境中的存在形式及其迁移转化的方式,在生物体内的存在形式及其在生物圈内的迁移转化等。  相似文献   

3.
聚丙烯酰胺降解菌的分离和鉴定   总被引:1,自引:0,他引:1  
三次采油产生的大量含聚丙烯酰胺(PAM)的污水急需处理,其核心问题是PAM的生物化学降解。文章叙述了从含聚合物油田污水中分离到七株PAM降解菌的过程,并对其营养物体系进行了初步研究及分子生物学鉴定。结果表明,分离到的七株菌可以以PAM为唯一氮源和碳源进行生长,但是生长速度较慢,添加液蜡或酵母膏等可导致微生物菌群的共代谢,能加快PAM的生物降解。七株菌分别归类于放线杆菌纲和α-变形菌纲及芽孢杆菌,与数据库中已知菌的同源性均超过98%。  相似文献   

4.
回收与降解聚驱采出水的工艺探讨   总被引:1,自引:0,他引:1  
含聚污水的处理是困扰石油行业的难题之一。基于聚驱采出水的特点,围绕聚合物的回收利用和降解理论及技术,探讨国内外含聚污水处理技术的研究与应用现状,对比分析现有处理技术存在的问题及适应性,提出采用化学混凝、气浮和水质改性等技术来回收利用PAM(聚丙烯酰胺)的新思路,打破了降解PAM的传统思维,同时分析含聚污水处理与利用技术的可行性与应用前景,有望实现含聚污水的循环利用。  相似文献   

5.
聚丙烯酰胺化学降解技术是目前油田含聚污水处理的重要技术之一,包括氧化降解法、光降解法和光催化降解法。文章介绍了此项技术在降解机理和应用方面的研究进展,并通过实验证明了聚丙烯酰胺氧化降解和光降解的可行性,对油田污水中聚丙烯酰胺的化学降解处理具有一定的指导意义。  相似文献   

6.
研究了用聚合氯化铝(PAC)、聚合硫酸铁(PFS)、聚丙烯酰胺(PAM)及改性蒙托石等不同无机—有机高分子絮凝剂复配使用处理炼钢厂连铸含油废水的除油效果,考察了不同絮凝剂的复配以及絮凝剂的不同复配比例对处理效果的影响。试验结果表明,用聚合氯化铝(PAC)+聚合硫酸铁(PFS)+聚丙烯酰胺(PAM)3种絮凝剂复配使用除油效果最佳,当3种絮凝剂的复配比为2∶2∶3时除油效果最好,除油率达到88.2%,达到国家排放标准。  相似文献   

7.
研究絮凝剂硫酸铝Al2(SO4)3与助凝剂聚丙烯酰胺(PAM)联合处理生活污水的效果。研究表明:Al2(SO4)3与PAM联用比单独用Al2(SO4)3处理生活污水效果更好;Al2(SO4)3 PAM对生活污水CODCr和浊度具有良好的去除能力;当投加1:1的50mg/L的Al2(SO4)3 0.5mg/L的PAM,调节水体pH=7时,处理效果最理想,CODCr去除率可达95.8%,浊度去除率可达97.5%。为复合絮凝剂Al2(SO4)3 PAM处理生活污水的应用提供了有价值的参考依据。  相似文献   

8.
采用Fenton试剂氧化降解含油废水中的聚丙烯酰胺,研究了H2O2用量、催化剂种类及用量对降解聚丙烯酰胺效果的影响。结果表明,H2O2用量为聚丙烯酰胺的20%为宜;CuCl2具有和FeSO4、Fe(NO3)3、FeCl3相近的催化效果,并且可以作为一种在较高pH值条件下应用的催化剂;在优选条件下该氧化体系可以使聚丙烯酰胺黏度大大降低。  相似文献   

9.
本文针对上海某水厂污泥调质后脱水性能不好、泥饼的含固率不高等问题,开展了污泥调质的优化实验。研究表明,4种调质方式中采用"PAM+Ca(OH)2"联合调质的污泥脱水性能最好,药剂费用适中,滤液pH从7上升至10左右;PAM单独调质在经济上最优,干污泥产生量最少,但污泥比阻值最高,且脱水污泥的资源化难度大。结合水厂已有设施,建议采用PAM与石灰联合调质方式,投加剂量分别为PAM投加2.0‰、Ca(OH)2加入5.0%。  相似文献   

10.
采用阶梯式驯化法,控制温度在18℃~24℃,pH在6—8,溶解氧在4—8mg/L,在容积为6L的驯化器中对活性污泥进行培养驯化。经过25d的培养之后,得到了稳定降解丙烯酰胺的活性污泥。驯化后的活性污泥SVI为85—132,COD去除率达70%。  相似文献   

11.
The degradation of polyacrylamide (PAM) in simulate wastewater was studied in UV/Fenton/C4H4O62? system. The factors such as molecular ratio of H2O2/Fe2+/C4H4O62?, pH, and the dosage of Fenton reagent that could affect the PAM degradation in the UV/Fenton/C4H4O62? system were investigated. The experimental results showed that adding C4H4O62? to UV/Fenton system could form photosensitive ferrous complexes, which led to higher degradation efficiency of PAM. The degradation rate of PAM could be up to 95.2% under the following conditions: the concentration of H2O2, Fe2+, and C4H4O62? were 22.5, 2.25, and 2.25 mmol/L, respectively (i.e., molecular ratio of H2O2/Fe2+/C4H4O62? was 10:1:1), the pH value was 3.0.  相似文献   

12.
Polyacrylamide (PAM) treatment of irrigation water is a growing conservation technology in irrigated agriculture in recent years. There is a concern regarding the environmental impact of PAM after its application. The effects of anionic PAM on the sorption characteristics of four widely used herbicides (metolachlor, atrazine, 2,4-D, and picloram) on two natural soils were assessed in batch equilibrium experiments. Results showed that PAM treatment kinetically reduced the sorption rate of all herbicides, possibly due to the slower diffusion of herbicide molecules into interior sorption sites of soil particles that were covered and/or cemented together by PAM. The equilibrium sorption and desorption amounts of nonionic herbicides (metolachlor and atrazine) were essentially unaffected by anionic PAM, even under a high PAM application rate, while the sorption amounts of anionic herbicides (2,4-D and picloram) were slightly decreased and their desorption amounts increased little. The impact mechanisms of PAM were related to the molecular characteristics of PAM and herbicides. The negative effects of PAM on the sorption of anionic herbicides are possibly caused by the enhancement of electrostatic repulsion by presorbed anionic PAM and competition for sorption sites. However, steric hindrance of the large PAM molecule weakens its influence on herbicide sorption on interior sorption sites of soil particles, which probably leads to the small interference on herbicide sorption, even under high application rates.  相似文献   

13.
External loading of phosphorus (P) from agricultural surface discharge (tailwater) is the main cause of excessive algae growth and the eutrophication of the Salton Sea, California. Continuous polyacrylamide (PAM) applications to agricultural irrigation water inflows were evaluated as a means of reducing sediment and P in tailwater. Zero (control) and 1 mg L(-1) PAM (PAM1) treatments were compared at 17 Imperial Valley field sites. Five and 10 mg L(-1) PAM treatments (PAM5, PAM10) were conducted at one site. The particulate phosphorus (Pp) fraction was determined as the difference between total phosphorus (Pt) and the soluble phosphorus (Ps) fraction. We observed 73, 82, and 98% turbidity reduction with PAM1, PAM5, and PAM10 treatments. Although eight field sites had control tailwater sediment concentrations above the New River total maximum daily loads (TMDL), all but one were made compliant during their paired PAM1 treatments. While PAM1 and PAM10 reduced tail water Pp by 31 and 78%, none of the treatments tested reduced Ps. This may have been caused by high irrigation water Na concentrations which would reduce Ca adsorption and Ca-phosphate bridging on the PAM. The PAM1 treatments resulted in <0.5 mg L(-1) drain water polyacrylamide concentrations 1.6 km downstream of PAM addition, while PAM5 and PAM10 treatments produced > 2 mg L(-1) drain water polyacrylamide concentrations. We concluded that, although PAM practically eliminates Imperial Valley tailwater sediment loads, it does not effectively reduce tailwater Ps, the P fraction most responsible for the eutrophication of the Salton Sea.  相似文献   

14.
Polyacrylamide (PAM) is applied to 400000 irrigated hectares annually in the USA to control irrigation-induced erosion, yet the fate of dissolved PAM applied in irrigation water is not well documented. We determined the fate of PAM added to furrow streams under two treatments: Initial-10, 10 mg L(-1) PAM product applied only during the initial hours of the irrigation, and Cont-1, 1.0 mg L(-1) PAM product applied continuously during the entire irrigation. The study measured PAM concentrations in 167-m-long PAM-treated furrow streams and along a 530-m tail ditch that received this runoff. Soil was Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) with 1.5% slope. Samples were taken at three times during the irrigations, both during and after PAM application. Polyacrylamide was adsorbed to soil and removed from solution as the streams traversed the soil-lined channels. The removal rate increased with stream sediment concentration. Stream sediment concentrations were higher when PAM concentrations were <2 mg L(-1) a.i., for early irrigations, and when untreated tributary flows combined with the stream. In these cases, PAM concentration decreased to undetectable levels over the flow lengths used in this study. When inflows contained >6 mg L(-1) PAM a.i., stream sediment concentrations were minimal and PAM concentrations did not change down the furrow, though they decreased to undetectable levels within 0.5 h after application ceased. One percent of applied PAM was lost in tail-ditch runoff. This loss could have been eliminated by treating only the furrow advance or not treating the last two irrigations.  相似文献   

15.
ABSTRACT: Irrigation reduces infiltration rates for subsequent irrigations or rains, thus decreasing the efficiency of water use and impacting watersheds in agricultural areas. Reduced infiltration causes greater runoff with its accompanying erosion, pollution, and sedimentation. Small rates of polyacrylamide (PAM) improve infiltration and reduce erosion on irrigated fields. The effects of PAM on infiltration of rainwater, the longevity of the effects of various rates of PAM, and the effects of repeated or intermittent PAM applications are not understood. This study measured the effects of four PAM application rates (0, 10, 25, and 40 ppm) on the subsequent infiltration of wastewater or simulated rainwater for seven weeks following the initial treatments. Also, effects of repeated and intermittent PAM applications on infiltration were determined. Hydraulic conductivity was determined for each soil column using the falling head method. Two soil types from the coastal plain of south Texas were tested — a soil high in clay (Victoria) and a sandy loam (Willacy). Effects of PAM rates were significant, but effects of water type were not (P > 0.05). Benefits from single PAM applications disappeared within two weeks. Water enriched with PAM is so viscous and infiltrates so slowly that applying PAM in every irrigation event may not be feasible. However, repeating PAM applications every two weeks maintained high infiltration rates on the alternate weeks. This intermittent application of PAM may be a practical approach for improving infiltration rates on irrigated lands.  相似文献   

16.
一种高效复合絮凝剂对多种废水的处理效果   总被引:1,自引:0,他引:1  
用聚合氯化铝(PAC)和聚丙烯酰胺(PAM)复配成复合絮凝剂(PAC+PAM)应用于污染河水、生活污水、工业废水和餐饮废水等6种废水的处理,结果表明。PAC、PAM、PAC+PAM对污染河水的CODc。SS、浊度有显著降低作用,PAC+PAM的净水效果明显优于PAC和PAM;PAC+PAM对6种废水中COD的去除率为81.5%~90.4%,平均84.6%。对SS的去除率为81.9%~96.5%,平均88.9%,对浊度的去除率为91.3%-98.0%,平均95.1%;处理后悬浮物基本被絮凝沉降,水体变得较清澈透明,异味或臭味消除。说明本PAC+PAM复合絮凝剂对各种废水均有良好的净水效果,具有重要的应用价值。  相似文献   

17.
Knowledge of how polyacrylamide (PAM) penetrates and distributes in a soil profile after application in irrigation water is important for understanding PAM conditioning depth and evaluating its environmental effects. Little is known, however, about PAM distribution in soil because of the difficulty in quantifying PAM content in natural soils. By using a recently modified substrate-borne PAM quantification method, PAM distribution in columns of organic matter-removed soils was determined. Results showed that penetration of PAM into the soil was affected by salt level of irrigation water, soil texture, initial soil water content, water application method, and other factors. Polyacrylamide penetration depth was about one-eighth to one-half of the water penetration depth, with a particularly high PAM retention in the top few centimeters of the soil. Under different experimental conditions, the PAM retained in the top 0 to 2 cm of soil ranged from 16 to 95% of the total applied amount. More favorable solution-soil contact conditions, longer solution-soil contact time, and lower initial soil moisture caused much more PAM retention in the top few centimeters of the soil. High sorptive affinity of PAM on soil is the main reason for its low penetration into the soil. Although these results were not obtained from natural soils, they are still helpful in improving our understanding of PAM transport behavior in soils.  相似文献   

18.
ABSTRACT: Erosion from construction sites significantly affects water quality in receiving streams. A rainfall simulator was used to evaluate the effectiveness of different methods for controlling erosion from construction sites. Erosion control methods investigated included dry and liquid applications of polyacrylamide (PAM), hydroseed, and straw mulch. Fertilizer was also applied to each plot to examine the effectiveness of the methods in reducing nutrient losses in runoff. Runoff samples were analyzed for total suspended solids (TSS), nitrate, total Kjeldahl nitrogen (TKN), ammonium, total phosphorus (TP), and orthophosphate. Among all treatments investigated, straw mulch was the most effective treatment for controlling TSS and nutrient losses during short term and long term simulations. The low liquid PAM (half the recommended PAM) treatment resulted in the highest reduction in runoff, TSS bound nitrogen, and total nitrogen (TN) concentrations and loadings. The study results indicate that a high application rate (twice the recommended rate) of PAM could actually increase runoff and TSS losses. At a low application rate, both liquid and dry PAM were effective in reducing TSS and nutrient losses in runoff. However, application of the liquid form of PAM to construction sites is more practical and perhaps more economical than applying the PAM in the dry form.  相似文献   

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