改性沸石去除污染水体中磷的实验研究

用沸石做载体,将六水氯化铁负载其上,进行除磷的实验研究。通过正交试验优化了改性工艺,在沸石与FeCl3.6H2O的质量比为8∶2,煅烧温度300℃,煅烧时间4 h时,去除效果最好。探讨了沸石用量、吸附时间、溶液的pH值、溶液初始浓度对改性沸石除磷效果的影响。实验表明:此吸附剂对于模拟含磷废水具有较好的去除性能,当模拟含磷废水的浓度为5 mg/L、时间2 h,用量为10 g/L,pH为7左右,其去除率达到了80%以上。本实验研究对于富营养化水体的治理具有一定的参考价值。     

Fenton试剂处理选矿废水的试验研究

研究用Fenton试剂处理含苯胺黑药(二苯胺基二硫代磷酸)模拟废水和实际选矿废水,分别考查了反应初始pH值、Fe2+浓度及H2O2用量对COD去除率的影响。结果表明:氧化时间为10 min,反应初始pH值为4,ρ(Fe2+)=1.83 g/L,ρ(H2O2)=5.55 g/L,模拟废水苯胺黑药的质量浓度为300 mg/L时,COD去除率达到83.6%;对于实际废水,当ρ(Fe2+)=50mg/L,pH值=3.5,ρ(H2O2)=1800mg/L时,出水ρ(COD)从1000mg/L降到32 mg/L,COD去除率为96.8%,达到废水排放标准,药剂成本估计为每处理1 m3废水需要费用18元。     

两级中和沉淀-混凝工艺处理高浓度含氟废水试验研究

高浓度酸性氟磷废水回用处理中,一级处理后的低浓度含氟废水如采用传统活性氧化铝工艺存在操作管理复杂等问题.以某磷肥厂为例,提出了两级中和沉淀-混凝吸附工艺,并通过试验研究了中和沉淀及混凝的药剂投加种类及投加量,同时考察了pH及搅拌速度等因素对除氟的影响.研究结果表明当进水中F-为178～190 mg/L、PO3-4为146～155 mg/L、pH为2～4.2时,一级和二级中和药剂采用CaO,投加量分别为2.5 g/L和1.2 g/L;出水可达到F-≤10 mg/L、P3-4≤0.6mg/L、SS≤70 mg/L,在聚氯化铝投加量为1.5 g/L及pH为7.5的条件下,经进一步混凝吸附后,出水可达到F-≤1 mg/L、P3-4≤0.6 mg/L、SS≤70 mg/L,满足了回用水的要求,并具有抗冲击负荷能力强,处理效果稳定,操作管理简便及运行经济等优点.     

基于正交试验的沸石改性去除污水中磷的研究

利用硫酸铝和硫酸镁改性沸石来进行含磷废水的处理,通过正交试验得出最佳的沸石改性条件为:沸石、硫酸铝、硫酸镁=8∶2∶1(质量比),400℃下焙烧4 h,改性后的沸石相对于未改性的沸石对磷的去除效果提高了20%。探讨了改性沸石投加量、吸附时间、pH、初始浓度对除磷率的影响,并对改性沸石进行了正交试验研究,结果表明:改性沸石除磷的最佳条件:吸附时间70 m in、pH为6.5、投加量4 g、初始浓度为1.5 mg/L。     

几种吸附剂对磷的等温吸附特性研究

研究了钢渣、炉灰、蜂窝煤渣、天然土壤4种常用吸附剂对磷的吸附和解吸特征．结果表明4种吸附剂在振荡12h后达到吸附平衡，吸附量随着初始浓度的增加而增加。钢渣和天然土壤对磷的吸附效果明显（吸附量分别为4．39mg／g和3．35mg／g），炉灰和蜂窝煤渣效果次之（吸附量分别为2．27mg／g和2．14mg／g），因此钢渣可以作为最好的吸附材料。     

改性粉煤灰处理氨氮废水的实验研究

通过正交实验研究改性粉煤灰处理氨氮废水的吸附条件。实验结果表明：改性粉煤灰对氨氮的吸附条件重要性依次为pH值、投加量、吸附时间、氨氮废水的浓度;当改性粉煤灰投加量为6g（50mL氨氮废水）,初始氨氮浓度为10mg/L,pH值为3,振荡时间为30 min的条件下,氨氮的去除率最好为94.53%。     

浅析粉煤灰处理含磷废水实验

本文以粉煤灰为吸附剂对含磷实验室模拟废水进行处理，研究了粉煤灰的投量、吸附时间及pH值等因素对处理效果的影响。结果表明对于含磷10mg／L的溶液，粉煤灰用量为12g／L、吸附时间为60min、pH值约为7时，吸附效率达98％以上，粉煤灰除磷有很好的研究和应用价值。     

改性粉煤灰处理含磷生活污水试验

为了防止水体富营养化和有效处理生活污水,以改性粉煤灰为吸附剂,对含磷生活污水进行吸附脱磷试验,并研究粉煤灰粒径、投加量、pH值、温度、振荡强度以及吸附时间等因素对脱磷效果的影响。结果表明:在粉煤灰粒径为160~200目、投加量为25 g/L、溶液pH值为3.5、水温为50℃的条件下,对磷质量浓度为6.8 mg/L的生活污水,以140 r/min的强度振荡吸附150 min,磷的去除率可高达95.3%,水样中的磷质量浓度降至0.5 mg/L以下。     

砂样钢渣对酸性Cr(Ⅵ)的吸附动力学与机理研究

以砂样钢渣作为吸附剂,研究了去除废水中Cr6+的工艺条件和机理。结果表明,最佳工艺条件分别为：pH值0.8~1.5,温度为20℃~25℃,钢渣投放量为5 g,废水初始体积以150~200 mL为宜。铬去除量与钢渣水溶液静置时间呈线性关系,且颗粒内扩散模型、准一级和二级速率方程、Langmuir和Freundlich吸附等温模型拟合曲线的相关系数较大,属于单分子层的吸附方式并具有较好的吸附性。通过机理分析可知,砂样钢渣对Cr6+的吸附过程分为还原（降毒）、水化、沉淀、吸附等4个阶段,钢渣最大吸附量为45.872 mg/g,占砂样钢渣的比例较小。钢渣完成吸附铬后,仍可用来配制砂浆、混凝土等。     

稀土冶炼氯氨废水氨氮去除试验研究

针对稀土冶炼氯氨废水中氨氮污染物浓度高的特点,选择化学沉淀法进行试验研究。当控制影响因素为pH=9,反应时间t=1h,Mg:N:P摩尔比为1.3:1:1.1时,经三次化学沉淀,废水中氨氮浓度由原来的13031mg/L降至220mg/L,化学沉淀去除率可达60％～85％,为进一步降低氨氮浓度创造了条件。     

Effect of phosphorus concentration on phosphorus removal and biomass

Membrane bioreactor (MBR) process was employed to study the effect of biological phosphorus removal (bio-P removal) and P-content in treated sludge with increased phosphorus concentration present in the wastewater. Further, the following four test fractions of raw wastewaters was obtained having different P-concentrations viz., run 1: P-20 mg/L, run 2: P-40 mg/L, run 3: P-60 mg/L, run 4: P-80 mg/L. The effective P-removal obtained for these four test fractions were found to be 23.07 mg/L (98.17%), 41.35 mg/L (88.16%), 45.75 mg/L (72.04%) and 55.80 mg/L (66.82%) respectively for run 1, 2, 3 and 4 fractions. Moreover, the similar increase in phosphorous concentration i.e., from 20 to 80 mg/L caused an apparent increase in total solid (TS) values from 7 to 8.3 g TS/L, whereas the total volatile solid (TVS) content remained constant (i.e. 4.5 g TVS/L). These results inferred that the proportion of TVS in the TS decreased from 70 to 55%. Moreover, by increasing the initial P-concentration from 20 to 80 mg/L, the corresponding P-proportion of excess sludge was increased from 2 to 6.2%.     

Demonstrating the relationship between soil phosphorus measures and phosphorus solubility: Implications for Ohio phosphorus risk assessment tools

Approximately 80% of the land area draining into the western Lake Erie Basin is in Ohio, much of which is agricultural. Therefore, the potential for agricultural phosphorus (P) loading from Ohio is a concern for the water quality of western basin rivers, embayments and open water. This work demonstrates soil P relationships across Ohio soils and its implications for potential revisions of Ohio P risk assessment tools. The objectives were, using a selection of soils representative of soils across Ohio, (i) to determine if soil survey classification (series) could be an indicator of hydrous oxide content and, (ii) to determine if agronomic soil test P (STP) Mehlich 3 (M3-P), Bray P, or alternative measures of soil P saturation (Psat) were comparable to oxalate Psat for predicting P solubility, and therefore, useful for Ohio P risk assessment tools. Results showed no significant difference (P > 0.01) in soil hydrous oxide content when grouped by soil series. However, significant (P < 0.01) inflection points, reflecting a rapid increase in P solubility, were identified for oxalate P saturation (11.8%), M3-P saturation (12.4%), M3-P extractable P (181 mg/kg), and Bray-P extractable P (122 mg/kg). This suggests a separate pre- and post-inflection point consideration of STP may be appropriate for revised Ohio P risk assessment tools to better reflect increased post-inflection offsite P transport risk and thereby be sufficiently protective of water quality. Identifying fields with high offsite P transport risk is critical to implementing management decisions to reduce P transport risk to receiving waters including Lake Erie.     

Characterisation of enhanced biological phosphorus removal activated sludges with dissimilar phosphorus removal performances

A sequencing batch reactor (SBR) was operated for enhanced biological phosphorus removal (EBPR) and dramatic differences to the P removing capabilities were obtained in different stages of the operation. At one stage extremely poor P removal occurred and it appeared that bacteria inhibiting P removal overwhelmed the reactor performance. Changes were made to the reactor operation and these led to the development of a sludge with high P removing capability. This latter sludge was analysed by fluorescent in situ hybridisation (FISH) using a probe specific for Acinetobacter. Very few cells were detected with this probe indicating that Acinetobacter played an insignificant role in the P removal occurring here. Analysis of the chemical transformations of three sludges supported the biochemical pathways proposed for EBPR and non-EBPR systems in biological models. A change in operation that led to the improved P removal performance included permitting the pH to rise in the anaerobic periods of the SBR cycle.     

Biological phosphorus and nitrogen removal with biological aerated filter using denitrifying phosphorus accumulating organism.

In order to accomplish the biological nutrient removal with a weak sewage at low temperature, a hybrid process consisted of anoxic denitrifying phosphorus accumulating organism (dPAO) and nitrifying biological aerated filter (BAF) was studied in both lab and field pilot plants with weak sewage. The biofilm BAF was used as a post-nitrification process that provided sufficient nitrate to suspended growth dPAO. The anoxic/BAF configuration could remove nitrogen and phosphorus appreciably compared to other BNR systems. The enhanced biological phosphorus removal (EBPR) was mainly occurred in anoxic zone of suspended growth reactor. It has been found that P removal efficiency of dPAO was enhanced with an addition of a short oxic zone in suspended reactors compared to that of without oxic zone. However, the degree of aerobic P uptake in oxic zone was far lower than anoxic P uptake. The operating results of field plant indicated that dPAO/BAF configuration successfully reduced the adverse temperature effects at lower than 15 degrees C.     

Fixed film phosphorus removal--flexible enough?

While biological phosphorus removal (BPR) has been practised for 30 years, up to recently it has been restricted mainly to activated sludge processes, with the corresponding need for large basin volumes. Yet, research with biofilm reactors showed that the principle of alternate anaerobic and aerated conditions was applicable to fixed bacteria by changing the conditions in time rather than in space. Attached growth enhanced biological phosphorus removal (EBPR) systems are attractive because of their compactness and capability to retain high biomass levels. However, the phosphorus extraction depends on backwashes to enhance the phosphorus-rich attached biomass, and correct control of unsteady effluent quality created by frequently modified process conditions. Accordingly, EBPR remains a challenging task in terms of combining nitrogen and phosphorus removal using attached growth systems. Nevertheless, a combination of activated sludge and biofilm carriers, in the integrated fixed-film activated sludge system, provides treatment opportunities not readily available using suspended growth systems. Current practice is only at the beginning of exploiting the full potential of this combination, but the first full-scale results show that compact tankage and low nutrient results based on biological principles are possible.     

Agricultural use of municipal wastewater sludges: phosphorus availability of biological excess phosphorus removal sludges.

Reuse of sewage sludges as phosphorus fertiliser requires the estimation of the plant availabilities of phosphorus (P) from different sludges. This study investigates the effect of lime stabilisation on the phosphorus availability from biological phosphorus removal sludges. In the first part of the study, pot experiments were carried out to assess the fertilising effect of a dewatered biological phosphorus removal sludge. Availability of P was determined in terms of plant-uptake. In the second part of the study, incubation tests were carried out to observe the change in the available P with time when the waste activated sludge (WAS) from an enhanced biological phosphorus removal (EBPR) process is mixed with the same soil. In this part, the plant available P was measured in terms of Olsen extractable P. A P-deficient, alkaline soil was used in the experiments and Lollium Perenne was selected as the testing plant. The results of the pot experiments revealed that lime-stabilisation of the sludge considerably decreased or retarded the availability of P in the sludge. In the incubation tests, the availability of phosphorus in the lime stabilised and nonstabilised sludge amended soil samples was close to each other. In general, P-availability was increased due to the sludge application except for the lime-stabilised dewatered sludge.     

反硝化除磷工艺影响因素研究进展

概述了反硝化除磷工艺原理，介绍了关于碳源、硝酸盐和亚硝酸、温度、pH值、HRT、SRT等影响因素的研究进展，并分析了该反硝化除磷技术的发展前景，建议开展关于反硝化除磷工艺厌氧阶段、以NO3^--N和NO2^--N为电子受体的缺氧阶段各影响因素的多因素正交试验研究。     

化学除磷在城市污水处理中的应用

阐述了城市污水处理中除磷的重要性和迫切性,而在普遍采用的生物除磷技术不能满足出水磷的排放标准时可考虑采用化学除磷技术.系统分析了化学除磷的原理、方法、工艺、研究进展及应用前景,并指出了现阶段化学除磷技术研究与发展的目标.     

上覆水磷浓度对沉积物孔隙水中磷垂向分布的影响

为探究上覆水磷浓度对沉积物孔隙水中磷垂向分布的影响,通过室内实验,利用薄膜扩散平衡技术(DET)对孔隙水中磷浓度进行测量,分析孔隙水磷浓度的垂向变化规律,并揭示平衡时上覆水磷浓度与孔隙水磷浓度以及上覆水-沉积物界面孔隙水磷浓度的关系。结果表明:上覆水磷浓度越高,则沉积物孔隙水中磷垂向分布达到平衡所需的时间越长,相同垂向位置处孔隙水磷浓度及其浓度梯度越大;孔隙水磷浓度及其浓度梯度随深度增加而降低,表层沉积物孔隙水中磷的扩散作用最强,下层沉积物孔隙水磷浓度受上覆水磷浓度变化影响较小;吸附平衡后,沉积物孔隙水磷浓度和上覆水-沉积物界面孔隙水磷浓度均与上覆水磷浓度呈幂函数关系,而留存在沉积物孔隙水中的磷浓度仅占2.26%～3.80%,上覆水中减少的磷大部分被沉积物吸附。     

铁盐除磷技术机理及铁盐混凝剂的研究进展

综述了铁盐除磷技术的机理与过程,铁盐溶于水后,Fe3+通过溶解和吸水发生强烈水解, 生成Fe2(OH)24+、Fe3(OH)45+、Fe5(OH)96+、Fe5(OH)87+、Fe5(OH)78+、Fe6(OH)126+、Fe7(OH)129+等多核羟基络合物。这些含铁的羟基络合物能有效地降低或消除水体中胶体的(?)电位,使胶体凝聚,再通过沉淀分离将磷去除。合适的pH可以提高磷的去除率,对于正铁离子,最适宜的pH为4．5～5; 对于亚铁离子,则为7～8。阐述了三氯化铁、硫酸亚铁和硫酸铁、复合亚铁、聚氯化铝铁、聚硫酸氯化铝铁等铁盐混凝剂的最新研究进展和优缺点,认为铁盐混凝剂必将朝着高分子化、复合化和多功能化的方向发展。