双波长紫外分光光度法测定渗滤液COD的研究

针对重铬酸钾法测定COD药剂耗费高、操作时间长、连续监测难、废液二次污染等问题,以垃圾渗滤液为例,阐述了双波长紫外分光光度法预测污水COD的操作方法及其消除悬浮物干扰的原理。结果表明,在水样悬浮物波动较大时,选取272 nm及550 nm的双波长预测模型较单波长预测模型和神经网络预测模型的预测结果更为准确。无需对水样进行任何化学预处理,不需过膜,便可消除悬浮物对测定结果的干扰,是一种准确、便捷的COD测定方法。     

絮凝耦合过硫酸钠氧化处理实际含糖废水

含高浓度污染物和色度实际含糖废水的高效处理一直是水处理领域的难点。针对单一絮凝沉淀和过硫酸钠氧化体系的技术局限性,首次构建了絮凝耦合过硫酸钠氧化体系,同步实现了对废水中COD和色度的高效去除,并深入探究了污染物的转化机理。结果表明：在最佳实验条件下,絮凝耦合过硫酸钠氧化体系对实际含糖废水中COD的去除率高达95.74%,色度去除率高达96%。紫外全波长扫描和GC-MS分析结果表明,絮凝沉淀过程优先去除不含发光基团的大分子聚合物、长链烷烃等有机污染物,含发光基团的大分子有机污染物部分被去除;在后续过硫酸钠氧化过程中,实际废水中含发光基团的大分子有机污染物几乎被彻底去除,小分子有机污染物得到高效去除。本研究可为复杂的实际含糖废水的达标排放提供参考。     

Fenton-混凝法处理焦化废水的试验研究

对Fenton预氧化-混凝法联用技术处理焦化废水进行了研究,探讨了Fenton氧化阶段H2O2投加量、混凝阶段pH值以及混凝剂投加量等因素对焦化废水COD去除率的影响,确定了最佳处理条件.结果表明,Fenton预氧化-混凝法处理焦化废水取得了良好效果,COD去除率达97.5%,为该工艺实际处理焦化废水提供了实验依据.     

催化氧化/两级生物滤池在有机胺废水深度处理工程中的应用

采用催化氧化/两级生物滤池组合工艺,以生化处理后的有机胺废水为研究对象,重点考察该组合工艺对有机胺废水COD和氨氮的去除效果.结果表明,采用催化氧化预处理工艺,能有效降低废水中的抑制性物质,提高废水的BOD5/COD;末端采用两级串联生物滤池处理该废水,能有效降低废水中的COD和氨氮.当进水COD在700～900 mg/L、氨氮在250～370 mg/L时,出水水质能够达到当地环境保护的要求(COD≤300mg/L、氨氮≤35 mg/L);同时说明该工艺能够应用于高浓度有机胺废水的深度处理,为有机胺废水的达标处理提供了一条有效的途径.     

复合式MBR处理印染废水

采用复合式膜生物反应器(MBR)对印染废水进行处理研究,系统在不同的停留时间下,各运行了一段时间,试验结果表明,复合式MBR与水解酸化预处理联用工艺处理印染废水,出水水质良好,而且比较稳定.系统出水COD、氨氮、色度较低,无SS.该工艺的特点是在MBR中加装了填料,既保证了微生物对有机物的去除效率,又大大降低了混合液中进入膜分离的悬浮物,有效控制了膜污染.     

Fenton-混凝法处理焦化废水的试验研究

对Fenton预氧化-混凝法联用技术处理焦化废水进行了研究，探讨了Fenton氧化阶段H2O2投加量、混凝阶段pH值以及混凝剂投加量等因素对焦化废水COD去除率的影响，确定了最佳处理条件。结果表明，Fenton预氧化一混凝法处理焦化废水取得了良好效果，COD去除率达97．5％，为该工艺实际处理焦化废水提供了实验依据。     

采气废水中有机物去除方法

新疆油田天然气开采过程中产生的大量高矿化度、高COD的含油废水,难以处理处置,严重影响了气田的正常生产活动,危害到气田周边土壤安全和荒漠植被的生存.为实现该类废水的达标排放,选取COD和总石油烃含量为考察指标,研究比较了紫外(UV)、臭氧(O3)及紫外臭氧联合处理(UV/O3)法对该类废水的处理效果,进一步考察了pH和O3发生量对UV/O3法处理效果的影响.研究结果表明,3种方法处理废水60 min后,废水COD由处理前的563 mg/L分别下降至处理后的479、334.9和314 mg/L,去除率分别达到14.9％、32.7％和44.2％;而总石油烃含量由处理前的3.86 mg/L分别降至处理后的3.05、1.26和0.20 mg/L,去除率分别达到21.2％、67.4％和94.8％;其中,UV/O3法处理90 min后废水COD降低至148 mg/L,达到《废水综合排放标准GB8978-1996》二级排放标准;pH为7,臭氧发生量为10 g/L时,UV/O3法可应用于采气废水的处理.     

加压活性污泥法处理有机中间体废水的研究

对加压活性污泥法处理有机中间体废水进行了研究,主要考察了停留时间(HRT)、污泥浓度(MLSS)和反应压力等条件对COD去除率的影响.有机中间体废水经铁炭预处理后,COD从原来的8 000 mg/L降到5 000 mg/L左右,BOD5/COD由原来的0.20升高到0.40左右.当反应器内废水混合后COD 2 000 mg/L时,在反应压力0.10 MPa、污泥质量浓度3～5 g/L、停留时间8～10 h条件下,出水COD小于600 mg/L,COD去除率大于70%;出水经混凝沉淀处理后COD小于400 mg/L,可以达到<污水综合排放标准>(GB 8978-1996)三级标准.与常规的活性污泥处理方法相比,加压活性污泥法具有处理速度快、降解效率高和容积负荷大等优点.     

混合型乳化液膜萃取分离处理工业化纤废水

为了去除工业化纤废水中的水溶性污染物,采用混合型乳化液膜法对废水样品进行了处理,以紫外吸收值和COD去除率为指标。结果表明,不同的表面活性剂、废水浓度、反应时间、液膜组成及处理工艺(包括内相酸浓度、油水比、乳水比)等对处理效果都会产生影响;其中T-152是最合适的表面活性剂,当体系pH=4,油内比为1∶1,乳水比为1∶3,废水初始COD为1 000 mg/L左右,表面活性剂的量:溶剂煤油的量:膜固定剂(TOA)三者体积比为5∶25 000∶1时,搅拌处理30 min,废水中紫外吸收光谱的最强吸收峰红移且峰强减小,COD的去除率达到96.5%,出水COD小于100 mg/L;处理后,废水的色度和浊度均得到显著降低,去除率达到98%以上,达到了排放要求。     

催化湿式氧化技术处理山梨酸生产废水的研究

采用催化湿式氧化技术处理生产山梨酸过程中产生的高浓度有机废水,对催化剂组分进行优选.对反应温度、O2分压(Po2)和废水pH等工艺条件进行考察.实验结果表明:采用自制CuO-Cr2O3-La2O3/TiO2为复合催化剂处理该有机废水时表现出较好的催化活性;在190℃、Po2=2.1 MPa、pH=6.1、COD=10 030.0 mg/L时,反应90 min的COD去除率达到98.3%,而在相同条件下未加催化剂的湿式氧化的COD去除率只有60.1%.     

Treatability studies on wastewater from textile dyeing factories in Bursa, Turkey

The textile industry is one of the most rapidly developing industries in Turkey. It generates a large amount of wastewater, with corresponding concerns about pollution. The main sources of pollution in wastewater are the dyeing and finishing processes. The dyestuffs and polyvinyl alcohol (PVA) are the main refractory organics of concern in terms of meeting more stringent effluent standards of chemical oxygen demand (COD) and colour. In this study, wastewaters from textile dyeing factories in Bursa were characterised, and physical, chemical and biological treatability studies were carried out. In the physical and chemical studies, 60.80% COD, 80% suspended solids (SS) and 10.92% turbidity removal efficiencies were obtained. In the biological studies, 90% COD and 40% SS removal were obtained. The initial soluble inert COD of wastewater was determined by using comparison methods. The initial inert COD of wastewater and the microbial product concentration were determined as 37 mg/l and 13 mg/l, respectively.     

皮革废水混凝处理实验研究

采用混凝剂对皮革废水进行混凝处理。对3种无机混凝剂和一种有机混凝剂进行了筛选,研究了pH值和投药量对废水中SS、COD、铬和色度等污染物去除效果的影响。结果表明,当pH值在酸性和中性时,效果不明显;当pH值为碱性时,效果显著。硫酸亚铁、硫酸亚铁+PAM和聚合氯化铝(PAC)+PAM 3种混凝剂组合具有良好的混凝效果,在合适的pH值和投药量下,SS和COD的去除率分别达到80%和30%以上,铬和色度的去除率分别达到95%和50%以上。且硫酸亚铁混凝效果好,成本低,适合小型皮革企业需求。     

Organic pollution and salt intrusion in Cai Nuoc District, Ca Mau Province, Vietnam.

In Ca Mau, Vietnam, farmers converted from rice to shrimp farming, while ignoring the degradation of the aquatic environment. We assessed the seasonal variations in organic pollution of the surface water and salt intrusion in one district and assessed the difference in chemical characteristics of the surface water of shrimp ponds and canals. Several variables reflecting salinity and organic pollution were measured in the wet and dry season. The results show that in the dry season salinity increased to 37.36-42.73 g l(-1) and COD and suspended solids increased to a maximum of 268.7 mg l(-1) and 1312.0 mg l(-1), respectively. In the wet season salinity values of 8.16 to 10.60 g l(-1) were recorded, indicating that salinity could no longer be washed out completely in this season. It is concluded that salinity and suspended solids in the aquatic environment in the Cai Nuoc district are increased by shrimp monoculture, whereas organic pollution is contributed by human population pressure.     

Coagulation and precipitation as post-treatment of anaerobically treated primary municipal wastewater.

The main objective of this study was to investigate the feasibility of coagulation as a post-treatment method of anaerobically treated primary municipal wastewater. Both mesophilic and ambient (20 degrees C) temperature conditions were investigated in a laboratory-scale upflow anaerobic sludge bed (UASB) reactor. In addition, optimization of the coagulant, both in terms of type and dose, was performed. Finally, phosphorus removal by means of aluminum and iron coagulation and phosphorus and ammonia nitrogen removal by means of struvite precipitation were studied. Anaerobic treatment of primary effluent at low hydraulic retention times (less than 15 hours) resulted in mean chemical oxygen demand (COD) removals ranging from 50 to 70%, while, based on the filtered treated effluent, the mean removals increased to 65 to 80%. Alum coagulation of the UASB effluent gave suspended solids removals ranging from approximately 35 to 65%. Turbidity removal reached up to 80%. Remaining COD values after coagulation and settling were below 100 mg/L, while remaining total organic carbon (TOC) levels were below 50 mg/L. Filterable COD levels were generally below 60 mg/L, while filterable TOC levels were below 40 mg/L. All coagulants tested, including prepolymerized aluminum and iron coagulants, demonstrated similar efficiency compared with alum for the removal of suspended solids, COD, and TOC. Regarding struvite precipitation, optimal conditions for phosphorus and nitrogen removal were pH 10 and molar ratio of magnesium: ammonia-nitrogen: phosphate-phosphorus close to the stoichiometric ratio (1:1:1). During struvite precipitation, removal of suspended solids reached 40%, while turbidity removal reached values up to 80%. The removal of COD was approximately 30 to 35%; yet, when removal of organic matter was based on the treated filterable COD, the removal increased to approximately 65%. In addition, nitrogen was removed by approximately 70%, while phosphorus removal ranged between approximately 30 and 45% on the basis of the initial phosphorus concentration. Finally, size fractionation of the organic matter (COD) showed that the various treatment methods were capable of removing different fractions of the organic matter.     

The efficiency of electrocoagulation in treating wastewater from a dairy industry, part I: iron electrodes

Iron electrodes were used for electrocoagulation (EC) treatment of wastewater from a dairy plant. Electrolysis time, pH, current density and distance between electrodes were considered to assess the removal efficiency of chemical oxygen demand (COD), total solids (TS) and their fractions and turbidity. Samples were collected from the effluent of a dairy plant using a sampling methodology proportional to the flow. The treatments were applied according to design factorial of half fraction with two levels of treatments and three repetitions at the central point. The optimization of parameters for treating dairy industry effluent by electrocoagulation using iron electrodes showed that electric current application for 15 minutes, an initial sample pH close to neutral (pH 7.0) and a current density of 50 A (.)(m-2) resulted in a significant reduction in COD by 58 %; removal of turbidity, suspended solids and volatile suspended solids by 95 %; and a final treated effluent pH of approximately 9.5. Negative consequences of the type of electrode used were the emergence of an undesirable color and an increase in the proportion of dissolved solids in the treated effluent.     

Simple digestion procedure followed by the azomethine-H method for accurate boron analysis and discrimination between its fractions in wastewater and soils

Excess boron is a growing environmental problem. It often affects agricultural yields, where reuse of wastewater for irrigation is practiced. This problem raises the need for reliable, simple and economical methods to monitor boron concentrations in wastewater and soil extracts. One such method, the commonly used azomethine-H spectrophotometric method, suffers from color interference, originating from high concentrations of dissolved organic matter, when applied to many wastewater and agricultural soil extracts. Moreover, this method only quantifies free dissolved boron and lacks the ability to quantify boron that is adsorbed to either the dissolved organic matter or suspended solids that are present in the sample. This work suggests a modification of the standard azomethine-H method, in which the solution is digested with potassium persulfate prior to the standard procedure. We show that this pretreatment can overcome the color interference and lead to highly accurate and precise boron analyses in wastewater. In soil extracts, the boron concentrations obtained using the suggested procedure were better correlated to inductively coupled plasma (ICP) spectrometry results than those measured by the standard method, because whereas the standard method quantifies the free dissolved boron only, the modified method, like the ICP method, quantifies the total dissolved boron in the sample. Thus, the suggested modification can be used to quantify the respective distributions of free dissolved boron, boron adsorbed to dissolved organic matter and boron adsorbed to suspended solids in soil extracts and water samples.     

Analysis of extinction in ultraviolet and visible spectra of water bodies of the Paraguay and Brazil wetlands

The extinction spectra in ultraviolet and visible radiation were analyzed using filtered and unfiltered water samples obtained in 11 open water bodies in the Neembucù (Paraguay) and Pantanal (Brazil) wetlands. The role of dissolved and suspended matter in the total extinction was analyzed between 260 nm and 700 nm. The chromophoric dissolved organic matter (CDOM) was the major component in extinction of considered ultraviolet radiation (260-400 nm). The differences in CDOM concentrations explained the main pattern of extinction of the ultraviolet radiation in the samples. Nevertheless, differences between the studied water bodies were found also to depend on the rate of photodegradation and photobleaching. The methodology developed in the present study was to distinguish "humic optic waters" according to quantity and quality of dissolved and suspended matter present. In the "humic optic water", the penetration of 10% of incident UV radiation and the photoactive layer are estimated. The influence of particulate matter increases in the total extinction of the wavelengths higher than 400 nm. The integral of the extinction curve of suspended matter in the visible wavelengths (400-700 nm) was found to relate with the total suspended solids and chlorophyll concentrations.     

The efficiency of electrocoagulation in treating wastewater from a dairy industry,Part I: Iron electrodes

Iron electrodes were used for electrocoagulation (EC) treatment of wastewater from a dairy plant. Electrolysis time, pH, current density and distance between electrodes were considered to assess the removal efficiency of chemical oxygen demand (COD), total solids (TS) and their fractions and turbidity. Samples were collected from the effluent of a dairy plant using a sampling methodology proportional to the flow. The treatments were applied according to design factorial of half fraction with two levels of treatments and three repetitions at the central point. The optimization of parameters for treating dairy industry effluent by electrocoagulation using iron electrodes showed that electric current application for 15 minutes, an initial sample pH close to neutral (pH 7.0) and a current density of 50 A ^{. m?2} resulted in a significant reduction in COD by 58 %; removal of turbidity, suspended solids and volatile suspended solids by 95 %; and a final treated effluent pH of approximately 9.5. Negative consequences of the type of electrode used were the emergence of an undesirable color and an increase in the proportion of dissolved solids in the treated effluent.     

自配消解液分光光度法测定污水中的COD

以自配消解液代替ThermoFisher公司AQ4001COD测定系统的专用消解液,比较了自配消解液分光光度法与国家标准重铬酸钾法(GB 11914-1989)测定化学需氧量(COD)的差异。对比试验表明,自配消解液分光光度法测定COD的结果精确度和准确度高,与国家标准方法无显著性差异。自配消解液分光光度法测定水样COD值的相对标准偏差;低量程(30～150 mg/L)为1.38%～2.53%,中量程(0～1 500 mg/L)为0.47%～3.63%,高量程（2 000～15 000 mg/L）为0.17%～3.53%,在国家标准方法测试水样COD值的允许误差范围内。除制革废水外,自配消解液可以代替AQ4001COD测定系统的专用消解液,适用不同量程范围内污水COD的测定。自配消解液分光光度法具有试剂使用量少、速度快、经济、二次污染小等优点,值得在环境科学领域及废水水质监测中推广应用。     

光催化氧化处理有机废水

介绍了光催化氧化法的原理,对光催化氧化法处理有机废水的可行性进行了试验,探讨了ＣＯＤ随反应时间的变化规律及催化剂用量,温度、浓度的影响。试验表明,光催化氧化可降解象洗涤剂这样难降解的有机物,反应１２０ｍｉｎＣＯＤ去除率可达５０％以上。