蒽醌染料活性艳蓝KN-R的化学氧化脱色和矿化

研究了使用NaClO化学氧化处理活性艳蓝KN-R模拟染料废水。分别以592nm、380nm、255nm波长处的吸光值为主要指标,跟踪染料的脱色降解。考察了NaClO投加量、染料浓度、温度和13H值等主要因素对模拟废水脱色的影响。结果表明：用NaClO化学氧化处理0．1mmolL^-1的活性艳蓝KN-R模拟染料废水,当NaClO与染料的摩尔比为18,T=30℃,13H值为7时,反应30分钟,脱色率可达到100％。pH值对脱色和TOC的去除有很大影响,酸性或中性条件下,染料快速脱色,30分钟后吸光值基本恒定,反应6个小时TOC的去除仍不明显;碱性条件下,染料缓慢脱色,但反应6个小时TOC的去除率可以达到40％左右。     

钛-钌电极电催化氧化焦化厂湿熄焦循环冷却水

为了解决湿法熄焦中熄焦循环水达标回用的问题,以钛涂钌电极作为电极,研究利用电解池对焦化厂熄焦循环水TOC和NH_3-N的去除效果。结果表明当两个极板间距为1 cm,6个极片组成电解池,电解电压为10 V,p H值为8,氯离子使其含量达到0.2 mol/L,电解时间2 h时,废水中TOC指标的去除率为40%,NH_3-N去除率达到95%,满足《炼焦化学工业污染物排放标准》中循环水对NH_3-N的要求,表明电解法降解熄焦循环水中NH_3-N的效果良好。经过电解2 h以后,污水颜色基本接近透明。     

纺织印染废水TOC值和CODCr值的相关性研究

文章对纺织印染废水TOC值和COD Cr值的相关性进行了理论论证，对实际监测的TOC值和COD Cr值进行回归分析，并用数理统计方法进行显著性检验，表明纺织印染废水TOC值和COD Cr值有良好的相关性。使TOC在污水处理工程中成为一个可操作的控制指标，对环境监测和污水处理工程的运行管理具有较强的指导意义。     

赛里木湖和喀纳斯湖水体中CODMn与TOC相关性分析

分析2012年赛里木湖和喀纳斯湖湖区和主要出入湖河流水质,测定总有机碳(TOC)和高锰酸盐指数(CODMn),研究他们之间的相关性,建立TOC和CODMn的线性回归方程,统计计算值与实测值的相对误差.研究结果表明,CODMn和TOC呈现良好相关性,相关系数为0.854((p＜0.01,n=42);赛里木湖和喀纳斯湖通过TOC计算CODMn的回归方程分别为CODMn=1.302TOC+0.36(R =0.966,α＜0.01)和CODMn=0.594TOC+0.661(R=0.823,α＜0.01);计算值与实测值相对误差范围是3.2％～16.7％.     

土壤样品中TOC的测定浅析

环境土壤中的TOC(总有机碳)含量是反应土壤有机污染的一个重要指标。文章描述了应用总有机碳测定仪和固体进样装置对土壤中TOC含量的测定方法,建立TC(总碳)和IC(无机碳)测定标准曲线,利用差减法计算出TOC含量。实验结果表明,利用该方法建立的标准曲线线性良好,多次测定样品的相对标准偏差较小,该方法精密度、准确度较高。     

TOC＋TN仪测定清洁地表水、地下水中总氮方法的研

以华北某地区地表水和地下水为试材，采用GB11894—89和TOC＋TN仪两种方法进行总氮测试比较。分析结果表明：TOC＋TN仪法测定总氮简便、快速、准确、环保。     

多主枝孢粗毒素提取及抑菌活性研究

采用生长速率法和孢子萌发法研究多主枝孢毒素粗提物TIC和TOC对小麦赤霉病菌、番茄早疫病菌菌丝生长和孢子萌发的抑制作用.结果表明,TIC和TOC对两种供试病菌菌丝生长和孢子萌发都有一定的抑制作用,且对菌丝生长抑制作用的强度与毒素浓度呈正相关.TOC对番茄早疫病菌菌丝生长的抑制作用强于对小麦赤霉病菌的抑制作用,而TIC在较高浓度下对番茄早疫病菌菌丝生长的抑制作用较强.TIC和TOC对番茄早疫病菌孢子萌发的抑制作用均强于小麦赤霉病菌.     

TOC+TN仪测定清洁地表水、地下水中总氮方法的研究

以华北某地区地表水和地下水为试材,采用GB 11894-89和TOC+TN仪两种方法进行总氮测试比较。分析结果表明:TOC+TN仪法测定总氮简便、快速、准确、环保。     

Ti/PbO2电极与Ti/IrO2+Ta2O5电极催化体系降解酸性大红染料废水的比较研究

为比较Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系降解酸性大红(GR)染料废水的处理效果,并确定体系最佳工艺参数。分别对Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系内初始pH、染料初始浓度、电流密度、电解质浓度对GR染料降解率的影响进行了探索,比较工艺参数优化后两催化体系的GR降解率、电极形貌及TOC去除率。结果表明,工艺参数优化后(初始pH 6.38,染料初始浓度100 mg/L,电流密度50 mA/cm²,电解质浓度0.1 mg/L),Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系GR去除率分别可达98.3%和61.1%,TOC去除率为25.4%和13.5%;结合电极表面形貌分析,Ti/IrO₂+Ta₂O_5<...     

永定河怀来段沉积物营养元素分布特征及评价

为了解永定河怀来段沉积物环境现状,对永定河怀来段14个采样点的沉积物中总氮(TN)、总磷(TN)、总有机碳(TOC)进行测定,用有机氮和有机指数进行有机污染评价,用内梅罗污染指数进行生态风险评价。结果表明,永定河怀来段沉积物TP、TN和TOC含量平均值分别为206.40 mg/kg、525.59 mg/kg和1 135.70 mg/kg;有机氮平均值为0.050%,有机指数平均值为0.006 8,两者空间变化特征相似;内罗梅污染指数范围是0.342～1.181,部分为轻度污染,TN的生态风险较高,TOC、TP的风险较低。     

Advanced oxidation treatment of pulp mill effluent for TOC and toxicity removals

Pulp mill effluent was treated by different advanced oxidation processes (AOPs) consisting of UV, UV/H2O2, TiO2-assisted photo-catalysis (UV/TiO2) and UV/H2O2/TiO2 in lab-scale reactors for total organic carbon (TOC) and toxicity removals. Effects of some operating parameters such as the initial pH, oxidant and catalyst concentrations on TOC and toxicity removals were investigated. Almost every method resulted in some degree of TOC and toxicity removal from the pulp mill effluent. However, the TiO2-assisted photo-catalysis (UV/TiO2) resulted in the highest TOC and toxicity removals under alkaline conditions when compared with the other AOPs tested. Approximately, 79.6% TOC and 94% toxicity removals were obtained by the TiO2-assisted photo-catalysis (UV/TiO2) with a titanium dioxide concentration of 0.75gl(-1) at pH 11 within 60min.     

电化学氧化处理焚烧厂渗滤液膜浓缩液混凝出水的研究

为了降低城市生活垃圾焚烧厂渗滤液膜浓缩液混凝出水中的有机物浓度,采用电化学氧化对渗滤液膜浓缩液混凝出水进行了处理.同时,考察了阳极材料、电流密度、初始pH值和电解时间对有机物的去除影响,使用三维荧光光谱分析了有机物的去除特性,并通过氯离子的转化探讨了有机物的降解机理.结果 表明,钌铱(Ru-Ir/Ti)阳极对有机物的去...     

Temporal and spatial distributions of sediment total organic carbon in an estuary river

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.     

Oxidative destabilization of dissolved organics and E. coli in domestic wastewater through immobilized cell reactor system

Domestic wastewater contains a considerable amount of pathogenic organisms besides non-biodegradable organics. The conventional technologies followed for the treatment of domestic wastewater are less efficient in removing pathogenic organisms despite substantial removal of dissolved organics. The focal theme of the present investigation was to use a chemo-autotrophic activated carbon oxidation (CAACO) system, an immobilized cell reactor using chemoautotrophs (Bacillus sp.) for the treatment of domestic wastewater. The oxidation of organics and Escherichia coli in wastewater is controlled by the parameters space time, O(2)/COD, bed height and cod loading. The scheme comprised of anaerobic treatment, sand filtration and CAACO treatment removed BOD. COD, Total organic carbon (TOC), dissolved protein, total Kjeldhal nitrogen (TKN) and bacterial count (most probable number (MPN)) by 81%, 92%, 84%, 94%, 93% and 99.9997%, respectively. The low concentration of E. coli in the CAACO-treated wastewater was completely eliminated through UV irradiation in 3 min at 254 nm.     

Changes in crested wheatgrass root exudation caused by flood, drought, and nutrient stress

Root exudates can chelate inorganic soil contaminants, change rhizosphere pH, and may increase degradation of organic contaminants by microbial cometabolism. Root-zone stress may increase exudation and enhance phytoremediation. We studied the effects of low K+, high NH4+/NO3- ratio, drought, and flooding on the quantity and composition of exudates. Crested wheatgrass (Agropyron cristatum) was grown in Ottawa sand in sealed, flow-through glass columns under axenic conditions for 70 d. Root exudates were collected and analyzed for total organic carbon (TOC) and organic acid content to compare treatment effects. Plants in the low K+ treatment exuded 60% more TOC per plant per day (p = 0.01) than the unstressed control. Drought stress increased cumulative TOC exuded per gram dry plant by 71% (p = 0.05). The flooded treatment increased TOC exuded per gram dry plant by 45%, although this was not statistically significant based on the two replicate plants in this treatment. Exudation from the high NH4+/NO3- ratio treatment was 10% less than the control. Exudation rates in this study ranged from 8 to 50% of rates in four other published studies. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that malic acid was the predominant organic acid exuded. Fumaric, malonic, succinic, and oxalic acids were also detected in the exudates of all treatments. These results demonstrate that nutrient and water stress have significant effects on the quantity and composition of root exudates. Cultural manipulations to induce stress may change the quantity of root exudates and thus increase the effectiveness of phytoremediation.     

Sorption and stability of the polycyclic nitramine explosive CL-20 in soil

The polycyclic nitramine CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) is being considered for use as a munition, but its environmental fate and impact are unknown. The present study consisted of two main elements. First, sorption-desorption data were measured with soils and minerals to evaluate the respective contributions of organic matter and minerals to CL-20 immobilization. Second, since CL-20 hydrolyzes at a pH of >7, the effect of sorption on CL-20 degradation was examined in alkaline soils. Sorption-desorption isotherms measured using five slightly acidic soils (5.1 < pH < 6.9) containing various amounts of total organic carbon (TOC) revealed a nonlinear sorption that increased with TOC [K(d) (0.33% TOC) = 2.4 L kg(-1); K(d) (20% TOC) = 311 L kg(-1)]. Sorption to minerals (Fe(2)O(3), silica, kaolinite, montmorillonite, illite) was very low (0 < K(d) < 0.6 L kg(-1)), suggesting that mineral phases do not contribute significantly to CL-20 sorption. Degradation of CL-20 in sterile soils having different pH values increased as follows: sandy agricultural topsoil from Varennes, QC, Canada (VT) (pH = 5.6; K(d) = 15 L kg(-1); 8% loss) < clay soil from St. Sulpice, QC, Canada (CSS) (pH = 8.1; K(d) = 1 L kg(-1); 82% loss) < sandy soil provided by Agriculture Canada (SAC) (pH = 8.1, K(d) = approximately 0 L kg(-1); 100% loss). The faster degradation in SAC soil compared with CSS soil was attributed to the absence of sorption in the former. In summary, CL-20 is highly immobilized by soils rich in organic matter. Although sorption retards abiotic degradation, CL-20 still decomposes in soils where pH is >7.5, suggesting that it will not persist in even slightly alkaline soils.     

Runoff water quality during drought in a zero-order georgia piedmont pasture: nitrogen and total organic carbon

Approximately 11% of the Southern Piedmont (1.8 million ha) is used for pasture and hay production, mostly under low-input management. Few studies have investigated in the region long-term nitrogen and carbon losses in surface runoff, which can be significant. We present 1999 to 2009 hydrologic and water quality data from a rotationally grazed, 7.8-ha, zero-order pasture (W1) near Watkinsville in the Georgia Piedmont. Annual rainfall was 176 to 463 mm below the long-term average (1240 mm) in 7 of the 11 yr. There were 20 runoff events during 86 mo of below-average rainfall (deficit period), compared with 54 events during 46 mo of nondeficit period. Mean event flow-weighted concentration (in mg L) was 0.96 for nitrate-nitrogen (NO-N), 0.97 for ammonium-nitrogen (NH-N), 3.70 for total nitrogen (TN), and 9.12 for total organic carbon (TOC) ( = 43-47; limited due to instrument problem). Nutrient loads (in kg ha per event) averaged 0.04 for NO-N, 0.03 for NH-N, 0.19 for TN, and 0.54 for TOC. Total loads for N and TOC were 6 to 11 times greater from nondeficit than from deficit periods. The observed N concentrations, while well below maximum drinking water standard limits, could pose risk for eutrophication, which can be stimulated at lower concentrations. However, the ability of headwater streams, such as the one downstream of W1, to reduce nutrient concentrations might partially alleviate this concern. The results of this study point to the need to use a long-term dataset that includes measurements made in drought and wet years when evaluating the efficacy of water quality standards.