Distribution of Iron, Manganese, Zinc and Atrazine in Groundwater in Parts of Palar and Cheyyar River Basins, South India

A study was carried out in a part of Palar and Cheyyar river basin to evaluate the current status of iron, manganese, zinc and atrazine concentrations, their origin and distribution in groundwater. Groundwater samples were collected during post-monsoon (March 1998 and February 1999) and pre-monsoon (June 1999) periods from 41 sampling wells distributed throughout the study area. The groundwater samples were analyzed for trace metals using AAS and atrazine using HPLC. The concentration of the trace elements in groundwater is predominant during pre-monsoon period. Distribution pattern indicates that the concentration of these elements increases from west to northeast and towards Palar river. Lower concentrations in the central part may be due to recharge of fresh water from the lakes located here. During most of the months, as there is no flow in Palar river, the concentrations of trace elements in groundwater are high. Drinking water standards indicate that Mn and Zn cross the permissible limit recommended by EPA during the pre-monsoon period. A comparison of groundwater data with trace element chemistry of rock samples shows the abundance of trace elements both in the rock and water in the order of Fe > Mn > Zn and Fe > Zn > Mn. This indicates that iron in groundwater is derived from lithogenic origin. Further, Fe, Mn and Zn have good correlation in rock samples, while it is reverse in the case of water samples, indicating the non-lithogenic origin of Mn and Zn. Atrazine (a herbicide) was not detected in any of the groundwater samples in the study area, perhaps due to low-application rate and adsorption in the soil materials.     

Response of the Ascorbate-Peroxidase of Selenastrum capricornutum to Copper and Lead in Stormwaters

The green alga Selenastrum capricornutum expresses a uniqueascorbate peroxidase, that responds to copper and lead. Attemptswere made to test if this peroxidase could be used to monitor thelevels of copper and lead in natural waters. When S.capricornutum was exposed to a stormwater sample, the specificactivity of the peroxidase in the cell extract was commensuratewith the combined copper and lead contents in the sample. Theperoxidase responses were also correlated with the 96 hr biomasstoxicity assay of S. capricornutum. However, unlike thebiomass toxicity assay, the peroxidase activity was not affectedby the anions in the samples. The use of this peroxidase can beused as a marker for testing heavy metal toxicity in the water.     

Preparation of rare-earth metal complex oxide catalysts for catalytic wet air oxidation

Catalytic wet air oxidation (CWAO) is one of the most promising technologies for pollution abatement. Developing catalysts with high activity and stability is crucial for the application of the CWAO process. The Mn/Ce complex oxide catalysts for CWAO of high concentration phenol-containing wastewater were prepared by coprecipitation. The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis. The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller (BET) analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry (ICP-AES). The results show that the catalysts have high catalytic activities even at a low temperature (80°C) and low oxygen partial pressure (0.5 MPa) in a batch reactor. The metallic ion leaching is comparatively low (Mn<6.577 mg/L and Ce<0.6910 mg/L, respectively) in the CWAO process. The phenol, COD_Cr, and TOC removal efficiencies in the solution exceed 98.5% using the optimal catalyst (named CSP). The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater. Translated from Techniques and Equipment for Environmental Pollution Control, 2005, 6(2): 40–44 [译自: 环境污染治理技术与设备]     

川西北草原土壤硼、锰丰缺状况初探

根据110余个表层土壤样品硼、锰含量的测定结果和土壤缺乏硼、锰的临界值指标,探究了川西北草原土壤中硼、锰的有效性及其丰缺状况.结果表明,本区土壤中全硼全锰含量丰富分别达166.0ppm和736.6ppm,但有效硼和锰的含量仅分别为0.45ppm和5.11ppm,土壤缺乏硼和锰比较普遍.为该区推广施用硼、锰微肥提供了初步的科学依据.     

暴雨后水库中铁、锰超标成因分析

以福建省某水库为例，对南方地区暴雨后水库中铁锰超标现象从外污染源、地下水、土壤、底质多方面进行了分析，找出了该类型水库中铁、锰超标的原因，并提出建议。     

废干电池中锌和汞的分布及其处理

由于民众缺乏环境意识和国家没有相应法规 ,大多数废干电池都随手丢弃 ,回收的废电池处于不同程度的腐蚀状态。介绍了锌、汞在废干电池中的分布状态以及腐蚀对其分布的影响 ,并根据它们的分布特点提出用真空法回收废干电池中的锌、汞。     

高锰酸钾与接触氧化协同除锰及硬度对除锰效果的影响

针对日益严重的地表水锰污染，本实验采用高锰酸钾与接触氧化的方法协同除锰；通过调配进水中Ca²⁺、Mg²⁺含量模拟我国不同地区硬度差异显著的地表水，探究水体硬度对锰的去除效果的影响.结果表明：Mn²⁺被高锰酸钾氧化并形成"锰质活性滤膜"，可在停药后实现稳定有效除锰.成熟滤池的除锰效果会显著受到硬度的影响，进水硬度在40、200、400 mg·L^-1及700 mg·L^-1（CaCO₃计）时，接触氧化滤池分别在48、56、64 d及72 d实现稳定除锰，而4根滤柱对Mn²⁺去除的极限浓度分别为1.8、1.7、1.2 mg·L^-1及0.7 mg·L^-1.     

久效磷对海洋微藻毒性机理的初步研究Ⅲ.超氧化物歧化酶和过氧化物酶活性的变化

报道了久效磷对３种海洋微藻细胞内２种清除活性氧的关键性酶－超氧化物歧化酶和过氧化酶活性的影响。结果显示：１．在久效磷的胁迫下，扁藻和三角褐指藻细胞的超化物歧化酶活性均表现出下降的总变化趋势，而叉鞭金藻细胞的ＳＯＤ活性时而上升，时而下降，在整个胁迫过程中呈现出无规律性的变化。２．随着久铲磷胁迫时间的延长，３种微藻细胞的过氧化酶活性均逐渐下降，表现出相同的变化规律性。     

土壤重金属污染的酶学诊断——紫色土中的镉、铜、铅、砷对水稻根系过氧化物酶的影响

通过四川酸性紫色土、中性紫色土,石灰性紫色土中不同浓度的Cd、Cu、Pb、As对水稻根系过氧化物酶的影响研究,揭示了过氧化物酶受抑制与产生抗性的过程.在低浓度时,上述元素对过氧化物酶的影响能反映土壤类型影响的差别.确定了三种紫色土中Cd、Cu、Pb、As的临界浓度.     

混凝沉淀法处理锰锌铁氧体生产废水

锰锌铁氧体生产废水采用混凝沉淀法处理 ,悬浮物去除率可达 99.9% ,浊度去除率可达 99% ,出水水质达到国家排放标准。