Long-term Changes in Environmental Variables of Traunsee,an Oligotrophic Austrian Lake Impacted by the Salt Industry,and Two Reference Sites Hallstättersee and Attersee

Morphometric, hydrological and basic physico-chemicalcharacteristics of three deep Alpine lakes, Traunsee,Hallstättersee and Attersee as well as their long-termbahaviour are presented. The deep Alpine lakesHallstättersee and Traunsee have been influenced by saltmining and the traditional salt industry for over 100 years. Waste products from these activities, entering the lakes, have mainlyaffected the chemistry of these water bodies, especially bysubstantially increasing the chloride concentrations up to 170 mg L^-1. As a consequence of the increased density, mixing conditions of the lakes were altered. The resulting incomplete mixing led to oxygen depletionin deeper layers. In addition, increased nutrientload from the catchment rised the trophic level in the 70s and 80sof the last century in turn, affecting the oxygen content in thehypolimnion. Finally a situation developed where the risk becamehigh for these lakes to become meromictic induced by humanactivity. In fact, Hallstättersee became facultativelymeromictic. This process was interrupted by increased chlorideinput of more than 30 mg L^-1 due to accidental wash outfrom an upstream salt mine rendering Hallstätterseehomogenous in 1978 to 1980 resulting in complete over-turn. Conditions substantially improved in both lakes after miningpractices were altered and restoration measures againsteutrophication were initiated. Chloride and phosphorusconcentrations declined, while oxygen conditions substantiallyimproved in the following years. Conditions in Traunseesubstantially improved and chloride levels near the sedimentdecreased to less than 140 mg L^-1. The third lakeconsidered here, Attersee, always remained in a near-naturalstate although some signs of increased nutrient levels becamevisible in the late 1970s. Chloride concentrations of around 3 mgL^-1 in this lake can be considered as background levels.Attersee can now serve as a reference site for deep Alpine lakesbecause of its ultra-oligotrophic and pristine nature.     

CWAO处理亚甲蓝水溶液中催化剂的筛选

CWAO（催化湿式氧化）技术处理COD为2 g/L的亚甲蓝水溶液过程中,实验对18种可溶盐进行了广泛而细致的研究.可溶盐投加量以金属离子计50 mg/L,实验得出Cu^2＋、Cr^3＋、Fe^2＋、Zr^4＋具有较好的催化活性;进而对Cr-Cu、Fe-Cu、Zr-Cu组合进行3∶1、1∶1、1∶3的配比实验研究.结果表明配比是1∶1的催化剂催化性能最强,其次是1∶3的配方,再次是3∶1的配方;对较优的催化剂,实验得出了它们催化性能由高到低的排列顺序.铜催化作用下, 在较温和的条件120℃、 1.0 MPa下反应120 min,水样COD去除率达到91.1%,脱色率达到99.92%.     

絮凝法预处理高浓度垃圾渗滤液的实验研究

在用絮凝法对CODCr高达19 200～22 500 mg·L-1的垃圾渗滤液进行预处理当中,以垃圾渗滤液的CODCr去除率为考察指标,通过不同混凝剂对CODCr去除效果的比较,确定了最佳混凝剂.通过单因素实验和正交实验确定了最佳混凝剂用量以及最佳反应条件.研究结果表明,采用自制聚合氯化铁絮凝剂在投药比为1 000:3,pH值为10.5左右,搅拌时间为5.0 min,沉降时间为20 min时,能够使垃圾渗滤液的CODCr去除率达到64%以上,减轻了下一步生物处理的负荷.     

In vitro assessment of natural plant extracts Withania somnifera,Cassia fistula,Saraca asoca,and Eucalyptus tereticornis using primary chicken embryo fibroblast cell culture treated with urea or mercuric chloride (II)

The present investigation examined the detoxifying potential of methanolic herbal extracts, namely the leaf and bark extract of Eucalyptus tereticornis, bark extract of Saraca asoca, Cassia fistula and Withania somnifera in vitro using primary chicken embryo fibroblast (CEF) cells against damaging effects of urea and mercuric chloride (HgCl) (II). The influence of 20?mM urea and 10?µM?HgCl (II) was determined on cell viability or proliferation of cells after treatment with plant extracts. Higher survival rate of primary CEF cells treated with higher concentrations of plant extracts was observed due to their protective ability against urea and HgCl (II). Cassia fistula bark extract (10?mg?mL^?1) was found to be most effective against 20?mM urea as it protects 90% of CEF cells whereas W. somnifera protects 86% of the cells within 24?h. After treating cells with10?µM HgCl, W. somnifera and E. tereticornis leaf extracts were found to be more effective among all other extracts as they protect approximately 86% and 70% of CEF cells, respectively, within 24?h. These results indicate that C. fistula and W. somnifera has the highest potential amongst all the five plant extracts for protecting CEF cells against damaging effects of urea and HgCl (II), respectively.     

Protective role of Curcuma longa extract and curcumin on mercuric chloride-induced nephrotoxicity in rats: evidence by histological architecture

Mercury (Hg) is a potent nephrotoxin. The aim of this study was to investigate the protective role of Curcuma longa extract and curcumin against HgCl₂-induced nephrotoxicity. Male Sprague Dawley rats were administered HgCl₂ (12 μmol kg^?1, ip; once only) followed by treatment of Curcuma longa extract (200 mg kg^?1, po) and curcumin (80 mg kg^?1, po) for three days after 24 h of HgCl₂ administration. The present results showed that mercuric chloride administration caused an impairment of renal function system which was evident from significant increase in urea, creatinine, uric acid, and blood urea nitrogen concentration in serum. In addition, the swelling in glomerulus and degenerated renal tubules with obstructed lumen was also observed by acute mercuric chloride administration. Treatment with Curcuma longa extract and curcumin was effective in restoring all variables of kidney functions near to control group, which was consistent with kidney histoarchitecture. In conclusion, these results suggest that Curcuma longa extract and curcumin protect against HgCl₂-induced nephrotoxicity. This study could be important for the further understanding of mercury toxicity in renal tissues and in the development of better treatments for people and/or animals exposed to the metal.     

Cytotoxic activity of spark‐decomposed sulfur hexafluoride and analysis of cytotoxic contributions of individual spark decomposition products†

Sulfur hexafluoride decomposed by electrical sparks has been found to by cytotoxic to hamster cells when tested in an in vitro cell survival assay, while SF₆ shows no cytotoxic activity. Chemical analysis of spark‐decomposed SF₆ has identified and quantified the following compounds: SOF₂, SO₂F₂, SF₄, SOF₄, SiF₄, SO₂ and HF. Each of these gases, at concentration ranges expected in spark‐decomposed SF₆, were tested for cytotoxic activity toward hamster cells. Of the gases showing cytotoxic activity, SO₂F₂ and SOF₄ were similar in activity, as were SOF₂ and SF₄, while the behavior of SiF₄ was different from the rest. None of these individual gases, at concentrations expected in spark‐decomposed SF₆, has sufficient cytotoxic activity to account for the cytotoxic effect of spark‐decomposed SF₆ observed in our assay system. A four‐component mixture of some of the gases enumerated above (at concentrations overestimating their abundance in spark‐decomposed SF₆) was much less cytotoxic than the spark‐decomposed SF₆ gas. A mathematical simulation of the cytotoxic activity of a mixture of gases at concentrations found in spark‐decomposed SF₆ was made, assuming independent cytotoxic effects from each component. The simulated cytotoxic effect thus computed was less than that seen in spark‐decomposed SF₆. Since individual components or mixtures of the major decomposition products do not account for the observed biological activity of spark‐decomposed SF₆, this suggests there may be one or more components, present in the spark‐decomposed gas at very low concentrations, which may have a very strong cytotoxic activity.     

Effects of polyaluminium chloride on the freshwater invertebrate Daphnia magna

In a number of countries across the world, aluminium in the form of polyaluminium chloride has been used in the treatment of freshwaters for the direct removal of cyanobacteria, or phosphorus removal, but knowledge about its effect on zooplankton species is poor. In our study, polyaluminium chloride toxicity was tested on both artificial and natural freshwaters for a better understanding and prediction of effects in real ecosystems. Our results indicate that prediction of effects in a real ecosystem based on standard ISO methods is insufficient, and tests with nontarget species (including invertebrates) should be done before each treatment using the water samples from the treated location. Effective concentrations of polyaluminium chloride can differ markedly according to the type of water composition used in the assay. Our experiments proved that EC₅₀ values can fluctuate between 9.89 and 54.29 mg·L^?1 of Al³⁺, and the toxicity is dominantly dependent on the treated water conductivity. This parameter seems to be the dominant source of different effects on zooplankton species after treatment and thus should be properly tested before each use of polyaluminium chloride as a treatment compound.     

高锰酸钾及氯化锰对日本青鳉的急、慢性毒性(Toxic Effects of Potassium Permanganate and Manganese Chloride on the Early Life Stage of Japanese Medaka（Oryzias latipes）)

饮用水生产中投加高锰酸钾可能引起高锰酸钾及其副产物二价锰的毒性效应.利用日本青鳉的胚胎-幼鱼发育阶段评价了以高锰酸钾为预氧化剂的饮用水生产工艺安全性.结果表明,高锰酸钾对日本青鳉的LC50-96h为1.48mg·L-1.慢性暴露中,对孵化时间影响的最低可观察效应浓度(LOEC30d)为0.1mg·L-1;暴露于0.4mg·L-1的高锰酸钾对30d后日本青鳉的体长、体重、累计死亡率均有显著影响,但对孵化率率无显著影响.氯化锰(Mn2+)对日本青鳉的LC50-96h为550mg·L-1,对体重影响的LOEC30d为3.2mg·L-1.当高锰酸钾的使用浓度在0.5～1.5mg·L-1之间,其在滤后水中的高锰酸钾残余浓度低于检出限,而降解中间体产物Mn2+浓度小于0.5mg·L-1,均低于本文报道的LOECs数值.     

三氯化铝在酸性环境中对斑马鱼幼鱼运动及学习记忆能力的影响

以斑马鱼胚胎和幼鱼为实验对象,探讨三氯化铝(Al Cl3)在酸性环境中对斑马鱼幼鱼运动能力及学习记忆的影响。将受精后6 h(hours post-fertilization)的斑马鱼胚胎分成2个大组,分别为对照组和三氯化铝组,以观察三氯化铝的毒性作用。每一大组又分为中性(pH7.4)、微酸(pH6.4)和酸性(pH5.4)组,以观察酸性环境分别及与三氯化铝的共同毒性作用。分别采用72 hpf斑马鱼幼鱼机械逃避反射实验、144 hpf斑马鱼幼鱼自发运动、168 hpf单一多次光刺激斑马鱼幼鱼实验等探讨在中性、微酸和酸性环境下暴露铝离子对斑马鱼幼鱼运动能力以及学习记忆的影响。结果显示:与中性环境下的三氯化铝组相比,微酸和酸性环境下的三氯化铝组可以使斑马鱼幼鱼机械逃避次数减少(P0.05),平均速度和移动距离下降(P0.001),斑马鱼幼鱼运动轨迹杂乱无章,自发触壁活动减少;单一多次光刺激实验结果发现,微酸和酸性环境下的三氯化铝组使斑马鱼幼鱼到达平台速度的光照次数显著增加且差异具有统计学意义(P0.001)。以上结果说明,三氯化铝在微酸和酸性环境下,能导致斑马鱼幼鱼运动能力及学习记忆能力下降,并且酸度值越小,对斑马鱼幼鱼运动和学习记忆的影响更显著。酸度值与三氯化铝之间存在协同作用,酸性环境可以使三氯化铝毒性增加。