AN ASSESSMENT OF SEDIMENT PHOSPHORUS INACTWATION,KEZAR LAKE,NEW HAMPSHIRE1

ABSTRACT: Aluminum sulfate and sodium aluminate were utilized as sediment phosphorus inactivants to improve the water quality of a northeastern eutrophic lake. A four-year monitoring program has provided an extensive lake-database utilized to evaluate the short-and long-term effectiveness of sediment phosphorus inactivation as a lake restoration technique. An immediate impact of treatment was marked by a reduction in hypolimnetic BOD and dissolved oxygen deficit, lower chlorophyll-a and phosphorus concentrations, improved transparency, and the elimination of obnoxious blue-green phyto-plankton blooms. For two to three years after treatment, these pa-rameters continued to exhibit both less variability and improved values over the pre-treatment conditions. The improved water quality conditions warranted an upgrade of the lake trophic status from eutrophic to mesotrophic. Four years after the treatment, the mean hypolimnetic total phosphoru.s and chlorophyll-a have increased and transparency has decreased from initial post-treatment levels. Although long-term trends show water quality decreasing since the treatment, the water quality has stabilized at a level suitable for recreation. A major benefit is an increase in the average attendance at the lake by almost 2,000 people per summer.     

含锌废水的微生物处理技术

从失活生物体和活性生物体两个角度出发，介绍了目前应用微生物法去除废水中重金属锌的研究现状，详细阐述了生物絮凝、生物吸附和硫酸盐还原菌(SRB)的代谢产物(硫化氢)去除锌的机理。     

高含氯水样高锰酸盐指数测定新方法

在高锰酸盐指数的测定中,干扰最为严重且难以消除的是氯离子(Cl-)的影响。高浓度氯离子的干扰会导致测定结果偏差大,无法界定高锰酸盐指数是否达标。对高含氯水样高锰酸盐指数测定新方法(改进的高锰酸盐指数法)的实验研究结果表明,在采用标准高锰酸钾法对高含氯水样进行的高锰酸盐指数测定中,利用稀释方法,在碱性条件下用硫酸锰作催化剂,可以避免氯离子的干扰,提高了高锰酸钾对有机物的氧化率,能真实地反映水样中有机物的污染程度。     

厌氧消化中硫酸盐毒性的控制

探讨了厌氧消化中硫酸盐还原菌与产甲烷菌对分子氢的两种竞争作用及硫酸盐的致毒机制，归纳分析了目前对含硫酸盐有机废水厌氧处理可能采用的几种毒性控制对策及其存在问题。     

Impact of Coal Ash from Electric Power Production on Changes in Water Quality1

ABSTRACT: Since 1972 the use of coal in the U.S. has increased much more rapidly than predicted, with much of this increased use by electric power generating plants. Residue after combustion consists primarily of inorganic materials, with the majority of chemical elements concentrated in fly ash as is sulfate. The concentration of sulfate in this ash fraction most affects the chemical and physical state of other elements when fly ash comes in contact with water by lowering the pH. In a properly constructed and operated ash settling basin, however, major water quality parameters of effluent may be improved as compared to source water. It is necessary, however, to consider the solubility or deposition in sediment of potentially toxic chemical elements from fly ash as these may affect reuse of this water, or as they may impact other parts of the aquatic environment.     

利用矾泥制备铵明矾

采用酸熔法分离矾泥中的铝与硅，不仅克服了碱浸工艺脱硅的复杂过程和铝回收率低的不足，而且解决了酸浸工艺中产品纯度低和设备材质要求高等问题，通过试验确定了酸熔最佳工艺条件为：温度200℃，时间30min，酸铝比1.18，活性铝的回收率为96.69%，铵明矾的纯度在99.5%以上。     

SIDE EFFECTS OF 58 YEARS OF COPPER SULFATE TREATMENT OF THE FAIRMONT LAKES,MINNESOTA1

The shallow Fairmont Lakes in southern Minnesota have been treated with copper sulfate for 58 years to reduce excessive algal growth. Copper sulfate was applied to five lakes at cumulative rates upo to 1647 kg/ha (1470 1b/acre), totaling 1.5 million kilograms. Data collected since treatment of the Fairmont Lakes began in 1921 provide alarming insights into lake responses to sustained chemical treatment with copper sulfate. Short-term and long-term effects have occurred. Short-term effects include: a) the intended temporary killing of algae, b) dissolved oxygen depletion by decomposition of dead algae, c) accelerated phosphorus recycling from the lake bed and recovery of the algal population within 7 to 21 days, and d) occasional fish kills due to oxygen depletion or copper toxicity or both. Long-term effects are shown to include: a) copper accumulation in the sediments, b) tolerance adjustments of certain species of algae to higher copper sulfate dosages, c) shift of species from green to blue-green algae and from game fish to rough fish, d) disappearance of macrophytes, and e) reductions in benthic macroinvertebrates. The conclusion is that while copper sulfate treatments enjoy great popularity because they kill and remove algae almost instantaneously, other immediate or cumulative side effects can be harmful to many other aquatic organisms.     

磷钼蓝分光光度法测定水中磷的改进

用硫酸亚铁铵和葡萄糖作为混合还原剂,建立了用分光光度法测定磷的方法,确定了最佳测定条件。在浓度为0.6mol/L的H2SO4介质中,硫酸亚铁铵-葡萄糖将磷钼杂多酸还原成杂多蓝,其最大吸收波长为820nm,表观摩尔吸光系数为1.38×104L/(mol·cm),PO3-4质量浓度在0～2.8mg/L范围内符合比耳定律,线性回归方程A=0.1453ρ 0.02744,相关系数(r)=0.9933。用硫酸亚铁铵-葡萄糖混合还原剂还原速度快,灵敏度高,产物稳定性好,线性范围宽。将该方法用于环境水样中磷的测定,结果令人满意。     

氨法烟气脱硫工艺实验研究

利用亚硫酸铵作为吸收剂进行氨法烟气脱硫模拟实验,主要考察了吸收液进塔pH值、液气比、吸收液浓度、进口SO2浓度、进口烟气温度等主要影响因素对脱硫效率的影响,并从理论上分析了它们之间的内在关系,得出了适宜的操作条件范围。     

硫酸根对颗粒铁去除铬动力学影响研究

铁渗透反应格栅是铬污染地下水的有效去除技术,但地下水中SO42-对铁格栅长期运行性能影响还不清楚。文章采用批实验和柱实验的方法,分别研究了硫酸根离子浓度对颗粒铁从液相去除常量C(rVI)(20mg/L)的动力学影响及这种影响随时间的变化。批试验表明,随SO42-浓度的增加,C(rVI)的面积标准化速率系数kSA增加。柱试验采用三个平行柱实验系统连续输入含20mg/LC(rVI)的模拟地下水(含或不含SO42(-1000mg/L))。柱实验表明,运行100PV以前,SO42-显著增大颗粒铁对C(rVI)的面积标准化速率常数kSA,随后SO42-增强作用逐渐减弱,运行337PV时,SO42-没有明显的影响。硫酸根离子通过在铁表面形成配合物而加速铁的溶解,增加颗粒铁的表面活性,从而增强颗粒铁对C(rVI)的去除,生物作用不强时可以不考虑硫酸根对铁格栅长期运行性能的影响。