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961.
DerivingfreshwaterqualitycriteriaofsulphocyanicsodiumfortheprotectionofaquaticlifeinChinaZhangTongDepartmentofEnvironmentalE...  相似文献   
962.
浙江三门中生代火山——沉积盆地的形成演化可分四个阶段。每一阶段均伴产有不同成因和各具特色的金属矿床,显示了陆相火山作用较为完整的成矿体系。其中层状矿床具有同生和后生的双重特征,多成因,多来源,是较典型的火山沉积——后期热液迭加改造型矿床。本文着重介绍它的主要特征及盆地的形成演化对火山成因矿床的控制。  相似文献   
963.
重金属污染对环境造成了严重破坏,并威胁着人类的生命健康和财产安全。本文从重金属环境污染现状、重金属污染对微生物影响、微生物对重金属离子污染的修复作用、微生物修复方法的作用机理等方面,综述了微生物在重金属污染修复及治理中的研究概况,并对微生物修复及治理重金属污染存在的局限性进行分析,进一步提出相关改进建议,为处理重金属离子污染提供了理论依据。  相似文献   
964.
经过对PH玻璃电极对比观测实验,总结其在日常观测中衰减变化规律,以及PH电极失效前所具有的特征;讨论了对现有PH观测数据进行修正的方法,并编著相关修正程序;分析日常存在的测量误差,提出提高观测精度的措施。  相似文献   
965.
通过取样检测、实验分析,论证了养猪场废水中固体悬浮物(SS)含量与化学需氧量(COD)浓度的相关关系,讨论了SS对COD的影响趋势。结果表明,通过测定SS的含量,可以快速确定二沉池出水的COD浓度。  相似文献   
966.
ABSTRACT

Electrostatic precipitators (ESP) have been considered as the main particulate matter (PM) removal facility in the energy industry. This paper presents a real-time optimization method for a one-chamber industrial ESP in an ultra-low emission power plant with an intelligent optimization system (IOS). The IOS seeks to optimize the energy consumption of ESP subject to the outlet concentration requirement in real-time. A coordination control logic is designed to regulate the optimized operation set points with varying operation conditions. The operation optimized by the IOS is compared with the operations under PID (proportion-integral-derivative) and manual control. The results show that the IOS improves the emission compliance rate from 95% of manual control to 100% and the medium concentration is tuned to be 46.6% closer to the emission target. Furthermore, a good balance between emission and energy consumption is achieved, with 35.50% energy conservation for the same emission upper limit of 30 mg/m3. These results prove that the IOS significantly contributes to the efficient operation and economic PM removal by ESP for the energy industry.  相似文献   
967.
Liu X  Zhang S  Shan X  Zhu YG 《Chemosphere》2005,61(2):293-301
Effects of different concentrations of arsenite and arsenate (0-16 mg/l) on seed germination, relative root length and shoot height, arsenic accumulation in young seedlings, alpha-amylase, beta-amylase and total amylolytic activity in wheat were investigated in order to elucidate the toxicity of arsenic in the early developmental stage. Germination percentages of different wheat varieties had different responses to arsenic species and decreased significantly with increasing arsenic concentrations except Duokang 1. Relative root length (RRL) and relative shoot height (RSH) of wheat seedlings decreased with increasing concentrations of arsenite and arsenate. The relative root lengths were correlated with the relative shoot heights for arsenite (r2 = 0.79) and arsenate (r2 = 0.77). Arsenic uptake by seedlings increased with the increasing concentrations of arsenite or arsenate and followed the Michaelis-Menten kinetics function. The average total amylolytic activity and beta-amylase activity had no significant difference comparable to that of controls at the concentration 2 mg/l arsenite or arsenate, but decreased apparently when the concentration was higher than 2 mg/l. Whereas the alpha-amylase activity decreased with increasing concentrations of arsenite or arsenate over the whole concentration range. Arsenite decreased all the endpoints more remarkably than arsenate. In comparison, shoot height and root length were more sensitive to arsenic than other endpoints and might be used as indicators for arsenic toxicity.  相似文献   
968.
Treatment of refectory oily wastewater by electro-coagulation process   总被引:7,自引:0,他引:7  
Xu X  Zhu X 《Chemosphere》2004,56(10):889-894
Electro-coagulation was used to treat refectory wastewater with high oil and grease contents. Different operational conditions were examined, including pH, current density, reaction time, conductivity, electrode distance and inlet concentration. The optimum current density was 10-14 A m(-2) within 30 min depending on the wastewater properties tested. Conductivity had little effect on the treatment efficiency. Although the addition of extra salts (e.g., sodium chloride) to the wastewater did not help increase the pollutant removal efficiency, it could save the power consumption significantly. The COD(Cr) and oil removal efficiency descended with increasing electrode distance. The optimal electrode distance was determined to be 10 mm for this equipment in consideration of the treatment cost and efficiency together. The pH effect on the performance of the electro-coagulation process was not very significant in the range of 3-10. The removal efficiency of oil and COD(Cr) under normal condition exceeded 95% and 75%, respectively.  相似文献   
969.
本文通过中和、混凝沉降法除氟过程,研究了彩色显像管工业废水除氟的适宜工艺条件。现场试验表明:应用泥回流处理技术,采用高效絮凝剂处理含氟废水,排放废水氟含量可稳定在4-6mg/L之间,低于排放标准(10mg/L),同时废水处理的成本大大降低。  相似文献   
970.
本试验采用混凝 -A/O系统组合工艺处理二步法腈纶废水 ,该系统处理效果良好 ,出水水质符合排放标准 ,可直接排入水体。A/O系统试验装置总容积 80L ,水力停留时间 5 8— 70h ,缺氧池与好氧池的容积比为 1∶3 ,回流比 ( 2—3 )∶1,COD和BOD总去除率分别约为 84%和 98%。  相似文献   
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