利用电石渣代替石灰处理酸性废液

文章介绍了一种以废治废的新工艺,该工艺利用电石渣代替石灰作为中和剂处理酸性废液,具有成本低,使用方便等特点,不仅可以节约酸性废液的处理成本,改善操作环境,而且使电石渣得到了综合利用,减轻环境污染,达到"以废治废"的目的,环境效益及经济效益显著.同时该工艺对危险废物处理广的这行也有一定的借鉴作用.     

喷雾吸收法处理烟气中S02的试验

在内径300mm的塔内,采用旋涡式压力喷嘴作雾化器,以石灰作为吸收剂进行烟气脱硫模拟试验研究。试验考察了吸收液PH值、吸收浆液浓度、循环浆液停留时间、液气比、空塔气速及进气SOZ浓度等对脱硫率的影响。结果表明:单级喷雾可获得39％以上的脱硫率,整个试验过程中,喷嘴引起的塔压降很小。此外,还观察了脱硫过程中吸收塔内的结垢情况。通过烟气脱硫模拟试验,为进一步利用喷雾法对国内现有中小型锅炉麻石水膜除尘器的改造,提供了必要的基础数据。     

Ca and OH release of ceramsites containing anorthite and gehlenite prepared from waste lime mud

Lime mud is a kind of solid waste in the papermaking industry, which has been a source of serious environmental pollution. Ceramsites containing anorthite and gehlenite were prepared from lime mud and fly ash through the solid state reaction method at 1050°C. The objective of this study was to explore the efficiency of Ca^2 + and OH⁻ release and assess the phosphorus and copper ion removal performance of the ceramsites via batch experiments, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that Ca^2 + and OH⁻ were released from the ceramsites due to the dissolution of anorthite, gehlenite and available lime. It is also concluded that gehlenite had stronger capacity for Ca^2 + and OH⁻ release compared with anorthite. The Ca^2 + release could be fit well by the Avrami kinetic model. Increases of porosity, dosage and temperature were associated with increases in the concentrations of Ca^2 + and OH⁻ released. Under different conditions, the ceramsites could maintain aqueous solutions in alkaline conditions (pH = 9.3–10.9) and the release of Ca^2 + was not affected. The removal rates of phosphorus and copper ions were as high as 96.88% and 96.81%, respectively. The final pH values of both phosphorus and copper ions solutions changed slightly. The reuse of lime mud in the form of ceramsites is an effective strategy.     

低床层烟炱和石灰粉混合物吸附脱硫试验研究

利用燃油锅炉本身排出的烟炱和石灰粉的混合物作脱硫吸附,在布袋除尘器内进行烟气脱硫试验。结果表明,在烟气温度110℃、过滤风速0．6－0．7m/min、吸附床层厚度为2－3mm等工艺条件下,烟炱和石灰粉的较佳混合比为5：1,吸附时间在60min内的平均脱硫70．54％。     

石灰与石灰石作湿法脱硫剂的比较

石灰、石灰石是最常用的湿法脱硫剂。从反应机理、运行控制指标、液气比和钙硫比（化学过量比）、浆液循环池等方面对其性能作了比较。两者的脱硫机理、运行控制指标不同,受温度的影响程度也不同。两系统的最小液气比分别为10．0和5．6,化学过量比分别为1．05～1．15和1．25～1．60。前者的脱硫效力优于后者。     

石灰—硫酸亚铁法处理高浓度砷和氟酸性废水试验研究

采用二级石灰－硫酸亚铁法处理砷和氟浓度分别高达１１０ｍｇ／Ｌ和６５０ｍｇ／Ｌ以上的酸性废水。当一、二级控制条件分别为ｐＨ９．５和９．０、Ｆｅ／Ａｓ比为２．５和１５时，一级砷和氟去除率分别可达９９．５％和９４％，二级出口砷和氟残余浓度分别可低至０．１ｍｇ／Ｌ和１３．８ｍｇ／Ｌ，Ｃｕ、Ｚｎ和Ｐｂ等重金属离子均达检不出水平。     

烟炱和石灰粉混合物吸附脱硫试验

利用燃油锅炉本身排出的烟炱和石灰粉的混合物作脱硫吸附剂 ,进行了在布袋除尘器内可以实现的烟气脱硫试验。结果表明 ,在烟气温度 1 1 0℃、过滤风速 0 .6～ 0 .7m/min、吸附床层厚度为 2～ 3 mm等工艺条件下 ,烟炱和石灰粉的较佳混合比为 5∶ 1 ,吸附时间在 60 min内的平均脱硫率为 70 .54%。     

Long-term sustainability of metal immobilization by soil amendments: Cyclonic ashes versus lime addition

A soil column leaching experiment was used to gain insight into the long-term metal immobilization capacity of cyclonic ashes (CAH) compared to lime (LIME). Twenty six years of rainfall were simulated. Initially, all amended soils were brought to an equal soil pH. This was done to obtain optimal conditions for the detection of metal immobilization mechanisms different from just a pH effect. During the simulation period, soil pH in all treatments decreased in parallel. However, the evolution of metal mobility and phytoavailability showed a clearly distinct pattern. The strong reduction in metal immobilizing efficiency observed in the lime treatment at the end of the simulation period was much less pronounced, or even absent, in the CAH treatments. Moreover, metal accumulation in plants grown on the CAH amended soil was significantly lower compared to the untreated and the lime treated soil. CAH + SS treatment delivered the strongest reductions in metal mobility and bioavailability.     

石灰和石灰石湿法脱硫系统运行控制指标探讨

钙基脱硫剂湿式脱硫系统是目前市场上广泛采用的烟气脱硫系统。文章分析了石灰和石灰石自身不同的物理化学特性对湿法脱硫系统运行控制指标的影响,得出了对于采用石灰和石灰石作为脱硫剂的湿式脱硫系统的最佳pH为8．0和5．8～6．2,脱硫浆液流量与烟气流量之比为10．0和5．6,钙硫比(化学过量比)为1．05～1．15和1．25～1．60。     

Polychlorinated -dibenzo-p-dioxins/furans and -dioxin-like biphenyls in eggs of common terns from lime island,St. Mary's river,Michigan, USA

Population collapse of common tern (Sterna hirundo) from Lime Island in the St. Mary's River, Michigan, USA were related to the 2,3,7,8-chlorine substituted dioxins, furans, dioxin-like PCBs, and other possible factors using unhatch egg target contaminant analysis. The most toxic congeners, 2,3,7,8-TCDD/DF was found in all samples at noticeable concentrations. Magnitude of sum 2,3,7,8-PCDD/DFs were within the range of 39–93?pg/g wet wt. Dioxin-like PCBs were within the range of 360–1230?ng/g wet wt. Great Toxic Equivalent Quantity (TEQ) contributions by 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, and dioxin-like PCBs such as CB-77, CB-126 and CB-105 are considered greatly due to their influence of poor embryo development and consequent damage of embryos of common terns in egg injection studies. However, other organochlorines, heavy metals, and/or synergistic effects also taken in to account. On the whole, TEQs in the tern eggs were greater than the Lowest-Observable-Adverse Effect Level (LOAEL) for bald eagle (Haliaeetus leucocephalus) embryos observed in British Columbia, Canada. Concentrations of dioxin-like PCBs, dioxins, furans in the St. Mary's River food chain are at levels for concern for nesting colonial waterbirds. Eventually, the possible movements of analyzed chemicals downstream from a man-made flood event are discussed.