Predicting the Thermal Effects of Dam Removal on the Klamath River

The Klamath River once supported large runs of anadromous salmonids. Water temperature associated with multiple mainstem hydropower facilities might be one of many factors responsible for depressing Klamath salmon stocks. We combined a water quantity model and a water quality model to predict how removing the series of dams below Upper Klamath Lake might affect water temperatures, and ultimately fish survival, in the spawning and rearing portions of the mainstem Klamath. We calibrated the water quantity and quality models and applied them for the hydrometeorological conditions during a 40-year postdam period. Then, we hypothetically removed the dams and their impoundments from the models and reestimated the rivers water temperatures. The principal thermal effect of dam and reservoir removal would be to restore the timing (phase) of the rivers seasonal thermal signature by shifting it approximately 18 days earlier in the year, resulting in river temperatures that more rapidly track ambient air temperatures. Such a shift would likely cool thermal habitat conditions for adult fall chinook (Oncorhynchus tshawytscha) during upstream migration and benefit mainstem spawning. By contrast, spring and early summer temperatures could be warmer without dams, potentially harming chinook rearing and outmigration in the mainstem. Dam removal might affect the rivers thermal regime during certain conditions for over 200 km of the mainstem.     

Recovery of biomass cellulose from waste sewage sludge

In our previous work, the primary sludge from wastewater treatment plants was shown to contain a considerable amount of cellulose (about 20%, based on suspended solids) owing to the discharge of toilet paper. For the purpose of using the cellulose as a biomass resource, this study examined a simple method for its recovery. When fibrous cellulose was suspended in 0.3% sulfuric acid and autoclaved at 130°C for 60 min, 85%–88% of the initial solids remained without dissolving. Under these conditions, an activated sludge sample not containing cellulose was strongly hydrolyzed and only 7% of the initial solids remained. The prescribed amounts of cellulose added to the activated sludge sample were quantitatively recovered by the autoclaving treatment. In the treatment of primary sludge containing >20% cellulose, residual solids with relatively high levels of cellulose (>69%) could be obtained. The results indicate that the method proposed here could recover cellulose practically from waste sewage sludge for biomass utilization. Received: July 17, 2000 / Accepted: July 4, 2001     

几种常见废有机溶剂的回收利用

蒸馏在有机化工生产中具有较为广泛的应用。经过简单蒸馏对一些废有机溶剂进行回收利用，一般是通过间歇蒸馏和萃取蒸馏来处理，只要根据不同的有机物沸点适当地调节蒸馏温度即可，简单蒸馏不但生产工艺简单，而且回收成本低，回收率高，既减少了废水有机溶剂对环境的危害性，又可以使废物得到充分的回收利用，实现了环境治理中“减量化，资源化，无害化”的方针，在目前环保治理中具有较为广泛的应用价值。     

铁矿开采业的生态保护对策——阜新市典型铁矿生态问题解析

以阜新地区几家典型铁矿为例 ,分析了铁矿开采对生态环境所造成的破坏 ,指出了当前在生态建设方面存在的一些问题。提出一些可行的生态保护对策 ,展望了恢复后的生态效果     

化学镀镍老化液中镍、磷的处理与回收

以 Ca(OH) 2 作为沉淀剂 ,调节溶液 p H =1 2 ,在 80℃条件下反应 1 h,使化学镀镍老化液中镍浓度降到1 / mg· L- 1 ;分离沉淀后的溶液用硫酸调节 p H=8,按 Ca(Cl O) 2 与总 P重量比为 3 .5∶ 1 .0的比例加入 Ca(Cl O) 2 ,老化液中的磷酸盐通过形成沉淀得到去除 ,从而使化学镀镍老化液中的镍、磷含量均达到国家排放标准。对于含 Ni(OH) 2 的沉淀 ,以稀硫酸溶解回收其中的镍 ,剩余沉渣建议填埋处理 ;磷酸盐沉淀可以作为磷肥资源回用于农业生产。     

用氟化钾水溶液从制药废液中回收异丙醇的工艺研究

采用普通精馏与加盐分相技术回收异丙醇。测定了异丙醇－水－氟化钾体系在恒温（40℃）时的液－液相平衡数据，并用Pitzer理论和Wilson方程对液－液相平衡数据进行了理论计算。结果表明：计算值与实验值符合良好；采用氟化钾水溶液回收异丙醇，当60.0%氟化钾浓溶液与50％异丙醇－50％水的物料的质量比为2.0时，有机相中异丙醇的纯度可达95.62%（质量百分数），水相中氟化钾稀溶液经蒸发回收后循环使用不影响分离性能。采用以上技术从制药废液中回收异丙醇，每年可获经济效益342万元。     

头孢类抗生素生产过程中的废渣处理

从头孢噻肟钠、头孢三嗪生产废渣中回收2-硫醇基苯并噻唑合成二硫化二苯并噻唑,二硫化二苯并噻唑的收率达23.8%,产品质量达到HGB 2-158-61标准.小试表明,方法可行,操作稳定、简便,既减轻了废渣造成的污染,又回收了用途广泛的化工原料,有一定的环境效益和经济效益.     

钢珠制造工业废水的处理

采用无机氧化、凝聚的物化方法和沉淀池设计应用竖向折板反应等的高效组合装置，处理钢珠制造工业废水。结果表明，排放水的ＣＯＤ去除率达到９８％以上，水循环回用率达到８８％，并回收了大量的铁资源。     

广州市生活垃圾填埋场新场选址的比较研究

广州市现使用的李坑、大田山垃圾埋场将于２０００年前后满容，拟选垃圾填埋场有黄陂、金坑、兴丰、荔枝山四处，经过地质钻探、可行性研究与环境影响评价，最后确定兴上增圾填埋场。本文通过对四场址的比较研究，提出了７个选址条件，包括符合城市总体规划；不违背当地环境功能区的要求；相应的盆谷位置，地形与合适的地质基础；具有社会、经济、环境效益，不会引起不良的社会反映，便于垦复和复貌条件。     

合理回收和再利用涤纶POY废油剂

洛阳石油化工总厂长丝车间POY废油剂原来是各条生产线分别收集，然后由污水处理场处理。设计合理的POY废油剂回收方案，将回收的POY油剂经多级过滤，再利用于生产，可以节约油剂消耗量，同时大大减少了环保处理费用。