甲醛污染水的生物学效应

本实验研究甲醛污染的淡水和海水对细菌、植物和动物的生物学效应。甲醛的毒害作用是显著的。含0.036—0.36%甲醛的纯水能引起鼠伤寒沙门氏菌组氨酸缺陷型菌株TA100的回复突变,含0.036%、0.0036%、0.00036%甲醛的水溶液行短期(6h)处理紫露草花枝基部,24h休复后发现四分体细胞中微核率显著增高。含0.0018%、0.0036%、0.018%甲醛的水处理蚕豆根,引起根尖细胞中微核率明显增高。0.00018%甲醛的海水使马粪海胆幼虫在45min内死亡。0.0072%甲醛的海水使该幼虫在2min内死亡。0.0072%甲醛的海水能使贻贝担轮幼虫在5min内死亡。0.00018%甲醛的海水使贻贝幼虫在48h内死亡。0.000108%甲醛的海水使马粪海胆幼虫在72h内死亡。实验证明蚕豆根尖细胞和海胆幼虫是良好的监测淡水与海水污染的材料,甲醛能引起DNA中碱基对置换突变。甲醛在海水中产生增效效应。     

中国出口家电反向物流网络及其优化研究

文章分析了反向物流网络的特征、分类以及影响废旧家电回收反向物流构建的因素及构建原则;运用博弈论知识论证了进行废旧家电反向物流的必然性,在此基础上构建了废旧家电反向物流网络,运用混合整数线性规划模型对其进行优化.最后,本文运用例子证明了混合整数线性规划及其算法-分枝定界法的实用性和有效性.     

酶催化合成草浆木质素-对甲酚共聚物的研究

在反相微乳液体系 (十六烷基三甲基溴化铵 \正丁醇 \异辛烷 \水 )中 ,用辣根过氧化物酶催化合成木质素 对甲酚共聚物 ,证实了反应的可行性。红外光谱的结果表明 ,木质素与对甲酚发生了聚合反应 ,差示扫描量热分析的结果也表明 ,引入对甲酚改善了木质素的热性能 ,合成的共聚物最高分子量可达 189万     

上海春季大气PM_1分布特征

利用2015年春季(3月—5月)上海地区9个大气成分站在线观测获得的地面PM_1质量浓度数据,研究该地区PM_1浓度时空分布特征。结果表明,上海地区各站PM_1污染浓度水平总体较高,整个上海地区的PM_1小时平均浓度为26.3μg?m~(-3),最大值为126.4μg?m~(-3),最小值为2.4μg?m~(-3);各站PM_1浓度的日变化分布表现为峰值类型和峰值时间不一;各站PM_1三个主要粒径段的质量浓度比值均有一定的差异,其中东滩PM_1比例最大,宝山最小;上海春季PM_1的浓度逆周末效应,可能是由于春季气象条件周期性影响。     

烟台市环境空气自动监测中PM10与PM2.5数据异常情况分析研究

根据2014年烟台市范围内全部环境空气自动监测点位的PM 10和PM2.5数据,分析了不同监测仪器组合下PM10和PM2.5的倒挂情况,选取了倒挂率较高的4种监测仪器组合,将监测数据分为不同季节和时段比较分析,结果表明:大气湿度较高的季节倒挂率高于其他季节,夜间倒挂率高于昼间,雾霾等重污染天气时高于其他时段.数据采集频率、监测方法、监测仪器、采样管加热方式不同以及测量误差等都是产生倒挂现象的因素.     

渗滤液反渗透浓缩液回灌出水水质变化规律的研究

为更科学合理地选择回灌填埋体提供一定的理论依据,对3个不同年份垃圾柱的回灌出水进行了水质变化规律的研究.采用成都某垃圾填埋场的渗滤液反渗透浓缩液,对装填了填埋龄为1、5和15 a垃圾的垃圾柱开展了回灌实验,研究了回灌出水中酸碱度、总有机碳、氨氮、硝态氮、重金属的变化规律.结果表明,1 a垃圾柱处于产甲烷化阶段,具有较好的去除硝态氮的能力,硝态氮的降解率达到了88%以上,但出水有机物、氨氮浓度较高,对指标的改变主要通过生物作用;5 a垃圾柱已接近稳定化,但还没有矿化垃圾的典型特征,吸附能力与生物作用均较差,对有机物、盐分、Cr、Ni的削减能力较小;15 a柱具有较好的吸附能力和络合能力,对有机物、盐分、Cr、Ni具有较好的削减能力,初期的去除率分别达到了90%、78%、93%、74%,但随着回灌进行会接近或达到吸附容量,需要控制回灌过程和进度.     

SURFACE WATER RESOURCES OF ST. JOHNS RIVER,FLORIDA1

ABSTRACT: The St. Johns River basin is the largest watershed entirely within the State of Florida, and is one of the few northward flowing rivers in the United States. The river basin contains 11,431 square miles, of which 9,430 square miles are drained by the river and its tributaries. The remainder drains into the Atlantic Ocean or the Intracoastal Waterway. Its largest sub-basin is the Oklawaha River basin, which has a drainage area of 2,870 square miles. Ground elevations range from sea level to 200 feet above mean sea level in the main river basin and as high as 300 feet above mean sea level in the Oklawaha River basin. This study was designed to investigate the surface water resources of the St. Johns River and the existing consumptive uses. The analysis revealed that the river is an extremely large and valuable resource which has been under-utilized and could play a much stronger role in serving the needs of the people in the basin.     

DESALTING SALINE WATER FOR IRRIGATION A CASE STUDY,COACHELLA AREA,CALIFORNIA1

ABSTRACT .A case study was performed to evaluate potential applications of desalted saline water for agriculture using 2 distillation type processes and 2 membrane type processes. The investigation determined the costs and benefits associated with desalting saline water at concentrations of 1,500, 900, 400, 200, and 50 ppm. Benefits from desalting are generated by shifts to more profitable crops, reduced costs for drainage, and reduction in fertilizer and labor requirements with better quality water. Costs are based on the project features such as desalting plants, raw water diversion facilities, storage reservoirs, conveyance and distribution systems, brine disposal, blending facilities, and gypsum addition systems. Hydrologic studies determined the crop irrigation requirements, water demand schedules, desalted water storage requirements, brine disposal requirements, and size of facilities required. Reconnaissance design layouts were made for producing desalted water using a combination of 14 schemes. The study also included a review of irrigation practices. The benefit-cost ratios range from 0.4 to 1.0 for 1,500 ppm irrigation water to 0.8 to 1.0 for 50 and 200 ppm water. Investment costs per acre are high, ranging from $12,900 to $20,900. Irrigation benefits are based on the increase in production from a desert condition with no water supply to the irrigation conditions studied.     

膜法处理精对苯二甲酸精制废水

采用“沉淀—超滤—反渗透—电去离子”工艺处理精对苯二甲酸精制废水,产水作为生产工艺用水回用于生产系统,考察了各工艺单元的操作条件。实验结果表明,在沉淀时间为4 h、超滤膜截留分子量为1 000且采用错流过滤模式、反渗透运行压力为1.8~2.2 MPa且温度控制在25~30 ℃、电去离子单元出水电阻率为5 MΩ·cm的操作条件下,最终出水水质优于GB/T 50109—2014《工业用水软化除盐设计规范》中的二级除盐水指标,可回用为生产工艺用水。     

琥珀山庄污水处理厂污泥上浮的成因与控制

污水处理厂的污泥上浮会影响污水处理系统的操作、运行和出水水质.活性污泥上浮以后,如不及时处理会造成污泥大量流失、氧化沟内MLSS值降低、微生物量锐减,导致运行彻底失败.本文以合肥市琥珀山庄污水处理厂的工艺运行为实例,寻求活性污泥上浮的原因及其控制对策.通过多年的观察与实践,认为污泥上浮的主要原因有污泥老化与腐化、污泥反硝化、冲击负荷、曝气过度、污泥携油上浮等.实践表明,气温、气压和水温的变化也是污泥上浮的重要原因.常用的控制污泥上浮的方法有增加污泥回流量、及时排除剩余污泥、降低混合液浓度、缩短污泥龄、降低溶解氧、消除沉淀池的死角区、加大池底坡度以及改进池底刮泥设备等.