Material balances of organics and nutrients in an oxidation pond

A series of experiments concerning a tertiary oxidation pond was performed from 10 January to 12 November 1979, using a model oxidation pond of 21 m² in capacity. The concentrations of organics and nutrients in influent and pond water were measured so as to consider the conversion of water quality in a tertiary oxidation pond. The sedimentation rates were measured weekly, and the final sediments were analyzed at the end of experiments, so that the material balances in respect to carbon, nitrogen and phosphorus were calculated and the various transition reactions were evaluated quantitatively. The result of the material balances showed that there were three main reactions in pond: the assimilation to algae; the sedimentation of suspended substance; and the decomposition of sediments. The regeneration rates of nutrients from sediments were so active that the removal of nutrients by algal solidification were not effective. Consequently, the overall removal efficiency of nutrients was 45% in total nitrogen and 43% in total phosphorus by a tertiary oxidation pond with 16 days detention time.     

The Mineral River—A Unique Tributary Chloride Load to Lake Superior

The Mineral River contributes a significant amount of chloride to Lake Superior, more than one-third of the total U. S. tributary input. This unique discharge is attributed largely to the mine dewatering process of the White Pine Copper Company. Chloride concentrations as high as 2,000 mg/L have been recorded at the mouth of the Mineral River. The impact of this discharge on Lake Superior is not known; however, it is postulated that increased chloride concentrations may enhance the introduction and adaptation of marine organisms into the Great Lakes.     

海藻中总硒含量及各赋存形态的分布研究

研究了各类海藻中总硒的含量及硒的赋存形态的分布。采用连续浸提法研究各海藻中硒的赋存形态,经湿法消化后,采用氢化物-原子荧光分光光度法测定各组分中的含硒量。结果表明,12种海藻样品中,总硒含量范围为:0.0268～0.2234μg/g,海藻中硒的各赋存形态分布情况:碱溶态>残渣态>水溶态>盐溶态>乙醇态。     

二氧化氯预氧化半生产试验研究

通过在水厂进行的半生产性对比试验得出,二氧化氯预氧化的投加量为1．0mg／L时,就可较为彻底地去除藻污染,并有效控制藻毒素的释放;能够显著提高对浊度、色度、藻类和有机物的去除率;能够抑制藻类在平流沉淀池中的再生长。游离二氧化氯能稳定持续地氧化积累在滤池中的藻类及胞内物质,有效解决了滤后水中藻毒素及致嗅物质升高问题。二氧化氯预氧化可以作为应急除藻、解决嗅味问题的有效措施,具有一定的推广应用价值。     

冬季黄河水源水库中藻类变化特征研究

对冬季以黄河水为水源的水库水在不同深度取样分析,得到了水库中藻类的分布情况,并分析了藻类繁殖原因、藻类种属及藻类数量的变化特征,为水厂有效了解藻类及去除异嗅味提供了参考.试验结果表明,水中溶解氧充足、氮磷等营养物质浓度过高、合适的温度以及缓慢流动的水体等为藻类提供了适宜生长的条件;水中藻类数量较大,最高值为4.5×107个/L,其中绿藻门、隐藻门和硅藻门三大类的藻类占藻类总数的90%以上.     

磁化处理对水中藻类的去除效果研究

采用强磁场对藻类含量高的水体进行磁化处理,探讨了磁化处理过程中水样流速、循环时间、藻类初始浓度对磁化处理效果的影响。研究发现磁化处理对藻类的去除有明显的效果,通过对各个影响因素的研究表明在水样流速为3．78m/s,循环时间为360min时,藻类的去除效果比较好。     

化学预处理对用高岭土助凝去除铜绿微囊藻的影响的研究

用高锰酸钾和硫酸铜分别对铜绿微囊藻进行化学预处理,再通过烧杯搅拌试验研究以高岭土为助凝剂,用PAC絮凝去除经过了化学预处理后的铜绿微囊藻的效果。结果表明,高锰酸钾或硫酸铜预处理以不同方式影响叶绿素a（Chla）和浊度的去除。Chla的去除率随高锰酸钾投加量的增加而增加,且在1.0 mg/L投加量时达到92.6%。而硫酸铜预处理时Chla的去除率在其投加量为0.2 mg/L时最高,但在1.0 mg/L时减少到72.8%。高锰酸钾或硫酸铜化学预处理的除藻效果一般不如用高岭土助凝。甚至经高锰酸钾或硫酸铜预处理后,再用高岭土助凝除藻的效果也有所下降。就处理效率和饮用水安全而言,用高岭土助凝是优于用高锰酸钾或硫酸铜进行除藻预处理的技术。     

5种绿藻对几种常用抗生素的敏感性

考察莱茵衣藻、亚心形扁藻、四爿藻、微绿球藻和小球藻5种绿藻对几种常用抗生素的敏感性,结果表明,莱茵衣藻对卡那霉素、四环素敏感,敏感浓度(细胞致死浓度,下同)均为25μg/mL,对氯霉素敏感性次之,而对氨苄青霉素不敏感;亚心形扁藻和四爿藻对氯霉素敏感,敏感浓度均为25μg/mL,对四环素、卡那霉素和氨苄青霉素不表现敏感性;小球藻和微绿球藻对实验中的4种抗生素都不敏感。     

Evaluation of process performance on biohydrogen production in continuous fixed bed reactor (C-FBR) using acid algae hydrolysate (AAH) as feedstock

In this study, a novel inoculation method to mitigate the inhibition of 5-hydroxymethylfurfural (5-HMF) is proposed. Acid algae hydrolysate containing 1.5 g 5-HMF/L and 15 g hexose/L hexose was fed to a continuous fixed bed reactor (C-FBR) partially packed with hybrid-immobilized beads. The inoculation method enabled a high rate of H₂ production, due to the reduction of 5-HMF inhibition and enhanced biofilm formation. Maximum hydrogen production was achieved at a hydraulic retention time of 6 h with a hydrogen production rate (HPR) of 20.0 ± 3.3 L H₂/L-d and a hydrogen yield (HY) of 2.3 ± 0.4 mol H₂/mol hexose _added. Butyrate and acetate were the major soluble metabolic products released during fermentation. Quantitative real-time polymerase chain reaction analysis revealed that Clostridium butyricum comprised 94.3% of the total bacteria, which was attributed to the high rate of biohydrogen production.