Novel synthesis of aluminum hydroxide gel-coated nano zero-valent iron and studies of its activity in flocculation-enhanced removal of tetracycline

A newly designed aluminum hydroxide gel-coated nanoscale zero-valent iron(AHG@NZVI)with enhanced activity and dispersibility of NZVI was successfully synthesized.The AHG@NZVI composite was synthesized via control of the surface AHG content.AHG@NZVI-1,AHG@NZVI-2 and AHG@NZVI-3 were prepared under centrifugal mixing speeds of 1000,2000 and 4000 r/min,respectively.The activity of AHG@NZVI was evaluated by its tetracycline(TC) removal efficiency.The effects of AHG content,pH value,reaction temperatu...     

选矿废水过滤性能的实验研究

通过实验得出 ,不经加药处理的选矿废水 ,污泥比阻 r=33.1× 1 0 1 1 cm/g太大 ,较难过滤 ;加药处理后 ,污泥比阻r=0 .0 6× 1 0 1 1 cm/g变小 ,可以采用较先进的机械脱水处理。     

A comparative study of biopolymers and alum in the separation and recovery of pulp fibres from paper mill effluent by flocculation

Recovery of cellulose fibres from paper mill effluent has been studied using common polysacchatides or biopolymers such as Guar gum, Xanthan gum and Locust bean gum as flocculent. Guar gum is commonly used in sizing paper and routinely used in paper making. The results have been compared with the performance of alum, which is a common coagulant and a key ingredient of the paper industry. Guar gum recovered about 3.86 mg/L of fibre and was most effective among the biopolyrners. Settling velocity distribution curves demonstrated that Guar gum was able to settle the fibres faster than the other biopolymers; however, alum displayed the highest particle removal rate than all the biopolymers at any of the settling velocities. Alum, Guar gum, Xanthan gum and Locust bean gum removed 97.46%, 94.68%, 92.39% and 92.46% turbidity of raw effluent at a settling velocity of 0.5 cm/min, respectively. The conditions for obtaining the lowest sludge volume index such as pH, dose and mixing speed were optimised for guar gum which was the most effective among the biopolymers. Response surface methodology was used to design all experiments, and an optimum operational setting was proposed. The test results indicate similar performance of alum and Guar gum in terms of fioc settling velocities and sludge volume index. Since Guar gum is a plant derived natural substance, it is environmentally benign and offers a green treatment option to the paper mills for pulp recycling.     

Fate of a stilbene-type fluorescent whitening agent (DSBP) in the presence of Fe(III) aquacomplexes: from the redox process to the photodegradation

The behaviour of 4,4′-bis(2-sulfostyryl)biphenyl (DSBP), a fluorescent whitening agent, was investigated in the presence of Fe(III) aquacomplexes at room temperature. In the dark, a two-step reaction was observed when adding Fe(III) to a solution of DSBP: an initial fast redox reaction between DSBP and the monomeric species Fe(OH)²⁺ and a slower reaction leading to the coagulation of oxidised DSBP and iron. This phenomenon is due to the formation of a complex or an ion-pair between Fe(II) and/or Fe(III) with oxidised DSBP and it probably occurs by charge neutralisation in our experimental conditions. The precipitation of DSBP depends on the initial concentration in Fe(OH)²⁺ and is achieved for a ratio [Fe(OH) ²⁺]/[DSBP] of 5 approximately. Under irradiation at 365 nm, a complicated behaviour was observed: a complexation of iron by oxidised DSBP favoured by irradiation and a degradation of DSBP induced by an intramolecular electron transfer in the complex or by a photoredox of Fe(OH)²⁺ species generating OH radicals in the supernatant. The complete degradation of DSBP is reached four times faster in the presence of Fe(III) with respect to the direct photolysis of DSBP alone. Moreover, the total mineralization of DSBP obtained in less than 120 h upon irradiation at 365 nm is only observed in the presence of the ferric ions, enlightening the efficiency of the method involving Fe(III) and UV irradiation.     

壳聚糖季铵盐处理玉米酒精清糟液的研究

介绍了新型高效无毒天然高分子混凝剂壳聚糖季铵盐（GTCC）的制备，将GTCC和壳聚糖对玉米酒精发酵清糟液分别进行絮凝处理，结果表明，GTCC的絮凝效果明显优于壳聚糖，以黑龙江肇东华润金玉酒精厂清糟作为研究对明，当GTCC投加量为3mg/L（用量仅为壳聚糖的二十分之一左右）时，CODCr的去除率率达到25％，浊度去除率达78％，初步分析表明，壳聚糖季胺盐强的电中和能力是具有好的絮凝能力的主要原因。     

“三泥”处理现状

国内石化“三泥”处理现状及其存在的问题和发展趋势。     

淀粉—丙烯酰胺接枝共聚物的合成及其污水絮凝实验研究

研究了在高锰酸钾 /草酸引发体系下 ,淀粉与丙烯酰胺的接枝共聚合反应 ,并将该接枝共聚物作为絮凝剂用于城市污水、造纸污水等的絮凝实验中 ,实验结果表明 ,其 CODCr去除率均略高于聚丙烯酰胺 (3 0 0万 )产品     

生物滤池—固体接触新技术及应用

介绍污水处理新技术生物滤池——固体接触工艺和工业试验，以及应用该新技术建成的日处理１万ｔ生活污水装置的运行情况和特点     

木薯淀粉废水的絮凝法处理

对木薯淀粉废水的絮凝进行了试验研究，结果表明，某些进口高分子絮凝剂有较好的絮凝效果，CODCr去除率大于60％，最高可达99．3％，总固形物去除率大于45％，最高可达66．8％，絮凝最佳pH值为7．0～8．5，最佳加药量为2～6mg/L，生石灰量为0．25～0．5kg/t,废水，总药剂费小于0．3元／t废水，絮凝下沉物含水率为92％左右，易脱水分离，因此，可用于木薯淀粉废水的前处理。     

脱硫废水处理试验研究

湿法烟气脱硫工艺产生的废水中含有大量污染物 ,严重危害环境和人民的身体健康。试验研究了脱硫废水的处理工艺 ,研究探讨中和沉淀、硫化物沉淀和絮凝沉淀的处理药剂、最佳加药量和反应条件 ;并进行动态模拟试验