黑钛液净化用絮凝剂制备及絮凝性研究

本文研究了硫酸法钛白各黑钛液沉降净化用絮凝改性内烯酰胺的制备，研究了改性反应条件对产物阳离子化度及黑钛液絮凝沉降的影响，从其影响关系确定出适合于攀枝花钛精矿黑钛液絮凝沉降用絮凝剂较佳的制备工艺条件，并在国内首次将两性高分子絮凝剂用于黑钛液的沉降净化，与原工艺条件相比黑钛液杂质沉降速度及净化率有较大程度改善。     

一种微生物絮凝剂产生菌的培养及絮凝条件的优化

为了从活性污泥和土壤中分离筛选具有较高絮凝活性的微生物絮凝剂产生菌,并优化其培养及絮凝条件,通过采用常规菌种的培养分离方法来获得目标菌株,运用单因素法考察培养温度、培养基pH、絮凝剂用量及助凝剂的用量对絮凝活性的影响。结果表明,通过对絮凝条件的优化,得到絮凝活性较高的菌株,在最佳絮凝温度为30℃,pH为7.0,絮凝剂与助凝剂用量分别为0.15、1.2 mL时,絮凝率最高,絮凝活性最好。     

DF-3絮凝剂产生菌培养条件的优化

从花园土壤中筛选到一株有絮凝能力的菌株编号为DF-3,在温度为30℃,通气量（以摇床转速表示）为160r／min时通过实验确定DF-3的最佳培养条件：初始pH为8;20g／L果糖和5g／L葡萄糖为碳源;0．3g／L蛋白胨,0．5g／L酵母膏,0．5g／L尿素和0．2g／L（NH4）2SO4为最佳氮源;无机盐为2g／LKH2PO4,5g／L K2HPO4和0．1g／L NaCl。在这种条件下培养36小时所产微生物絮凝剂对高岭土悬浊液的絮凝率超过90％。     

微生物絮凝剂的研究

微生物的絮凝性在生物法处理废水过程中具有很重要的作用。微生物絮凝体的形成除受微生物的种属影响外，微生物的外部生长环境也直接影响絮凝体形成。创造条件，生成大而密实的微生物絮凝体是提高废水处理效率的有效途径。     

电絮凝法预处理苎麻废水实验研究

采用可溶性Fe阳极材料通过电絮凝法预处理苎麻废水。实验研究废水的pH值、电流密度、电解时间、极板间距等因素对废水COD、BOD及色度去除率的影响,并确定最适宜工艺条件:pH=8.5,电流密度Id=6.25A/dm~2,电解时间T=15min,极板间距d=20mm,此时苎麻废水的COD、BOD及色度去除率可分别达到30.02%、23.27%、84.17%。     

生物絮凝剂产生菌的N+注入诱变选育及其培养条件研究

为获得高絮凝活性菌株,采用低能氮离子诱变方法,对生物絮凝剂产生菌FJ-7进行诱变选育,筛选得到一株絮凝活性高、遗传稳定性良好的突变株NIM-192.发酵产絮凝剂曲线表明,其菌体生长速度稍慢于原始菌株,但絮凝活性一直高于原始菌株,絮凝率比原始菌株提高了34.26%.进一步研究表明,蔗糖、葡萄糖、半乳糖是NIM-192产生絮凝剂的适宜碳源,酵母膏:尿素为1:1的混合氮源为最佳氮源,培养基起始pH为7～9时,发酵液的絮凝效果最好.     

聚合氯化铝复合羧甲基淀粉絮凝剂的制备及絮凝性能

以氯化铝和马铃薯淀粉为原料,制备了聚合氯化铝复合羧甲基淀粉(PAC-CMPS)絮凝剂,通过FT-IR、TG、SEM等对其结构和表观形貌进行了表征。考察了絮凝时间、废水pH、絮凝剂加入量等因素对PAC-CMPS絮凝性能的影响,最佳实验条件下COD去除率可达到87.8%。     

改性粉煤灰吸附焦化废水中氨氮的研究

以粉煤灰为原料采用湿法碱熔,加入氢氧化钠、硫酸铝和十二烷基磺酸钠进行水热合成,通过SEM、IR等手段进行了形貌和结构分析,用纳氏试剂法测定废水中NH3-N的含量。改性粉煤灰对NH3-N的吸附速率符合Lagergren一级动力学方程。对氨氮的吸附为放热过程,吸附特性符合Langmuir和Freundlich吸附规律。改性粉煤灰对焦化废水中NH3-N去除率可达91.5%,净化效果良好。     

絮凝剂处理含油废水的研究动态及发展趋势

含油废水处理技术，按其作用原理和去除对象一般可分为物理化学法，化学法和生物处理法。目前处理含油废水絮凝剂有无机、有机和复合型三种。     

试论焦化废水的处理技术

焦化废水是一种氨氯和有机物浓度较高的难生物降解有机废水，该废水严重污染环境，必须进行综合治理。本文对焦化废水常用的几种处理技术进行了综述。     

Advanced treatment of coking wastewater by coagulation and zero-valent iron processes

Advanced treatment of coking wastewater was investigated experimentally with coagulation and zero-valent iron (ZVI) processes. Particular attention was paid to the effect of dosage and pH on the removal of chemical oxygen demand (COD) in the two processes. The results showed that ZVI was more effective than coagulation for advanced treatment of coking wastewater. The jar tests revealed that maximal COD removal efficiency of 27.5-31.8% could be achieved under the optimal condition of coagulation, i.e. 400mg/L of Fe(2)(SO(4))3 as coagulant at pH 3.0-5.0. On the other hand, the COD removal efficiency could be up to 43.6% under the idealized condition of ZVI upon 10 g/L active carbon and 30 g/L iron being dosed at pH 4.0. The mechanisms for COD removal in ZVI were dominated by coagulation, precipitation and oxidation-reduction. ZVI would also enhance the biodegradability of effluent by increasing BOD5/COD from 0.07 to 0.53. Moreover, some ester compounds could be produced in the reaction. Although ZVI was found more efficient than coagulation in eliminating low molecular weight (<2000 Da) compounds in the wastewater, there were still a few residual contaminants which could hardly be eliminated by either of the process.     

Mechanism for sludge acidification in aerobic treatment of coking wastewater

This work was undertaken to investigate the cause of sludge acidification that led to disruption of the activated sludge process treating coking wastewater from a steel-making plant in Taiwan. An activated sludge reactor (ASR) with a working volume of 80 L was used as a model system to simulate the behavior of the real wastewater treatment process. Parameters that may cause acidification or inactivation of the sludge (NH(3), SCN(-), S(2)O(3)(2-) and CN(-)) were studied individually to examine for their effects on the performance of the ASR. The results show that high loading of NH(3), SCN(-) and CN(-) did not lead to pH decrease, while the ASR attained 85% COD removal and nearly 100% SCN degradation. In contrast, when the wastewater was supplemented with ca. 1,000 mg/L of S(2)O(3)(2-), the pH dropped to nearly 4.0 in 2 days and the COD and SCN removal yields were significantly lower (at 50 and 0-20%, respectively). Thus, overloading of S(2)O(3)(2-) was apparently a key factor causing sludge acidification. The results suggest that to ensure a normal functioning of the activated sludge, the influent S(2)O(3)(2-) concentration should be closely monitored and that the pH control of the ASR is indispensable when the S(2)O(3)(2-) loading is in excess.     

Coagulation/flocculation process and sludge conditioning in beverage industrial wastewater treatment

Attempts were made in this study to examine the effectiveness of coagulation and flocculation process using ferric chloride and polyelectrolyte (non-ionic polyacrylamide) for the treatment of beverage industrial wastewater. Removal of organic matter (expressed as chemical oxygen demand, COD), total phosphorus (TP) and total suspended solid (TSS) using ferric chloride and organic polyelectrolyte during coagulation/flocculation process were investigated. Also, the optimum conditions for coagulation/flocculation process, such as coagulant dosage, polyelectrolyte dosage, and pH of solution were investigated using jar-test experiment. The effect of different dosages of polyelectrolyte in combination with coagulant was also studied. The results revealed that in the range of pH tested, the optimal operating pH was 9. Percentage removals of 73, 95 and 97 for COD, TP and TSS, respectively, were achieved by the addition of 300mg/L FeCl(3).6H(2)O, whereas 91, 99 and 97% removal of COD, TP and TSS, respectively, were achieved with the addition of 25mg/L polyelectrolyte to 100mg/L ferric chloride. The volume of sludge produced, when ferric chloride was used solely, was higher compared to the use of combination of polyelectrolyte and FeCl(3).6H(2)0. The combined use of coagulant and polyelectrolyte resulted in the production of sludge volume with reduction of 60% of the amount produced, when coagulant was solely used for the treatment. It can be concluded from this study that coagulation/flocculation may be a useful pre-treatment process for beverage industrial wastewater prior to biological treatment.     

Study on treatment of coking wastewater by biofilm reactors combined with zero-valent iron process

Experiments were conducted to investigate the behavior of the integrated system with biofilm reactors and zero-valent iron (ZVI) process for coking wastewater treatment. Particular attention was paid to the performance of the integrated system for removal of organic and inorganic nitrogen compounds. Maximal removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH(3)-N) and total inorganic nitrogen (TIN) were up to 96.1, 99.2 and 92.3%, respectively. Moreover, it was found that some phenolic compounds were effectively removed. The refractory organic compounds were primarily removed in ZVI process of the integrated system. These compounds, with molecular weights either ranged 10,000-30,000 Da or 0-2000 Da, were mainly the humic acid (HA) and hydrophilic (HyI) compounds. Oxidation-reduction and coagulation were the main removal mechanisms in ZVI process, which could enhance the biodegradability of the system effluent. Furthermore, the integrated system showed a rapid recovery performance against the sudden loading shock and remained high efficiencies for pollutants removal. Overall, the integrated system was proved feasible for coking wastewater treatment in practical applications.     

Feasibility investigation of oily wastewater treatment by combination of zinc and PAM in coagulation/flocculation

Poly-zinc silicate (PZSS) is a new type of coagulant with cationic polymer synthesized by polysilicic acid and zinc sulfate. It has been used in several sorts of wastewaters treatment, but not used in oily wastewater treatment. In this study, we investigated the coagulation/flocculation of oil and suspended solids in heavy oil wastewater (HOW) by PZSS and anion polyacrylamide (A-PAM). The properties of PZSS cooperated with A-PAM were compared with PAC and PFS in dosages, PAMs amount, settling time, pH value and flocs morphology. The results showed that PZSS was more efficient than PAC and PFS. Under the optimum experimental conditions of coagulation/flocculation (dosage: 100mg/L, A-PAM dosage: 1.0mg/L, settling time time: 40min and pH 6.5-9.5), more than 99% of oil was removed and suspended solid value less than 5mg/L by using PZSS cooperated with A-PAM, which could satisfy the demands of the pre-treatment process for HOW to be reused in the steam boiler or recycled into the injecting well.     

石油系油浆与煤系闪蒸油的焦化性能Ⅱ. 焦化条件的影响

考察了焦化温度和焦化压力对石油系油浆与煤系闪蒸油聚合后所得物料焦化性能的影响。根据在不同焦化条件下所得焦块光学结构的好坏确定了最佳的焦化温度和焦化压力分别为500℃和1MPa,并在此条件下应用"放气拉焦"的方法制得了以纤维为主的流线型光学结构的针状焦。     

Performance optimization of coagulation/flocculation in the treatment of wastewater from a polyvinyl chloride plant

This paper presents results of an experimental study of coagulation/flocculation process of wastewater generated from a polyvinyl chloride (PVC) plant. The wastewater contains fine chlorine-based solid materials (i.e. latex). Experiments were carried out using a model wastewater which is chemically identical to the actual plant but is more consistent. Inorganic ions (Al2(SO4)3, FeCl3 and CaCl2) and a water soluble commercial polyelectrolyte (PE) were added to the wastewater sample. Coagulation efficiency was determined by measuring both the turbidity of the supernatants and the relative settlement of the flocs in the jar test. It was found that aluminum and ferric ions were more efficient than calcium ions as coagulants. The addition of polyelectrolyte was found to improve substantially the coagulation/flocculation process. It was found that the (Al2(SO4)3) combined with the polyelectrolyte at certain pH and agitation speed gave the best results compared to calcium chloride or ferric chloride when combined with the same concentration of polyelectrolyte. Only 0.0375g of a solution of (0.5% Al2(SO4)3) was required to coagulate the model wastewater. Ferric chloride (2.5% FeCl3) combined with the polyelectrolyte, on the other hand, required 0.1g while the optimum turbidity is almost the same. As for calcium chloride (2.5% CaCl2) it was found to be the least effective. The coagulation/flocculation process was found to be dependent on both pH and the agitation speed.     

Different solvents for the regeneration of the exhausted activated carbon used in the treatment of coking wastewater

The solvents n-pentane, methylene dichloride, ethyl ether and dodecylbenzenesulphonic acid sodium were used to regenerate exhausted activated carbon used in the process of treating coking wastewater, and the efficiency, ability, and optimum conditions of the different solvents on this regeneration were investigated. The results indicate that n-pentane could effectively remove refractory organic compounds in the coking wastewater adsorbed on the surface of activated carbon and could repeatedly regenerate the exhausted activated carbon to recover its adsorption activity. Under the conditions of a regeneration time of 20 min, a regeneration temperature of 25°C, an activated carbon drying time of 300 min, and an activated carbon drying temperature of 150°C, n-pentane had the best regeneration efficiency, at 98.27%, for exhausted activated carbon. Gas chromatography-mass spectrometry analysis results show that the nature of the activated carbon regenerated by organic solvents had no remarkable change in adsorption for the main types of organic compounds in coking wastewater. The good regenerative effect of n-pentane on the activated carbon may be due its stronger desorption of esters embedded within the internal structure of activated carbon.     

Electrochemical treatment of deproteinated whey wastewater and optimization of treatment conditions with response surface methodology

Electrochemical treatment of deproteinated whey wastewater produced during cheese manufacture was studied as an alternative treatment method for the first time in literature. Through the preliminary batch runs, appropriate electrode material was determined as iron due to high removal efficiency of chemical oxygen demand (COD), and turbidity. The electrochemical treatment conditions were optimized through response surface methodology (RSM), where applied voltage was kept in the range, electrolyte concentration was minimized, waste concentration and COD removal percent were maximized at 25 degrees C. Optimum conditions at 25 degrees C were estimated through RSM as 11.29 V applied voltage, 100% waste concentration (containing 40 g/L lactose) and 19.87 g/L electrolyte concentration to achieve 29.27% COD removal. However, highest COD removal through the set of runs was found as 53.32% within 8h. These results reveal the applicability of electrochemical treatment to the deproteinated whey wastewater as an alternative advanced wastewater treatment method.