A Novel Adsorbent Prepared by Aluminum-Containing Waste Residue and Its Application for Congo Red Wastewater Decolorization

Modified aluminum slag (MAS) was applied as an adsorbent for Congo red (CR) prepared by the hydrothermal treatment of Ca(OH)2. At 25°C, with a MAS dosage of 0.3 g, initial CR concentration of 100 mg/L and initial pH = 5, and the adsorption time was 40 min, the CR removal efficiency was 98.41%. The adsorption trend of CR conformed to the second-order kinetics, and the adsorption isotherm follows the Freundlich isotherm model. Compared with RAS, MAS has a larger pore volume and specific surface area. The mechanism of action of MAS on CR was the interaction between membrane diffusion and internal diffusion, and the adsorption rate during the membrane diffusion was the fastest.

Multi-Effect Evaporation Coupled with MVR Heat Pump Thermal Integration Distillation for Separating Salt Containing Methanol Wastewater

Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration technologies were raised for the first time. The ELECNRTL thermodynamic model is used to simulate and optimize the evaporation rectification process. Energy consumption and total annual cost (TAC) are taken as objective functions. The results show that multi-effect evaporation coupled with conventional distillation process can save energy consumption and TAC by 44.12% and 39.14%. The multi-effect evaporation coupled with distillation process based on MVR heat pump technology can save energy consumption and TAC by 55.27% and 47.49%, which is super to three-effect evaporation coupled with conventional distillation process. The three-effect evaporation coupled with MVR heat integration process can save energy consumption and TAC by 81.32% and 58.55%, which is more economical than other processes. It can be clearly seen that three-effect evaporation coupled with MVR heat integration process is more competitive to deal with the salt containing methanol wastewater.

Screening and Domestication of High Effective Microorganism Used in Oil Containing Wastewater Remediation

According to the characteristics of oil containing wastewater, four strains of microorganism, named TA-11, TA-17, HA-9, HD-1, were picked out from the oil contaminated soil and activated sludge of biochemical treatment system of an asphalt plant wastewater in Panjin. They can degrade oil and CODCr in oil containing wastewater. The research result showed that each strain of microorganisms can remove oil and CODCr in oil containing wastewater effectively when the pH value was 7.0, the temperature was 30 degree Celsius, the rotation speed was 140r/min and the inoculation amount was 10%. Especially the highest removal ratio of CODCr was 68% after growth of 64 hours. The removal ratio of CODCr in oil containing wastewater of mixed bacilli was much higher than that of unitary bacilli, and mixing a certain amount of domestic sewage with the oil containing wastewater will also improve the removal rate of CODCr.

Degradation of Nitrobenzene-Containing Wastewater with O_3 and H_2O_2 by High Gravity Technology

Nitrobenzene-containing industrial wastewater was degraded in the presence of ozonecoupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and reaction time on the efficiency for removal of nitrobenzene was investigated. The experimental results show that the high gravity technology enhances the ozone utilization efficiency with O3 /H2O2 showing synergistic effect. The degradation efficiency in terms of the COD removal rate and nitrobenzene removal rate reached 45.8% and 50.4%, respectively, under the following reaction conditions, viz.: a high gravity factor of 66.54, a pH value of 9, a H2O2 /O3 molar ratio of 1:1, a liquid flow rate of 140L/h, an ozone concentration of 40mg/L, a H2O2 multiple dosing mode of 6mL/h, and a reaction time of 4h. Compared with the performance of conventional stirred aeration mixers, the high gravity technology could increase the COD and nitrobenzene removal rate related with the nitrobenzene-containing wastewater by 22.9% and 23.3%, respectively.

Profiling of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing wastewater

A technology of polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing(HSC)wastewater.The results showed that the heterotrophic genus of Acinetobacter and the autotrophic genera of Thiobacillus and Thiomonas could survive well in all of three operating conditions.Some special genera were also observed with changes of micro-ecoenvironment in the reacto...

Recovery of copper sulfate after treating As-containing wastewater by precipitation method

The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6.Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2:1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide.The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4:1 and copper arsenite was reduced by SO2 at 60℃for 1 h.The white powder was gained after the arsenious acid solution was evaporated and cooled.Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air.The results show that red residue is Cu3(SO3)2·2H2O and the white powder is As2O3.The leaching rate of Cu reaches 99.00%when the leaching time is 1.5 h,molar ratio of H2SO4 to Cu is 1.70,H2SO4 concentration is 24%and the leaching temperature is 80℃.The direct recovery rate of copper sulfate is 79.11%and the content of CuSO4·5H2O is up to 98.33%in the product after evaporating and cooling the copper sulfate solution.

Microwave enhanced chemical reduction process for nitrite-containing wastewater treatment using sulfaminic acid

High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process （MECRP） using sulfarninic acid （SA） was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite （NO2-） could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite （SA/NO2-） was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand （COD） removal with efficiency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand （BODs）/COD value of treated effluent after MECRP was increased from 0.05 to 0.36 （by 620%）, which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants.

Treatment of phosphate-containing oily wastewater by coagulation and microfiltration

The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca （OH）2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca（OH）2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.

Feasibility Study on the Treatment of Wastewater Containing High-concentration Hg by Coagulation Sedimentation-Adsorption

For the wastewater containing high-concentration Hg,the feasibility of high-concentration Hg in wastewater treated by coagulation sedimentation,adsorption and the combined process was studied. Research results showed that if using the single coagulation sedimentation process,when FeSO_4·7H_2O dosage was 1. 39 g / L,and NaOH dosage was 0. 40 g / L,it could meet discharge requirement,but the reagent cost was 13. 1yuan / t,which was high. Because that there was subsequent adsorption process,it was selected 0. 28 g / L of FeSO_4·7H_2O and 0. 36 g / L of NaOH,and the estimated reagent cost was 2. 62 yuan / t. In selection process of adsorption materials,powdered activated carbon,granular activated carbon and diatomite all could effectively adsorb Hg,and the technology was feasible. When using the combined process of coagulation sedimentation + adsorption to treat the wastewater containing high-concentration Hg( 800 μg / L),removal rate could reach 99%,and operation cost was 2. 71 yuan. It could meet the requirement of sewage discharged into sewer( 20 μg / L) at the technology,and was acceptable at the economy.Therefore,treatment of wastewater containing high-concentration Hg by the combined process was feasible at the aspects of technology and economy.

Field Test of Electrochemical Degradation and Oil-Removal Technology Used the Treatment of Wastewater Containing Polymer in Offshore Oilfield

Aimed at the current treatment status of the polymer-flooding wastewater in Bohai oilfield, electrochemical technology used for polymer-degradation and oil-removal was researched. It formed the process flow of cyclone mixed dosing → electrochemical removal oil → inclined tube removal oil → walnut shell filter, and a set of skid mounted wastewater containing polymer treatment plant was designed and manufactured, which was used for the field test of electrochemical treatment of wastewater containing polymer in offshore oilfield. The result shows that the oil removal rate of the electrochemical treatment process is over 98%, and the synergistic effect is significant especially used in conjunction with water clarifier of BHQ-04. When the amount of water clarifier is 50 - 150 mg/L, the oil content, the median particle diameter and the suspended solids content of the filtered water is 8 - 18 mg/L, 1.9 - 2.26 μm and 1.39 - 2.04 mg/L respectively, which reach the scene water quality standards for water injection.

Study on Treatment Technology of Methanol in the Low-concentration Methanol-containing Wastewater of a Gas Field

The low-concentration methanol-containing wastewater of a gas field mainly consists of the dehydrated water from natural gas,the water at the bottom of a rectifying tower,and the water used to clear tanks and pipes. The concentration of methanol as its characteristic component is mostly lower than 3%. Its production and water quality change seasonally. It is mainly produced in late autumn,winter,and early spring when temperature is low. In the low-concentration methanol-containing wastewater,the content of organic matter,suspended solids and salts and COD value are high,and it is acidic. According to the physical and chemical properties of methanol such as easily dissolving in water,dissolving in most organic solvents,and having strong molecular polarity,laboratory experiments were made to study the difficulties of using high-temperature rectification,biodegradation,membrane filtration and organic oxidation technology to treat low-concentration methanol in the wastewater as well as the feasibility of industrial application. Ultraviolet catalytic oxidation technology has the advantages of high treatment efficiency,no secondary pollution,and no addition of treatment agent. After the low-concentration methanol-containing wastewater was treated by ultraviolet catalytic oxidation for 90 min,methanol concentration in the wastewater reduced from about 3% to around 0. 1%,thereby rapidly and efficiently degrading methanol in the wastewater. Based on the experimental parameters,a pilot device of ultraviolet catalytic oxidation was developed and used in the continuous treatment of the wastewater. When the flow rate of inflow was 500 L/h,the intensity of UV light was 2 k W,and hydraulic retention time was 60 min,methanol could be removed completely from the wastewater with the methanol concentration of about 0. 3%. This study provides a method for the treatment of low-concentration methanol-containing wastewater of a gas field,and also provides an experimental basis for the efficient degradation of organic wastewater.

Renewable conversion of coal gangue to 13-X molecular sieve for Cd^(2+)-containing wastewater adsorption performance

Using coal gangue(CG)as raw material,a new type of all solid-waste-based 13-X molecular sieve material was controllably prepared by alkali fusion-hydrothermal method.The synthetic molecular sieve was used as a solid adsorbent to treat Cd^(2+)-containing wastewater,and its adsorption behavior on Cd^(2+)in aqueous solution was studied and analyzed.The microstructure and morphology of the molecular sieve were investigated by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM)and specific surface area analyzer.The results show that the synthesized 13-X molecular sieve has higher Brunauer–Emmett–Teller(BET)specific surface area with higher crystallinity and higher adsorption capacity for the heavy metal Cd^(2+).The adsorption process of Cd^(2+)by molecular sieve conforms to the Langmuir isotherm adsorption equation and Lagergren pseudo-second-order rate equation.Combined with thermodynamic calculation,it can be concluded that the adsorption process is physically monolayer,spontaneous and exothermic.In this study,a low-cost and naturally available synthesis method of 13-X molecular sieve is reported.Combined with its adsorption mechanism for Cd^(2+),it provides a feasible and general method for removing heavy metal ions from coal gangue and also provides a new way for the utilization of coal gangue with high added value.

Treatment of Toxic Phenolic Wastewater by Advanced Ozone Oxidization

在这研究， O3/BAC/TiO2 催化方法被用来对待酚移动上的起始的酚集中，臭氧集中， pH 价值，催化剂和另外的条件的效果评估的实验是的酉分的 wastewater.During investigated.The 测试结果看了那酚集中什么时候是 0.1 g/L ，包含臭氧的空气流动率是 0.05 m3/h ，臭氧集中是 3.58 mg/L ， pH 价值是 7.5 ，并且对待的时间是 30 分钟，酚移动率到达了99%

Two-stage treatment process of pickling wastewater in the cold-rolling production of stainless steel

Based on the characteristics of pickling wastewater in the cold-rolling production of stainless steel, a new processing route, featuring source sludge reduction, wastewater two-stage treatment, heavy metal-contained sludge and calcium salt sludge separating recovery, was proposed. As shown by the research results, after the two-stage process treatment, the effluent water can steadily reach the emission standards, the sludge yield can be decreased by more than 8% ; within the heavy metal-contained sludge, the recovery rates of Fc,Cr and Ni can either reach or surpass 95% ,and the total content ofF and S can drop to around 3%. Therefore,the sludge in the front part can be used as ferric dust. In the calcium salt sludge ,the recovery rate of F can either reach or surpass 85% ,and the total contents of Fe,Cr and Ni can fall below 0.5%. So the sludge in the rear part can be used as fluorgypsum or fluorite. Meanwhile,the results of the analysis on heavy metals leaching toxicity and morphologic distribution indicate that the two kinds of sectionalized sludge are not classified as hazardous wastes, which have a stable behavior and better utilization values compared with the former mixed- sludge.

Removal of Cr (Ⅵ) from Simulated Wastewater by FeOOH Supported on Organo-bentonite

FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)in the simulated wastewater were studied.The results indicated that the removal effect of Cr(Ⅵ)was good when the mass fraction of organo-bentonite was 3‰.The removal rate of Cr(Ⅵ)from the simulated wastewater could reach the maximum 98.37% under the following conditions:the dosage of the composite adsorbent was 1.0g;the temperature was 25℃;Cr(Ⅵ)concentration was 10mg/L;the oscillating time was 4h.

Pilot study on microbial treatment of high concentration chromium wastewater from cold rolling mills

The microbial treatment of wastewater containing a high concentration of chromium from cold rolling mills was carried out as a pilot study. The pilot-scale equipment, technological process and results are described in this paper. Two kinds of wastewater with a high concentration of chromium were tested ： one from a color coating line ; the other from a silicon steel line. The removal effect of Cr^6＋ , T-Cr and chemical oxygen demand （COD） in wastewater was studied. The results showed that this microbial treatment technology could be used to treat the above two kinds of chromium-containing wastewater. The average concentrations of Cr^6＋ in the color coating line effluent and the silicon steel line effluent were 0.02 mg/L and 0.04 mg/L respectively, and the average concentrations of T-Cr in the effluents were 0.71 mg/L and 0.74 mg/L respectively. Both were lower than the Sewage Discharge Standard （Cr^6＋ 〈 0.5 mg/L,T-Cr 〈 1.5 mg/L）. Furthermore, up to 60% of the COD was removed from chromate wastewater containing a high concentration COD （ 〉 3 g/L）. The removal rate of COD was lower than 25% for chromate wastewater containing a low concentration COD （ 〈 3 g/L）. Adding a flocculating agent was one of the effective ways of improving the COD removal rate from chromium-containing wastewater.

油水分离技术的研究进展

综述了含油废水的定义､油的存在形态､油水分离技术以及吸油材料的研究进展。油水分离技术包括物理分离法､化学分离法､物理化学分离法以及组合工艺等。阐述了各种油水分离技术的基本原理､流程和特点,综合比较分析发现,应依据含油废水中油品的性质及存在形式选择合适的油水分离技术,并且兼顾经济效益。组合工艺是油水分离的发展趋势;高性能低成本油水分离材料以及油水分离设备的研发是未来油水分离技术发展的重点。

综合法二氧化氯生产系统废水除铬实例

以某浆纸厂含铬废水处理工程实例为研究对象,针对综合利用自产化学药品和现有设备开发的间歇性六价铬(Cr^(6+))综合处理系统,探讨了二氧化氯车间Cr^(6+)废水产生原因及性质,根据不同的反应池pH值、反应温度、反应时间和硫磺投加量对废水中Cr^(6+)还原效果的影响,确定了二氧化硫还原法去除Cr^(6+)的最佳反应条件,并结合实际生产数据,展示了Cr^(6+)还原效果。结果表明,有效去除高浓度含铬废水中Cr^(6+)的条件为:pH值=2~4、反应温度控制在40~60℃、硫磺投加量为理论反应所需投加量的1.4~1.6倍、反应时间40 min。3次二氧化氯车间停修废水出水中Cr^(6+)含量均低于0.005 mg/L,总铬含量均低于0.06 mg/L,符合《污水综合排放标准》(GB 8978—1996)中的要求,证实了间歇性Cr^(6+)综合处理系统处理的有效性。

Mn_(3)O_(4)/CTS的制备及对含钼废水的解吸研究

因工业废水污染严重,该文研究制备了一种有效除钼吸附剂,探究对含钼废水的去除效果并找到最佳条件组合及最佳解吸方案。采用一步水解氧化法和交联法分别制备Mn_(3)O_(4)纳米粒子和Mn_(3)O_(4)/壳聚糖(Mn_(3)O_(4)/CTS)复合纳米粒子,使用正交法确定Mn_(3)O_(4)/CTS除钼的最佳组合,并将单因素控制变量法应用于解吸试验,分析不同解吸条件下的解吸性能。结果表明,无水乙醇12 mL、NaOH 110 mL、温度40℃、反应1.5 h为最佳制备Mn_(3)O_(4)粒子条件,除钼率达70%以上;Mn_(3)O_(4)/CTS粒子在壳聚糖与Mn_(3)O_(4)质量比为3∶1、乙酸30 mL、戊二醛2 mL、150 r/min转速下制备的除钼效果最佳,去除率为90.62%;影响除钼程度顺序为初始pH>吸附剂量>振荡速度>温度;确定最佳解吸液为0.05 mol/L的NaOH,解吸时间30 min,解吸温度40℃,在5次解吸后仍能满足除钼率超80%。制备的Mn_(3)O_(4)/CTS复合纳米粒子除钼效果好,具有优良且稳定的再生效果。

含硫酸盐废水对磷石膏胶结充填体材料性能的影响

鉴于矿山废水处理工艺具有一定的局限性,且磷石膏充填工艺需要消耗大量的水资源,将矿山含硫酸盐废水作为磷石膏充填用水并探讨其可行性。结果表明:废水中的硫酸盐能够促进磷石膏充填体的早期水化反应,进而提升充填体早期强度。当SO_(4)^(2-)浓度从0增加至30 000 mg/L时,充填体7 d强度由0.46 MPa升高至0.63 MPa,提高了37%;14 d强度由0.64 MPa升高至1.03 MPa,提高了61%。这主要跟水化产物钙矾石(AFt)和水化硅酸钙(C-S-H)的形成有关;但随着养护时间的增长,充填体28,60,90 d强度均在硫酸盐浓度为15 000 mg/L时达到最高。过量的SO_(4)^(2-)会干扰水化硬化过程,充填体后期强度因受到钙矾石的膨胀特性以及Na2SO4重结晶等影响而出现下降。研究结果可为矿山废水治理和磷石膏充填工艺优化提供新思路。