Treatment of hydroxyquinone-containing wastewater using precipitation method with barium salt

Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-containing wastewater has seldom been examined. This study used a precipitation method with barium salt to treat nano-silver industrial wastewater. The results show that barium chloride was a suitable reagent for significantly degrading COD and color from nano-silver wastewater. When the initial pH value was 10.5, 8 g of BaCl2·2H2O were added to 100 mL of wastewater. After reaction at 15℃ for 1 h, the removal efficiencies of COD and color in the nano-silver wastewater were 85.6% and 97.1%, respectively. Simulated wastewater containing sodium alizarin-3-sulfonate (ARS) or purpurin was used to further investigate the removal mechanism of hydroxyquinone compounds. Fourier transform infrared spectroscopy, X-ray diffraction, and some related experiments showed that hydroxyquinone compounds can directly react with barium ions in the solution so as to transfer from wastewater to precipitate. In addition, the newly produced barium sulfate particles have positive surface charges, which can improve the removal efficiency of hydroxyquinone compounds due to electrostatic attraction.

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.

Synthesis of carbon nitride in potassium hydroxide molten salt for efficient uranium extraction from radioactive wastewater

Photocatalysis-assisted removal of uranium has been proven as an effective method for the elimination of radioactive pollution from wastewater.In this work,carbon nitride materials were synthesized in potassium hydroxide(KOH)molten salt and applied to photocatalytic uranyl extraction.Obtained materials were confirmed to possess the triazine-s-heptazine structure by NMR,XPS and UV-Vis characterization,and exhibited a wider visible light absorption than graphitic carbon nitride(g-C_(3)N_(4)).The photocatalytic activity of the carbon nitride materials was tailored by varying the precursor mass fractions.The carbon nitride obtained at 80%melamine as precursor(K-CN-80)exhibited the highest photocatalytic extraction ability and its photocatalytic reaction rate is 6.6 times faster than that of g-C_(3)N_(4).The influence of sacrificial agents was studied and the results showed that triethanolamine inhibited U(Ⅵ)photoreduction,but methanol can accelerate U(Ⅵ)photoreduction by consuming photogenerated holes.This unary KOH molten salt synthesis method has exceptional potential applications in the preparation of carbon nitrides,and the obtained products showed potential in extracting U(Ⅵ)from aqueous solutions for use in nuclear fuel industry and for U(Ⅵ)environmental pollution cleanup.

Investigation on removing recalcitrant toxic organic polluters in coking wastewater by forward osmosis

Investigation was made on the efficiency of two commercial membranes in removing via forward osmosis(FO)the low molecular weight organic compounds typical of coking wastewater. The membranes were supplied by Poten and HTI companies. The organics in the simulated coking water were indole and pyrridine. Under FO mode, the rejection to the organics by Poten membrane was around 50%, whereas that for HTI membrane was obviously higher, ranging from 65% to 74%. The response of the two membranes in terms of Water flux and reverse salt flux(RSF) towards changing feed/draw solution(DS) flow rates in FO mode showed similar tendency,but different degree. Generally, the flux in FO using HTI membranes was lower. For HTI membrane, FO operated with pressure retarded osmosis(PRO) mode was also performed and the overall rejection of the organics was slightly lower than that in FO mode. In the long term FO test within 15 days, both Poten and HTI membranes displayed flux reduction and rejection enhancement. But the variation with Poten membrane was much more obvious. Discussion was carried out about the reasons and the mechanisms behind the FO performance difference between two membranes and the variation in flux and rejection with operation conditions. Characterizations by SEM, FTIR, AFM, XRD and XPS were tried to support the proposed explanations.

Treatment of Enzymolysis Wastewater by Centrifugation- Coagulation- Fenton Reagent Oxidation- Adsorption Process

[ Objective ] The study aimed to discuss the optimal conditions for the treatment of enzymolysis wastewater by centrifugation - coagu- lation - Fenton reagent oxidation - adsorption process. [ Metbod] According to the water-quality characteristics of wastewater from a heparin so- dium production factory of Jiangsu Province, enzymolysis wastewater was segregated from intestinal lavage wastewater and treated through cen- trifugation- coagulation- Fenton reagent oxidation-adsorption process, and the optimal technical parameters were determined. E Resultl After enzymolysis wastewater was centrifuged at a speed of 4 000 rpm, 0.6 g/L CTS as the coagulant was added to the supematant. Hereafter, pH of the coagulated effluent was adjusted to 3, and then 1.5% （V/V） H2O2 was added to the coagulated effluent; a certain amount of ferrous sul- fate （n H2O2-.n FeSO4 . 7H2O =8：1 ） was added to the mixture; the reaction conducted for 30 min, and then solution pH was adjusted to about 9. Finally, the oxidized effluent flowed through a resin red until the adsorptive capacity reached 240 BV, and COD of the effluent water was lower than 100 mg/L, meeting the Grade-I standard of Comprehensive Discharge Standard of Sewage （GB8978-1996）. [Condusio] The research could provide a new process for the treatment of enzymolysis wastewater.

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.

海水养殖尾水人工湿地处理系统及其脱氮过程研究进展和展望

利用人工湿地处理海水养殖尾水具有很大的应用前景,其中,脱氮是人工湿地的主要任务之一。基质上栽培的植物和附着的微生物参与的氮循环是人工湿地生物脱氮的主要路径,植物和多种氮代谢菌群在人工湿地内部相互协同与制约,构成了一个复杂的氮代谢网络。海水养殖尾水的高盐度和低碳氮比(C/N)又决定了此类人工湿地独特的处理环境和生物脱氮机制。同时,人工湿地的供氧模式、水力负荷(HRT)、水力停留时间(HLR)等水力条件参数对脱氮效能也有很大影响,对这些指标进行调控和优化,可以提高湿地的整体脱氮性能。本文从海水人工湿地的构建、基质的选取、耐盐植物的筛选、氮循环相关微生物以及运行参数调控四个方面,对近年来海水养殖尾水人工湿地生物脱氮方面的研究进展进行了综述和展望,以期为深入理解海水人工湿地脱氮机制和优化运行方式提供参考。

外源添加物对高盐废水厌氧消化的影响:综述

围绕铁基材料、相容性溶质以及碳材料等外源添加物对高盐废水厌氧生物处理效果的影响进行综述。在高盐度作用下,铁基材料和碳材料通过增强直接种间电子传递、富集功能微生物等作用来提高高盐度中厌氧消化产甲烷效率;相容性溶质可以被微生物吸收来平衡渗透压差,以帮助微生物更快地适应高盐环境,从而提高高盐废水的厌氧消化处理效果。

结晶技术在高盐工业废水处理中的应用研究

为了满足日益严格的废水排放标准要求,提高废水的有效回用率,结晶技术成为高盐工业废水处理项目的保障技术路线之一。介绍了常见结晶技术和结晶器类型,分析了料液浓度、停留时间、搅拌速率、结晶温度、杂质、晶种和结晶设备等结晶过程因素的影响,展望了高盐工业废水结晶技术发展方向,以期为后续高盐工业废水处理及资源化利用提供技术指导。

砷酸复盐矿化沉淀高效除砷行为及机理

针对常规化学沉淀法处理碱性含砷废水无法高效选择性除砷的问题,提出采用砷酸复盐矿化沉淀法处理含砷废水。对25℃的Mg^(2+)-NH^(+)_(4)-AsO^(3-)_(4)-OH^(-)-H_(2)O体系进行了热力学计算,研究了工艺参数对除砷率的影响,为砷酸复盐矿化沉淀过程建立了动力学调控机制,探索了杂质离子对除砷效果的影响。结果表明:pH对除砷率和砷渣品位的影响显著;增大镁盐和氨盐用量能在一定程度上提高除砷率,但镁盐过量时砷渣品位会随镁盐用量的增加而减小;增加镁盐用量有利于缩短达到平衡所需的时间;升温会明显降低除砷率和砷渣品位。杂质离子Ca^(2+)、Fe^(3+)和SiO^(2-)_(3)的加入会形成新的化合物并与砷共沉淀,对除砷具有促进作用,而加入PO^(3-)_(4)形成磷酸复盐与砷酸复盐的形成存在竞争关系,会抑制砷酸复盐矿化除砷。

高盐废水中硫酸铵和硫酸钠的分质结晶工艺研究

处理高盐废水并回收其中的盐资源是许多生产企业废水综合治理的难题。采用等温溶解平衡法测定了10、15、60、80℃下Na_(2)SO_(4)-(NH_(4))_(2)SO_(4)-H_(2)O的液固相平衡数据,基于相平衡数据划分了结晶区域。根据高盐废水的组成和液固相平衡数据,提出了分质结晶分离(NH_(4))_(2)SO4和Na_(2)SO_(4)的工艺路线,设计了结晶过程工艺参数并进行了实验验证。结果表明,废水经3步结晶回收得到的(NH4)2SO4纯度达到了99.2%、Na_(2)SO_(4)纯度达到了98.9%,满足GB/T 535—2020《肥料级硫酸铵》和GB/T 6009—2014《工业无水硫酸钠》的纯度指标要求。该研究可为高盐废水中(NH_(4))_(2)SO_(4)和Na_(2)SO_(4)的回收利用提供参考。

水产养殖废水灌溉耐盐水稻对土壤和植物的影响

[目的]水产养殖废水可以作为替代性水源进行农业灌溉,本研究旨在分析不同浓度的水产养殖废水灌溉耐盐水稻对土壤、植物及生态经济效益的影响。[方法]以耐盐水稻为供试植物进行盆栽试验,设置淡水与水产养殖废水体积比1∶1(DY)、水产养殖废水(Y)2种灌溉处理,以淡水(D)灌溉为对照,监测土壤理化性质变化情况、耐盐水稻生长及产量,以此为依据并结合稻田生态系统服务价值评估方法计算水产养殖废水灌溉耐盐水稻过程中产生的生态经济效益价值。[结果]水产养殖废水灌溉能够降低土壤pH值、提高土壤电导率(EC),同时水产养殖废水能够改善土壤物理性状,降低土壤容重,提高土壤孔隙度,改善土壤持水状况;水产养殖废水灌溉能够不同程度增加土壤有机质、全氮、全磷和速效磷含量,提高土壤肥力;与D灌溉相比,DY能有效增加耐盐水稻株高和生物量,提高耐盐水稻产量,增产达199%;D灌溉、DY灌溉、Y灌溉3种处理系统的生态经济效益按从大到小的处理依次为DY灌溉(30532.08元·hm^(-2))、Y灌溉(20980.63元·hm^(-2))、D灌溉(13208.60元·hm^(-2))。[结论]淡水与水产养殖废水按体积比1∶1混合灌溉能够改善土壤理化性质,增加土壤肥力,提高作物产量,并且可以带来较大的生态经济效益价值,为最优的灌溉模式。

癸炔二醇生产过程中钾盐的回收研究

采用实验室制备的含炔醇的碱液,探究活性炭吸附碱液中有机物的规律及吸附的最佳条件,并回收碱液中的钾离子得到优级纯硫酸钾产品。结果表明,活性炭吸附的最佳条件为:吸附温度为40℃、活性炭用量为2 g/100 mL、pH为5、吸附时间为40 min;pH为5时,溶液中的酯类有色物质会发生分解从而大幅度提高活性炭对有机物的去除率。

电渗析技术在含盐工业废水处理中的应用研究进展

为了处理含盐工业废水的高盐污染问题,电渗析技术(electrodialysis)因其独特优点成为含盐工业废水脱盐的研究重点。介绍了填充床电渗析工艺、频繁倒电极电渗析工艺、双极膜电渗析工艺3种新型电渗析工艺,阐述了近几年电渗析技术在稀土工业废水、煤化工废水、锂提取加工和锂电池回收方面的应用。结果显示,3种新型电渗析工艺表现了较好的脱盐效能和资源回收能力;同时电渗析技术适用于稀土工业废水、煤化工废水脱盐处理及水资源回收利用,也能够应用于锂提取加工和锂电池回收。现阶段,电渗析技术在脱盐成本和脱盐性能方面还存在不足,因此电渗析技术需要与其他工艺进行耦合、优化电渗析技术的系统结构和工艺参数、优化离子交换膜来作为重点研究方向。

泰妙菌素废盐活性炭的制备及吸附EDTA-Pb(Ⅱ)的研究

工业废水中的有机配体和重金属离子结合形成络合态重金属,络合态重金属的排放会导致严重的环境及人体健康问题。采用热解炭化法将医药固体废弃物——泰妙菌素废盐制备成废盐活性炭(WSAC)并用于去除模拟废水中的EDTA-Pb(Ⅱ),利用SEM、BET表征WSAC的性质;基于静态吸附试验研究了溶液初始pH、共存离子对WSAC吸附EDTA-Pb(Ⅱ)行为的影响;通过吸附动力学、等温线拟合,利用FTIR、TOC、Zeta电位等表征探究其吸附机理。结果表明:WSAC对EDTA-Pb(Ⅱ)的吸附过程符合伪一级动力学和Langmuir模型,吸附速率受物理过程主导且为单分子层均相吸附;随着pH的升高,WSAC对EDTA-Pb(Ⅱ)的吸附效果降低;共存阴离子的加入会与EDTA-Pb(Ⅱ)竞争吸附位点,对吸附起抑制作用;WSAC对EDTA-Pb(Ⅱ)的吸附机制主要为孔隙填充和静电吸附的协同作用。将WSAC用于吸附工业废水中的EDTA-Pb(Ⅱ),为泰妙菌素废盐的资源化利用提供一种途径,也为工业废水中EDTA-Pb(Ⅱ)的去除提供新方法。

两级A/O+铁盐耦合沉淀组合工艺处理酞菁铜生产废水

经除铜预处理后的酞菁铜生产废水含有大量难生物降解的酞菁等含氮有机物,采用传统的“生物处理+深度处理”组合工艺处理该废水时,处理效果不稳定,且出水总氮(TN)难以达标。采用“两级A/O+铁盐耦合沉淀”组合工艺处理该废水,考察其处理效果,并利用荧光光谱、紫外光谱、腐殖质(HS)含量测定探究废水中污染物的去除机理。结果表明,“两级A/O+铁盐耦合沉淀”组合工艺处理酞菁铜生产废水,化学需氧量(COD)、氨氮、TN的去除率分别为96.5%、99.8%、93.2%;两级A/O可有效去除废水中绝大部分污染物,并使出水中HS含量提高,再利用对HS和有机氮具有高效去除作用的铁盐耦合沉淀技术处理两级A/O出水,使最终出水的COD、氨氮、TN分别为29、0.5、23.8 mg/L,实现了出水达标排放。

曝气式增湿除湿蒸发工艺处理高盐废水的模拟分析与优化

高盐废水在废水中属于极难处理的一类,对环境危害极大。为了高效处理高盐废水,设计了一种直接接触的曝气式增湿除湿蒸发工艺,并利用Aspen Plus软件对该工艺进行模拟。通过实验验证发现模拟数据与实验数据的最大偏差不超过10%,确立了模型的可靠性及模拟结果的正确性。为降低曝气式增湿除湿蒸发工艺的能耗,对曝气式增湿除湿蒸发工艺进行多工况模拟。结果表明,蒸发速率随溶液温度的升高呈指数型增长,随盐度的增大而减少。冷凝效率随冷凝温度的升高而降低,随初始内部冷却水量的升高而升高。增湿除湿系统造水比随着溶液温度和冷凝温度的增大呈现先增大后减小的趋势,能量消耗比则呈现先减小后增大的趋势,最大造水比为1.79,最小能量消耗比为0.77。根据造水比和能量消耗比得出系统最佳工作范围:溶液温度为60~80℃,冷凝温度为20~40℃。

喷雾干燥法在高盐有机废水中无机盐回收和有机质分解的应用研究

采用喷雾干燥工艺,以高盐有机废水中溶解性有机污染物和无机盐为处理对象,重点研究了各温度下喷雾干燥工艺对无机盐的回收效果和对有机质的分解性能。通过扫描电子显微镜、傅里叶变换红外光谱仪及三维荧光光谱仪等对产物粉体进行分析。结果表明,雾化室加热蒸发过程中含羟基、羰基等亲水性基团的类腐殖酸大分子与脱水析出的Na Cl、Na_(2)SO_(4)等无机盐结合,形成开口空心球壳结构颗粒,粉体粒径集中分布在1.25~3.85μm。废水经喷雾干燥和旋风分离后得到白色粉末,经600℃焚烧,粉末中的难降解有机质可全部除尽,烧失率为6.23%;焚烧后的混盐经原子吸收光谱与X射线衍射分析表明,原始废水中含量较多的金属元素如Na^(+)、K^(+)等得到保留,可供进一步分盐后循环利用。在0.2 MPa、140℃的最佳工艺条件下,废水有机物分解转化率为93.1%,溶解性有机碳、氨氮、总氮、总磷等水体富营养化污染物的降解率在64.7%以上,无机盐总回收率达87.2%,为高盐废水综合处置与清洁利用提供了新思路。

海洋小红酵母H117利用高盐有机废弃物的特性分析

高盐有机废弃物属于难处理的污染物,为探究利用微生物处理高盐有机废弃物的可行性,本研究以海洋小红酵母H117为研究对象,经形态观察、生理生化、26S rRNA序列分析,确定为小红酵母(Rhodotorula minuta)。在此基础上,通过海洋小红酵母H117在高盐模拟有机废水、高盐酱油废水、高盐酱油残渣中培养后的菌落计数分析,发现其能耐受9%(m/v)盐浓度;以高盐酱油残渣为基料生长良好,最大活菌数为2.91×10^(9)cfu/mL,而在高盐酱油废水中菌落数目略少。本研究为海洋小红酵母H117转化高盐有机废弃物制备海水养殖用微生态制剂的深入研究提供了数据支撑。

锂电池三元前驱体的原料制备过程中萃取废水处理工艺设计

介绍了四川某三元前驱体合成前原料制备萃取工段废水处理的工艺流程及设计参数。针对该废水的水质特点,采用气浮除油、化学沉淀除重金属、臭氧催化氧化除COD、树脂深度除重金属和MVR蒸盐相结合的处理工艺,产出工业无水硫酸钠产品(纯度95%,Ⅲ类合格品),且实现废水零排放,对同类工业废水的处理具有重要参考价值。