Growth properties of mixed liquor suspended solids in SMBR for pharmaceutical wastewater treatment

This paper presents the performance results of a 366-day pilot-scale submerged membrane bioreactor (SMBR) for treating high-strength pharmaceutical wastewater. The study focuses on the growth properties of mixed liquor suspended solids (MLSS) in SMBR operated at high volumetric loading rates. The influences of MLSS on COD removal,sludge yield,oxygen utilization rates and sludge viscosity are studied. Results show that the bioreactor can be operated at higher volumetric loading rate with a low sludge yield. VSS/SS and observed sludge yield coefficient (Yo) present a decreasing trend with the decrease of hydraulic retention time (HRT) . Sludge oxygen utilization rate decreases with the increase of mixed liquor volatile suspended solids (MLVSS) . A mathematical model between sludge viscosity and MLSS is developed.

Performance Evaluation of the Halophilic Crude Oildegrading Bacterial Consortium XH-1 for Oilfield Wastewater Treatment

A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to create the mixed bacterial agent XH-1.These four strains were identified through 16S rRNA gene-based sequencing as belonging to Acinetobacter,Bacillus paramycoides,Rhodococcus sp.,and Enterobacter sp.,respectively.The optimal cultivation time for the mixed consortium XH-1 was found to be 48 h,and a nitrogen-phosphorus molar ratio of 10:1 was determined to be beneficial for crude oil degradation.XH-1 showed notable crude oil degradation even at a salinity of up to 30 g/L,with little inhibition observed at sulfide concentrations as high as 150 mg/L and initial oil concentrations of 500 mg/L.Gas chromatography analysis revealed that XH-1 was able to efficiently degrade C9–C29 n-alkanes.Moreover,a bio-contact oxidation reactor enhanced by XH-1 showed promising results in treating oilfield wastewater.These findings suggest that XH-1 can be applied for the treatment of oilfield wastewater.

Recent advances in flat sheet mixed matrix membrane modified by Mg-based layered double hydroxides(LDHs)for salt and organic compound separations

Magnesium(Mg)is a widely used and attractive metal,known for its unique physical and chemical properties,and it has been employed in the manufacture of many practical materials.Layered Double Hydroxides(LDHs),particularly Mg-based LDHs,rank among the most prevalent two-dimensional materials utilized in separation processes,which include adsorption,extraction,and membrane technology.The high popularity of Mg-based LDHs in separation applications can be attributed to their properties,such as excellent hydrophilicity,high surface area,ion exchangeability,and adjustable interlayer space.Currently,polymer membranes play a pivotal role in semi-industrial and industrial separation processes.Consequently,the development of polymer membranes and the mitigation of their limitations have emerged as compelling topics for researchers.Several methods exist to enhance the separation performance and anti-fouling properties of polymer membranes.Among these,incorporating additives into the membrane polymer matrix stands out as a cost-effective,straightforward,readily available,and efficient approach.The use of Mg-based LDHs,either in combination with other materials or as a standalone additive in the polymer membrane matrix,represents a promising strategy to bolster the separation and anti-fouling efficacy of flat sheet mixed matrix polymer membranes.This review highlights Mg-based LDHs as high-potential additives designed to refine flat sheet mixed matrix polymer membranes for applications in wastewater treatment and brackish water desalination.

Anaerobic hydrogen production of molasses from mixed microbial communities immobilized by activated granular carbon

Molasses wastewater was evaluated as substrate for biohydrogen production by anaerobic fermentation in a novel continuous mixed attached growth reactor ( CMAGR ) with aeration pretreated sludge attached onto granular activated carbon under continuous flow condition.It was indicated that the CMAGR system was operated at the conditions of influent COD of 2000～6000mg / L , hydraulic retention time ( HRT ) of 6hand temperature of 35 ℃ , when the pH value and oxidation-reduction potential ( ORP ) ranged from 4.16and-434 mV respectively , stable ethanol-type fermentation was formed with the sum of ethanol and acetate concentration ratio of 89.3%to the total liquid products after 40days operation.The H 2 content in biogas and chemical oxygen demand ( COD ) removal were estimated to be 46.6% and 13% , respectively.It was also investigated that the effects of organic loading rates ( OLRs ) on CMAGR hydrogen production system.It was found that hydrogen production yield increased from 3.72 mmol / hL to 12.51 mmol / hL as OLRs increased from 8 kg / m 3 d to 32 kg / m 3 d.The maximum hydrogen production rate of 12.51mmol / hL at a OLR of 32kg / m 3 d and the maximum hydrogen yield by substrate consumed was 130.57 mmol / mol happened at OLR of 16 kg / m 3 d.Greater pHs appeared to be favour to butyrate production and the maximum of 0.51mol / mol was obtained at pH of 4.14.However , ethanol / acetate ratio was greater than 1.1at pH fluctuated between 3.4 - 3.6and 4.1 - 4.4which indicated that these pHs were favour to ethanol type fermentation.Therefore , the continuous mixed attached growth reactor ( CMAGR ) could be a promising attached growth system for biohydrogen fermentation.

Evaluation of the Purification Performance of the Kossodo Wastewater Treatment Plant in Ouagadougou

The efficiency of a wastewater treatment system is classically measured by the quality of its discharge into the aquatic environment. This quality can only be achieved if certain aspects are taken into account, such as the design and operation of the system in place. The objective of the present work is to evaluate the purification performance of this system after 17 years of operation. It should be noted that the lagoon plant (WWTP) has a total of eight basins, three of which are anaerobic (ANA). The evaluation of the physicochemical and microbiological parameters in the anaerobic basins and in the maturation basins allowed us to note slightly basic pH values in the maturation basins (8.7 to 9.2) against values from 6.8 to 7.4 in the anaerobic basins. Also, the values in terms of organic and bacteriological pollution have also evolved. For COD and BOD5, we obtained respectively abatements of more than 73% for filtered COD, 55% for gross COD and 81% for BOD5 even if the residual concentrations do not respect the standards of wastewater discharge in our country. Also, the residual concentrations of ammonia nitrogen in the output effluents (on average 12.43 mg/L), do not meet the standard of discharge into surface waters of Burkina Faso (1.29 mg/L). Thus, nutrients such as nitrogen and phosphorus pollution have average abatement rates of 31% and 27% respectively. In sum, we can say that the lagoon system set up does not meet the requirements in terms of quality of discharges, which remains an environmental problem for the receiving environment.

Treatment of Chinese traditional medicine wastewater in a submerged membrane bioreactor

A pilot scale test was conducted in a submerged membrane bioreactor SMBR with capacity of 10. 0 m^3/d for 120 days to treat high-strength Chinese traditional medicine wastewater. Performance of the SMBR was investigated with a sludge retention time （ TSR ） of 50 days, a hydraulic retention time （ THR ） of 8.0 h, membrane flux of 8. 0 IV（ m^2 · h） and dissolved oxygen （DO） concentration of 2. 0 - 3. 0 mg/L, respectively. It was observed that the SMBR had high capacity of COD and suspended solid （SS） removal. The influent COD concentration was fluctuated between I 000 and 5 000 mg/L, while the averaged effluent COl） concentration was only 44. 6 mg/L. The influent SS concentration was fluctuated between 1 000 and 1 600 mg/L, while little effluent SS was detected. It was found that the COD remove rate increased with mixed liquor suspended solids （MLSS） and organic loading rate （ROL）. In order to obtain good-quality effluent, the operational conditions of the SMBR were suggested as follows： the temperature was controlled above 10 ℃, MLSS about 7000 mg/L, R,L under 24. 76 kg/（ m^3 · d）, low vacuum value and constant water flux.

Mixed culture of Chlorella sp. and wastewater wild algae for enhanced biomass and lipid accumulation in artificial wastewater medium

The purpose of this work is to study the co-cultivation of Chlorella sp. and wastewater wild algae under different cultivation conditions （i.e. CO2, light intensity, cultivation time, and inoculation ratio） for enhanced algal biomass and lipid productivity in wastewater medium using Response SuHhce Methodology （RSM）. The results show that mixed cultures ofd7llorella sp. and wastewater wild algae increase biomass and lipid yield. Additionally, findings indicate that CO2, light intensity and cultivation time significantly affect algal productivity. Furthcnnore, CO2 concentration and light intensity, and CO2 concentration and algal composition, have an interactive effect on biomass productivity. Under dii＂ferent cultivation conditions, the response of algal biomass, cell count, and lipid productlvlty ranges from2,5 to 10.2 mg/mL 1.1 × 10 to 8.2 × 10 cells/mL and 1.1 × 10^6 to 6.8 × 10^12 total fluorescent units/mL, respectively× The optimum conditions tbr simt, ltaneot, s biomass and lipid accumulation are 3.6% of CO2 （v/v）, 160 μmol/m^2/s of light intensity, 1×6/2.4 of inoculation ratio （wastewater-algae/Chlorella）, and 8.3 days of cultivation time. The optimal productivity is 9,8 （g/L） for dry biomass, 8.6 E ＋ 08 （cells/mL） for cell count, and 6.8 E ＋ 12 （Total FL units per mL） fbr lipid yield, achieving up to four times, eight times, and seven times higher productivity compared to non- optimized conditions. Provided is a supportive methodology to improve mixed algal culture for hioenergy feedstock generation and to optimize cultivation conditions in complex wastewater environments. This work is an important step tbrward in the development of sustainable large-scale algae cultivation for cost-efficient generation of biofuel.

Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture

The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.

Distribution,characteristics and daily fluctuations of microplastics throughout wastewater treatment plants with mixed domestic-industrial influents in Wuxi City,China

In wastewater treatment plants(WWTPs),microplastics(MPs)are complex,especially with mixed domestic–industrial influents.Conventional random grab sampling can roughly depict the distribution and characteristics of MPs but can not accurately reflect their daily fluctuations.In this study,the concentration,shape,polymer type,size,and color of MPs were analyzed by micro-Raman spectroscopy(detection limit of 0.05 mm)throughout treatment stages of three mixed domestic–industrial WWTPs(W1,W2,and W3)in Wuxi City,China,and the daily fluctuations of MPs were also obtained by dense grab sampling within 24 h.For influent samples,the average MP concentration of 392.2 items/L in W1 with 10%industrial wastewater was much higher than those in W2(71.2 items/L with 10%industrial wastewater)and W3(38.3 items/L with 60%industrial wastewater).White polyethylene granules with a diameter less than 0.5 mm from plastic manufacturing were the most dominant MPs in the influent of W1,proving the key role of industrial sources in MPs pollution.In addition,the daily dense sampling results showed that MP concentration in W1 influent fluctuated widely between 29.1 items/L and 4617.6 items/L within a day.Finally,few MPs(less than 4.0 items/L)in these WWTPs effluents were attributed to the effective removal of wastewater treatment processes.Thus,further attention should be paid to regulating the primary sources of MPs.

催化超临界水氧化法处理焦化废水的试验研究

焦化废水是在煤气净化、煤制焦炭和回收焦化产品的过程中产生的,其成分复杂,危害性大,常规的处理方法很难达到理想的效果。本次试验采用超临界水氧化技术对焦化废水进行处理研究,对废水中COD,NH_(3)-N等污染指标进行检测,通过采用新型混合催化剂,降低超临界水氧化所需反应条件,使出水效果满足GB 16171-2012炼焦化学工业污染物排放标准。

Singlet oxygen-dominated peroxymonosulfate activation by layered crednerite for organic pollutants degradation in high salinity wastewater

Advanced oxidation processes have been widely studied for organic pollutants treatment in water,but the degradation performance of radical-dominated pathway was severely inhibited by the side reactions between the anions and radicals,especially in high salinity conditions.Here,a singlet oxygen(^(1)O_(2))-dominated non-radical process was developed for organic pollutants degradation in high salinity wastewater,with layered crednerite(CuMnO_(2))as catalysts and peroxymonosulfate(PMS)as oxidant.Based on the experiments and density functional theory calculations,^(1)O_(2)was the dominating reactive species and the constructed Cu-O-Mn with electron-deficient Mn captured electron from PMS promoting the generation of^(1)O_(2).The rapid degradation of bisphenol A(BPA)was achieved by CuMnO_(2)/PMS system,which was 5-fold and 21-fold higher than that in Mn_(2)O_(3)/PMS system and Cu_(2)O/PMS system.The CuMnO_(2)/PMS system shown prominent BPA removal performance under high salinity conditions,prominent PMS utilization efficiency,outstanding total organic carbon removal rate,wide range of applicable pH and good stability.This work unveiled that the^(1)O_(2)-dominated non-radical process of CuMnO_(2)/PMS system overcame the inhibitory effect of anions in high salinity conditions,which provided a promising technique to remove organic pollutants from high saline wastewater.

基于物联网的电镀铬镍混合废水浓度监控系统

监测废水中的铬和镍浓度有助于早期发现和处理潜在的问题,减少对自然环境和水资源的污染风险。为此,设计了基于物联网架构的电镀铬镍混合废水浓度监控系统。在指挥层中使用LoRaWAN通信方式连接电化学传感器和监控系统,监控系统可以实时采集废水中的铬和镍浓度数据。在网络层中使用箱线图对指挥层中采集的数据进行异常值识别,并去除这些异常值。为保证数据的安全性和稳定性,通过物联网技术中的监控系统软件协议代码将数据传输至云平台。在云平台中利用孤独森林算法对传输到云平台的数据进行模式识别和监测,通过感知层将废水浓度数据以可视化的形式展示出来,使用户能够直观地了解混合废水的浓度情况。实验结果表明,本文系统的监测准确度保持在95%以上,且数据传输效率保持在96%以上,具有较高监测准确度的同时具有良好的运行性能。

Fe_(2)O_(3)/Al_(2)O_(3)修饰的混合金属氧化物降解维C生化废水

针对维C废水在二级生化处理后很难达到排放标准的问题,以铁铝混合粉末作为载体(Fe_(2)O_(3)/Al_(2)O_(3),FA)与其他金属氧化物粉末混合掺杂,通过滚动造粒法制备混合金属氧化物(MMO)臭氧催化剂,用于降解维C生化废水。结果表明,CuO、Ni_(2)O_(3)协同催化,所制备的MMO臭氧催化剂Cu-Ni/FA具有较好的催化性能和力学性能。通过SEM、TEM、BET、XRD、XPS对样品的理化性能进行表征,发现催化体系中NiFe_(2)O_(3)和Cu_(4)O_(3)发挥了重要作用。在废水COD浓度为248.31 mg/L,pH为7,催化剂投加量35 g/L以及臭氧浓度10 mg/L条件下,60 min时COD去除效率达到70%。超声120 min后催化剂脱落率为2.724%,对每次超声后的催化剂进行催化臭氧氧化实验,COD去除率为65%~69%,表明该催化剂具有良好的抗脱落性和稳定性。

基于混合胺的PVDF复合疏松纳滤膜及其在染料废水处理中的应用

为了对染料废水中的染料和盐进行有效的分离、促进染料的回收利用,文章探讨了在共沉积与界面聚合组合法制备PVDF复合疏松纳滤膜过程中,GAZ/PEI对PVDF复合疏松纳滤膜选择层的微观结构、表面粗糙度、过滤性能及其在模拟活性黑5(RB5)染料废水处理中的应用等情况的影响。研究结果表明随着GAZ/PEI的增加,PVDF复合疏松纳滤膜表面结节减小,选择层厚度降低,表面粗糙度减小,纯水通量增大,PEG800截留率降低,染料废水通量增大,GAZ/PEI为9/91时,膜性能最佳,此时纯水通量和染料溶液通量较单一胺分别提高了91.6%和109.1%,RB5和NaCl的截留率分别为94.3%和2.1%,在运行时间内,基于混合胺的PVDF复合疏松纳滤膜体现了较好的运行稳定性。

SRB处理硫酸盐废水的影响因素探究

采用上流式固定床厌氧生物膜(UFAB)反应器处理人工模拟废水,研究了利用硫酸盐还原菌(SRB)处理硫酸盐废水的影响因素,考察了碳硫比、碳源种类、水力停留时间以及硫酸盐浓度等因素对硫酸盐去除效果的影响。结果表明:UFAB反应器在n(TOC)/n(SO_(4)^(2-))为6,甲酸-乙酸-乳酸钠混合碳源(三者物质的量比为1∶1∶4),进水硫酸盐质量浓度为1200 mg/L,水力停留时间为9 h的条件下,对硫酸盐平均去除率达83.80%,有较强的脱硫能力,出水硫酸盐平均质量浓度为194.4 mg/L,达到了GB 3838—2002《地表水环境质量标准》中作为集中式生活饮用水地表水源地的水质要求。

纳滤膜提纯工业混盐废水及资源化利用

以陕西延长中煤榆林能源化工股份有限公司化工园区生产的废水“零排放”项目为例,研究纳滤(NF)膜在其工业废水提纯中的应用,通过NF分离高浓废水中NaCl/Na2SO4,NF产水进入六效降膜蒸发单元结晶精制工业盐,产品氯化钠质量分数≥92%,资源化利用率可达63%以上,实现经济效益4011万元/a。

正渗透混合无机盐作汲取液处理废水的研究进展

近年来,具有低能耗、低污染、可循环利用等优点的正渗透技术开始广泛应用于污水处理等方面,如何选择高效、稳定的汲取液是正渗透技术所要解决的核心问题。综述了近10年正渗透工艺在处理污水中的应用,重点阐述了不同汲取液进行正渗透的评价指标及其影响因素,并展望了未来混合无机盐作汲取液工艺规模化,以推动混合无机盐作汲取液的正渗透工艺在处理污水领域的应用。

铜强化铁碳微电解陶粒阴极对硝基苯废水的降解研究

采用电镀法,考察Cu 2+浓度、电流密度、电镀时间对镀层形貌及电镀速率的影响,以SEM-EDS、XRD、CV等分析方法对所获得的铜电镀污泥碳进行表征;并进一步制备三元微电解陶粒,考察不同加铜方式对陶粒性能的影响。结果表明:在Cu 2+浓度为0.15 mol/L、电流密度为12.5 mA/cm 2时镀层均匀、致密;铜电镀掺杂制备的三元微电解陶粒对硝基苯废水的降解有更高的去除效果,在初始pH为3且废水中的硝基苯浓度为100 mg/L时,反应180 min即可达到90.61%的硝基苯去除率,且对硝基苯的降解符合伪一级动力学反应,反应速率常数可达到0.01058 min-1。

NaCl/Na_(2)SO_(4)混盐溶液纳滤脱盐分质效果研究

为探究纳滤技术在工业高盐废水处理中的脱盐分质效果,在实验室搭建的纳滤装置上,采用纳滤膜VNF1-4040,研究了NaCl和Na_(2)SO_(4)混盐溶液的脱盐分质过程,考察了在不同质量浓度比混盐进料条件下膜通量、进料质量浓度、进料温度对纳滤脱盐效果的影响.研究结果表明,在所考察工况条件下,纳滤膜对Na2SO4始终有着良好的脱除效果,截留率保持在97.5%以上.对于质量比为1∶9 NaCl/Na_(2)SO_(4)混盐,其Na_(2)SO_(4)截留率均优于相同运行条件下的其它混盐溶液.膜通量越低,进料质量浓度和进料温度越高,NaCl截留率越低,脱盐效果越好.当膜通量、进料质量浓度和进料温度分别为26 LMH、2 g/L和10℃时,Na_(2)SO_(4)截留率最高,分别为98.41%、98.24%和98.80%.纳滤膜对混盐溶液中NaCl的分质效果较好,产水中NaCl的质量浓度占比保持在96%以上.

一种新型旋混式生物反应器的设计及其对工业废水中氨氮和有机物的同步去除效果评价

评估了新型旋混式生物反应器的有效性。新型旋混式生物反应器是一种多模块系统,可在同一反应单元中耦合多个生物过程,以去除合成废水或工业废水中的含氮和含碳化合物。研究结果表明:CODs和氨的生物降解是多步骤的,取决于每个模块给定的环境条件;合成废水的化学成分影响所涉及的生物过程,通过硝化、异养活性、反硝化和产甲烷作用去除合成废水中的氨氮和CODs;而在工业废水中,通过部分硝化、异养活性和反硝化去除氨氮和CODs。采用多模块新型旋混式生物反应器是处理复杂工业废水的可行技术。