Objective:To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad(testes)of mice.Methods:Twenty-four Swiss alb...Objective:To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad(testes)of mice.Methods:Twenty-four Swiss albino mice at 4-weeks old were divided into four groups(n=6 per group).Mice of group 1 supplied with normal drinking water were served as the control group.Mice of group 2,3 and 4 were supplied normal drinking water mixed with textile dyeing wastewater at 5%,10% and 20% concentration,respectively.After completing 24 weeks of treatment,different hematological profile,weight of testes,gonadosomatic index(GSI),sperm concentration and morphology were measured.Moreover,histopathological changes in testes were examined.Results:Hematocrit value and hemoglobin concentrations were decreased in all groups of wastewater-treated mice compared to the control group.Likewise,weight of testes,GSI and sperm concentration were decreased significantly in wastewater-treated mice in comparison to the control group.The percentage of morphologically healthy epididymal sperm was significantly reduced in wastewater-treated mice.Histopathological examination revealed degenerative changes in seminiferous tubules,a smaller number of spermatogenic cells,elongation of seminiferous tubules and degenerative changes of seminiferous tubules in wastewater-treated mice.Conclusions:Textile dyeing wastewater has harmful effects on hematological profile and reproductive health of male mice.展开更多
BLUE calico is a traditional Chinese handmade printed fabric.Dyed in indigo,it has a blue base with white patterns.Tongxiang,a city in east China’s Zhejiang Province,is well-known for printing and dyeing blue calico....BLUE calico is a traditional Chinese handmade printed fabric.Dyed in indigo,it has a blue base with white patterns.Tongxiang,a city in east China’s Zhejiang Province,is well-known for printing and dyeing blue calico.The craft boasts a history of a millennium in the town with its heyday in the Tang(618-907)and Song(960-1279)dynasties.The technique was widely applied by the general public during the Ming and Qing dynasties(1368-1911).展开更多
As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conduc...As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.展开更多
Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability,specifically in the field of azo dye wastewater degradation.However,the problem...Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability,specifically in the field of azo dye wastewater degradation.However,the problems like difficulty in preparation and poor cycling stability need to be solved.At present,Mg-based amorphous alloys applied in wastewater degradation are available in powder and ribbon.The amorphous alloy powder fabricated by ball milling has a high specific surface area,and its reactivity is thousands of times better than that of gas atomized alloy powder.But the development is limited due to the high energy consumption,difficult and costly process of powder recycling.The single roller melt-spinning method is a new manufacturing process of amorphous alloy ribbon.Compared to amorphous powder,the specific surface area of amorphous ribbon is relatively lower,therefore,it is necessary to carry out surface modification to enhance it.Dealloying is a way that can form a pore structure on the surface of the amorphous alloys,increasing the specific surface area and providing more reactive sites,which all contribute to the catalytic performance.Exploring the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition,choosing suitable method to preparation and surface modification,reducing cost,expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice.展开更多
Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular slu...Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.展开更多
Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan p...Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan particles (FCCP), was examined. The effects ofpH, stirring time, sedimentation time and temperature on color, COD, turbidity and NH3-N removal were determined. The optimum dosage of FCCP and the influence of individual factors on removal efficiency were tested. The optimum parameters determined using the L16 (45) orthogonal experiment were as follows: FCCP (weight ratio of chitosan to fly-ash 1:6) dosage, 4 g.L^-1; temperature, 35℃; pH, 4. The stirring time and sedimentation time were 20 min and 5 h, respectively. Under these optimum conditions, the color, COD and NH3-N removal ratios were 97%, 80% and 75%, respectively.展开更多
In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics ...In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.展开更多
The problem of colority control of printing and dyeing wastewater has become a technical problem that plagues related companies.Bentonite is an adsorbent with excellent properties.Modification of bentonite with enviro...The problem of colority control of printing and dyeing wastewater has become a technical problem that plagues related companies.Bentonite is an adsorbent with excellent properties.Modification of bentonite with environmentally friendly substances can improve its decolorization performance.In this experiment,the simulated printing and dyeing wastewater was taken as the control object,and the bentonite was modified with environmentally friendly materials such as sodium carboxymethyl cellulose(CMC)and lignin to prepare a new modified bentonite;then the modified bentonite was used to adsorb the simulated wastewater to reduce the water colority and COD;finally the relevant design of the adsorption process was made.Results indicate that M lignin∶M CMC∶M original bentonite=1∶2∶97 had the optimum treatment effect,the optimum modification temperature was 30℃ and the modification time was 4 h;the optimum conditions for the adsorption process were:pH=5,temperature=30℃,reaction time=60 min,dosage=0.05 g of modified bentonite/mL simulated dye solution.The final removal rate of colority and COD reached 95.0% and 98.2%,respectively.Compared with the original bentonite,this new modified bentonite has greater adsorption capacity and thus has greater application value.展开更多
Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kin...Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics pa-rameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the mod-erate-removal stage with B/C<0.1, COD removal could be described by a first order reaction. Then Monod equation was introduced to indicate COD removal. The reaction rate constant (K) and half saturation constant (KS) were 0.0208-0.0642 L/(gMLSS)h and 0.44-0.59 (gCOD)/L respectively at 20 C-35 C. Activation energy (Ea) was 6.05104 J/mol. By comparison of kinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.展开更多
In the past year,the downside risks of the world economy increased,and China's domestic economy was impacted by multiple factors such as pandemic situation and extreme weather disasters,and the uncertainty of the ...In the past year,the downside risks of the world economy increased,and China's domestic economy was impacted by multiple factors such as pandemic situation and extreme weather disasters,and the uncertainty of the dyeing and printing industry increased significantly.Last year,the production and benefit of the industry showed an obviously downward trend.The export of major dyeing and printing products has maintained growth,and the export performance has been good,but the rate has gradually declined.Generally speaking,in 2023,the industry and enterprises are stillfacing considerable production and operation pressure.展开更多
Textile dyeing is the second-largest polluter of water worldwide,not including salt use.After the salt is used,it is transported to landfills or the ocean.Oceans have increased 0.5%salinity over past 10 years.Textile ...Textile dyeing is the second-largest polluter of water worldwide,not including salt use.After the salt is used,it is transported to landfills or the ocean.Oceans have increased 0.5%salinity over past 10 years.Textile dyeing produces 2.8%of Global GHG,because of its huge demand of power from its operations.Now,the world’s dyeing and printing industry energy saving,consumption reduction,emission reduction,green,safety requirements are increasing.Green dyeing and printing have become the mainstream of global dyeing and printing industry in future.The continuous innovation and improvement of textile dyeing process and dyestuff is of extraordinary significance in today’s increasingly severe energy situation.展开更多
This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis ...This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis methods,and composite materials on the degradation efficiency of these pollutants.Our analysis reveals the versatile and promising nature of magnesium ferrite-based catalysts,offering the valuable insights into their practical application for restoring the environment.Due to the smaller band gap and magnetic nature of magnesium ferrite,it holds the benefit of utilising the broader spectrum of light while also being recoverable.The in-depth analysis of magnesium ferrites'photocatalytic mechanism could lead to the development of cheap and reliable photocatalyst for the wastewater treatment.This concise review offers a thorough summary of the key advancements in this field,highlighting the pivotal role of the magnesium ferrite based photocatalysts in addressing the pressing global issue of organic pollutants in wastewater.展开更多
Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examinat...Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examination of magnesium oxide(MgO)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye removal.The review comprehensively explores various aspects of MgO nanoparticles,including their structural characteristics and synthesis techniques.The article delves into the morphology and crystallographic arrangement of MgO nanoparticles,offering insights into their structural attributes.Given the complexity of adsorption processes,the review identifies and analyzes parameters influencing the adsorption efficiency of MgO nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing ions.The interplay between these parameters and the adsorption capability of MgO nanoparticles emphasizes the importance of optimizing operational conditions.Furthermore,the review assesses various synthesis methods for MgO nanoparticles,including sol-gel,hydrothermal,precipitation,green synthesis,solvothermal,and template-assisted techniques.It discusses the advantages,limitations,and resulting nanoparticle characteristics of each method,enabling readers to grasp the implications of synthesis processes on adsorption efficiency.This comprehensive review consolidates current insights into the effectiveness of MgO nanoparticles as a potent nanoadsorbent for removing heavy metals and dyes from wastewater covering a wide spectrum of aspects related to MgO nanoparticles.Moreover,there is a need to investigate the use of MgO in the treatment of actual wastewater or river water,in order to leverage its cost-effectiveness and high efficiency for practical water treatment applications in real-time.展开更多
A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was exc...A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.展开更多
[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, lac...[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, laccase dosage on the decolorization of indigo dyeing wastewater by laccase/HBT, and then the synergism of laccase and acid cellulase was analyzed. [Result] Using ABTS as the substrate, the kinetic parame- ters, K,, and Vmax, were 0.318 mmol/L and 0.035 5 mmol/( L . min) respectively. The decolorization rate of indigo reached 96.5% when the lacca- se acted on indigo for 40 min with HBT as an introducer at temperature 50 ℃, pH =4.5, indigo concentration 100 mg/L, HBT concentration 0.1% and laccase dosage 100 lU/L. Due to the synergism of laccase and acid cellulase during the bio-finishing of blue jeans, the backstaining degree of blue jeans reduced by 85% when the amount of laccase added was 15 000 IU/kg. Menawhile, the synergism of the laccase and acid cellulase de- creased indigo concentration in wastewater by 83.8%. [ Conclusion ] The laccase from Coriolus versicolor had a good prospect in the bio-finishing of blue jeans and the decolorization of indigo dyeing wastewater.展开更多
Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems: underwater pulsed electrical discharge (UPED) and underwater dielectric barrier discharge (UDBD). Reacti...Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems: underwater pulsed electrical discharge (UPED) and underwater dielectric barrier discharge (UDBD). Reactive Blue 4 (RB4) and Acid Red 4 (AR4) were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.展开更多
Considering that Fe,Al elements in bauxite residue are active components for water purification,an effective polyaluminum ferric chloride(PAFC)coagulant derived from bauxite residue,with Fe2O3 content>5.1%,Al2O3%&g...Considering that Fe,Al elements in bauxite residue are active components for water purification,an effective polyaluminum ferric chloride(PAFC)coagulant derived from bauxite residue,with Fe2O3 content>5.1%,Al2O3%>6.5%,basicity>65%,was successfully prepared.The effect of as-prepared PAFC on the zeta potential for printing and dyeing wastewater was investigated.Comparing with polyferric chloride(PFC)and polyferric sulfate(PFS)for printing and dyeing wastewater treatment,prepared bauxite residue-based PAFC exhibited the optimal performance in the aspects of chromaticity and chemical oxygen demand(COD)removal rate.Furthermore,the combination of bauxite residue-based PAFC and PFS for synergy coagulation of such wastewater demonstrated an obvious positive effect.With the proportion between as-prepared PAFC and PFS to be 2.5:1,the COD of treated wastewater could be further reduced to meet the national level A standard of China,providing a promising route to solve the problem of substandard printing and dyeing sewage outfall by a simple coagulation strategy.展开更多
The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons(Zr-AC, Ni-AC, Zn-AC) were successfully fabricated through microwave irradiation method. The synthesized nanoparticles ...The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons(Zr-AC, Ni-AC, Zn-AC) were successfully fabricated through microwave irradiation method. The synthesized nanoparticles were characterized using XRD, HR-SEM, XPS and BET. The optical properties of Zr-AC, Ni-AC and Zn-AC composites were investigated using UV–Vis diffuse reflectance spectroscopy. The photocatalytic efficiency was verified in the degradation of textile dyeing wastewater(TDW) in UV light irradiation. The chemical oxygen demand(COD) of TDW was observed at regular intervals to calculate the removal rate of COD. Zn-AC composites showed impressive photocatalytic enrichment, which can be ascribed to the enhanced absorbance in the UV light region, the effective adsorptive capacity to dye molecules, the assisted charge transfer and the inhibited recombination of electron-hole pairs. The maximum TDW degradation(82% COD removal) was achieved with Zn-AC. A possible synergy mechanism on the surface of Zn-AC was also designed. Zn-AC could be reused five times without exceptional loss of its activity.展开更多
An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio ...An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio of BOD 5/COD was less than 0.13. By the A/O MBR process, the average removal of COD, BOD 5, color and turbidity was 82%, 96%, 71% and 99%, respectively. The average COD, BOD 5, color and turbidity of effluent was 37 mg/L, 0.8 mg/L, 40 DT and 0.44 NUT respectively. The effluent COD met the local standard of reuse water in Beijing, China. The average COD volume load of the anaerobic biological tank was 0.0483 kgCOD/(m 3·d) and that of the aeration tank of the MBR was 0.3589 kgCOD/(m 3·d). The sludge load of the MBR was 0.19 kgCOD/(kg·MLSS·d) on average and the maximum of that was 0.4 kgCOD/(kg·MLSS·d). The flux of the A/O membrane bioreactor could be remained at larger than 50 L/(h·m 2·0.1MPa). The results indicated that A/O membrane bioreactor has technical feasibility for treatment of woolen mill wastewater.展开更多
The research investigated the performance of combined process (flocculation pretreatment-pho- to catalysis). The characteristics of nano flocculation and photocataly were evaluated by simulated dye and surfactant wast...The research investigated the performance of combined process (flocculation pretreatment-pho- to catalysis). The characteristics of nano flocculation and photocataly were evaluated by simulated dye and surfactant wastewater. In the coagulation and settling period, decolorization rate of five dyes wastewater by nano flocculant was higher than 95%. In the photocatalytic period, degradation of twelve sodium dodecyl benzene sulfonate reached 33%. Washing and dyeing wastewater treated by combined process conformed to the “textile dyeing and finishing industry back to the water quality standard” (FZ/T 01107-2011). The results showed that the combined process was highly advanced treatment for washing and dying wastewater.展开更多
基金funded by the Ministry of Science and Technology of the Government of People’s Republic of Bangladesh(163-BS/2020-2021).
文摘Objective:To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad(testes)of mice.Methods:Twenty-four Swiss albino mice at 4-weeks old were divided into four groups(n=6 per group).Mice of group 1 supplied with normal drinking water were served as the control group.Mice of group 2,3 and 4 were supplied normal drinking water mixed with textile dyeing wastewater at 5%,10% and 20% concentration,respectively.After completing 24 weeks of treatment,different hematological profile,weight of testes,gonadosomatic index(GSI),sperm concentration and morphology were measured.Moreover,histopathological changes in testes were examined.Results:Hematocrit value and hemoglobin concentrations were decreased in all groups of wastewater-treated mice compared to the control group.Likewise,weight of testes,GSI and sperm concentration were decreased significantly in wastewater-treated mice in comparison to the control group.The percentage of morphologically healthy epididymal sperm was significantly reduced in wastewater-treated mice.Histopathological examination revealed degenerative changes in seminiferous tubules,a smaller number of spermatogenic cells,elongation of seminiferous tubules and degenerative changes of seminiferous tubules in wastewater-treated mice.Conclusions:Textile dyeing wastewater has harmful effects on hematological profile and reproductive health of male mice.
文摘BLUE calico is a traditional Chinese handmade printed fabric.Dyed in indigo,it has a blue base with white patterns.Tongxiang,a city in east China’s Zhejiang Province,is well-known for printing and dyeing blue calico.The craft boasts a history of a millennium in the town with its heyday in the Tang(618-907)and Song(960-1279)dynasties.The technique was widely applied by the general public during the Ming and Qing dynasties(1368-1911).
文摘As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.
基金supported by the National Natural Science Foundation of China(Grant No.52071276)the Natural Science Foundation of Chongqing,China(Grant No.CSTB2022NSCQ-MSX0440)the Fundamental Research Funds for the Central Universities(Grant No.SWUXDJH202313,SWU-KQ22083).
文摘Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability,specifically in the field of azo dye wastewater degradation.However,the problems like difficulty in preparation and poor cycling stability need to be solved.At present,Mg-based amorphous alloys applied in wastewater degradation are available in powder and ribbon.The amorphous alloy powder fabricated by ball milling has a high specific surface area,and its reactivity is thousands of times better than that of gas atomized alloy powder.But the development is limited due to the high energy consumption,difficult and costly process of powder recycling.The single roller melt-spinning method is a new manufacturing process of amorphous alloy ribbon.Compared to amorphous powder,the specific surface area of amorphous ribbon is relatively lower,therefore,it is necessary to carry out surface modification to enhance it.Dealloying is a way that can form a pore structure on the surface of the amorphous alloys,increasing the specific surface area and providing more reactive sites,which all contribute to the catalytic performance.Exploring the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition,choosing suitable method to preparation and surface modification,reducing cost,expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice.
文摘Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.
基金Supported by the Science and Technology Development Foundation of Foshan (No.2005060071)
文摘Printing and dyeing industry is a considerable source of environmental contamination. In this study treatment of printing and dyeing wastewater with a new type of sewage treatment agent, fly-ash coated with chitosan particles (FCCP), was examined. The effects ofpH, stirring time, sedimentation time and temperature on color, COD, turbidity and NH3-N removal were determined. The optimum dosage of FCCP and the influence of individual factors on removal efficiency were tested. The optimum parameters determined using the L16 (45) orthogonal experiment were as follows: FCCP (weight ratio of chitosan to fly-ash 1:6) dosage, 4 g.L^-1; temperature, 35℃; pH, 4. The stirring time and sedimentation time were 20 min and 5 h, respectively. Under these optimum conditions, the color, COD and NH3-N removal ratios were 97%, 80% and 75%, respectively.
基金Supported by Key Project of National Water Pollution Control and Treatment Science and Technology(2014ZX07211-001)Demonstration Study on Integration Model of Environmental Public Utilities in Industrial Parks of Key Watershed(2014ZX07211-001-04)
文摘In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.
基金Supported by Project of Shandong Province Natural Science Foundation of China(ZR2015PC022&BS2014HZ011)
文摘The problem of colority control of printing and dyeing wastewater has become a technical problem that plagues related companies.Bentonite is an adsorbent with excellent properties.Modification of bentonite with environmentally friendly substances can improve its decolorization performance.In this experiment,the simulated printing and dyeing wastewater was taken as the control object,and the bentonite was modified with environmentally friendly materials such as sodium carboxymethyl cellulose(CMC)and lignin to prepare a new modified bentonite;then the modified bentonite was used to adsorb the simulated wastewater to reduce the water colority and COD;finally the relevant design of the adsorption process was made.Results indicate that M lignin∶M CMC∶M original bentonite=1∶2∶97 had the optimum treatment effect,the optimum modification temperature was 30℃ and the modification time was 4 h;the optimum conditions for the adsorption process were:pH=5,temperature=30℃,reaction time=60 min,dosage=0.05 g of modified bentonite/mL simulated dye solution.The final removal rate of colority and COD reached 95.0% and 98.2%,respectively.Compared with the original bentonite,this new modified bentonite has greater adsorption capacity and thus has greater application value.
文摘Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics pa-rameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the mod-erate-removal stage with B/C<0.1, COD removal could be described by a first order reaction. Then Monod equation was introduced to indicate COD removal. The reaction rate constant (K) and half saturation constant (KS) were 0.0208-0.0642 L/(gMLSS)h and 0.44-0.59 (gCOD)/L respectively at 20 C-35 C. Activation energy (Ea) was 6.05104 J/mol. By comparison of kinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.
文摘In the past year,the downside risks of the world economy increased,and China's domestic economy was impacted by multiple factors such as pandemic situation and extreme weather disasters,and the uncertainty of the dyeing and printing industry increased significantly.Last year,the production and benefit of the industry showed an obviously downward trend.The export of major dyeing and printing products has maintained growth,and the export performance has been good,but the rate has gradually declined.Generally speaking,in 2023,the industry and enterprises are stillfacing considerable production and operation pressure.
文摘Textile dyeing is the second-largest polluter of water worldwide,not including salt use.After the salt is used,it is transported to landfills or the ocean.Oceans have increased 0.5%salinity over past 10 years.Textile dyeing produces 2.8%of Global GHG,because of its huge demand of power from its operations.Now,the world’s dyeing and printing industry energy saving,consumption reduction,emission reduction,green,safety requirements are increasing.Green dyeing and printing have become the mainstream of global dyeing and printing industry in future.The continuous innovation and improvement of textile dyeing process and dyestuff is of extraordinary significance in today’s increasingly severe energy situation.
文摘This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis methods,and composite materials on the degradation efficiency of these pollutants.Our analysis reveals the versatile and promising nature of magnesium ferrite-based catalysts,offering the valuable insights into their practical application for restoring the environment.Due to the smaller band gap and magnetic nature of magnesium ferrite,it holds the benefit of utilising the broader spectrum of light while also being recoverable.The in-depth analysis of magnesium ferrites'photocatalytic mechanism could lead to the development of cheap and reliable photocatalyst for the wastewater treatment.This concise review offers a thorough summary of the key advancements in this field,highlighting the pivotal role of the magnesium ferrite based photocatalysts in addressing the pressing global issue of organic pollutants in wastewater.
基金the support of the Khalifa University internal funding CIRA-2021-071(8474000416),Khalifa University,UAEthe financial support from the Science batch of 1976-1980 of the University of Peradeniya,Sri Lanka。
文摘Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examination of magnesium oxide(MgO)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye removal.The review comprehensively explores various aspects of MgO nanoparticles,including their structural characteristics and synthesis techniques.The article delves into the morphology and crystallographic arrangement of MgO nanoparticles,offering insights into their structural attributes.Given the complexity of adsorption processes,the review identifies and analyzes parameters influencing the adsorption efficiency of MgO nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing ions.The interplay between these parameters and the adsorption capability of MgO nanoparticles emphasizes the importance of optimizing operational conditions.Furthermore,the review assesses various synthesis methods for MgO nanoparticles,including sol-gel,hydrothermal,precipitation,green synthesis,solvothermal,and template-assisted techniques.It discusses the advantages,limitations,and resulting nanoparticle characteristics of each method,enabling readers to grasp the implications of synthesis processes on adsorption efficiency.This comprehensive review consolidates current insights into the effectiveness of MgO nanoparticles as a potent nanoadsorbent for removing heavy metals and dyes from wastewater covering a wide spectrum of aspects related to MgO nanoparticles.Moreover,there is a need to investigate the use of MgO in the treatment of actual wastewater or river water,in order to leverage its cost-effectiveness and high efficiency for practical water treatment applications in real-time.
文摘A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.
基金Supported by the Foundation for Young Scholars of Educational Commission of Jiangxi Province,China (Foundation)National Natural Science Foundation of China (51064011)
文摘[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, laccase dosage on the decolorization of indigo dyeing wastewater by laccase/HBT, and then the synergism of laccase and acid cellulase was analyzed. [Result] Using ABTS as the substrate, the kinetic parame- ters, K,, and Vmax, were 0.318 mmol/L and 0.035 5 mmol/( L . min) respectively. The decolorization rate of indigo reached 96.5% when the lacca- se acted on indigo for 40 min with HBT as an introducer at temperature 50 ℃, pH =4.5, indigo concentration 100 mg/L, HBT concentration 0.1% and laccase dosage 100 lU/L. Due to the synergism of laccase and acid cellulase during the bio-finishing of blue jeans, the backstaining degree of blue jeans reduced by 85% when the amount of laccase added was 15 000 IU/kg. Menawhile, the synergism of the laccase and acid cellulase de- creased indigo concentration in wastewater by 83.8%. [ Conclusion ] The laccase from Coriolus versicolor had a good prospect in the bio-finishing of blue jeans and the decolorization of indigo dyeing wastewater.
基金supported by the Ministry of Education, Science & Technology (MEST)the National Research Foundation of Korea (NRF)
文摘Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems: underwater pulsed electrical discharge (UPED) and underwater dielectric barrier discharge (UDBD). Reactive Blue 4 (RB4) and Acid Red 4 (AR4) were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.
基金Project(BE2015628)supported by Jiangsu Province Science and Technology Support Program,China
文摘Considering that Fe,Al elements in bauxite residue are active components for water purification,an effective polyaluminum ferric chloride(PAFC)coagulant derived from bauxite residue,with Fe2O3 content>5.1%,Al2O3%>6.5%,basicity>65%,was successfully prepared.The effect of as-prepared PAFC on the zeta potential for printing and dyeing wastewater was investigated.Comparing with polyferric chloride(PFC)and polyferric sulfate(PFS)for printing and dyeing wastewater treatment,prepared bauxite residue-based PAFC exhibited the optimal performance in the aspects of chromaticity and chemical oxygen demand(COD)removal rate.Furthermore,the combination of bauxite residue-based PAFC and PFS for synergy coagulation of such wastewater demonstrated an obvious positive effect.With the proportion between as-prepared PAFC and PFS to be 2.5:1,the COD of treated wastewater could be further reduced to meet the national level A standard of China,providing a promising route to solve the problem of substandard printing and dyeing sewage outfall by a simple coagulation strategy.
基金financial support rendered by the Salesians of Don BoscoDimapur Province+1 种基金NagalandNorth East India
文摘The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons(Zr-AC, Ni-AC, Zn-AC) were successfully fabricated through microwave irradiation method. The synthesized nanoparticles were characterized using XRD, HR-SEM, XPS and BET. The optical properties of Zr-AC, Ni-AC and Zn-AC composites were investigated using UV–Vis diffuse reflectance spectroscopy. The photocatalytic efficiency was verified in the degradation of textile dyeing wastewater(TDW) in UV light irradiation. The chemical oxygen demand(COD) of TDW was observed at regular intervals to calculate the removal rate of COD. Zn-AC composites showed impressive photocatalytic enrichment, which can be ascribed to the enhanced absorbance in the UV light region, the effective adsorptive capacity to dye molecules, the assisted charge transfer and the inhibited recombination of electron-hole pairs. The maximum TDW degradation(82% COD removal) was achieved with Zn-AC. A possible synergy mechanism on the surface of Zn-AC was also designed. Zn-AC could be reused five times without exceptional loss of its activity.
文摘An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio of BOD 5/COD was less than 0.13. By the A/O MBR process, the average removal of COD, BOD 5, color and turbidity was 82%, 96%, 71% and 99%, respectively. The average COD, BOD 5, color and turbidity of effluent was 37 mg/L, 0.8 mg/L, 40 DT and 0.44 NUT respectively. The effluent COD met the local standard of reuse water in Beijing, China. The average COD volume load of the anaerobic biological tank was 0.0483 kgCOD/(m 3·d) and that of the aeration tank of the MBR was 0.3589 kgCOD/(m 3·d). The sludge load of the MBR was 0.19 kgCOD/(kg·MLSS·d) on average and the maximum of that was 0.4 kgCOD/(kg·MLSS·d). The flux of the A/O membrane bioreactor could be remained at larger than 50 L/(h·m 2·0.1MPa). The results indicated that A/O membrane bioreactor has technical feasibility for treatment of woolen mill wastewater.
文摘The research investigated the performance of combined process (flocculation pretreatment-pho- to catalysis). The characteristics of nano flocculation and photocataly were evaluated by simulated dye and surfactant wastewater. In the coagulation and settling period, decolorization rate of five dyes wastewater by nano flocculant was higher than 95%. In the photocatalytic period, degradation of twelve sodium dodecyl benzene sulfonate reached 33%. Washing and dyeing wastewater treated by combined process conformed to the “textile dyeing and finishing industry back to the water quality standard” (FZ/T 01107-2011). The results showed that the combined process was highly advanced treatment for washing and dying wastewater.