Printing Wastewater Research Articles

Influence of Influent pH on Ceramic Printing Wastewater Treatment

Investigated the influence of absorbency, turbidity and suspended substance in printing wastewater treatment by regulating the pH value of water treatment. Firstly, was acidified the wastewater samples to 5, 4, 3, 2, then alkalize them to 8、9、10、11、12. Calculated decolorization removal, turbidity removal and the suspended substance removal. The results show that, the decolorization removal and the turbidity removal were low after acidification. While after alkalized treatment the decolorization removal and the turbidity removal were all rise. The decolorization removal and turbidity removal increased following with the increase of pH of samples that first acidified and then alkalized. And it was the most obvious when the pH was 12. When the wastewater samples first acidized the pH to 4 and then alkalized the pH to 12, the dispose effects was the best. In these conditions, the decolorization removal and turbidity removal could reach 57.7 % and 72.8 %. After acidification, the suspended solids removal came down followed with the rise of pH value. As the water samples in same acidification value and then alkalized, with the increase of pH, the suspended solids removal first rose and then came down. It could get the best dispose effects at the pH 11, the suspended solids removal could reach 41.4 %.

Beneficial role of ZnO photocatalyst supported with porous activated carbon for the mineralization of alizarin cyanin green dye in aqueous solution

The present investigation depicts the development of a simple and low cost method for the removal of color from textile dyeing and printing wastewater using ZnO as photocatalyst supported with porous activated carbon (AC). Photocatalytic degradation studies were carried out for water soluble toxic alizarin cyanin green (ACG) dye in aqueous suspension along with activated carbon (AC) as co-adsorbent. Different parameters like concentration of ACG dye, irradiation time, catalyst concentration and pH have also been studied. The pseudo first order kinetic equation was found to be applicable in the present dye-catalyst systems. It was observed that photocatalytic degradation by ZnO along with AC was a more effective and faster mode of removing ACG from aqueous solutions than the ZnO alone.

Study on a New High-Efficiency Treatment Method of Printing and Dyeing Wastewater

The large quantity of dyeing and printing wastewater, which contains high organics which can be hardly decomposed, is one of the main sources of water pollution. Based on summarizing the existing problems of traditional processing methods, the technology of cavitation jet and impinging streams were organically combined, which has great potential in wastewater treatment field, as a new method for degrading printing and dyeing wastewater, and then the “cavitation impinging streams (CIS)” concept was proposed, in which the superior features in wastewater degradation with CIS was expounded, and the problems to be further studied were pointed out.

Integrated biological and ozone treatment of printing textile wastewater

Textile effluents are among the most difficult industrial wastewaters to treat because of their compositional variability and of the presence of numerous different chemicals intentionally designed to resist degradation. Though biological technologies offer a cheaper and more environmental friendly alternative for the treatment of textile effluents, an additional step to remove recalcitrant compounds is still needed. Integrated biological and chemical treatment is a rather new approach that allows improving treatment performance and stability without increasing too much treatment costs. Ozone integration in a sequencing batch biofilter granular reactor was tested at laboratory scale for treating a printing wastewater characterized by high concentrations of surfactants and nitrogen. The process was optimized in terms of applied organic load and ozone dose. The results have shown that the process assures the possibility to comply with the limits for direct discharge for all investigated parameters by operating at an organic load value lower than 1.5kgCOD/m3d and with an ozone dose of 135mg/l. A synergetic biological and chemical oxidation activity was observed with a ratio between ozone dose and COD removed lower than 0.75. Finally, the process was characterized by a sludge production as low as 0.17kgTSS/kgCODremoved due to the high biomass concentration in the biological system used.

Studies on reduction of colour, COD and TSS in textile dyeing and printing wastewater by coagulation and adsorption method

Studies on reduction of colour, COD and TSS in textile dyeing and printing wastewater by coagulation and adsorption method

Startup Research of DIC Hydrolysis Acidification Reactor in Printing and Dyeing Wastewater Treatment

As the main source of textile industrial pollution, printing and dyeing wastewater is usually difficult to be biodegraded. In this paper, a unique hydrolysis acidification reactor with double circulation sludge recycling system (DIC) is designed to treat simulated printing and dyeing wastewater. The results show that DIC reactor can realize quick startup with concentrated sludge of sludge concentration tank as inoculated sludge. And DIC reactor has high removal capabilities for CODcr and chroma, with efficiencies of about 70% and 60%, respectively. The sludge concentration is obviously increased. Moreover, the biodegradability of wastewater has been greatly increased to 0.38, which is favorable to the removal of organic pollutants in wastewater.

Preparation of Polysilicate Aluminium Ferric (PSFA) Using Effluents and its Application on Banknote Printing Wastewater Treatment

Based on the concept of “waste control by waste”, a kind of inorganic polymeric flocculants which was called Polysilicate Aluminium Ferric (PSFA) was made from bentonite, wastewater containing Al3+, wastewater containing Fe3+ and sulfuric acid under normal temperature conditions, and it was adopted to treat banknote printing wastewater. The experiment results revealed that the maximal Chemical Oxygen Demand (COD) removal efficiency of 95.52% with residual COD of 3571mg/L and color removal efficiency of 96% with residual color of 40 times could be achieved at the optimal dosage of 48g/L wastewater, a number of big and dense alum flocs appeared quite fast, the flocs and water could be obviously separated in a short time, the pH of coagulating effluent of which color was light green was about 4.01, the effects of coagulation were very well.

Engineering Example of High Concentration Printing and Dyeing Wastewater Processed by UBF Craft

The multi-methods of UBF-biological contact oxidation - enhanced coagulation- precipitation - fiber sand filtration has been applied to treatment a dyeing and printing wastewater, because it is with the characteristics of large flow, high CODcr, high chromaticity and toxic substances. The result showed: when the feed wate under the conditions of CODcr, BOD5, SS quality concentrations were 15000mg / L, 250mg / L,> 800mg / L and chromaticity blow 1000 times, effluent water quality can meet grade one of the national integrated wastewater discharge standards (GB8978-1996).

Study of Printing and Dyeing Wastewater Treatment by Membrane Bioreactor Enhanced by Bio-Ferric

Bio-ferric membrane bioreactor(MBR) was made through adding ferric hydroxide to traditional MBR and forming bio-ferric sludge. Through analyzing treatment efficiency of dyeing and printing wastewater in bio-ferric MBR and traditional MBR respectively, the results showed: COD removal efficiency in bio-ferric MBR was more better than that in traditional MBR which increased 10% or so, but the influence of HRT on COD removal efficiency wasn’t evident; Via changing SRT, it was obtained: bio-ferric MBR could operate in longer SRT while treatment effect couldn’t be impacted that could discharge less sludge than traditional MBR which coule get sludge minimization; bio-ferric sludge flocs could provide better survival environment for nitrobacteria that made NH3-N removal efficiency stable. The experiment illuminated: the biochemical and physical function of bio-ferric sludge could strengthen the holistic stability of the system.

Photocatalytic degradation of hazardous Ponceau-S dye from industrial wastewater using nanosized niobium pentoxide with carbon

The present communication deals with the development of a low cost method for the removal of color from textile dyeing and printing wastewater by using nanosized semiconductor Nb2O5 as photocatalyst. Photocatalytic degradation studies were carried out for water soluble hazardous Ponceau-S dye in Nb2O5 aqueous suspension along with commercial activated carbon (CAC) as co-adsorbent. Different parameters like catalyst concentration, substrate concentration, pH, and contact time have been studied. It was observed that photocatalytic degradation by nanosized Nb2O5 along with CAC was a more effective, economic and faster mode of removing Ponceau-S dye from aqueous solutions. The optimum conditions for the degradation of the dye were initial concentration 40ppm, pH 8 and catalyst concentration 5gl−1 with CAC 1gl−1. The adsorption capacity was found to be 41.05mg/g.The SEM and XRD studies were carried for morphological feature characteristics of Nb2O5/C semiconductor materials. Besides the above kinetics and isotherm studies have also been carried out.

Preparation of Interior Latex Coatings by Recycling Banknote Printing Wastewater

This paper related to the recycling of banknote printing wastewater, using which as raw materials, a low cost interior latex coatings has been developed. This coatings is formulated based on styrene-acrylic emulsion and silicon sol as main film former. It has been shown that the performance of of this product meets the state standard of GB/T 9756-2009.

Digital textile printing (DTP) wastewater treatment using ozone and membrane filtration

Digital textile printing (DTP) is considered as an environmentally benign process because its wastewater production is relatively small compared with the conventional textile printing system. DTP is usually practiced at building office in an urban area rather than in a textile industrial complex, so that process development for on-site treatment of the DTP wastewater is currently needed. The aim of this study was to propose a DTP wastewater treatment system suitable for operation in building and to verify if the proposed system has a rationale treatment system should be compact and reliable because it should be installed near the DTP system. Thus, a hybrid system consisting of ozone, ultrafiltration (UF) and reverse osmosis (RO) was proposed for treatment of DTP wastewater. Prior to UF and RO, ozone was introduced to the DTP wastewater to reduce organic loadings to membrane filtration as well as to treat the concentrates recycled from UF and RO. When ozone was injected with C-T value of 255 g·s/L, the removal efficiency of COD and color was 63 and 81%, respectively. Ozonation of the DTP wastewater led to aggregation of colloidal particles, so that the cake resistance ( R c ) calculated after ozone and UF was lower than that of the control (= without ozonation), suggesting that pre-ozonation is beneficial to not only flux enhancement but also to good permeate water quality. Further treatment of UF permeates using RO was carried out since the UF permeates was not enough for direct discharge or reuse. Final effluents through the whole process of ozonation, UF and RO met the criteria of direct discharge and reuse, suggesting that the proposed hybrid system could be used for DTP wastewater treatment satisfactorily.

Post-treatment of banknote printing wastewater using polysilicate ferro-aluminum sulfate (PSFA)

In this paper, a new kind of inorganic polymeric flocculant (IPF)—polysilicate ferro-aluminum sulfate (PSFA) was adopted to treat banknote printing wastewater. Effects of flocculants dosage on the colour and Chemical Oxygen Demand (COD) removal were examined. Experiments revealed that maximal colour removal efficiency of 98% and COD removal efficiency of 85% could be achieved at the optimal dosage of 30.33 g/L. And the colour and COD removal results treated by the PSFA flocculant were compared with those treated by aluminum sulfate. Experimental results showed that the most attracting parts of PSFA as compared with that of Al 2(SO 4) 3 were: (i) lower COD and colour contained effluents; (ii) less quantity and volume sludge; (iii) better dewatering behaviour and solid–liquid separation flocs; (iv) providing a possibility to eliminate the high labour intensity plate-frame pressure procedure and replace it by ordinary filtration. Therefore, the using of PSFA generally offered a lower cost of operation and maintenance choice to treat banknote printing wastewater as compared to that of Al 2(SO 4) 3.

A New Method with Supersonic Focalize Decomposition and Chemical Flocculate Floating-Air to Process the Dyeing and Printing Wastewater

According to dyeing and printing wastewater of high chroma and difficult decomposition, a new ultrasonic focalize decomposition method is provide, which can decompose those are difficult to do. In this article, Dynamic adding-pressure dissolving-air, ultrasonic focalize and flocculate floating-air are assembled to advance the treatment effect. Through the research, the dynamic models of adding pressure and dissolving air and flocculate floating-air are constructed. Based on the theory research, a experiment device is designed. The effect and influence factors are discussed, which provides a new way to process dyeing and printing wastewater of high chroma and difficult decomposition.

Removal of organic compounds during treating printing and dyeing wastewater of different process units

Wastewater in Shaoxing wastewater treatment plant (SWWTP) is composed of more than 90% dyeing and printing wastewater with high pH and sulfate. Through a combination process of anaerobic acidogenic [hydraulic retention time (HRT) of 15 h], aerobic (HRT of 20 h) and flocculation–precipitation, the total COD removal efficiency was up to 91%. But COD removal efficiency in anaerobic acidogenic unit was only 4%. As a comparison, the COD removal efficiency was up to 35% in the pilot-scale upflow anaerobic sludge bed (UASB) reactor (HRT of 15 h). GC–MS analysis showed that the response abundance of these wastewater samples decreased with their removal of COD. A main component of the raw influent was long-chain n-alkanes. The final effluent of SWWTP had only four types of alkanes. After anaerobic unit at SWWTP, the mass percentage of total alkanes to total organic compounds was slightly decreased while its categories increased. But in the UASB, alkanes categories could be removed by 75%. Caffeine as a chemical marker could be detected only in the effluent of the aerobic process. Quantitative analysis was given. These results demonstrated that GC–MS analysis could provide an insight to the measurement of organic compounds removal.

The influence of aerobic sludge retention time on anaerobic co-digestion of dyeing and printing wastewater and sewage sludge

Two pilot-scale activated sludge systems comprising anaerobic baffled reactor (ABR) and aerobic plug flow reactor (PFR) were operated aiming to minimize excess sludge output of the activated sludge process through coupled alkaline hydrolysis and anaerobic digestion. Variations in the effluent total chemical oxygen demand (TCOD) and NH4 +-N concentration proved that the process not only could minimize excess sludge production but also guarantee the effluent TCOD well below the discharging limit (150 mg/l) if the inverse ratio of the aerobic sludge recirculation to anaerobic reactor did not exceed 60% for system A with 10 d aerobic sludge retention time (SRT) and 40% for system B (SRT was 25 d). The sludge activity at aerobic SRT of 25 d was evidently lower than aerobic SRT of 10 d. Those differences of sludge characteristics affected the inverse sludge ratio obviously. Aerobic bacteria after internal and external decay were converted to anoxic or anaerobic biomass. The distinct differences in sludge yield of aerobic and anaerobic/anoxic processes could explain how aerobic SRT decided excess sludge activity which consequently affected anaerobic codigestion of printing and dyeing wastewater and sewage sludge.

Research on a Banknote Printing Wastewater Monitoring System based on Wireless Sensor Network

In this paper, a banknote printing wastewater monitoring system based on WSN is presented in line with the system demands and actual condition of the worksite for a banknote printing factory. In Physical Layer, the network node is a nRF9e5-centric embedded instrument, which can realize the multi-function such as data collecting, status monitoring, wireless data transmission and so on. Limited by the computing capability, memory capability, communicating energy and others factors, it is impossible for the node to get every detail information of the network, so the communication protocol on WSN couldn't be very complicated. The competitive-based MACA (Multiple Access with Collision Avoidance) Protocol is introduced in MAC, which can decide the communication process and working mode of the nodes, avoid the collision of data transmission, hidden and exposed station problem of nodes. On networks layer, the routing protocol in charge of the transmitting path of the data, the networks topology structure is arranged based on address assignation. Accompanied with some redundant nodes, the network performances stabile and expandable. The wastewater monitoring system is a tentative practice of WSN theory in engineering. Now, the system has passed test and proved efficiently.

Effect of Color and Surfactants on Nanofiltration for the Recovery of Carpet Printing Wastewaters

Carpet printing wastewater (CPW) was spiked with metal‐complex dyes at concentrations of 10 and 30 mg/L to investigate the effect of feed color on separation performance of nanofiltration (NF). The rejection was excellent; 98–100% for color and COD under all spiking conditions. Although the flux decline increased with increasing dye concentration, the concentration polarization was the main cause of the flux decline. The effect of surfactants on NF separation performance was also investigated by preparing synthetic wastewaters with dyes and auxiliary chemicals. The presence of a non‐ionic penetrant did not adversely affect the color rejection whereas the COD rejection was reduced from 100% to 91%. Furthermore, fouling became dominant when surfactants were used.

Decolorization of triphenylmethane, azo, and anthraquinone dyes by a newly isolated Aeromonas hydrophila strain

A broad-spectrum dye-decolorizing bacterium, strain DN322, was isolated from activated sludge of a textile printing wastewater treatment plant. The strain was characterized and identified as a member of Aeromonas hydrophila based on Gram staining, morphology characters, biochemical tests, and nearly complete sequence analysis of 16S rRNA gene and the gyrase subunit beta gene (gyrB). Strain DN322 decolorized a variety of synthetic dyes, including triphenylmethane, azo, and anthraquinone dyes. For color removal, the most suitable pH and temperature were pH 5.0-10.0 and 25-37 degrees C, respectively. Triphenylmethane dye, e.g., Crystal Violet, Basic Fuchsin, Brilliant Green, and Malachite Green (50 mg l(-1)) were decolorized more than 90% within 10 h under aerobic culture condition and Crystal Violet could be used as sole carbon source and energy source for cell growth. The color removal of triphenylmethane dyes was due to a soluble cytosolic enzyme, and the enzyme was an NADH/NADPH-dependent oxygenase; For azo and anthraquinone dyes, e.g., Acid Amaranth, Great Red GR, Reactive Red KE-3B, and Reactive Brilliant Blue K-GR (50 mg l(-1)) could be decolorized more than 85% within 36 h under anoxic condition. This strain may be useful for bioremediation applications.

Dyeing and printing wastewater treatment using a membrane bioreactor with a gravity drain

A laboratory-scale membrane bioreactor (MBR) with a gravity drain was tested for dyeing and printing wastewater treatment from a wool mill. The MBR was operated with continuous permeate by gravity and without chemical cleaning for 135 days. Results showed that excellent effluent quality could meet the reuse water standard in China. The average concentrations of COD, BOD5, turbidity and color in the effluent were 36.9 mg l−1, 3.7 mg l−1, 0.2 NTU and 21 dilution times (DT), respectively. The average removal rates of COD, BOD5, turbidity and color were 80.3%, 95.0%, 99.3% and 58.7%, respectively. The membrane flux increased with increasing of aeration intensity, and its increasing rate was related to pressure-heads. The higher the pressure-head, the greater the impact of aeration intensity on membrane flux. Statistical analysis also showed that both the pressure-head and aeration intensity significantly affected membrane flux. Due to its compact design, simple operation and easy maintenance, MBR with a gravitational filtration system hs low energy consumption and is cost-effective to build and operate. If the life expectancy of the membrane is set for 3–4 years and the membrane flux is set at 15 l/m2·h, such a MBR would be very competitive.