Clean Water the Clean Way
One product is the solution for problems over the decades in wastewater treatment, fish kills, dead zone, aquatic food chain, aquaculture, agriculture...
Nualgi facilitates the growth of diatoms. It prevents the growth of waterweeds, water hyacinth, Green algae and blue-green algae and other waste plants in lakes, ponds, rivers and other water bodies. Other algae like blue Green algae disrupt the ecosystem in water.
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The paper-making process is one of the most water-intensive industrial production processes. This is because, without the physical properties of water, it would not be possible for a consistent structure to be achieved when the constituents of paper are processed in sludge. A high level of water consumption is inevitable in the processing of natural raw materials (wood, Cellulose vegetable fibers) and also in the process of recycling waste paper. This creates a high level of wastewater for processing. The residues in the wastewater are a problem particularly in the case of de-inking: the process of recycling printed waste paper.
This section provides details on the latest developments and efforts in the petrochemical industry waste water treatment.
We have discussed the following:
- Current Wastewater Treatment Process - Paper and Pulp Industry
- New Technologies in the Paper and Pulp Industry Waste Water Treatment.
- Paper Recycling
- Advanced Treatment by Chemical Oxidation of Pulp And Paper Effluent from A Plant Manufacturing Hardboard From Waste Paper
- The Treatment of Pulp And Paper Mill Effluent: A Review
- Application of Ultrafiltration - Complexation Process for Metal Removal from Pulp and Paper Industry Wastewater
- Advanced Oxidation of a Pulp Mill Bleaching Wastewater
- Treatment of Pulp And Paper Mill Wastewater by Polyacrylamide (PAM) in Polymer Induced Flocculation
- Biological Treatment of a Pulp and Paper Industry Effluent by Fomes Lividus and Trametes Versicolor
- Optimized Design of Wastewater Treatment Systems: Application to the Mechanical Pulp and Paper Industry: I. Design and Cost Relationships
Current Treatment Process Wastewater Treatment - Paper and Pulp Industry
Pollution Characteristics of Paper and Pulp Mill Waste1
The Kaft process is an alkaline process. The lignin is cracked by NaOH or Na2S, which is very effective at different kind of woods especially the wood contains pollutions. Disadvantage is the odour problem, based on thiols and sulfides.
The sulphite process is a procedure based on acids. The effect is not the same compared to the alkaline process. The procedure is more sensitive, against pollution. Branches and bark disturb the chemical process and will not solute as well as the wood. Also resin disturbs the process.
- The NSSC (Neutral Sulphite Semichemical) is most used. The yield of this process is approximately 75%,
- The TMP (Thermo-Mechanical Process) is generally used for newsprint paper.
- The new CTMP (Chemi-Thermo-Mechanical Process) is high efficient (approx. 95%)
Combinations of anaerobic and aerobic treatment processes are found to be efficient in the removal of soluble biodegradable organic pollutants. Color can be removed effectively by fungal treatment, coagulation, chemical oxidation, and ozonation. Chlorinated phenolic compounds and adsorable organic halides (AOX) can be efficiently reduced by adsorption, ozonation and membrane filtration techniques.3
Biological Treatment of Wastewater by Anaerobic or Aerobic Processes
The Purac company offers Customized Water and Wastewater Treatment Plants and Solutions. Wastewater can be treated anaerobically (ANAMET) followed by an activated sludge stage, or by a biofilm aerobic method alone or in combination with an activated sludge stage.
Some of the methods used for wastewater treatment in a paper and pulp industry are as follows:
- Dissolved Air Flotation (DAF)
- Sand filtration
- Floofilter™, combining flotation and filtration in one unit
- Lamella sedimentation
- High-loaded pressure sand filtration
- Membrane filtration
The Purac DAFRapide™ is an improved Dissolved Air Flotation (DAF) system, which increases the surface loading by four to six times - while still reducing capital costs. The new DAF technology was first installed at Fiskeby Board AB in Sweden as a final chemical precipitation treatment after a biological treatment plant. The second installation of DAFRapide™ was successfully started at the beginning of 2004 for production of 1,300m³/h of raw water for Stora Enso Nymölla's production of pulp and fine paper.
Advanced Treatment by Chemical Oxidation of Pulp and Paper Effluent from a Plant Manufacturing Hardboard from Waste Paper
This study attempts to evaluate the applicability of chemical oxidation processes to polish biologically treated effluent of a plant manufacturing hardboard from waste paper to comply with the discharge limit of 120 mg l-1 chemical oxygen demand (COD). In the first step, a chemically assisted settling was applied. The optimum results were obtained with alum plus lime with the alum dose of 200 mg l-1. In the second step, chemically assisted settling effluent was fed into an activated sludge system and over 80% COD removal was achieved. In the last step of the experimental study, a series of ozone oxidation and Fenton oxidation methods were tested to remove residual COD. Ozone oxidation provided 80% COD removal. An ozone dose of 40 mg min-1 with a reaction time of two hours was found to be optimum. Catalytic ozonation by using ferric iron, as well as high pH ozonation, Fenton process and H2O2/O3 oxidation did not prove to be more efficient than plain ozonation under this study conditions.4
The use of enzymes for wastewater treatment in the pulp and paper industry is reviewed as a new possibility. There is currently a lot of research activity in the enzymology of lignin degradation. Ligninase, cellulase, peroxidase, etc. are the most important enzymes, especially peroxidase, which is used for color removal in bleaching effluents. It is also possible to mix enzymes together with special microbes, which normally do not have high enzyme activity, and remove recalcitrant and harmless compounds from wastewater. The use of novel enzymes and rDNA technology in sludge and wastewater treatment will also be discussed.5
Depending of the agents to bleach the pulp, waste water has to be treated. Bleaching with peroxides, oxygen and ozone is not as efficient as using chlorine or chlorine dioxide, but the water has generally a very low or no amount of to treatment chemicals. By using chloride or chloride dioxide, the water contains these agents which increase the AOX. On the other hand, chloride bleaching is the most efficient.
The waste water of paper recycling contains also particles which have to be filtrated. Rests of plastics, metal parts (paper clips, etc.) other waste have to be removed.6
The Treatment of Pulp and Paper Mill Effluent: A Review
The manufacture of paper generates significant quantities of wastewater; as high as 60 m3/tonne of paper produced. The raw wastewaters from paper and board mills can be potentially very polluting. Indeed, a recent survey within the UK industry has found that their chemical oxygen demands can be as high as 11 000 mg/l. This paper reviews the processes involved in paper making and examines the effects which they could have on the environment. It also evaluates the treatment processes which are used to minimise these effects. In line with the majority of UK practice, it focuses mainly on aerobic biological treatment and, in particular, on the activated sludge process. This means that there is an in-depth discussion about the problems associated with filamentous bacteria and sludge “bulking”. The paper also discusses the way in which anaerobic digestion can be applied to the treatment of liquid wastes from the manufacture of paper.7
Application of Ultrafiltration-Complexation Process for Metal Removal from Pulp and Paper Industry Wastewater
In recent years, the pulp and paper industries have been trying different technologies to reduce fresh water consumption in paper mills. This has led to a fast development of new wastewater treatment technologies for industrial reuse. Lately, water-soluble polymeric ligands have shown to be powerful substances to remove trace metals from industrial wastewater through ultrafiltration (UF). In the present study, polyethyleneimine (PEI) and polyvinylalcohol (PVA) were used as water-soluble polymeric macroligands. The UF experiments were carried out in stirred dead-end cells. The membrane used was formed from polyvinilidene fluoride (PVDF). The performance of water-soluble polymeric ligands was evaluated by determining metal removal and chemical oxygen demand (COD). In general, the complexation–ultrafiltration process was efficient for metal removal from wastewater, leading to a better effluent quality when compared to ultrafiltration without any ligands addition.8
Advanced Oxidation of a Pulp Mill Bleaching Wastewater
The degradation, by several advanced oxidation reactions, of a pulp mill ECF bleaching effluent, was studied. The initial biodegradability of the organic matter present in the effluent, estimated as the BOD5/COD, was low (0.3). When the effluent was submitted to ozonation and to five different advanced oxidation systems (O3/UV, O3/UV/ZnO, O3/UV/TiO2, O2/UV/ZnO, O2/UV/TiO2), the biodegradability increase significantly. After five minutes of reaction, the O3/UV system appears as the most efficient in to transform the organic matter to more biodegradable forms. A similar effect was observed when the effluent was submitted to an activated sludge treatment. The COD, TOC and toxicity reduction correlated well with the biodegradability enhancement after AOPs treatments.9
Treatment of Pulp and Paper Mill Wastewater by Polyacrylamide (PAM) in Polymer Induced Flocculation
The Flocculation performances of nine cationic and anionic polyacrylamides with different molecular weights and different charge densities in the treatment of pulp and paper mill wastewater have been studied. The experiments were carried out in jar tests with the polyacrylamide dosages range of 0.5–15 mg l−1, rapid mixing at 200 rpm for 2 min, followed by slow mixing at 40 rpm for 15 min and settling time of 30 min. The effectiveness of the polyacrylamides was measured based on the reduction of turbidity, the removal of total suspended solids (TSS) and the reduction of chemical oxygen demand (COD). Cationic polyacrlyamide Organopol 5415 with very high molecular weight and low charge density is found to give the highest flocculation efficiency in the treatment of the paper mill wastewater. It can achieve 95% of turbidity reduction, 98% of TSS removal, 93% of COD reduction and sludge volume index (SVI) of 14 ml g−1 at the optimum dosage of 5 mg l−1. SVI values of less than 70 ml g−1 are found for all polyacrylamide at their respective optimum dosage. Based on the cost evaluation, the use of the polyacrylamides is economically feasible to treat the pulp and paper mill wastewaters. This result suggests that single-polymer system can be used alone in the coagulation–flocculation process due to the efficiency of the polyacrylamide. Sedimentation of the sludge by gravity thickening with settling time of 30 min is possible based on the settling characteristics of the sludge produced by Organopol 5415 that can achieve 91% water recovery and 99% TSS removal after 30 min settling.10
Biological Treatment of a Pulp and Paper Industry Effluent by Fomes Lividus and Trametes Versicolor
White rot fungi Fomes lividus and Trametes versicolor, isolated from the Western Ghats region of Tamil Nadu, India, were used to treat pulp and paper industry effluents on a laboratory scale and in a pilot scale. On the laboratory scale a maximum decolourization of 63.9% was achieved by T. versicolor on the fourth day. Inorganic chloride at a concentration of 765 mg/l, which corresponded to 227% of that in the untreated effluent, was liberated by F. lividus on the 10th day. The chemical oxygen demand (COD) was also reduced to 1984 mg/l (59.3%) by each of the two fungi. On the pilot scale, a maximum decolourization of 68% was obtained with the 6-day incubation by T. versicolor, inorganic chloride 475 mg/l (103%) was liberated on the seventh day by T. versicolor, and the COD was reduced to 1984 mg/l corresponding to 59.32% by F. lividus. These results suggested that F. lividus seems to be another candidate efficient for dechlorination of wastewater.11
Optimized Design of Wastewater Treatment Systems: Application to the Mechanical Pulp and Paper Industry: I. Design and Cost Relationships
Four different end-of-pipe waste-treatment processes applicable to mechanical pulp and paper manufacture were modelled. Calculated costs for an average mill were capital $34-$44 million, operating cost $3.5-$6 million/year and discounted (10 years) $60-$85 million. Compared with mill reported values, capital and operating costs of activated sludge treatment (AST) were higher by 17 and 29%, respectively; those for aerated stabilization basin (ASB) were higher by 27 and 180%. Major variables affecting the costs were BOD and TSS levels and the wastewater-to-pulp ratio. It was concluded that ASB is more economical than AST and that anaerobic treatment plus AST could be advantageous at high BOD levels.12
1 B.C. Punmia, Ashok Kumar Jain., 1998. Waste Water Engineering .New Delhi : Laxmi Publications (p) Ltd.
4Nay O. T; Erdeml E; Kabdali I; lmez T, 2008. Advanced treatment by chemical oxidation of pulp and paper effluent from a plant manufacturing hardboard from waste paper. Environmental Technology, 29 (1045 – 1051).
5Pratima Bajpai and Pramod K. Bajpai, 1994. Biological colour removal of pulp and paper mill wastewaters. Journal of Biotechnology, 33 (211-220).
7Thompsona G., Swainb J., Kayb M.and Forster C. F, 2001. The treatment of pulp and paper mill effluent: a review. Bioresource Technology 77 (275-286).
8Vieiraa M, Tavaresa C. R, Bergamascoa R and Petrus J. C. C, 2001. Application of ultrafiltration-complexation process for metal removal from pulp and paper industry wastewater. Journal of Membrane Science, 194 (273- 276).
9MaCristina Yeber, Jaime Rodríguez, Juanita Freer, Jaime Baeza, Nelson Durán and Héctor D. Mansilla. 1999. Advanced oxidation of a pulp mill bleaching wastewater. Chemosphere, 39 (1679-88).
10Wonga S.S, Tengb T.T, Ahmada A.L, Zuhairia A and Najafpourc G, 2006. Treatment of pulp and paper mill wastewater by polyacrylamide (PAM) in polymer induced flocculation. Journal of Hazardous Materials 135 (378- 388).
11Selvam K, Swaminathan K, Myung Hoon Song and Keon-Sang Chae , 2002. Biological treatment of a pulp and paper industry effluent by Fomes lividus and Trametes versicolor. Journal World Journal of Microbiology and Biotechnology 18 (523- 526).
12Mort Fels, János Pintér, David S. Lycon, 2009. Optimized design of wastewater treatment systems: Application to the mechanical pulp and paper industry: I. Design and cost relationships. The Canadian Journal of Chemical Engineering, 75 (437- 451).