Utilization of fly ash and waste lime from pulp and paper mills in the Argon Oxygen Decarburization process

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

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ENVIRONMENTAL IMPACT OF PULP AND PAPER MILLS

Environmental Engineering and Management Journal ◽

10.30638/eemj.2012.012 ◽

2012 ◽

Vol 11 (1) ◽

pp. 81-85 ◽

Cited By ~ 5

Author(s):

Dan Gavrilescu ◽

Adrian Catalin Puitel ◽

Gheorghe Dutuc ◽

Grigore Craciun

Keyword(s):

Environmental Impact ◽

Pulp And Paper ◽

Pulp And Paper Mills ◽

Paper Mills

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Water Pollution Abatement in Small Paper Mills in India

Water Science & Technology ◽

10.2166/wst.1988.0006 ◽

1988 ◽

Vol 20 (1) ◽

pp. 37-48 ◽

Cited By ~ 1

Author(s):

L. Panneerselvam

Keyword(s):

Water Pollution ◽

Wastewater Treatment ◽

Raw Materials ◽

Pollution Abatement ◽

Pulp And Paper ◽

Operating Costs ◽

Small Scale ◽

Pulp And Paper Mills ◽

Paper Mills ◽

Recovery System

In order to reduce the demand for the forest based raw materials by the organised industrial sectors like the large integrated pulp and paper mills, the Government of India started promoting several small-scale pulp and paper mills based on non-wood agricultural residue raw materials. However promotion of these small mills has created another environmental problem i.e. severe water pollution due to non-recovery of chemicals. Because of the typical characteristics like high silica content etc. of the black liquor produced and the subsequent high capital investment needed for a recovery system, it is not economically feasible for the small Indian mills to recover the chemicals. While the quantity of wastewater generated per tonne of paper produced by a small mill is same as from a large integrated pulp and paper mill with a chemical recovery system, their BOD load is four times higher, due to non recovery of chemicals. However the existing wastewater disposal standards are uniform for large and small mills for e.g. 30 mg BOD/l. To meet these standards, the small mills have to install a capital intensive wastewater treatment plant with heavy recurring operating costs. Therefore the feasible alternative is to implement various pollution abatement measures, with the objective of not only reducing the fibre/chemical loss but also to reduce the investment and operating costs of the final wastewater treatment system. To illustrate this approach, a case study on water pollution abatement and control in a 10 TPD mill, will be discussed.

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Biotreatability test of bleach wastewaters from pulp and paper mills

Water Science & Technology ◽

10.2166/wst.1997.0492 ◽

1997 ◽

Vol 35 (2-3) ◽

pp. 101-108

Author(s):

X. Wang ◽

T. H. Mize ◽

F. M. Saunders ◽

S. A. Baker

Keyword(s):

Wastewater Treatment ◽

Pulp And Paper ◽

Reductive Dehalogenation ◽

Continuous Reactor ◽

Batch Reactors ◽

Aerobic Treatment ◽

Pulp And Paper Mills ◽

Paper Mills ◽

Degradation Rates ◽

Adsorbable Organic Halide

Research is focused on an integrated way to simultaneously optimize the bleaching operations and subsequent wastewater treatment for pulp and paper mills. Bleach wastewaters from ClO2-bleached pulping studies at Institute of Paper Science and Technology (IPST) were used as the feed for batch reactors to test and rank the treatability and kinetics. The key aspect of the system is the use of sequential anaerobic/aerobic phases to enhance reductive dehalogenation of chloro-organic materials. Two continuous reactor systems, one operated in an anaerobic-aerobic mode and a second in an aerobic-aerobic mode, received bleaching wastewater obtained from a full-scale plant. Acclimated cultures from both continuous reactors were used to quantify the AOX (Adsorbable Organic Halide) and COD removal from various bleaching wastewaters. In general, the sequential anaerobic/aerobic treatment of bleach wastewater can improve both biotreatability and degradation rates.

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Neutralization of Acidic Wastewater from a Steel Plant by Using CaO-Containing Waste Materials from Pulp and Paper Industries

Materials ◽

10.3390/ma14102653 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2653

Author(s):

Tova Jarnerud ◽

Andrey V. Karasev ◽

Pär G. Jönsson

Keyword(s):

Fly Ash ◽

Pulp And Paper ◽

Waste Materials ◽

Paper Mills ◽

Steel Mills ◽

Lime Mud ◽

Set Up ◽

Pulp And Paper Industries ◽

The Given ◽

Acidic Wastewater

In this study, CaO-containing wastes from pulp and paper industries such as fly ash (FA) and calcined lime mud (LM) were utilized to neutralize and purify acidic wastewaters from the pickling processes in steel mills. The investigations were conducted by laboratory scale trials using four different batches of wastewaters and additions of two types of CaO-containing waste materials. Primary lime (PL), which is usually used for the neutralization, was also tested in the same experimental set up in the sake of comparison. The results show that these secondary lime sources can effectively increase the pH of the acidic wastewaters as good as the commonly used primary lime. Therefore, these secondary lime sources could be potential candidates for application in neutralization processes of industrial acidic wastewater treatment. Moreover, concentrations of metals (such as Cr, Fe, Ni, Mo and Zn) can decrease dramatically after neutralization by using secondary lime. The LM has a purification effect from the given metals, similar to the PL. Application of fly ash and calcined lime mud as neutralizing agents can reduce the amount of waste from pulp and paper mills sent to landfill and decrease the need for nature lime materials in the steel industry.

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