alexa Commentary on Appropriate Wastewater Treatment System for a Natural Rubber Processing Factory | Open Access Journals
ISSN: 1948-5948
Journal of Microbial & Biochemical Technology
Like us on:
Make the best use of Scientific Research and information from our 700+ peer reviewed, Open Access Journals that operates with the help of 50,000+ Editorial Board Members and esteemed reviewers and 1000+ Scientific associations in Medical, Clinical, Pharmaceutical, Engineering, Technology and Management Fields.
Meet Inspiring Speakers and Experts at our 3000+ Global Conferenceseries Events with over 600+ Conferences, 1200+ Symposiums and 1200+ Workshops on
Medical, Pharma, Engineering, Science, Technology and Business

Commentary on Appropriate Wastewater Treatment System for a Natural Rubber Processing Factory

Daisuke T*

Department of Civil and Environmental Engineering, National Institute of Technology, Kure College, Japan

*Corresponding Author:
Daisuke T
Department of Civil and Environmental Engineering
National Institute of Technology
Kure College, Japan
E-mail: [email protected]

Received date: July 05, 2017; Accepted date: July 11, 2017; Published date: July 18, 2017

Citation: Daisuke T (2017) Commentary on Appropriate Wastewater Treatment System for a Natural Rubber Processing Factory. J Microb Biochem Technol 9:159-161. doi:10.4172/1948-5948.1000360

Copyright: © 2017 Daisuke T. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Visit for more related articles at Journal of Microbial & Biochemical Technology

Abstract

In this commentary, the process performance of natural rubber processing wastewater systems was evaluated and compared. The key factors evaluated in here comprised the following: the type of wastewater, the prevention of system clogging by coagulated rubber, and the reduction of greenhouse gas (GHG) emissions. This commentary examined these variables in existing systems and in a pilot-scale reactor system for wastewater treatment. Then an appropriate wastewater treatment system was proposed.

Keywords

Natural rubber processing wastewater; Greenhouse gas emissions; Two stage UASB-DHS system; Sulfate reduction; Energy and resource recovery

Introduction

The natural rubber industry is one of the most important agroindustries in South-east Asia [1]. In a natural rubber processing factory, natural rubber latex (NR latex) extracted from para rubber trees is processed into three types of rubber products: ribbed smoked sheet (RSS) rubber, technically specified rubber (TSR), and concentrated latex (CL) [2-4]. Both RSS and TSR are categorized as block rubber, which is produced by the coagulation of NR latex. Conversely, the centrifugation of NR latex produces CL.

On average, 20 m3 of wastewater is discharged for each ton of rubber produced [5]. The major pollutants in the wastewater are ammonia and organic acids such as acetic acid and formic acid, used to preserve and coagulate NR latex, respectively [6]. Furthermore, CL wastewater contains high concentrations of sulfate. Sulfuric acid is used in the processing of skim latex. Currently, open-type, anaerobicaerobic systems, such as conventional lagoon systems, are used to treat wastewater [7]. However, these systems have high environmental loading of greenhouse gas (GHG) emissions, low effluent water quality, malodor, groundwater pollution, and other negative environmental effects [8,9]. Therefore, an appropriate wastewater treatment system for the natural rubber industry is required [10]. In this commentary, the performance of both existing open-type wastewater treatment systems, i.e., the pilotscale two-stage up-flow anaerobic sludge blanket (UASB) and the downflow hanging sponge (DHS) reactor systems (two-stage UASB-DHS systems), were compared. Finally, an appropriate wastewater treatment system was proposed based on the findings.

The process performance of existing open-type wastewater treatment systems in natural rubber processing factories

Tanikawa et al. investigated the process performance of four existing treatment systems for treating natural rubber processing wastewater in Thailand (one factory) and Vietnam (three factories) [11-13]. These factories applied the open-type, anaerobic-aerobic system for wastewater treatment (Figure 1). Most of the factories achieved the effluent standard or water quality in the final effluent water (in the Vietnam factories, standard B). Process performance of these systems was similar with other wastewater treatment system of Vietnamese and Malaysian natural rubber processing factories [1-5]. However, these factories consumed large amounts of electricity for wastewater treatment, particularly for the aerobic treatment of CL wastewater and in the post-treatment phase of anaerobic treatment. In case of two Vietnamese factories (factory B and C), power consumption for wastewater treatment was higher than that for natural rubber production due to the stricter effluent standard required for nitrogen compounds. Furthermore, methane and nitrous oxide were emitted as GHGs from the anaerobic treatment system; nitrous oxide accounted for 65% of the total GHG emissions (surveyed at factory D). In general, methane is considered to be the main GHG emitted from open-type anaerobic systems that treat organic wastewater. GHG emissions from natural rubber processing wastewater treatment systems were not considered because in this treatment process, the chemical oxygen demand (COD) concentration is lower than that seen in other agro-industrial wastewaters, such as palm oil mill effluent (POME) and molasses wastewater. However, the potential for the nitrous oxide to be emitted from natural rubber processing wastewater treatment systems was estimated to be approximately the same as nitrous oxide emissions emitted from POME treatment. Therefore, the natural rubber industry should be considered as a target industry for clean development mechanism applications, as is the palm oil industry (Figure 1).

microbial-biochemical-technology-wastewater-treatment

Figure 1: Flow chart for the existing wastewater treatment system in the natural rubber processing factories (In Thailand: factory A; In Vietnam: factory B, C and D).

The process performance of the two-stage UASB-DHS system for the treatment of CL and RSS wastewater

Tanikawa et al. conducted a pilot-scale experiment of a two-stage UASB-DHS system (Figure 2) for treating CL wastewater, a highly contaminated wastewater containing high concentrations of organic matter, ammonia nitrogen, and sulfate, in Thailand (at factory A) [13]. The system achieved 95.7% of COD removal at 0.8 kg COD/(m3.d). In the treatment of sulfate-rich wastewater, methanogenesis was inhibited by the hydrogen sulfide that was produced by sulfate reduction [14]. In the first stage of the UASB, 80% of the COD removed was degraded by sulfate reduction, with more than 90% sulfate consumption. As a result, both generation and inhibition of hydrogen sulfide were reduced in the second stage of the UASB. Therefore, it was suggested that by separating the stages of COD removal caused by sulfate reduction, methane production, a higher efficiency of CL wastewater treatment could be achieved. Furthermore, the power consumption of the twostage UASB-DHS system was estimated to be 95% less than that of the existing activated sludge system.

microbial-biochemical-technology-installed-factory

Figure 2: Flow chart for the two-stage UASB-DHS system installed in factory A and D.

Watari et al. conducted a pilot-scale experiment of the two-stage UASB-DHS system (Figure 2) for the treatment of RSS wastewater, which contained residual rubber particles, in Vietnam (at factory D) [15]. The system achieved 94.9% COD removal at 1.5 kg COD/(m3.d). In case of RSS wastewater treatment, the system was clogged due to the coagulation of rubber particles in the wastewater. In addition, retained sludge containing rubber particles floated in the first stage of the UASB treatment due to its lower specific gravity. This material washed out in the second stage of the UASB. At this instance, the second stage of the UASB was configured as a sedimentation tank. Therefore, recovery of residual rubber particles in the wastewater should be considered to prevent system failure in RSS wastewater treatment. Regarding GHG emissions, the two-stage UASB-DHS system reduced 92% of GHG emissions compared with existing wastewater treatment system. These results indicated that a closed system can reduce nitrous oxide by recovery in addition to reducing methane emissions.

In both CL and RSS wastewater treatments, the DHS achieved a higher removal efficiency of COD and nitrogen with less aeration than the existing aerobic systems, such as aerated lagoons and activated sludge systems. Furthermore, the recovered methane was estimated to meet the standards of operation for natural rubber production wastewater treatment systems (Figure 2 and Table 1).

Waste water treatment system CDO removal (%) GHG s Emission
(t-CO2 e/m3-ww)
Power consumption
(k Wh/m3-ww)
Factory A 92.4 0.072 0.5
Factory B 97.6 0.192 9
Factory C 97.6 0.175 4.6
Factory D 94.5 0.157 0.001
Two-staged UA SB-DHS system 94.9 0.011 0.05

Table 1: Process performance of wastewater treatment system in factory A, B, C, D and two-stage UASB-DHS system.

Table 1 shows the process performance of wastewater treatment system in factory A, B, C, D and two-stage UASB-DHS system. These results indicated that two-stage UASB-DHS system has advantages for not only COD removal, but also reduction of GHG emissions and power consumption.

Conclusion

In the treatment of natural rubber processing wastewater, hydrogen sulfide inhibition and the clogging of the system by coagulated rubber need to be considered in the wastewater processing method used for CL and block rubber, respectively. In addition, both GHG emissions and power consumption need to be reduced in wastewater treatment. Hydrogen sulfide inhibition was prevented during COD removal by sulfate reduction and methane production in the two stage system. Both GHG emissions and power consumption were reduced by the application of a closed anaerobic system. However, coagulated rubber still clogged the system. In currently used open-type wastewater treatment systems, accumulation of coagulated rubber was confirmed at the surface and it was recovered later in the process as a rubber resource. However, GHGs were emitted from this system. Therefore, a pretreatment system for rubber recovery without the associated GHG emissions is required. Hence, a combination system of both an anaerobic baffled reactor (ABR), which is a high-rate closed anaerobic system, and a DHS (ABRDHS system) was proposed for natural rubber processing wastewater treatment. The ABR separated wastewater treatment into phases, which included rubber recovery, hydrolysis, acidification, sulfate reduction, and methane production by compartmentalization. In addition, ABR demonstrated a high performance of solid/liquid separation. Thus, ABR can achieve rubber resource recovery, sulfate reduction, and methane recovery in a single reactor. In future, our research of the ABR-DHS system for natural rubber processing wastewater treatment will be reported.

Acknowledgement

This research was supported by the ESCANBER (Establishment of Carbon- Cycle-System with Natural Rubber) project supported by the JST/JICA, SATREPS (Science and Technology Research Partnership for Sustainable Development), JSPS KAKENHI (Grant No.: 16K18176) and Iwatani Foundation’s Research Grant, Japan.

References

Select your language of interest to view the total content in your interested language
Post your comment

Share This Article

Relevant Topics

Recommended Conferences

Article Usage

  • Total views: 247
  • [From(publication date):
    August-2017 - Oct 23, 2017]
  • Breakdown by view type
  • HTML page views : 212
  • PDF downloads :35
 

Post your comment

captcha   Reload  Can't read the image? click here to refresh

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords