Greenhouse gas emissions from open-type anaerobic wastewater treatment system in natural rubber processing factory

Abstract

We evaluated greenhouse gases (GHGs) emissions from an open-type anaerobic system (OAS) treating ribbed smoked sheets (RSS) wastewater in a processing factory. The emitted biogas comprised 57.7%-60.8% methane, 14.5%-31.5% carbon dioxide, 10.8%-24.7% nitrogen, and 329-423 ppm of nitrous oxide. In the OAS, the chemical oxygen demand (COD) degraded as the methane emission rate increased from influent to effluent. Finally, 94.4% of the total COD was removed. More than 90% of the removed COD converted to methane. Methane emitted from the bottom and the wall surface of the OAS. Methane-producing bacteria was detected by a cloning analysis of the 16S rRNA gene. The predominant species differed depending on the degradation characteristics of the RSS wastewater in the OAS. The emission rate of methane and nitrous oxide ranged between 2.58 and 8.85 NL/(m 2 .hr) and between 0.074 and 0.410 NL/(m 2 /hr), respectively. Moreover, 0.153 t-CO 2eq of GHGs were emitted from 1 m 3 of RSS wastewater treatment. Nitrous oxide accounted for 65% of the total GHGs emissions because of its high global warming potential. Therefore, both nitrous oxide and methane that emitted from the treatment of wastewater from a natural rubber processing factory must be considered as significant contributors to the GHGs.

Anaerobic Baffled Reactor in Treatment of Natural Rubber Processing Wastewater: Reactor Performance and Analysis of Microbial Community

“…The proliferation of Methanosaeta in group II showed correlation between the microbiomes and the degradable COD in terms of the VFA variation and gas production. Although, among acetoclastic methanogens Methanosarcina typically predominates over Methanosaeta at high acetate concentrations because of their considerably higher maximum specific utilization rate [26], Methanosaeta predominated over Methanosarcina in the sludge of the anaerobic reactors treating rubber wastewater [5][6][7]10]. The result from the relative rates between these two methanogens in this study is in good agreement with those reported previously.…”

“…Arcobacter, which grows under microaerophilic conditions, is a facultative anaerobic bacterium that reduces nitrate to nitrite [23]. In addition, Tanikawa et al have reported that ammonia was oxidized to nitrate and nitrite at the surface of an open-type anaerobic baffled lagoon [10]. Therefore, ammonia in the wastewater can be oxidized or retained in the influent and utilized by Arcobacter.…”

“…Moreover, the compartmentalization may promote phase separation (hydrolysis, acidogenesis and methanogenesis) longitudinally down the reactor. Laboratory-scale [7,9] and pilot-scale [10,11] studies on the use of ABR for the treatment of natural rubber processing wastewater have been reported. However, different profiles of the wastewater discharged from natural rubber processing are observed because of the chemicals used during the coagulation of rubber latex, for example, sulfuric acid [9,12] or organic acids [6,7] in Thailand or Vietnam, respectively.…”

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

“…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][12][13]. These factories applied the open-type, anaerobic-aerobic system for wastewater treatment (Figure 1).…”

Application of Anaerobic Baffled Reactor for Agro-Industrial Wastewater Treatment

“…5 In the treatment of wastewater from natural rubber processing, the compartments of the ABR near the inlet serve as rubber traps from which rubber material can be recovered and reactor clogging can be prevented. 6,7 Previous studies describe the treatment of sulfate-rich wastewater including molasses and concentrated latex wastewater using a two-stage system that separates the biodegradation process into a sulfate reduction phase and a methane production phase to prevent hydrogen sulfide inhibition of methane-producing archaea. [3][4][5][6][7][8] The ABR, on the other hand, can separate the sulfate-reduction and methane-production phases using different compartments within a single-stage reactor.…”