In rubber skim block production process, use of sulfuric acid is a general practice making this wastewater acidic (pH 2.4±0.5) and high in organics (COD 14,911±1,819 mg/L) and sulfate (6,506±1,038 mg/L). When combined with those from other parts of the factory, it will cause difficulty in anaerobic treatment systems due to the hydrogen sulfide (H2S) produced from sulfate reduction. This gas is odorous, corrosive to metals and toxic to microorganisms in the treatment system. This work is thus divided into 2 parts; the first part aimed to pretreat this wastewater in separate prior to combining with other wastewaters which could facilitate efficient anaerobic digesters that follow, and the second part focused on the conversion of H2S to sulfuric acid which can be re-used in the factory. Results indicated that pH of the wastewater should be adjusted to around 8 to maintain neutral pH in the reactor to allow effective sulfidogenesis. The anaerobic sequencing batch reactor (ASBR) had shown superior performance over UASB in promoting sulfate reduction due to the ability to retain biomass within the reactor. As for H2S conversion, higher air mix to the biogas gave higher sulfide removals and sulfuric acid production in organic media biofilter. However, high mixture of air would render biogas unsuitable for use due to the substantial dilution of methane. Other ways to supply oxygen to the biofilm must be sought. Without any nutrient addition, a wastewater from rubber skim block production was proven to effectively be used as liquid medium in the biofilter. Therefore, pretreating sulfate rich wastewater and recovering sulfuric acid by bioconversion could be possible in concentrated latex industry.