Papers by Keyword: BOD

Abstract: The tofu industries in Indonesia produce a considerable amount of liquid waste. Most of these tofu industries do not treat waste properly. Liquid waste is channeled directly to the nearest water stream, and thus the values of COD, BOD and TSS are considerably high, which can damage the aquatic ecosystems. According to the Indonesian government rule (Permen LH no.5/2014), the maximum levels of COD, BOD and TSS are 300 mg/L, 150 mg/L, and 200 mg/L. One of alternative methods to reduce these three parameters is the ozonation method. Ozone is able to break down organic components well because of its strong oxidative properties (2.07 mV) and it can decompose into OH radicals which have stronger oxidative properties (2.80 mV). The objectives of this study are to reduce the levels of COD, BOD and TSS of tofu liquid waste into below of the maximum level set by the Indonesian government rule and to study the effect of pH conditions on the effectiveness of ozonation process. Ozonation is carried out under conditions at acidic pH, alkaline pH, and neutral pH, and with a waste concentration of 10%. Ozonation is done by flowing ozone directly into the waste for 120 minutes with an interval of 30 minutes. The levels of BOD, COD, and TSS before ozonation were 1,200 mg/L, 880 mg/L and 600 mg/L. After ozonation, it was found that the levels of COD, BOD and TSS of the waste without any pre-treatment (or acidic condition) was able to be reduced by 46.6%, 44.5% and 41.6%, respectively. Whereas, in neutral conditions the decreases of COD, BOD, and TSS were about 64.3%, 67.0%, and 62.4%, respectively. Optimum ozonation was found in alkaline conditions with the decreases in COD, BOD, and TSS values were about 85.4%, 84%, and 100%, respectively.

Abstract: Alcohol wastewater is a high concentration organic wastewater, the influent BOD, high COD ratio, biodegradability is very good, should take the treatment process with biological treatment as the core. UASB+Bio-contact oxidation+ICEAS process is a new technology, sewage in the reaction process, in the anaerobic - aerobic - anoxic - aerobic anaerobic alternately, for high concentration organic wastewater by removing effect is very good. UASB+Bio-contact oxidation+ICEAS process , continuous flooding, intermittent drainage, overcomes the shortcomings of SBR process intermittent inflow; ICEAS reaction tank is arranged on the whole system, a sedimentation pool, no single set sedimentation tank, can reduce the amount of sludge.

Abstract: This paper deals with the advanced oxidation using Electro-fenton reagent for the degradation of azo-dyes in textile effluents. Discharge of textile effluents causes inevitable pollution of water resources which calls for further treatment methods. In this experiment, textile effluent samples were treated with iron electrodes with the reagents, hydrogen peroxide and ferrous sulfate .The acid dye effluents which were used in this study are Acid Orange 7, Acid Red 88, and Acid Violet 7. The temperature was set to 40° C. Samples of 20 ml were analyzed for Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Colour reduction. Experiments were carried out at voltage variations of 2, 4, 6 and 8 volts. From the results, COD and Colour were observed to be reduced drastically from respective original values before treatment with Fenton’s reagent using electro-chemical method.Key words--- Advanced oxidation, Electro-fenton, BOD, COD, Colour reduction

Abstract: COD and BOD of the inflow of aeration basin and the effluent of secondary sedimentation tank were detected through orthogonal test.The test use removal rate of COD and BOD as evaluation index, B/C as analysis index. The result of the test indicated that the best working condition can be achieved when there are 3 water pumps for inflow, the concentration of activated sludge stands at 1600mg/L, and HRT in the aeration basin and secondary sedimentation tank stand at 1.86 hours and 2.87 hours respectively. The test demonstrated that short-time aeration can reduce the energy consumption and, therefore, the cost effectively, while insure the effluent reach the outlet qualitative standard. This is suitable for sewage treatment plants in south China since the concentration of their inflow is low.

Abstract: A general three stages process to treat the integrated waste water in a laboratory scale, including anaerobic, aerobic and intensive coagulating treatment, was discussed in this paper. After being filtrated and coagulation simply, the effluent was treated with two steps of biological process combined with one step of intensive coagulation process. The result shows that the chemical impurities, including COD, BOD, colored substances and turbidity were removed efficiently,and after anaerobic biological treatment, effluent become easy to be biologically treated, and after aerobic aeration treatment, the BOD of the effluent from the clarifier was lower than 25 mg/l，and the BOD total removal ratio was as high as 90%. The result shows also that when poly aluminum silicate chloride (PASC) combing with APAM was effective to remove the colored substances more than 95%. Being treated for the three stages, the water quality of the treated effluent was higher than that discharge requirements by National Effluent Discharge Standards in China.

Abstract: As the Anaerobic Baffled Reactor (ABR) is very applicable to the wastewater treatment plant of Chinese small town, we studied about the performance of ABR at different Hydraulic Retention Times (HRTs) 、the degradation effect of the four compartments of ABR and the effect of temperature to the degradation, to offer the useful reference and instruction for actual operation.

Abstract: Pilot scale “Waste Stabilization pond” was evaluated for treating high quality waste water using aerobic process. The method involved the measure of the molecular oxygen utilized during a specified incubation period for the biochemical degradation of organic matter and oxygen used to oxidize inorganic material. Operation of the pond involved engineering construction to reduce the risk of soil and groundwater contamination. Calibration of the model using laboratory tests showed BOD for 5, 10 and 15 days as 101.9mg/l. 273.3mg/l and 426mg/l respectively. Pond efficiency was 76.19%. The design experience and post design results provided knowledge about the efficiency of a waste stabilization pond and the basis of recommendation and practice in developed cities.

Abstract: In the present study biodegradable copolymers of ethylene vinyl acetate and polylactic acid were synthesized using transesterification reactions, the structure, morphology, mechanical properties and biodegradability of the produced materials were characterized. Ethylene vinyl acetate was modified with polylactic acid in an internal mixer using titanium propoxide as transesterification catalyst. The graft copolymers were characterized by elemental analysis, infrared spectroscopy, rheology, scanning electron microscopy and thermal analysis. Selective extractions for all copolymers were made, and the results indicate that a maximum of 25 % of EVA-g-PLA copolymer was synthesized by this method. Biodegradation tests were carried out using the standard ISO 14851 (1999), which specifies a method for determining the biochemical oxygen demand in a closed respirometer. This procedure allowed to synthesize biodegradable copolymers with mechanical properties similar to conventional polymers.

Abstract: Batch treatment of palm oil mill effluent (POME) was investigated using physical, chemical and biological methods. Physiochemical parameters such as pH, sulphate (SO42-), total dissolved solids (TDS), total suspended solid (TSS), chloride ion (Cl-), biological oxygen demand (BOD), chemical oxygen (COD) and metals (Fe2+, Zn2+, Ca2+ and Mg2+) concentrations were determined using American Public Health Association (APHA) methods. The results revealed that significant treatment was achieved at each stage. However, the biological method proved to be the best with percentage reductions of 45.6%, 97.6%, 71,0%, 50.1%, 80.4%, 93.8%, 72.0%, 85.4%, 93.2%, 77.7%, 86.2% and 85.7% for pH, SO42-, TS, TDS, TSS, Cl-, BOD, COD, Fe2+, Zn2+, Ca2+ and Mg2+ respectively. The concentrations after treatment were in conformity with the minimum acceptable standard of FEPA and WHO.

Abstract: This study was conducted to test the performance of various combinations of coagulants for effective wastewater treatment of the tire recycling industry. From the Jar-test results, two kinds of coagulants, namely AlSi-1 and PASi-1, were found to be effective in decreasing BOD and CODCr values from the polluted wastewater among various combinations of coagulants. In comparison to Al-based or Si-based singular salts, the Si-Al combined salts (PASi-1) exhibited a higher removal efficiency of 90% turbidity, 93% SS, 70∼85% BOD5 and 85∼91% CODCr at 15± 2°C, pH7.5∼9.5 and 2.0mM of coagulant dosage. At 30±2°C of tire recycling effluents, the combination effect was clearly shown in the removal of CODCr over a wider range of pH. The reaction mechanisms of AlSi-1 and PASi-1 were also schematically studied.