Modernization of Anaerobic Bioreactor for Waste Water Purification Plant

Analysis of literature sources suggests that the use of anaerobic treatment methods is especially effective for high concentrations of contaminants in wastewater, as well as for large volumes of water supplied for treatment, which is typical for industrial wastewater. In biotechnological production and food industry, waste water has a high level of pollution with organic compounds, it is advisable to use anaerobic treatment methods. Anaerobic wastewater treatment processes are characterized by low energy consumption and the ability to recover energy through the combustion of methane. To ensure the required temperature regime for the operation of the bioreactor, a new design of the heat exchange device of the anaerobic bioreactor with immobilized microorganisms has been developed. This design of the bioreactor can provide the required degree of wastewater purification at significantly lower costs for construction, operation, and material and energy resources. For clarity, the design features were designed bioreactor with a plane load of bundled software SOLIDWORKS and a mathematical model of the processes of anaerobic wastewater treatment.

Design flaws in compact plants for wastewater treatment in food industry enterprises

The results of adjustment work, carried out at the local sewage treatment plants of food industry enterprise are presented in this paper. The enterprise has two sites, designed for the treatment of high and medium concentration effluents with a low pH value (3.5-5.5). Concentrated effluents are treated under anaerobic conditions in a compact installation consisting of a waste receiver, an anaerobic bioreactor, centrifuge thickener, centrifuge, flocculant preparation units and reagents. Wastes of medium concentration after neutralization are treated under aerobic conditions. The structure of this compact unit includes first-stage flotators, aerotanks operating for incomplete biological treatment, and second-stage flotators. Foam of the first stage and excess activated sludge of flotation devices of the second stage are dewatered on filter presses without treatment. The essence of the commissioning work consists in a detailed analysis of design solutions for both sites, study of the wastewater composition of high and medium concentration, systematization of operational data, which will allow operation to select the optimal operating mode of the main structures (anaerobic bioreactor and aeration tank). On the basis of the performed work, the optimal technological scheme of the unit for anaerobic digestion of high-concentration effluents has been developed and proposed. It is recommended to abandon the use of reagents, introduced before the flotation devices of the first and the second stages, due to an increase in the working pressure in the saturator for a compact installation designed for the treatment wastewater of medium concentration.

Investigating the effect of temperature gradient on biogas production from pretreated maize straw and rice husk using multistage anaerobic bioreactor

The share of biogas in renewable energy sources is increasing as variety of feedstocks are now used for biogas production among which lignocellulosic biomass is emerging feedstock that can be used after proper pretreatment under best suited temperature. Although lot of pretreatments and temperature combinations have been tested but still there is a gap that can be filled by the current study focused on the effect of the temperature gradient (mesophilic and thermophilic) on biogas production potential of maize straw and rice husk using a modified Gompertz equation. Pretreatment was done by using alkali (NaOH and Ca(OH)2) and acids (HCl and H2SO4) each at 2, 4 and 6%.The pretreatment of crop residue with 6% NaOH degraded lignin contents significantly. The pretreated crop residue was further used for biogas production. A multistage anaerobic bioreactor containing three diagonally inline reactors provided with one water bath connected to reactors for better utilization of energy was used for biogas production. The temperature of water bath was adjusted to that the first reactor achieved 37°C and 55 °C for different experiments. The working temperatures found to be 31-37°C and 46-55°C were achieved to maintain the internal temperature of the reactors within mesophilic and thermophilice temperature ranges, respectively. The 36 days incubation time was equally divided for three reactors. The biogas production rate was297 mL/g-VSadded and 244.07 mL/g-VSadded from maize straw and rice husk under mesophilic conditions, respectively. The results showed an increased biogas yield for both feedstocks under mesophilic conditions as compared to thermophilic conditions. The central reactor showed better production as compared to other two rectors in all experiments.

Decomposition of High Organic and Moisture Content Municipal Solid Waste in Bioreactor Landfills

With the increase in waste recycling, municipal solid waste (MSW) with high organic and moisture contents are found in various landfills worldwide. If this kind of waste were put into anaerobic condition directly, the pH values will decrease sharply, which will seriously affect the biodegradation of the wastes. This study is aimed to investigate the decomposition of the type of MSW in aerobic condition before the anaerobic biodegradation. In the study, the effects of air addition and biosolids addition on the biodegradation of MSW with high organic and moisture contents were examined. Moreover, the flushing technology was compared with the leachate recirculation technology. Six simulated bioreactor landfills were set up. After about 100 days' operation, it was observed that (1) the mass reduction rate in the aerobic-anaerobic bioreactor was approximately five times of that in the anaerobic bioreactor, the leachate quality was much better than that in the anaerobic bioreactor based on the final COD, BOD 5, TS, and NH 3 concentrations. (2) biosolids have strong buffering effects and the addition of biosolids accelerated the anaerobic biodegradation progress to a great extent. Therefore, it was concluded that initially degrading MSW under aerobic condition before anaerobic degradation with biosolids addition is the optimum strategy for the decomposition of MSW with high organic and moisture contents.

Decomposition of High Organic and Moisture Content Municipal Solid Waste in Bioreactor Landfills

With the increase in waste recycling, municipal solid waste (MSW) with high organic and moisture contents are found in various landfills worldwide. If this kind of waste were put into anaerobic condition directly, the pH values will decrease sharply, which will seriously affect the biodegradation of the wastes. This study is aimed to investigate the decomposition of the type of MSW in aerobic condition before the anaerobic biodegradation. In the study, the effects of air addition and biosolids addition on the biodegradation of MSW with high organic and moisture contents were examined. Moreover, the flushing technology was compared with the leachate recirculation technology. Six simulated bioreactor landfills were set up. After about 100 days' operation, it was observed that (1) the mass reduction rate in the aerobic-anaerobic bioreactor was approximately five times of that in the anaerobic bioreactor, the leachate quality was much better than that in the anaerobic bioreactor based on the final COD, BOD 5, TS, and NH 3 concentrations. (2) biosolids have strong buffering effects and the addition of biosolids accelerated the anaerobic biodegradation progress to a great extent. Therefore, it was concluded that initially degrading MSW under aerobic condition before anaerobic degradation with biosolids addition is the optimum strategy for the decomposition of MSW with high organic and moisture contents.