Following the need for the use of environmentally friendly, renewable resource in industrial processes, this work explores the potential of an effective application in pilot scale of Afzelia bella seed as a coag-flocc...Following the need for the use of environmentally friendly, renewable resource in industrial processes, this work explores the potential of an effective application in pilot scale of Afzelia bella seed as a coag-flocculant. The study evaluates the coag-flocculation efficiency and functional kinetic parameter response to varying pH and dosage of coal washery effluent and ABC respectively. The maximum coag-flocculation performance is recorded at rate constant, K of 3.3333 x 10-3m3/kg.s, dosage of (0.3 and 0.2kg/m3);pH of 2 and coagulation period, τ1/2of 28.1216 s while the minimum is recorded at K of 1.6667 x 10-4m3/kg.s, dosage of 0.2kg/m3, pH of 10 and τ1/2 of 562.365 s. The least value of coag-flocculation efficiency, E (%)>89.00. Simulated and unsimulated values of rate constants Ks and K respectively are in close agreement, validating the concept of perikinetics. The potential of ABC as an effective organic coag-flocculant has been established. The results confirm that theory of rapid coagflocculation holds for the aggregation of coal washery effluent using ABC and at the conditions of the experiment.展开更多
An advanced anaerobic biofilter（AF） was introduced for the treatment of coal gasification wastewater（CGW）,and effluent recirculation was adopted to enhance phenol removal and methane production.The results indicat...An advanced anaerobic biofilter（AF） was introduced for the treatment of coal gasification wastewater（CGW）,and effluent recirculation was adopted to enhance phenol removal and methane production.The results indicated that AF was reliable in treating diluted CGW,while its efficiency and stability were seriously reduced when directly treating raw CGW.However,its performance could be greatly enhanced by effluent recirculation.Under optimal effluent recirculation of 0.5 to the influent,concentrations of chemical oxygen demand（COD） and total phenol in the effluent could reach as low as 234.0 and 14.2 mg/L,respectively.Also,the rate of methane production reached 169.0 m L CH_4/L/day.Though CGW seemed to restrain the growth of anaerobic microorganisms,especially methanogens,the inhibition was temporary and reversible,and anaerobic bacteria presented strong tolerance.The activities of methanogens cultivated in CGW could quickly recover on feeding with glucose wastewater（GW）.However,the adaptability of anaerobic bacteria to the CGW was very poor and the activity of methanogens could not be improved by long-term domestication.By analysis using the Haldane model,it was further confirmed that high effluent recirculation could result in high activity for hydrolytic bacteria and substrate affinity for toxic matters,but only suitable effluent recirculation could result in high methanogenic activity.展开更多
This study investigated the coag-flocculation performance of oxidized starch coagulant (OSC) and its blends with alum and FeCl3 in removing turbidity from coal washery effluent at room temperature. A conventional labo...This study investigated the coag-flocculation performance of oxidized starch coagulant (OSC) and its blends with alum and FeCl3 in removing turbidity from coal washery effluent at room temperature. A conventional laboratory bench-scale jar test apparatus was employed for the experiments. Coag-flocculation parameters such as reaction order α, rate constant K, coagulation time τ, etc. were determined. The optimum pH was observed at 4.0, while the blend of 30.0 mg/L FeCl3 and 250.0 mg/L OSC achieved the optimum turbidity removal. Turbidity removal efficiency was recorded between 96.0% and 99.9% for various dosages and pH studied. The coagulation rate constants, K recorded range from 9.393 × 10-5 L/mg.min to 8.294 × 10-1 min-1, while coagulation periods τ, range from 3.8 s to 235.7 s for various dosages and pH studied. The use of OSC blended with FeCl3 showed high level of efficiency, for the treatment of coal washery effluent.展开更多
This work investigates the influence of pH variation on coag-flocculation kinetics and performance of Chitin Derived Coag-flocculant (CDC) in removal of Suspended and Dissolved Particles (SDP) from Coal washery efflue...This work investigates the influence of pH variation on coag-flocculation kinetics and performance of Chitin Derived Coag-flocculant (CDC) in removal of Suspended and Dissolved Particles (SDP) from Coal washery effluent (CWE) medium. Key parameters such as rate constant Km, half life t1/2,, and pH etc. were investigated. The best coag-flocculation performance is recorded at Km, of 0.007 l/mg.min, t1/2, of 0.0362min, pH of 8, dosage of 100mg/l and efficiency E(%) of 99.933. Minimum efficiency (%) > 94.00 was achieved at 30 minutes of coagflocculation, establishing CDC as an effective water treatment agent at the conditions of the experiment.展开更多
文摘Following the need for the use of environmentally friendly, renewable resource in industrial processes, this work explores the potential of an effective application in pilot scale of Afzelia bella seed as a coag-flocculant. The study evaluates the coag-flocculation efficiency and functional kinetic parameter response to varying pH and dosage of coal washery effluent and ABC respectively. The maximum coag-flocculation performance is recorded at rate constant, K of 3.3333 x 10-3m3/kg.s, dosage of (0.3 and 0.2kg/m3);pH of 2 and coagulation period, τ1/2of 28.1216 s while the minimum is recorded at K of 1.6667 x 10-4m3/kg.s, dosage of 0.2kg/m3, pH of 10 and τ1/2 of 562.365 s. The least value of coag-flocculation efficiency, E (%)>89.00. Simulated and unsimulated values of rate constants Ks and K respectively are in close agreement, validating the concept of perikinetics. The potential of ABC as an effective organic coag-flocculant has been established. The results confirm that theory of rapid coagflocculation holds for the aggregation of coal washery effluent using ABC and at the conditions of the experiment.
文摘An advanced anaerobic biofilter（AF） was introduced for the treatment of coal gasification wastewater（CGW）,and effluent recirculation was adopted to enhance phenol removal and methane production.The results indicated that AF was reliable in treating diluted CGW,while its efficiency and stability were seriously reduced when directly treating raw CGW.However,its performance could be greatly enhanced by effluent recirculation.Under optimal effluent recirculation of 0.5 to the influent,concentrations of chemical oxygen demand（COD） and total phenol in the effluent could reach as low as 234.0 and 14.2 mg/L,respectively.Also,the rate of methane production reached 169.0 m L CH_4/L/day.Though CGW seemed to restrain the growth of anaerobic microorganisms,especially methanogens,the inhibition was temporary and reversible,and anaerobic bacteria presented strong tolerance.The activities of methanogens cultivated in CGW could quickly recover on feeding with glucose wastewater（GW）.However,the adaptability of anaerobic bacteria to the CGW was very poor and the activity of methanogens could not be improved by long-term domestication.By analysis using the Haldane model,it was further confirmed that high effluent recirculation could result in high activity for hydrolytic bacteria and substrate affinity for toxic matters,but only suitable effluent recirculation could result in high methanogenic activity.
文摘This study investigated the coag-flocculation performance of oxidized starch coagulant (OSC) and its blends with alum and FeCl3 in removing turbidity from coal washery effluent at room temperature. A conventional laboratory bench-scale jar test apparatus was employed for the experiments. Coag-flocculation parameters such as reaction order α, rate constant K, coagulation time τ, etc. were determined. The optimum pH was observed at 4.0, while the blend of 30.0 mg/L FeCl3 and 250.0 mg/L OSC achieved the optimum turbidity removal. Turbidity removal efficiency was recorded between 96.0% and 99.9% for various dosages and pH studied. The coagulation rate constants, K recorded range from 9.393 × 10-5 L/mg.min to 8.294 × 10-1 min-1, while coagulation periods τ, range from 3.8 s to 235.7 s for various dosages and pH studied. The use of OSC blended with FeCl3 showed high level of efficiency, for the treatment of coal washery effluent.
文摘This work investigates the influence of pH variation on coag-flocculation kinetics and performance of Chitin Derived Coag-flocculant (CDC) in removal of Suspended and Dissolved Particles (SDP) from Coal washery effluent (CWE) medium. Key parameters such as rate constant Km, half life t1/2,, and pH etc. were investigated. The best coag-flocculation performance is recorded at Km, of 0.007 l/mg.min, t1/2, of 0.0362min, pH of 8, dosage of 100mg/l and efficiency E(%) of 99.933. Minimum efficiency (%) > 94.00 was achieved at 30 minutes of coagflocculation, establishing CDC as an effective water treatment agent at the conditions of the experiment.
