Journal Article

Performance of full-scale coagulation-flocculation/DAF as a pre-treatment technology for biodegradability enhancement of high strength wastepaper-recycling wastewater

Yaseen, Zaher Mundher, Ansari, Sepideh, Alavi, Javad

2018

Overview

Paper mill wastewater leads to a serious damage on the environment owing to the high content of organic matters, suspended solids, toxic substances, and lignin. Hence, exploring new treatment technologies is the passion of environmental engineers to minimize the effluent impact on the environment and cleaner production aspects. This research focused on the performance of full-scale coagulation-fluctuation/DAF system for pre-treatment of high strength wastepaper-recycling wastewater and its effect on biodegradability improvement. To optimize unit performance, optimum coagulant and flocculant doses were firstly determined by jar test without prior change and adjustment of pH in lab-scale experiments. The optimum dosages were obtained by 1500 mg L −1 polyaluminum chloride (PACl) as coagulant coupled with 40 mg L −1 cationic polyacrylamide (C-PAM) as flocculant. Percentage removals of 39 ± 10, 6.8 ± 3.6, 31.0 ± 6.7, 24.0 ± 3.8, and 33.0 ± 20.0 were achieved for COD, sCOD, BOD 5 , sBOD 5 , and color, respectively. The average BOD 5 to COD ratio after pre-treatment increased from 0.44 to 0.5, whereas the ratio of sBOD 5 /sCOD dropped from 0.65 to 0.53. A superior effectiveness in reduction of TSS (98.1%) and VSS (98.4%) was also achieved. The results show that the application process is able to prevent malfunction operation in the following bioreactors which is obtainable through bio-treatability enhancement of pre-treated wastewater and reducing the risks of clogging and sludge washout. Attached growth processes are suggested to be applied in the further anaerobic/aerobic processes because of high proportion of soluble fraction of COD in the effluent to avoid poor floc formation and dispersed growth problems.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Acrylic Resins - chemistry / Aluminum Hydroxide - chemistry / Anaerobic processes / Aquatic Pollution / Biodegradability / Biodegradation / Biodegradation, Environmental / Biological Oxygen Demand Analysis / Bioreactors / chlorides / Coagulants / Coagulation / color / Earth and Environmental Science / Ecotoxicology / Effluents / Environment / Environmental Chemistry / Environmental engineering / Environmental Health / Environmental impact / Environmental science / flocculants / Flocculation / High strength / Industrial Waste / Industrial wastewater / Jar tests / Lignin / Optimization / Paper industry wastes / polyacrylamide / Pretreatment / Pulp & paper mills / pulp and paper mills / Recycling / Research Article / Risk reduction / Sewage - chemistry / Sludge / Solid suspensions / Suspended solids / Toxic substances / toxicity / Variation / Waste Disposal, Fluid - instrumentation / Waste Disposal, Fluid - methods / Waste Water - chemistry / Waste Water Technology / Wastewater / Wastewater treatment / Water Management / Water Pollution Control