scholarly journals Treatment of wastewater from separators for rainfall runoff using electrochemical oxidation processes

2021 ◽  
Vol 8 (1-2) ◽  
pp. 32-38
Author(s):  
Morana Drušković ◽  
Dražen Vouk ◽  
Mario Šiljeg ◽  
Krešimir Maldini

In recent years, industry has increased and with it the amount of oily wastewater, which are considered hazardous waste because they contain various types of heavy metals and oils that endanger the environment and human health. In the last twenty years, there has been increased research on new technologies to treat wastewater as efficiently and environmentally friendly as possible. A recent approach to wastewater treatment is the application of electrochemical processes such as the electro-Fenton process, which belongs to the group of electrochemical advanced oxidation processes and electrocoagulation. The aim of this work was to remove organic contaminants and heavy metals from wastewater originating from oil and grease separators that clean stormwater runoff from traffic areas. The use of stainless steel, iron and aluminum electrodes results in electrooxidation, electroreduction and electrocoagulation. At a current of 15 A the treatment efficiency was 50% for COD and 73% for mineral oil. At a current of 110 A the treatment efficiency was 96% for COD and 90% for mineral oil.

1998 ◽  
Vol 37 (6-7) ◽  
pp. 395-402
Author(s):  
Guus C. Stefess

A full-scale (470 m3) process for biological treatment of dredging spoil from the Petroleum Harbour in Amsterdam has been monitored during a pilot project. The dredging spoil was heavily polluted with polycyclic aromatic hydrocarbons (PAH) and mineral oil. The remediation chain involved dredging, transport of dredged spoil, hydrocyclone separation, froth flotation of the coarse particles, and biological treatment of the silt fraction (<20 μm) in stirred bioractors. The independent monitoring was aimed at recording the environmental effects, product quality and performance of the biological process. Hydrocyclone separation (cut point 20 m) resulted in two bulk streams: 65% sand and 30% silt (based on total dry weight of the input). The sand was cleaned and could be reused as building material. PAH and mineral oil were successfully concentrated in the silt fraction (<20 μm), which was treated biologically. Biological treatment during continuous feeding of fine fraction, at a residence time of 8-10 days for the entire bioreactor system, resulted in considerably reduced mineral oil and PAH contents. Furthermore, the leaching of organic contaminants was reduced, as well as the ecotoxicity. The obtained silt product however did not meet the demands, and had to be landfilled. Minor emissions of contaminants were measured in wastewater and offgas. The energy and chemicals consumption were acceptable. The biological process appears to be promising for the treatment of less-severely contaminated dredged material.


1999 ◽  
Vol 39 (6) ◽  
pp. 175-181 ◽  
Author(s):  
Abdallah Shanableh ◽  
Pushpa Ginige

The biosolids industry in Australia is evolving around the beneficial use of biosolids as a resource. Phosphorus rich biosolids from biological nutrient removal (BNR) facilities are highly desirable for land application. However, the accumulation of toxic heavy metals and industrial organic contaminants may render the biosolids unsuitable for land application. The presence of toxic heavy metals has been identified by Local Authorities in Australia as a major constraint limiting the beneficial use of biosolids. The potential of off-site contamination due to the migration of nutrients is also a major concern especially when applying biosolids to acidic agricultural land. Accordingly, the relevant environment protection and conservation agencies are involved in either developing or finalising guidelines to control the beneficial use of biosolids products. Metals bioleaching is a process achieved through bio-acidification. Bio-acidification of biosolids prior to land application can be used to dissolve and remove a significant fraction of the heavy metals content of the product. However, the process also reduces the nutrients content of the resource. Bio-acidification of Loganholme (Queensland) BNR biosolids dissolved 76% of the total phosphorus and 38% of the TKN. The heavy metals solubilisation results reached 50% for Cr, 79% for Ni, 45% for Zn, 24% for Cu, 30% for Cd, and 82% for Pb.


Author(s):  
Chiu-Wen Chen ◽  
Nguyen Thanh Binh ◽  
Chang-Mao Hung ◽  
Chih-Feng Chen ◽  
Cheng-Di Dong

AbstractThe presence of polycyclic aromatic hydrocarbons (PAHs) in sediments is a major concern of risks associated with the aquatic ecosystems through bioaccumulation in food chains. To minimize the ecological risks due to contaminated sediments, processes that can degrade the sorbed PAHs are urgently needed. The present study aims at assessing the treatment efficiency of several chemical oxidation processes using potassium permanganate (KMnO


2017 ◽  
Vol 12 (1) ◽  
pp. 139-145 ◽  
Author(s):  
E. Kweinor Tetteh ◽  
S. Rathilal ◽  
K. Robinson

The use of coagulants is essential in the diverse disciplines of conventional water and wastewater treatment. This work aimed to select an economic and effective coagulant, to minimize the cost of treatment and the oil droplet content of the water, thus enhancing the efficiency of a local South African oil refinery effluent plant recovering water and oil for reuse by treating the industrial mineral oil wastewater. A standard dissolved air flotation jar test preceded evaluation of four coagulants, viz. aluminum sulfate (Alum), aluminum chloride, ferric sulfate and ferric chloride. Chemical oxygen demand, soap oil and grease, total suspended solids and turbidity were determined as water quality parameters to check coagulant efficiency. Removal of over 70% was achieved for each parameter. The results obtained at pH 5 and coagulant dose of 50 mg/L showed that alum was the best pretreatment coagulant for destabilizing and minimizing oil droplets in water, due to its trivalent cationic nature. It was also economically viable.


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