This paper deals with the study of bacteriological quality of effluents that have undergone consecutively different macrofiltration system (pressure sand filter or disc filter used as a secondary treatment) and UV254 irradiation process (used as a tertiary treatment). These two successive systems of treatment were evaluated to determine their possible application as commonly alternatives to the...

Co-treatment of landfill leachate and sewage in a traditional wastewater treatment plant (WWTP) is a very common leachate management method in the United States. However, biologically recalcitrant and humic-like leachate organic matters (the major fraction of mature leachate organics) cannot be truly removed by the aerobic biodegradation in WWTPs. Prior to effluent discharge from WWTPs, chlorin...

Hand, foot and mouth disease (HFMD), caused by a group of enteric viruses such as Enterovirus 71 (EV71), Coxsackievirus A16 (CVA16) and Coxsackievirus A10 (CVA10), is heavily epidemic in East Asia. This research focused on investigating the occurrence of HFMD pathogens in domestic sewage and secondary effluent before disinfection in a wastewater treatment plant (WWTP) in Xi'an, the largest mega...

Inactivation and microbial regrowth of penicillin-, ampicillin-, cefalexin-, tetracycline-, chloramphenicol-, and rifampicin-resistant bacteria were studied to explore risks associated with selection and regrowth of antibiotic-resistant bacteria after PAA disinfection. The results showed that after exposure to 20 mg/L PAA for 10 min, inactivation of ampicillin-resistant bacteria reached 2.3-log...

The latest NPDES permit adopted for the Sacramento Regional Wastewater Treatment Plant included a requirement for tertiary treatment, equivalent to the water quality requirements of Title 22, unrestricted use recycled water. Initial cost projections for the required plant upgrades exceeded $2 billion to upgrade the 691 ML/day (181 mgd) facility. To help in the selection process for tertiary tre...

Wastewater recycling and reuse through agricultural irrigation can provide an economical means of preventing pollution of surface water sources, while conserving water resources and valuable nutrients for increased crop production and grazing pastures. With proper methods of wastewater treatment, health risks to farmers and farm animals as well as to the public who consume agricultural produce ...

Cavitation, induced by ultrasound at low frequencies, is an effective means for the disintegration of bacterial cells. Two effects can be observed: At low ultrasound doses bacteria flocs can be declumped by mechanical shear stresses, and at increased doses ultrasound cavitation has an impact on the cell walls such that they are broken. In lab scale experiments a horn sonotrode operated at 20 kH...

The threat of bacterial contaminants in water distribution systems and in the environment is of unremitting concern for environmental engineers. This problem is compounded by the overuse of antibiotics and the resulting increased prevalence of antibiotic resistant pathogens in engineered waste streams and hospital wastewater effluents. Through defects in sewer systems these pathogens are furthe...

background: photoreactivation of microorganisms following uv disinfection is a disadvantage of using uv technology for wastewater treatment, since in some cases it may even reach several logarithms. the aim of this study was to evaluate the possibility of the photoreactivation of indicator bacteria (coliform and streptococci) in the irradiated effluent. methods: this study was performed using t...