Process engineering in biological aerobic waste‐water treatment

Abstract

A non-comprehensive review of several technical developments in the field of aerobic biological waste-water treatment engineering is camed out, eonsidering the active role the engineers have to play in this field. This paper brings together conventional and advanced problems in the field of aerobic biological waste-water treatment. Such an overview of biological waste-water treatment also precedes comments on some important aspects concerning the microorganisms responsible for waste-water treatment as well as considerations of the application of fundamentals and kinetics to the analysis of the biological processes used most commonly for aerobic biological waste-water treatment.A survey of the development of the biological activated-sludge process and some modifications are given. Some problems implied in the conventional activated-sludge waste-water treatment are analyzed, considering conventional processes and bioreactor models (the continuous stirred-tank reactor model and the plug-flow reactor models of the activated-sludge process) as well as aerated lagoons. Further, modifications of the activated-sludge process are presented. These include additional details on the bioreactor progress and applications. with emphasis on aspects concerning airlift bioreactors and their variants, deep-shaft bioreactors and reciprocating jet bioreactors which are considered as the third generation of bioreactors owing to their important advantages in design, operation and performance in waste-water treatment. Sequencing-batch reactors and aerobic digestion processes, including conventional aerobic digestion, high-purity oxygen digestion, thermophilic aerobic digestion and cryophylic aerobic digestion are also reviewed. Finally, some aspects regarding the operational factors that are involved in the selection of the reactor type are included.

Biological treatment of milk processing wastewater in a sequencing batch flexible fibre biofilm reactor

“…Similarly, the average of 750 mg l −1 of COD effluent (89.3% removal efficiency), obtained by using the SBR biofilm for treatment of milk industry wastewater at 3 days HRT, showed an effluent concentration decrease with increased HRT. [6] About 35 mg l −1 of effluent COD was obtained with 773 mg l −1 of a synthetic wastewater treated by a sequencing batch biofilm reactor. [19] Findings reported by Bandpi and Bazari [12] for a SBR system treating dairy wastewater achieved COD removal efficiency around 90% with COD concentrations varying from 400 to 2500 mg l −1 .…”

“…[5] Therefore, aerobic methods are generally considered to be more cost effective overall. [1,6] *Correspondence to: Mohamed Abdulgader, Griffith School of Engineering, Griffith University, Nathan Campus, Brisbane, Queensland, 4111, Australia. E-mail: m.abdulgader@griffith.edu.au These processes are classified as either attached growth (biofilm) or suspended growth system.…”

Novas tendências para o tratamento de resíduos industriais contendo espécies organocloradas

“…Nos últimos anos, o grande desenvolvimento da microbiologia tem propiciado muitas alternativas que viabilizam o tratamento biológico de efluentes industriais. Trabalhos recentes têm reportado que uma gama de efluentes são tratáveis por meio destes processos [35][36][37][38][39][40] .…”

Effect of trace amounts of polyacrylamide (PAM) on long-term performance of activated sludge

“…Activated sludge process, one of the ways of biological treatment, is commonly used in domestic wastewater treatment, or in the secondary treatment of the industrial wastewater, and over 90% of the municipal wastewater treatment plants use it as the core part of the treatment process [1,2]. The basic function of activated sludge process is to convert organics to carbon dioxide, water and bacterial cells [3].…”