Advanced oxidation processes (AOPs) constitute important, promising, efficient, and environmental-friendly methods developed to principally remove persistent organic pollutants (POPs) from waters and wastewaters. Generally, AOPs are based on the in situ generation of a powerful oxidizing agent, such as hydroxyl radicals (•OH), obtained at a sufficient concentration to effectively decontaminate waters. This critical review presents a precise and overall description of the recent literature (period 1990–2012) concerning the main types of AOPs, based on chemical, photochemical, sonochemical, and electrochemical reactions. The principles, performances, advantages, drawbacks, and applications of these AOPs to the degradation and destruction of POPs in aquatic media and to the treatment of waters and waste waters have been reported and compared.

Advanced Oxidation Processes in Water/Wastewater Treatment: Principles and Applications. A Review

The global population is increasing and because of this, the world may experience great fresh water scarcity. Our water resources are limited and, hence, water treatment and recycling methods are the only alternatives for getting fresh water in the coming decades. Therefore, there is a great need for the development of a suitable, inexpensive and rapid wastewater treatment techniques and reuse or conservation methods in the present century. The different types of water treatment and recycling techniques have been discussed in terms of their basic principles, applications, costs, maintenance and suitability. Additionally, a systematic approach to water treatment and recycling involving their understanding, evaluation and selection parameters has been presented. A brief guideline for the selection of the appropriate technologies for specific applications has been evaluated. This review adds to the global discussions on water scarcity solutions.

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Chemical treatment technologies for waste-water recycling—an overview

The role of ferrous ion in fenton and photo- fenton processes for the degradation of phenol

Biofouling is a critical problem in many membrane filtration processes. This review highlights the emerging strategies for polymer membrane modifications using organic and inorganic additives and surface modification to mitigate foulant deposition and biofilm formation. Constraints and opportunities for future implementation in membrane systems are outlined from the perspectives of water and wastewater treatment applications.

Strategies for controlling biofouling in membrane filtration systems: challenges and opportunities

Acid mine drainage: Prevention, treatment options, and resource recovery: A review

Photochemical oxidation of p-chlorophenol by UV/H2O2 and photo-Fenton process. A comparative study.

The use of membrane technology in the treatment of Acid Mine Drainage (AMD) can result in reduction of chemical usage and sludge production making the treatment process more environmentally friendly. This study deals with the optimization of membrane filtration performance in the treatment of AMD using two nanofiltration (NF) membranes (NF99 and DK) and one reverse osmosis (RO). All membranes were used in various tests treating a model solution at two different concentration levels in order to cover the concentration of actual AMD found in the mining industry. The main parameters which were studied to determine the optimal condition for AMD filtration are pressure, pH, temperature, and flow rate. Pressure and temperature were found to have a considerable influence on flux, while rejection was only slightly influenced by pressure. The feed flow rate had no effect on rejection. The highest flux with moderate rejection was determined for NF99 while RO had the lowest flux but highest rejection. Therefore, NF ...

Optimization Study for Treatment of Acid Mine Drainage Using Membrane Technology

Acid mine drainage (AMD) is recognized as one of the more critical environmental problems in the mining industry, with the potential of severe contamination of surface and groundwater, as well as soils. Different conventional methods are used to treat AMD such as lime neutralization, in which lime is added to AMD to raise pH and then precipitate the dissolved toxic heavy metals. In addition to a high concentration of sulphate, the sludge produced by this process has no economic value and has to be disposed of in large areas of land. Nanofiltration (NF) membranes are a new alternative method employed to treat AMD in this work. First, neutralization of AMD collected from the copper mine in Chile using both sodium hydroxide and lime will be investigated to find the optimum formed sludge. Then, three commercial NF membranes (NF99, DK, GE) have been used to filter AMD at two different pressures of 20 and 30 bar and at two different concentrations. The results showed that NF membranes successfully treated AMD w...

Nanofiltration of Acid Mine Drainage

Mine waters, rich in sulphate, acid and different metal species, are an environmental risk of great importance. Untreated mine waters released into the environment influence complete ecosystems and can reduce species of plant and animal life drastically from thousands to some microbial and algae species. Hence, mine waters are treated before released into the environment by state-of-theart procedures such as lime treatment or constructed wetlands which focusing on future legislation will not meet discharge criteria especially for sulphate. Therefore the Department for Thermal, Environmental and Natural Products Process Engineering of TU Bergakademie Freiberg investigated the applicability of membrane filtration using nanofiltration (Alfalaval NF99) and reverse osmosis (Alfalaval RO 98pHt) membranes. Experiments covered parameter and long-term studies to determine applicability of membrane filtration theory and appearance of scaling (precipitation of inorganic solutes). Results suggest applicability of des...

Mine water treatment by membrane filtration processes - Experimental investigations on applicability

The redox potential and/or the pH -value of the liquid are used to separate adjusted volume stream of the catholyte in the cathode and to separate adjusted volume stream of the anolyte in the anode connected to the adjustment of the electrical cell stream in the electrolytic cell at desired value. Process for adjusting redox potential and/or of pH -value of at least a liquid in an electrolytic cell for purifying a liquid or to prepare a liquid as reactive liquid for further processing involves directing a stream of liquid through a fluidized bed electrolytic cell having a cathode and anode, in which the fluidized body has an electrical charge. Independent claims are included for (a) an electrolytic cell and (b) use of process in the above claim.

Georg Härtel

Papers

Photochemical oxidation of p-chlorophenol by UV/H2O2 and photo-Fenton process. A comparative study.

Optimization Study for Treatment of Acid Mine Drainage Using Membrane Technology

Nanofiltration of Acid Mine Drainage

Mine water treatment by membrane filtration processes - Experimental investigations on applicability

Process and apparatus for electrolytically adjusting the ph and the redox-potential of fluids