Recent Patents on Chemical Engineering - Volume 6, Issue 2, 2013

The concerns on increasing awareness for systems development to improve water quality of effluents from wastewater treatment and industrial facilities have provided incentives to develop new technologies and improve performance of current technologies. In this paper, the patents on achievements of industrial wastewater treatment by wet oxidation (WO) and catalytic wet oxidation (CWO) processes during the period from 1993 to 2012 were reviewed. An assessment of the current and future outlook for development of CWO process, catalyst that can be used for wastewater treatment applications is presented.

Water shortage in the world has stimulated the rapid development of water treatment technology. As one of the most promising technologies, membrane separation has tremendous hopes in producing fresh water and dealing with wastewater. The blend of inorganic component into polymer membrane has become an efficient way to increase the antifouling property and realize the multifunction of polymer membrane. In this paper, we summarize recent results published in patent and literatures for the preparation and applications of organic-inorganic hybrid membranes (OIHM) used in water treatment. Special attentions are paid on the selection of new nanoparticles, improvement of fabrication process, and discussion about the new function and application of OIHM in water treatment. The emphasis is providing some efficient methods of preparing OIHM with high antifouling property and multifunction, and extending their application ranges in future water treatment.

A novel configuration for fluidized bed has been developed. It is basically a bubbling fluidized bed furnished with a spouted jet in the upper part of the bed. A part of gases is fed through the distributor to fluidize bed solids. The remaining part is fed through a vertical pipe creating a jet-fountain zone. A distinct feature of the novel configuration different from previous spouted bed patents and configurations is that the jet spout height is independent of the bed height. The experiments carried out using the novel configuration furnish promising results. The power consumption in delivering gases is found much lower when applying the novel configuration. Moreover, bubble sizes reduce considerably in the main bed as only a part of gases passes through it. Tests on combustion of a gaseous fuel indicate that the novel configuration enables smooth combustion of gaseous fuels and a rapid reliable method for initial heating of fluidized bed combustor. Staged air combustion technique is also applied. Drying silica gel has been tested in the novel configuration and in the conventional fluidized bed. Results demonstrate that the overall mass transfer rate is considerably higher in the novelconfiguration, particularly, at higher air flowrate.

Physical separation methods, especially membrane technology, can be a good substitute for biological wastewater treatment, due to its simple constructions and operations. There are many papers and patents in this field. Membranes need to be cleaned periodically to be able to operate economically, and need to be replaced after a while. Several factors can influence the membrane cleaning procedure, including pressure of backwash, acid and base concentration, duration of forward washing, and duration of acid-base backwashing. In this study the effect of these parameters was investigated to find an optimum condition which could result in a good polyethersulphone (PES) membrane cleaning with less material and energy consumption. To reach this goal, a design of experiment (DoE) method termed 25-1 fractional factorial design (FFD) was used to specify the best conditions and modeling the results.

Membrane technology has been widely used in gas separation, material separation and water treatment as a new separation technology. Membrane technology increasingly shows its important role and a bright future. This paper focused on membrane technology and apparatus, and reviewed achievements on patents of wastewater treatment by membrane technology, which contains nanofiltration (NF), ultrafiltration (UF) and reverse osmosis (RO). Membrane technology is an attractive technology that needs further research efforts and industrialization. However, membrane fouling still remains a major problem for all membrane reactors. Discussions are also made on how to resolve membrane fouling for wastewater treatment.

Acrylonitrile is widely used in chemical industry, mainly as raw materials to obtain acrylic fiber, nitrile rubber, ABS plastic and synthetic resins. However in the course of its production and uses, much colored organic wastewater will be released. Reducing COD and toxicity presents a challenge for the treatment. This paper focused on the introduction of acrylonitrile wastewater process and commented on patents of acrylonitrile wastewater removal technology. Furthermore, the advantages and disadvantages of the technologies were analyzed, and some suggestions were proposed.

High level of nitrogen pollutants was found to be the reason of eutrophication and have harmful effects on human health. Therefore, the nitrogen removal is obligatory from the environmental protection view. Several methods have been proposed to remove nitrogen compounds from wastewater. These methods can be classified as (I) biochemical and (II) physical treatment. So, making an assessment on nitrogen removal processes to select a more efficient one seems to be necessary. Generally, Nitrogen compound enters into the environment through several ways such as landfill leachate, animal waste, agricultural activities, human waste, and etc. In this paper, the methods applied in recent papers and patents for nitrogen removal from wastewater around the world have been reviewed.