Springer Science and Business Media LLC

Water pollution control is presently one of the major thrust areas of scientific research. While coloured organic compounds generally impart only a minor fraction of the organic load to wastewaters, their colour renders them aesthetically unacceptable. Stringent regulating measures are coaxing industries to treat their waste effluents to increasingly high standards. Colour removal, in particular, has recently become an area of major scientific interest as indicated by the multitude of related research reports. During the past two decades, several decolourization techniques have been reported, few of which have been accepted by some industries. There is a need to find alternative treatments that are effective in removing dyes and colourants from large volume of effluents, which are cost-effective, like the biological or integrated systems. This article reviews some of the widely used and most promising industrial wastewater decolourization methods. Data on decolourizing efficiencies of different causative agents, obtained by means of different physical, chemical and biological methods are discussed. Further a critical review is made on the various treatment methodologies and emerging technologies with a note on their advantages and disadvantages.

The depletion of fossil fuel reserves and greenhouse gas emissions led to limit the use of fossil fuels, including natural gas, coal, or petroleum, and demand a clean and sustainable source of energy. Many efforts are being made by the researchers to address these issues through the use of natural renewable resources (or lignocellulosic biomass), such as agricultural wastes and forest residues as a cleaner source of energy. But its poor properties like low energy density, high moisture content, irregular shape and size, and heterogeneity make it difficult to use in its natural form. Torrefaction, a simple heat treatment procedure, is widely employed to the natural bioresources to improve its thermal properties to be used as an energy source in the domestic power plants. The quality of the resultant torrefied solids (the so-called biocoal) is depending on the settings of heating conditions under the absence of oxygen, which can be improved by selecting and adjusting the processing conditions precisely. Typically, the process brings down the moisture content up to < 3 wt%, and increases the grinding energy up to 90%. Mainly, the calorific value and fixed carbon content of torrefied biomass increase by roughly 15–25 wt%, which makes it more appealing than non-torrefied biomass. The review emphasizes the available biomass torrefaction technologies, and it’s potential in the field of bioenergy generations. It also covers few case studies of biomass torrefaction and its application in the power generation sectors.

Việc tiêu thụ nước bị ô nhiễm với vi khuẩn đặt ra những rủi ro sức khỏe đáng kể trên toàn thế giới, điều này làm nổi bật nhu cầu cần thiết về việc phát hiện hiệu quả và hiệu suất của vi sinh vật trong nước. Công nghệ hiện tại cho việc giám sát chất lượng nước dựa trên việc lấy mẫu thường xuyên và các phương pháp nuôi cấy, điều này mất nhiều thời gian và không cho phép quá trình ra quyết định nhanh chóng. Có một nhu cầu rõ ràng đối với các phương pháp phân tích nhanh chóng và tiện lợi hơn cho phép việc sử dụng rộng rãi và góp phần vào các quy trình quản lý và ra quyết định. Các phương pháp dựa trên PCR, giải trình tự DNA và các phương pháp miễn dịch huỳnh quang là những chiến lược triển vọng cho việc phát hiện mầm bệnh. Việc phát triển các phương pháp sinh cảm mới hiện đang được tiến hành, mở ra những hướng đi mới cho việc phát hiện nhanh chóng và hiệu quả về chi phí các mầm bệnh. Trong bài đánh giá này, chúng tôi tóm tắt những tiến bộ và phát triển gần đây trong việc giám sát các tác nhân gây bệnh và sinh học trong các mẫu nước.

The need for ensuring resources and energy supplies has stimulated the use of renewable feedstocks for biorefineries. Among organic wastes, the organic fraction of municipal solid waste (OFMSW) outstands because of its increasing amounts and management requirements. Unlike other homogeneous organic waste from food and other industries, OFMSW is characterized by high instability, complexity, and heterogeneity. This review aims to unfold the potential of the OFMSW as feedstock for biorefineries through a discussion on recent valorization alternatives to the commonly employed anaerobic digestion for biogas production. Enzymatic hydrolysis has been identified as a key to unlock the capabilities of OFMSW through the fractioning of structural components into functionalized molecules. In addition, multiple scenarios for the subsequent utilization of such molecules are also presented, together with suitable configurations for processes integration. Lastly, challenges for the OFMSW biorefinery implementation have been identified.

On-line process control may cause substantial changes to the microbial community in a biological wastewater treatment system. Recent studies have shown such effects can be exploited in control system design to achieve an optimised microbial community. Excellent progress has been made on the elimination of nitrite-oxidising bacteria (NOB) in biological nitrogen removal wastewater treatment systems using on-line aeration control, enabling nitrogen removal via the nitrite pathway. Control methods for eliminating NOB are now available for both continuous systems and sequencing batch reactors, and have been demonstrated with both domestic and various types of industrial wastewaters. The elimination or reduced growth of glycogen accumulating organisms (GAOs), a competitor of polyphosphate accumulating organisms (PAOs), in enhanced biological phosphorus removal (EBPR) systems via pH and carbon source control has been conceptually demonstrated through the use of enriched cultures. However, these strategies are not yet ready for the control of practical EBPR processes. Sludge population optimisation also involves selecting the most desirable organism or a consortium of organisms to perform a required function. This is particularly important for nitrification, one of the most important and delicate steps in modern wastewater treatment plants. Results from both experimental and simulation studies suggest that reactor operation could have a major impact on the nitrifier community structure, which should be further investigated in future studies.

H2 is considered as the ultimate cleanest energy carrier to be generated from renewable sources. This minireview intends to point out that in addition to this function, biologically produced hydrogen is important for environmental biotechnological applications. The purple sulphur phototrophic bacterium, Thiocapsa roseopersicina BBS contains several NiFe hydrogenases. These enzymes can be used e.g., as fuel cell H2 splitting catalyst or in photoheterotrophic H2 production. Microorganisms that supply H2 in situ facilitate the biodegradation of organic material and concomitant biogas production. Fast, efficient, and economic treatment of organic waste, sludge, manure is achieved and generation of significant amount of renewable fuel from waste is intensified. The technology has been field tested under mesophilic and thermophilic conditions with positive results.

The use of organic matter such as vegetable oil to produce biodiesel fuel has been a practical technology for a number of years. However, the search for new technologies and raw materials for biodiesel fuel production has gained increased attention recently because of financial and environmental concerns. Of particular interest are raw materials that are not food-related. Microalgae have gained a great deal of attention as a potential biodiesel raw material because of their high growth rates and ability to accumulate oil, bind carbon dioxide, and remove contaminants from wastewater. This article is a literature review of technologies for biodiesel production from microalgae. The technologies relate to microalgal cultivation, microalgal growth enhancement to simultaneously increase biomass and reduce pollution, the preparation of microalgal biomass for biodiesel production, and biodiesel production itself.

Dissolved salts in seawater or brackish water are reduced to a potable level through separation techniques, like, distillation, multiple effect vapor compression, evaporation, or by membrane processes such as electro-dialysis reversal, nano-filtration, and reverse osmosis (RO). RO is the most widely used desalination process. Recent advances in RO technology has led to more efficient separation and now is the most cost effective process to operate. The performance of the reverse osmosis process is dependent on concentration of dissolved solids in the feed-water, feed-water pressure, and the membrane strength to withstand system pressure, membrane solute rejection, membrane fouling characteristics, and the required permeate solute concentration. RO is a promising tool that uses cellulose acetate (or) polyamide membrane and is widely chosen as the cost of production is reduced by the use of energy efficient and process control techniques. This paper presents a review on modelling, identification of parameters from single input-outputs and multi input/output lumped systems, dynamic modelling and control of desalination systems in the past twenty years by collecting more than 60 literatures.

The paper reviews river quality models on the basis of their conceptualization, processes, strengths and limitations. It analyzes advances in basic research and compares river quality models, namely AQUATOX, Branched Lagrangian Transport Model (BLTM), One Dimensional Riverine Hydrodynamic and Water Quality Model (EPD-RIV1), QUAL2Kw, Water Quality Analysis Simulation Program (WASP) and Water Quality for River-Reservoir Systems (WQRRS). All these models are widely used and ‘mechanistic’ in nature except for BLTM which was selected due its vast ‘useage’. In addition, the paper highlights the types of errors which occur during the modelling exercise. The paper also emphasizes on the pivotal role played by water quality models for development and formulation of various river restoration projects worldwide. The present review also suggests broad recommendation for choosing a river quality model.