Asher Kiperstok

Comparative energy life-cycle analyses of microalgal biomass production in open ponds and photobioreactors

An analysis of the energy life-cycle for production of biomass using the oil-rich microalgae Nannochloropsis sp. was performed, which included both raceway ponds, tubular and flat-plate photobioreactors for algal cultivation. The net energy ratio (NER) for each process was calculated. The results showed that the use of horizontal tubular photobioreactors (PBRs) is not economically feasible ([NER]<1) and that the estimated NERs for flat-plate PBRs and raceway ponds is >1. The NER for ponds and flat-plate PBRs could be raised to significantly higher values if the lipid content of the biomass were increased to 60% dw/cwd. Although neither system is currently competitive with petroleum, the threshold oil cost at which this would occur was also estimated.

Tratamento de água produzida de petróleo para remoção de óleo por processos de separação por membranas: revisão

The management of oil produced water (PW) constitutes a major challenge to oil companies. The options usually adopted for PW are disposal, injection and reuse. In all cases, a PW treatment is required in order to avoid damages to the environment and to production facilities or to allow its reuse without causing damage to processes in which the PW is used. The membrane separation processes (MSP) has been shown to be capable of treating effluent with high content of emulsified oil and with medium and small sizes particle, competing well with more complex treatment technologies such as flotation. The aim of this paper was to present a review of the PW treatment by MSP, discussing the main aspects of the PW and the conceptual aspects of the MSP, with emphasis on their application for removal of oil from the PW.

Resíduos da construção civil em Salvador: os caminhos para uma gestão sustentável

This paper discusses the environmental impacts caused by construction waste generation and its inadequate disposal, analyzing the regulation related to this subject and possibilities for its minimization in the city of Salvador. As a contribution measures are suggested to make viable waste construction prevention. It is proposed a draft model for construction waste streams that stimulates the reduction of losses of building materials in construction sites and, consequently, reduces costs in urban management as well as environmental impacts. This proposal suggests the possibility of a source generation reduction of 30%, a 37% diversion of materials from landfills and, still, 32.7% of construction waste generation, not absorbed in the recycling or reuse, remain following, directly, for landfill.

Estimating the potential water reuse based on fuzzy reasoning

Studies worldwide suggest that the risk of water shortage in regions affected by climate change is growing. Decision support tools can help governments to identify future water supply problems in order to plan mitigation measures. Treated wastewater is considered a suitable alternative water resource and it is used for non-potable applications in many dry regions around the world. This work describes a decision support system (DSS) that was developed to identify current water reuse potential and the variables that determine the reclamation level. The DSS uses fuzzy inference system (FIS) as a tool and multi-criteria decision making is the conceptual approach behind the DSS. It was observed that water reuse level seems to be related to environmental factors such as drought, water exploitation index, water use, population density and the wastewater treatment rate, among others. A dataset was built to analyze these features through water reuse potential with a FIS that considered 155 regions and 183 cities. Despite some inexact fit between the classification and simulation data for agricultural and urban water reuse potential it was found that the FIS was suitable to identify the water reuse trend. Information on the water reuse potential is important because it issues a warning about future water supply needs based on climate change scenarios, which helps to support decision making with a view to tackling water shortage.

Implementation of cleaner production practices with the support of a diploma course

Abstract This paper describes the initial proposal of a cleaner technologies network in the state of Bahia, in the northeast section of Brazil. This network intends to bring together industry, universities, and government to discuss the relationship between production and the environment. Its main objective is to support a change in the way this relationship is nowadays perceived, in order to make preventive practices a priority and improve eco-efficiency. Implementation of the network was preceded by a diploma course on environmental technologies and management directed at professionals in the workforce. The results of the course are helping to create an atmosphere that is beneficial for the start-up of the network.

ENVIRONMENTAL OPTIMISATION OF RELEASES FROM INDUSTRIAL SITES INTO A LINEAR RECEIVING BODY

Abstract Changes to environmental legislation are setting new challenges to both operators and regulators. Optimisation tools can help to turn subjective standards such as Best Practicable Environmental Option (BPEO) (HMIP, 1994: Sharratt, 1995) into more objective ones. Mixed Integer Non Linear Programming (MINLP) is used in this work to optimise overall environmental performance for a group of plants. These plants discharge their final effluents to the same receiving body — a river. The optimisation considers not only the possible configurations within each plant but also the behaviour of the receiving body. A two-stage optimisation is used. Examples illustrate the features of the model.

Life cycle assessment of the environmental influence of wooden and concrete utility poles based on service lifetime

PurposeMany applications of life cycle assessment do not consider the variability of the service lifetime of different structures, and this may be a relevant factor in an environmental impact assessment. This paper aims to determine the influence of the service lifetime on the potential environmental impacts of wooden and concrete poles in the electricity distribution system.MethodsThe estimation of service lifetime was conducted using the factorial method. The life cycle assessment was applied using SimaPro software and considered the entire life cycle of utility poles, from the extraction of raw materials to the final disposal. Then, an evaluation of the environmental impacts using the CML IA baseline method was performed. The study included the analysis of uncertainty using the Monte Carlo method.Results and discussionIn general, the wooden poles had a lower potential environmental impact compared to the concrete poles. The result of the sensitivity analysis considering the variability of the chromated copper arsenate wood preservative retention rate suggests that the frequency of maintenance affects the service lifetime. Often, the comparison of products in the LCA perspective is carried out by considering similar useful lifetime services for the different alternatives, and this study shows that the environmental performance of products or services is directly proportional to the lifetime. It is a crucial parameter that has to be clarified in order to reduce uncertainty in the results.ConclusionsThus, some factors such as material quality, design adjustments and routine maintenance extend the service lifetime of a product or process and are shown to be effective ways to reduce environmental impacts. Therefore, the service lifetime has a significant influence on the development of the life cycle assessment. Comparative LCA studies are often sensitive to parameters that may even change the ranking of selected impact categories. All in all, from the sensitivity analysis highlighted in this study, the variability of lifetime service has proven to be one of the most prominent factors influencing comparative LCA results.

Collection of benchmark test problems for data reconciliation and gross error detection and identification

Abstract In an industrial scenario, one can find measured data that do not satisfy the mass and energy laws of conservation. This problem can be approached by applying data reconciliation (DR) and gross error detection and identification (GEDI) techniques, however, authors generally validate their methods using a reduced set of problems, restricting the application of the proposed methods to them. The objective of this work is to present a collection of benchmark problems for DR and GEDI to help the evaluation of these methods in different types of flowsheets. First, challenges issues related with DR and GED are presented with examples. Then, a general overview of the benchmark collection set is presented. In conclusion, it can be observed that this challenging research area needs a common problem set for validating DR and GEDI and this paper fills this gap, helping the validation of the methods.

Life cycle assessment in the furniture industry: the case study of an office cabinet

PurposeIn an effort to reduce the environmental impacts of the furniture sector, this study aimed to diagnose the environmental performance of an office cabinet throughout its life cycle.MethodsAn attributional life cycle assessment (LCA) was used, based on the ISO 14044 Standard and ILCD Handbook. The scope of the study considered the entire supply chain, from cradle to grave, including the steps of pre-manufacturing, manufacturing, use, and post-use of the product. The impact assessment method was the International Reference Life Cycle Data System (ILCD) 2011 midpoint.Results and discussionThe results identified that the most significant environmental impact of the furniture life cycle was due to the distances covered and production of the main raw material, wood medium-density particleboard (MDP). The evaluation of transport scenarios showed environmental tradeoffs for truck fuel switches and environmental gains for the distribution of MDP from closer suppliers by truck, as well as from current supplier by truck and ship in the major categories. Furthermore, evaluation of the office cabinet post-use options showed that reuse, recycling, or energy recovery from waste cause significant environmental gains in the major categories. Wooden furniture is a potential carbon sink if its life cycle does not emit more greenhouse gases than its materials can store. The impacts of substitution scenarios varied depending on the type of product avoided.ConclusionsThe LCA proved a powerful method to diagnose and manage environmental impacts in complex product systems. The sensitivity analysis showed that it is possible to reduce the environmental impacts and, at the same time, make the furniture industry increase its economic gains and net carbon stock in the anthroposphere.

Cleaner production and life cycle design of upholstered furniture

This article presents some results of the environmental and organisational aspects that were obtained from a preliminary analysis of the process of manufacturing upholstered furniture at the furniture cluster in the State of Alagoas, Brazil. The method is based on the concepts of pollution prevention and cleaner production that are associated to the concept of product life cycle design. Data were collected through interviews with employees and from direct observation in the company selected for the study case. The results indicate the need for further studies to identify possible modifications in the product and/or in the processes of development of the upholstered furniture produced by the cluster. The partial conclusions suggest the need for the future application of life cycle assessment in one of the upholstered pieces of furniture to broaden the scope of analysis and improve the efficiency of production through cleaner environmental practices. The original character of the study is associated with the dissemination and incentive of the application of life cycle assessment in micro and small businesses in the Furniture Cluster in the town of Arapiraca in the State of Alagoas, in the Northeast of Brazil.