Sabino De Gisi

Public opinion and awareness towards MSW and separate collection programmes: A sociological procedure for selecting areas and citizens with a low level of knowledge

The principal aim of this study was to define and apply a procedure based on a structured questionnaire survey useful to analyze the peoples environmental knowledge in order to select the areas and age groups with a low level of knowledge in a municipality (in Southern Italy) and, therefore, suggest a specific educational campaign for each. The detailed sampling procedure made it possible to carry out a meticulous statistical analysis of the results. The youngest and oldest people showed the lowest level of awareness for each district. A high level of education did not necessarily imply a high level of environmental awareness as well as a greater acceptance of MSW facilities. The satisfaction level of the recycling program was higher amongst the oldest age group. All the citizens in the several areas were unanimous in pointing out the presence of dirt in the street as the main shortcoming of the bring separate collection program. Only the youngest age group self-criticised, considering that they revealed a low level of participation to the separate collection program. While, the oldest people retaining them less influential, claimed that the citizens were not responsible for the failure of the separate collection program. The prevailing opinion of the sample was that people protested against the construction of waste facilities because they were not well-informed, with the most significant opinion of all the age subdivisions being that incineration is a hazardous treatment. The presence of criminal organizations was indicated as the main reason why the Campania Region suffers a serious solid waste emergency. While, the percentage of people pointing their finger at politicians increases with the average age of the respondents with there being a very strong correlation (r(2)=0.9903).

Full-scale treatment of wastewater from a biodiesel fuel production plant with alkali-catalyzed transesterification

The treatment of wastewater derived from a biodiesel fuel (BDF) production plant with alkali-catalyzed transesterification was studied at full scale. The investigated wastewater treatment plant consisted of the following phases: primary adsorption/coagulation/flocculation/sedimentation processes, biological treatment with the combination of trickling filter and activated sludge systems, secondary flocculation/sedimentation processes, and reverse osmosis (RO) system with spiral membranes. All the processes were developed in a continuous mode, while the RO experiment was performed with batch tests. Two types of BDF wastewater were considered: the first wastewater (WW1) had an average total chemical oxygen demand (COD), pH and feed flow rate of 10,850.8 mg/L, 5.9 and 2946.7 L/h, respectively, while the second wastewater (WW2) had an average total COD, pH and feed flow rate of 43,898.9 mg/L, 3.3 and 2884.6 L/h, respectively. The obtained results from the continuous tests showed a COD removal percentage of more than 90% for the two types of wastewater considered. The removal of biorefractory COD and salts was obtained with a membrane technology in order to reuse the RO permeate in the factory production cycle. The rejections percentage of soluble COD, chlorides and sulphates were 92.8%, 95.0% and 99.5%, respectively. Because the spiral membranes required a high number of washing cycles, the use of plane membranes was preferable. Finally, the RO reject material should be evaporated using the large amount of inexpensive heat present in this type of industry.

Chemically Assisted Primary Sedimentation: A Green Chemistry Option

Chemically Assisted Primary Sedimentation (CAPS) consists of adding chemicals in order to increase the coagulation, flocculation and sedimentation of raw urban wastewater. The CAPS process can be developed in order to increase the efficacy of primary sedimentation as well as avoid any interference with biological treatment processes. The application of CAPS is particularly suitable as a technique for the upgrading of urban wastewater treatment plants (UWWTPs). In fact, CAPS does not require any further significant structural intervention (so saving investment costs and territory portions). The aim of this contribution is to emphasise the role of CAPS as a green chemistry option available in a UWWTP. In particular, a specific aim of the chapter is to focus the attention on the energetic importance of CAPS due to its capacity to increase the production of the primary sludge and consequently the energy production with an anaerobic digestion treating separately primary and secondary sludge. The energetic convenience and “green” propensity of the application of CAPS is discussed by means of the presentation of a paradigmatic case study containing economic evaluations, as well.

Sustainability assessment of alternative end-uses for disused areas based on multi-criteria decision-making method

The main aim of this study was to define and apply a multidisciplinary and multi-criteria approach to sustainability in evaluating alternative end-uses for disused areas. Taking into account the three pillars of sustainability (social, economic and environmental dimension) as well as the need for stakeholders to have new practical instruments, the innovative approach consists of four modules stated (i) sociological, (ii) economic, (iii) environmental and (iv) multi-criteria assessment. By means of a case study on a small Municipality in Southern Italy, three end-uses alternatives, representing three essential services for citizens, were selected: Municipal gym; Market area; Municipal Solid Waste (MSW) separate collection centre. The sociological module was useful to select the most socially sound alternative by means of a consultative referendum, simulated with the use of a structured questionnaire administered to a sample of the population. The economic evaluation was conducted defining the bill of quantities with regarding to six main items (soil handling, landfill disposal tax, public services, structure and services, completion work, equipment and furnishings). The environmental evaluation was performed applying the Delphi method with local technicians who were involved in a qualitative-quantitative evaluation of the three alternatives with regarding to eight possible environmental impacts (landscape impact, soil handling, odour, traffic, noise, atmospheric pollution, wastewater, waste). Finally, the Simple Additive Weighting was used as multi-criteria technique to define alternatives priorities. The obtained results showed how the multi-criteria analysis is a useful decision support tool able to identify transparently and efficiently the most sustainable solutions to a complex social problem.

Industrial Wastewater Treatment

This contribution deals with the technologies usually adopted for the treatment of wastewaters produced in major industrial sectors. After an overview of conventional and nonconventional technologies, wastewaters produced in the food processing and textile industries were investigated. By means of numerous case studies, several aspects such as wastewater characteristics, treatment technologies, main process parameters, and performance in terms of pollutant removals were investigated in depth. Furthermore, the two approaches to the issue of industrial wastewater treatment named Start-of-pipe and End-of-pipe were presented and discussed using the results of the recent European Commission “AquaFit4Use” project.