In this article, several archaeological, historical and other aspects of aqueducts in Crete, Greece, since the prehistoric times until today, are reviewed and presented. In Crete, since the Minoan era, various water management techniques that are found in modern water technologies were developed and applied. One of the most significant features of the Minoan civilization was the architecture of water supply systems in the palaces and other settlements. These technologies were continued and improved mainly during the Classical, Hellenistic and Roman periods and at the same time spread to other towns in the mainland and islands. The aqueduct technologies developed during the Classical and Hellenistic periods were further developed by Romans, mainly by enlarging their application scale (e.g., water bridges). Several paradigms of Cretan aqueducts are considered by which the significance of those technologies for water supply in areas with limited water resources is justified. A brief presentation and discussion of climatic conditions, the karst hydrogeology and the water resources management in Crete is also included. The article also describes the present water management profile of the island, in terms of the water plants, water supply–irrigation networks, and water renewable energy exploitation of dams and water pipelines. Full article

Throughout history, various civilizations developed methodologies for the collection and disposal of human waste. The methodologies throughout the centuries have been characterized by technological peaks on the one hand, and by the disappearance of the technologies and their reappearance on the other. The purpose of this article is to trace the development of sewage collection and transport with an emphasis on toilets in ancient civilizations. Evolution of the major achievements in the scientific fields of sanitation with emphasis on the lavatory (or toilets) technologies through the centuries up to the present are presented. Valuable insights into ancient wastewater technologies and management with their apparent characteristics of durability, adaptability to the environment, and sustainability are provided. Gradual steps improved the engineering results until the establishment of the contemporary toilet system, which provides a combined solution for flushing, odor control, and the sanitation of sewerage. Even though the lack of proper toilet facilities for a great percentage of the present day global population is an embarrassing fact, the worldwide efforts through millennia for the acquisition of a well-engineered toilet were connected to the cultural level of each period. Full article

The evolution of the major achievements in water lifting devices with emphasis on the major technologies over the centuries is presented and discussed. Valuable insights into ancient water lifting technologies with their apparent characteristics of durability, adaptability, and sustainability are provided. A comparison of the relevant technological developments in several early civilizations is carried out. These technologies are the underpinning of modern achievements in water engineering. They represent the best paradigm of probing the past and facing the future. A timeline of the historical development of water pumps worldwide through the last 5500 years of the history of mankind is presented. A chronological order is followed with emphasis on the major civilizations. Full article

This paper provides an overview of the Special Issue on Wastewater Treatment and Reuse: Past, Present, and Future. The papers selected for publication include advanced wastewater treatment and monitoring technologies, such as membrane bioreactors, electrochemical systems; denitrifying biofilters, and disinfection technologies. The Issue also contains articles related to best management practices of biosolids, the influence of organic matter on pathogen inactivation and nutrient removal. Collectively, the Special Issue presents an evolution of technologies, from conventional through advanced, for reliable and sustainable wastewater treatment and reuse. Full article

Water fountains are part of every human settlement, and historical and mythological stories. They are the source from which life-sustaining water was distributed to people until piped systems started providing fresh tap water inside buildings. In many places, people visit fountains to experience the freshness of running water, to prepare for prayers, or to make a wish. Fountains have also provided water for the people of cities under siege, and purified believers as part of holy rites. The Castalia shrine in Delphi, Greece, for its part, is a spot where various groups of people come to socialize, which greatly improves the quality of their lives. This paper is a look back through the history of fountains in various parts of the world. Experts from various areas have identified the historic, cultural, and ritualistic aspects of fountains and their findings are summarized. The paper concludes by providing a glimpse into the role of fountains in modern society and their continued influence in our lives today. Full article

This paper provides an outline of history of hydro-technologies in the west and the east. It is an overview of the special issue on “the evolution of hydro-technologies globally”, in which the key topics regarding the history of water and sanitation worldwide, and its importance to future cities are presented and discussed. It covers a wide range of relevant historical issues, and is presented in three categories: productivity assessment, institutional framework and mechanisms, and governance aspects. This paper concludes by discussing the challenges on future research in this field of study. Full article

Land application of olive mill wastewater (OMW) is considered a promising low-cost practice for olive-oil producing countries. The objectives of this work were to investigate: (i) OMW treatment potential of a land treatment system (LTS), planted with a E. camaldulensis species, regarding N, P, C, and phenols; (ii) the effects of OMW on chemical properties of soil and soil solution characteristics; and (iii) the performance of E. camaldulensis in terms of biomass production and N and P recovery. E. camaldulensis received OMW for two growing seasons at rates based on maximum organic loading. These rates were almost equivalent to the reference evapotranspiration of the area. Soil solution and soil samples were collected from three different depths (15, 30 and 60 cm) at specified time intervals. -Also, samples of plant tissues were collected at the end of application periods. OMW land application resulted in significant reduction in inorganic and organic constituents of OMW. At 15 cm of soil profile, the average removal of COD, TKN, NH₄⁺-N, TP, In-P, and total phenols approached 93%, 86%, 70%, 86%, 82%, and 85%, respectively, while an increase in soil depth (30 and 60 cm) did not improve significantly treatment efficiency. Furthermore, OMW increased soil organic matter (SOM), total kjeldahl nitrogen (TKN), and available P, particularly in the upper soil layer. In contrast, low inorganic N content was observed in the soil throughout the study period caused probably by increased competition among soil microorganisms induced by the organic substrate supply and high C/N ratio. Also, electrical conductivity (EC) and SAR increased by OMW addition, but at levels that may do not pose severe risk for soil texture. Enhancement of soil fertility due to OMW application sustained eucalyptus trees and provided remarkable biomass yield. In conclusion, land application of OMW has a great potential for organic matter and phenol assimilation and can be effectively used for OMW detoxification. Full article

This work investigates the effect of plant species (Eucalyptus camaldulensis vs. Arundo donax) on carbon (C) turnover during wastewater application to the land. The study was carried out in 40-liter pots under field conditions and plant species were treated either with pre-treated municipal wastewater or freshwater. Plant species had a strong effect on soil organic matter with pots planted with E. camaldulensis showing greater values than pots planted with A. donax. In accordance, greater respiration rates were measured in E. camaldulensis pots compared to those planted with A. donax. The respiration rate followed a decreasing trend with the progress of the season for both species. These findings suggest differences in soil microbial community composition and/or activity in the rhizosphere of plant species. Minor effects of plant species or effluent were observed in dissolved organic carbon, protein, and hexoses content. In conclusion, the results of the present study reveal an important role of plant species on C cycling in terrestrial environments with potential implications on the sequestration of C and release of nutrients and pollutants. Full article

Partial Least Squares Regression (PLSR) can integrate a great number of variables and overcome collinearity problems, a fact that makes it suitable for intensive agronomical practices such as land application. In the present study a PLSR model was developed to predict important management goals, including biomass production and nutrient recovery (i.e., nitrogen and phosphorus), associated with treatment potential, environmental impacts, and economic benefits. Effluent loading and a considerable number of soil parameters commonly monitored in effluent irrigated lands were considered as potential predictor variables during the model development. All data were derived from a three year field trial including plantations of four different plant species (Acacia cyanophylla, Eucalyptus camaldulensis, Populus nigra, and Arundo donax), irrigated with pre-treated domestic effluent. PLSR method was very effective despite the small sample size and the wide nature of data set (with many highly correlated inputs and several highly correlated responses). Through PLSR method the number of initial predictor variables was reduced and only several variables were remained and included in the final PLSR model. The important input variables maintained were: Effluent loading, electrical conductivity (EC), available phosphorus (Olsen-P), Na⁺, Ca²⁺, Mg²⁺, K²⁺, SAR, and NO₃⁻-N. Among these variables, effluent loading, EC, and nitrates had the greater contribution to the final PLSR model. PLSR is highly compatible with intensive agronomical practices such as land application, in which a large number of highly collinear and noisy input variables is monitored to assess plant species performance and to detect impacts on the environment. Full article

Although there is evidence of surface-based storm drainage systems in early Babylonian and Mesopotamian Empires in Iraq (ca. 4000–2500 BC), it is not until after ca. 3000 BC that we find evidence of the well organized and operated sewer and drainage systems of the Minoans and Harappans in Crete and the Indus valley, respectively. The Minoans and Indus valley civilizations originally, and the Hellenes and Romans thereafter, are considered pioneers in developing basic sewerage and drainage technologies, with emphasis on sanitation in the urban environment. The Hellenes and Romans further developed these techniques and greatly increased the scale of these systems. Although other ancient civilizations also contributed, notably some of the Chinese dynasties, very little progress was made during the Dark ages from ca. 300 AD through to the middle of the 18th century. It was only from 1850 onwards that that modern sewerage was “reborn”, but many of the principles grasped by the ancients are still in use today. This paper traces the development of the sewer from those earliest of civilizations through to the present day and beyond. A 6000 year technological history is a powerful validation of the vital contribution of sewers to human history. Full article

Beyond doubt, desalination is growing rapidly worldwide. However, there are still obstacles to its wider implementation and acceptance such as: (a) high costs and energy use for fresh water production; (b) environmental impacts from concentrate disposal; (c) a complex, convoluted and time-consuming project permitting process; and (d) limited public understanding of the role, importance, benefits and environmental challenges of desalination. In this paper, a short review of desalination in Greece is being made. Data on the cost of desalination shows a decrease in the future and the potential of water desalination in Greece. The paper summarizes the current status in southeastern Greece (e.g., Aegean islands and Crete), and investigates the possibility of production of desalinated water from brackish water. Full article

The aim of this paper is to present the evolution of aqueduct technologies through the millennia, from prehistoric to medieval times. These hydraulic works were used by several civilizations to collect water from springs and to transport it to settlements, sanctuaries and other targets. Several civilizations, in China and the Americas, developed water transport systems independently, and brought these to high levels of sophistication. For the Mediterranean civilizations, one of the salient characteristics of cultural development, since the Minoan Era (ca. 3200–1100 BC), is the architectural and hydraulic function of aqueducts used for the water supply in palaces and other settlements. The Minoan hydrologists and engineers were aware of some of the basic principles of water sciences and the construction and operation of aqueducts. These technologies were further developed by subsequent civilizations. Advanced aqueducts were constructed by the Hellenes and, especially, by the Romans, who dramatically increased the application scale of these structures, in order to provide the extended quantities of water necessary for the Roman lifestyle of frequent bathing. The ancient practices and techniques were not improved but survived through Byzantine and early medieval times. Later, the Ottomans adapted older techniques, reintroducing large-scale aqueducts to supply their emerging towns with adequate water for religious and social needs. The scientific approach to engineering matters during the Renaissance further improved aqueduct technology. Some of these improvements were apparently also implemented in Ottoman waterworks. Finally the industrial revolution established mechanized techniques in water acquisition. Water is a common need of mankind, and several ancient civilizations developed simple but practical techniques from which we can still learn. Their experience and knowledge could still play an important role for sustainable water supply, presently and in future, both in developed and developing countries. Full article

The use of water cisterns has been traced back to the Neolithic Age; this paper thus presents a brief historical development of water cisterns worldwide over the last 5500 years. This paper is not an exhaustive presentation of all that is known today about water cisterns, but rather provides some characteristic examples of cistern technology in a chronological manner extending from prehistoric times to the present. The examples of water cistern technologies and management practices given in this paper may have some importance for water resource sustainability for the present and future. Cisterns have been used to store both rainfall runoff water and aqueduct water originating in springs and streams for the purpose of meeting water needs through seasonal variations. Cisterns have ranged in construction from simple clay pots to large underground structures. Full article

In ancient Hellas, water management began in the early Minoan Era (ca. 3200–1100 BC) and was related to the geomorphology, the geology, the topography, and the local climatic, hydrological, and socio-political conditions. Historical and archaeological evidences show that ancient Greeks had developed even qanat-related technologies since the Classical times. During democratic periods, the focus of water management was on sustainable small scale, safe, and cost effective management practices, and institutional arrangements, whereas in oligarchic periods, emphasis was on the construction of large-scale hydraulic projects, including aqueducts and/or qanats, mostly related to the public sectors. Aqueducts-like qanats are gently sloping, artificially constructed underground galleries, which bring groundwater from the mountainous area to the lowlands, where water is used, sometimes several kilometers away. It is worth noticing that no large-scale lifting techniques were available, and water was transferred from the source (usually a spring) by aqueducts (qanats) from a higher elevation to a lower level by gravity. Historically, the aqueduct-like qanat technology was developed by Persians in the middle of 1st Millennium BC, and spread towards the Arabian Peninsula and Egypt. The expansion of Islam led to diffusion of qanats in Mediterranean countries (e.g., Spain, Italy, and Cyprus). Much of the population of Iran and other arid countries in North Africa and in Asia depend on water supply by aqueducts-like qanats, even today. This technology is characterized by its durability and sustainability, although an aqueduct-like qanat is expensive, both in construction and maintenance. It is pointed out that, the technique of tunneling was used during the Classical period in ancient Hellas. Since the well known tunnel at the island of Samos, Hellas, was designed and constructed by Eupalinos (ca. 530 BC), several underground tunnels (with and without well-like vertical shafts) in order to convey water from one location to another one located in a lower level were implemented in this country. Several aqueducts (qanat) paradigms (e.g., in Athens, on islands of Crete and Rhodes, and in the area of Serres in north country), which are in use even today, are presented and discussed. Overall, it seems that water-related problems of modern societies are not very different from those during antiquity. Full article

The aim of this study is to present water and wastewater technologies used during the Minoan (ca. 3200–1100 BC) and Etruscan (ca. 800–100 BC) civilizations. The basic technologies considered are: water harvesting and distribution systems, cisterns, groundwater and wells as well as drainage and sewerage systems. Minoan water collection and distribution systems primarily consisted of cisterns and pipes. The Etruscans’ hydro-technology also consisted of cisterns and pipes but was developed for urban areas and included distinctions between public and private water use. The long-term sustainability of Minoan cisterns is evidenced by the fact that this technique is still practiced today in rural areas of Crete. In addition to cisterns, wells have been used in Crete since Neolithic times, and enjoyed wide-spread use during the Etruscan era. All the Minoan palaces applied strategies to dispose of water and wastewater with open terracotta or stone masonry-conduits, and stone masonry sewers; while, the drainage and sewerage systems developed by the Etruscans were based both on a coordinated and comprehensive planning of the slopes of drainage channels on the sides of streets as well as on a massive use of drainage tunnels. Full article