The main focus of this paper was to investigate the spatial variability of denitrification rates in sediments from several streams and ponds considering their locations and characteristics; to study the main controlling factors that regulate the denitrification process; and to draw some lessons and deduce recommendations about pond management to control the impact of NO3− in such agricultural environments.

This chapter contributes to SDG 6 by introducing technologies for phosphorus remediation from contaminated water.

This chapter advances SDG 6 by discussing recent advancement in the usage of nanocellulose as an adsorbent for water and wastewater treatment and by highlighting current challenges and limitations related to nanocellulose derived material applications at an industrial scale.

This chapter advances SDG 6 by presenting an overview of the development of polymeric adsorbents from different agrowastes along with used physical and methods with their success and shortcomings.

Water is essential for the life, but many people lack the accessibility to clean and healthy drinking water and die as a consequence of water-borne infections.

It discussed the groundwater resource exploration & development

Many inhabited Greek/Mediterranean islands are unsustainable without mainland support due to lack of access to clean water and energy. This case study establishes the feasibility of sustainable green energy solutions for these settlements.

This time series study on water quality in chalk rivers demonstrates superstatistical behaviours of environmental and anthropogenic parameters.

This chapter advances SDGs 6 & 7 by presenting membrane technologies that can be used to purify wastewater and produce biomass for energy.

This chapter advances SDGs 6 & 7 by discussing how to convert gelatinous industry wastewater into useful chemicals and fuels.