Assessment of diesel-contaminated domestic wastewater treated by constructed wetlands for irrigation of chillies grown in a greenhouse

Abstract

In order to avoid environmental pollution and eliminate the need for using fertiliser, this study assessed for the first time the optimum performance of mature (in operation since 2011) vertical flow constructed wetlands in treating domestic wastewater (with and without hydrocarbon) and the subsequent recycling of the outflow to irrigate chillies (De Cayenne; Capsicum annuum (Linnaeus) Longum Group ‘De Cayenne’) grown in a greenhouse. Various variables were investigated to assess the treatment performance. Concerning chilli fruit numbers, findings showed that the highest fruit yields for all wetland filters were associated with those that received inflow wastewater with a high loading rate, reflecting the high nutrient availability in treated wastewater, which is of obvious importance for yield production. Findings also indicated that wetlands without hydrocarbon, small aggregate size, low contact time and low inflow loading rate provided high marketable yields (expressed in economic return). In comparison, chillies irrigated by filters with hydrocarbon contamination, small aggregate size, high contact time and high loading rate also resulted in high marketable yields of chillies, which pointed out the role of high contact time and high inflow load for better diesel degradation rates.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-016-7706-x) contains supplementary material, which is available to authorized users.

Willingness to Pay for Recreational Benefit Evaluation in a Wastewater Reuse Project. Analysis of a Case Study

“…Technical and economic feasibility evaluation of reclaimed water reuse projects for different purposes is becoming a need. The main reasons are increasingly frequent dry summers in the Mediterranean countries together with an awareness of the increasing deterioration of surface water quality due to the release of treated and untreated effluents and the withdrawal of larger volumes of fresh water for rural, civil, and industrial demands [1,2]. The main difficulties in completing direct reuse projects of treated wastewater are related to the investment and operational/maintenance costs of adequate end-of-pipe treatments and the stringent quality standards requested for the reclaimed water to be reused.…”

Diluted Sugar Mill Effluent Application with PGPR Improves the Performance of Maize (Zea mays L.) under an Arid Climate

“…The high grain yield with these treatments was the outcome of better leaf emergence, growth and improved stay-green which ultimately enhanced the number of grains per cob and the 100-grain weight, thus resulting in higher grain yields [6]. Indeed, grain weight is an important yield-contributing trait which is related to stay-green in cereals [30] under different abiotic stresses.…”

“…At present, the use of industrial effluents for irrigation is gaining momentum. In many areas of the world, treated and diluted industrial effluents have been used for irrigation purposes [2][3][4], owing to their positive influences on crop growth through the improvement in soil properties [5][6][7].…”

How to Overcome Barriers for Wastewater Agricultural Reuse in Sicily (Italy)?

“…Generally, in irrigation practices water quality controls should mainly salinity, heavy metals, and pathogens for minimizing any detriment to human, plants, and soils. Beyond the normative barriers, more general factors related to wastewater treatment plants (WWTPs) siting have to be considered [5]. Among those, some authors [6] reported the following: long distances between treatment facilities and agricultural demand areas; construction and maintenance costs of conveying pipe systems; necessity to store TW during fall-winter periods, since TW are continuously produced throughout the year, whereas irrigation demand is generally concentred during crops growing season of dry-summer periods.…”