Evaluating Fecal Indicator and Pathogen Relationships in Sewage Impacted Surface Waters to Blend with Reclaimed Water for Potable Reuse in North Carolina

Surface waters used for drinking water supply often receive upstream wastewater effluent inputs, resulting in de facto wastewater reuse for drinking water and recreation. As populations grow, demands on water supplies increase. As this trend continues, it creates the need to understand the risks associated with such reuse. In North Carolina, potable reuse has been proposed as a combination of at least 80% surface water with up to 20% tertiary-treated, dual-disinfected, reclaimed wastewater, which is then stored for 5 days and further treated using conventional drinking water treatment methods. The state of North Carolina has set standards for both intake surface water and for the reclaimed water produced by wastewater utilities, using indicator microorganisms to measure compliance. The goal of this study was to quantify fecal indicator microorganisms, specifically E. coli, coliphages, and C. perfringens as well as key pathogens, specifically Salmonella spp. bacteria, adenoviruses, noroviruses, and the protozoan parasites Cryptosporidium and Giardia, in two types of water representing potential candidates for potable reuse in North Carolina, (1) run of river surface water and (2) sewage-impacted surface waters, with the purpose of determining if there are predictive relationships between these two microorganism groups that support microbial indicator reliability.

Suitability of reclaimed wastewater effluent from decentralized wastewater plant for irrigation

Decentralized wastewater plants have been proven to be cost-effective, easy to construct and operate and widely used in small ruler communities. The suitability of reclaimed wastewater for irrigation purpose was evaluated in this study based on the various water quality parameters, international water quality standards and water–irrigation water quality guideline (JS 1766). Twenty-seven samples were collected from a decentralized wastewater plant that is located in Balqa Governorate in Salt city, Jordan. Samples were analyzed for pH, electrical conductivity, major anions and cations, as well as biological oxygen demand, chemical oxygen demand and total suspended solids. Study results show that water is slightly alkaline in nature. According to Jordanian domestic reclaimed wastewater standard, the use of water for irrigation has a mild-to-moderate degree of restriction. Using the US Salinity Laboratory classification scheme, there is high salinity and medium sodium water, 50% of samples falls in the area of (C3-S2) and this water is suitable for irrigation for many types of soil with low risk of increasing exchangeable sodium content. According to chloride hazards, the water for irrigation can be used for moderately tolerant plants. 74% of the samples have the residual sodium carbonate (RSC) less than 1.25 meq/L and hence suitable for irrigation. The study recommends that treated wastewater from decentralized wastewater a plant is considered as non-conventional source for irrigation.

Grey water footprint assessment of groundwater resources in southeastern Turkey: effect of recharge

This paper aimed to determine the grey water footprint (GWF) of groundwater resources. The effect of groundwater recharge on grey water footprint was investigated in Southeastern Turkey. In this paper, GWF has been monitored in October and March in terms of nitrate and arsenic concentrations for ten observation wells in the Harran Plain. In this study, a new approach was developed based on the GWF to determine the nitrate and arsenic pollution of groundwater. GWF of coagulation-flocculation and biochar adsorption processes were calculated and benchmarked with each other. In the second stage of the study, the effect of groundwater recharge using reclaimed municipal wastewater on GWF was investigated applying Monte Carlo simulation. The results revealed that nitrate led to higher GWF. According to the results, biochar application could reduce the GWF. Total reduction of GWF would be approximately 64.3% if groundwater recharge using reclaimed wastewater is applied. HIGHLIGHT The novelty of this study is that a new estimation model has been adapted for grey water footprint of groundwater resources. The other originality of this work is biochar application for groundwater treatment. Biochar application was carried out to treat groundwater in order to observe the GWF. Urfa Isot pepper which is traditional crop of Turkey was used to generate biochar with slow pyrolysis.