Influence of sand depth and pause period on microbial removal in traditional and modified biosand filters.

Three different-sized biosand filters (i.e., the center for Affordable Water and Sanitation Technology v10 concrete filter, a 5-gal bucket filter, and a 2-gal bucket filter with fine sand depths of 54, 15, and 10 cm, respectively), configured with and without the addition of iron nails to the diffuser basin, were evaluated for removal of bacteria, protozoa, and viruses over pause periods ranging from 1 to 72 hrs.

Dominant decomposition pathways in pit latrines: a commentary.

In a recent article an assessment of decomposition within pit latrines measured with regard to chemical oxygen demand (COD) reductions was reported on. Some fundamental concerns were raised with regard to a key assumption of the study. The alternative perspective that is presented here does not support the study's conclusion that anaerobic processes are the dominant decomposition pathway in pit latrines.

Effect of water-to-cement ratio and curing method on the strength, shrinkage and slump of the biosand filter concrete body.

The biosand filter is a household-level water treatment technology used globally in low-resource settings. As of December 2016, over 900,000 biosand filters had been implemented in 60 countries around the world. Local, decentralized production is one of the main advantages of this technology, but it also creates challenges, especially in regards to quality control.

Effect of Sand Bed Depth and Medium Age on Escherichia coli and Turbidity Removal in Biosand Filters.

The main objective of this study was to build several full-scale biosand filters (BSFs) and assess the long-term (9 month) efficacy for particulate and Escherichia coli removal under simulated real-world usage. Four replicates of three different filter designs were built: the traditional concrete BSF and two scaled-down versions that use a 5 or 2 gal bucket as the casing material. The smaller sand bed depths in the bucket-sized filters did not impact filter performance with respect to (i) turbidity and E.

Design for sustainable development--household drinking water filter for arsenic and pathogen treatment in Nepal.

In the last 20 years, the widespread adoption of shallow tubewells in Nepal Terai region enabled substantial improvement in access to water, but recent national water quality testing showed that 3% of these sources contain arsenic above the Nepali interim guideline of 50 microg/L, and up to 60% contain unsafe microbial contamination. To combat this crisis, MIT, ENPHO and CAWST together researched, developed and implemented a household water treatment technology by applying an iterative, learning development framework. A pilot study comparing 3 technologies against technical, social, and economic criteria showed that the Kanchan Arsenic Filter (KAF) is the most promising technology for Nepal.