Rural populations in Tanzania use unsafe drinking water from unimproved water sources which are inadequately treated using plant seed powder. The effectiveness of defatted crude seed extract (dCSE) of Moringa oleifera along with water filtration and solar disinfection (SODIS) for rural household water treatment was investigated. The performance of dCSE in turbidity and bacteria reduction was evaluated in 20 L buckets using river water with varied turbidities. Coagulation–flocculation processes were conducted using different dosages of 5% (Weight/Volume) dCSE. Optimum dosage for maximum turbid removal was established after 2–6 h of settling time. Optimum dosages of dCSE were 20, 30 and 80 mL/20 L for water with a turbidity of 150, 450 and 1,000 NTU with turbidity removal efficiencies of 98, 99 and 99%, respectively. The filtration process was able to remove about 66% of suspended solids from pretreated water by dCSE after coagulation/flocculation/sedimentation. SODIS of pretreated water in black painted and unpainted bottles removed 99 and 97.6%; 99.9 and 98.6% of total and fecal coliforms after 6 h of sunlight exposure, respectively. The pH and color of treated water were within Tanzania Standards. This study recommends dCSE, filtration and SODIS for use at household level for water treatment and storage using pots.

Hospitals wastewater contains a wide range of contaminants which may pose potential risks to the environment, public health, and ecological damage. However, knowledge on the extent to which the hospital wastewater is contaminated in Tanzania is still limited. The study aimed to investigate the quality of hospital wastewaters discharged from Muhimbili national (MNH) and Tumbi regional referral (TRH) hospitals. Eight sampling points were established and sampled in triplicates at each of the two hospitals and analyzed for physical, chemical and biological parameters following the standard methods as presented in APHA- AWWA-WEF (1998) and TZS 860:2005. The results showed that pH, electric conductivity, total dissolved solids, cadmium, chromium, zinc and Nickel are within Tanzania Standards. However, MNH, PO4 NO3 Pb and COD quality exceed the Tanzania standards. The COD ranged from 53 mg/l to 776 mg/l and 92 mg/l to 1099 mg/l for MNH and TRH, respectively. The COD has value higher than permissible level of 60 mg/l. Bacteriological results indicated that hospital wastewater is contaminated with pathogenic microorganisms. Faecal coliform (FC) and total coliform (TC) for MNH ranged from 5-23 x 106 cfu/100ml and 14 -41 x 106 cfu/100ml, respectively, while FC and TC ranged from 0.5 - 4x106 cfu/100 ml and 0.5-9 x 106 cfu/100ml for wastewater from TRH. The results of FC and TC from both hospitals are far higher than the allowable standard as specified in Tanzania standard (TZS 860:2005) which limits to 0.01x106 cfu/100ml, which may render the human health and other ecosystems. The hospital wastewater is polluted physically, chemically and biologically which need treatment before disposal in order to protect human health and another ecosystems’ life.

This study investigated the potential of agro-waste-derived substrates to support fungal-mediated biomineralization of calcium carbonate for the production of calcite-rich biocomposites with potential cementitious applications. Rice bran powder and eggshell powder were evaluated as organic...

Urbanisation-driven housing demand and the environmental burden of sewage sludge disposal highlight the need for low-carbon, circular construction materials. This study evaluates incinerated sanitary sludge ash (ISSA) as a supplementary cementitious material in stabilised earth blocks, aiming to reduce the use of cement and lime while valorising waste sludge. Lateritic soil blocks were produced with a binder-to-soil ratio of 1:7 by mass, in which ISSA partially replaced the primary stabilising binder (cement or lime) at a replacement level of 10–40% within the binder fraction. ISSA’s mineralogical characteristics were analysed using XRD and XRF. The compressive strength and density of earth blocks were measured at 7 and 28 days under curing conditions (29–36 °C; 60–75% humidity). Cement-stabilised blocks were water-cured to support cement hydration, whereas lime-stabilised blocks were air-cured to promote carbonation and pozzolanic reactions. The results, therefore, compared practical binder-specific curing regimes rather than strictly identical curing environments. ISSA exhibited moderate pozzolanic potential, and its incorporation enabled substantial partial replacement of both binders. Cement-stabilised blocks achieved higher strengths, up to 7.7 MPa, after 28 days of curing, whereas lime-stabilised blocks developed strength more gradually, reaching 4.8 MPa. Optimal mixtures were identified at 40% cement + 60% ISSA and 30% lime + 70% ISSA, balancing mechanical performance and binder reduction. A positive density–strength relationship was observed, but chemical bonding predominated over densification effects. ISSA-based stabilised earth blocks show promising structural performance and reduced binder use, but durability and life-cycle assessment need further evaluation before large-scale implementation.